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EDUCATIONAL PSYCHOLOGY

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THE MACMILLAN COMPANY

NEW YORK • BOSTON ■ CHICAGO • DALLAS ATLANTA • SAN FRANCISCO

MACMILLAN & CO., Limited

LONDON • BOUBAY • CALCUTTA UELBUURNE

TTTE MACMILLAN CO. OF CANADA. Ltd.

TORONTO

EDUCATIONAL PSYCHOLOGY

1^

BY DANIEL STARCH, Pn. D,

UNIVERSITY OF WISCONSIM

A

"P

Nftn fork THE MACMILLAN COMPANY

1920

Al rights reserved

Copyright, iqiq

By the MACMILLAN COMPANY

S«t up and cUxlrutypcU. Published June. io«<)

/

TO MY WIFE

yll

PREFACE

The preparation of this book has been carried out according to two fundamental purposes: First, to present that material which seems to be most useful and relevant to the problems of educa- tional psychology; and second, to maintain a strictly experimental, scientific viewpoint in discussing these problems. The result of these aims has been a considerable reduction in the amount of space usually devoted in texts on educational psychology to cer- tain topics such as, instinct, fatigue, and imagery, and the inclusion of new topics such as tests of intelligence, studying, transference of training in school subjects, the assignment of marks, and much of the material in Part III which has as yet not found a place in text-books.

The space devoted to the discussion of instinct has been ma- terially reduced for two reasons: In the first place, while the in- stincts are fundamental in human life, too much time has usually been devoted to their consideration for the amount of direct benefit gained. The actual use in school work that can be made of a detailed knowledge of instincts, which in our present stage of information is largely analytical and theoretical, is relatively small when it comes to dealing face to face with concrete school problems. In the second place, a great deal of experimental and statistical material has accumulated in recent years which is more immediately valuable in solving the problems of the psy- chology and pedagogy of learning.

It would have been desirable to include a discussion of the l)sychology of more of the high school subjects; but this is impossi- ble at the present time. The discussion of the school subjects in Part III has been confined to tangible, scientific investigations. Obviously there is little or no material of this sort on most of the high school subjects. The consideration of educational tests in the chapters of Part III is perhaps brief; but a detailed treatment of the theoretical and statistical principles underlying their con- struction belongs rather in special treatises. Chapter XII on How to Study is not altogether satisfactory, because of the scar- city of definite or substantial material '^in this field. It was, how-

v-iii rKKF-ACE

ev'cr, included because the topic is exceedingly important in school work and because it was hoped that its inclusion would stimulate discussion of it by teachers and prospective teachers.

I take pleasure in expressing my obligations to the persons who luve assisted me in various ways in the preparation of this book; namely, to Dr. Helen Hubbert Caldwell and Mr. A. O. Hansen, who have read the manuscript and ofTered many helpful sugges- tions, to Mr. W. R. Ames who has j)rei)ared the drawings, and e>IK-eially to Dr. C. L. Hull who has critically examined every [jortion of the manuscrij)! and has offered many suggestions which have Ix-en incoqxjrated in the book.

Daniel Starch.

•Madison, Wisconsin, October 5, 191S.

i^

CONTENTS

Chapter page

I. Problems and Scope of Educational Psychology i

Part I. The Native Equipment of Human Beings

II. The Instinctive Elements of Native Equipment 9

III. Variation in Human Capacities 26

IV. Correlation Among Human Capacities 49

\'. Sex Differences 63

VI. The Inheritance of Mental Traits 73

VII. The Measurement of Mental Capacities 97

Part II. The Psychology of Learning: A. In General

VIII. Analysis of Problems 115

IX. The Reception of Stimuli: A. Sensory Defects 121

X. The Reception of Stimuli: B. Perception and Obsgrvation of

Sensory Material 132

XL The Rate_andProgress of Learning 141

XII. How to Study 176

XIII. Transference of Training in Special Mental Functions '191

XIV. Transference of Training in Abilities in School Subjects. . . . 217

Part III. The Psychology of Learning: B. Of School Subjects

■ XV. The Psychology of Learning School Subjects 2^j>^-«

XVI. Reading 261

XVII. Handwriting 297

XVIII. Spelling 322

XIX. Language 349

XX. Arithmetic 374

XXI. History 416

XXII. Marks as Measures of School Work 426

Bibliography 45i

Index 465

ix

EDUCATIONAL PSYCHOLOGY

EDUCATIONAL PSYCHOLOGY

CHAPTER I

PROBLEMS AND SCOPE OF EDUCATIONAL PSYCHOLOGY

What is Education? The problems and the scope of educational psychology are necessarily determined by our conception of what education is. If we conceive education to be primarily self-devel- opment, our problems will be of one sort; if we conceive education to be fundamentally social adaptation, our problems will be of another sort. In the former case, education would mean the complete training of the mental and physical capacities irrespective of environment; in the latter case, education would mean the training of those capacities which will adapt the individual most adequately to the social and physical environment in which he is to live. For our present purpose it is not necessary to define in complete detail the aim and meaning of education. It will be suflScient to state in the simplest terms what education is as a psychological process.

In the broadest sense, education is the production of useful changes in hmnan beings, i These changes may be classified into three divisions: changes in knowledge, in skill, and in ideals. Through education the child is to acquire useful knowledge; he is to acquire skill, both motor and intellectual, in the use of his muscles and in the manipulation of ideas and concepts; and, finally, he is to acquire the right ideals of life which will actually function in his behavior. Probably all changes wrought in human beings which in any sense are educational, fall under these three heads. Obviously then, education is the most momentous, as well as the most essential, business of the human race; for the welfare of the race depends upon education as it depends upon nothing else.

' Thorndike has defined the purpose of education thus: "The aim of education is, as we have seen, to change human beings for the l)etter, so that they will have more humane and useful wants and be more able to satisfy them." ('12, p. 52.)

,, EDUCATIONAL PSVCHOLOCJV

Which changes arc ustful and which arc not is a (luestion that cannot \)c answered as easily as it would seem at first glance. U-aming to read or to figure are obviously useful modifications; l.ut it is not so easy to say whether the study of a given drama, or I III- kii..wli-<lj,'i- of certain facts of histor>', or the understanding of .1 certain theory of matter, or ability to read a given foreign lan- „'Uiige, are useful, or sufliciently useful to be included in the com- i school, in the high school, or in the university. The term 111 should not Ik- limited narrowly to the things which are iiiunediatelv applicable in making a living, but should include ill cluinges wliich will broaden and enrich the life of the in- dividual.

The Problems of Educational Psychology. In accordance with our detinltiiMi, the lund.tineiilal problem^ that we must raise voncerning education are as follows:

1. What changes arc to be made in human beings?

2. What are the agencies by which the changes may be broug\ic .iljout?

V What are the capacities which human beings possess for icquiring the changes?

4. What are the most economical methods by which these t hangeN nuiy be brought about?

'I'he first problem is j)rimarily a jtroblem for philosophy anti 4K iolog)'. What changes are ultimately to be made de[K*nds upon our ideals of life and our views of society. The nvxlifiaitions ihiit haye been sought by dilTerent nations and ditlerent sys- tems of c<lucation have varied fron\ century to century and from race to race. The ultimate aims of education sought by the ancient Greeks or by the mediaeval monks were very different from those sought by the modem Americans or I',uro|H-ans.

' < und problem dc*:ds primarily with the value of school

uid exercises in bringing about the changes that are to be

iii.KJe. To whxit extent will the study of arithmetic, the study of

U'r.iinnuir, or the study of physics or Latin be able to produce the

ir.iininL' that philosophy and sociology dictate? This problem is

' partly p.sychological. It is .sociological in

it ion of txiucational agencies depends upon

'h' i lul social environment of mankind; it is jisychological

iit .-«. ..I. .. li necessitates a study of mental processes affected or

PROBLEMS AND SCOPE 3

brought about by these agencies. This latter phase of the problem merges into problems three and four.

Problems three and four are fundamentally psychological and, together with the second phase of problem two, constitute the main scope of educational psychology. It is a psychological prob- lem to determine what capacity and eciuipment human beings have for acquiring the changes that are to be made. Likewise, it is fundamentally a psychological problem to discover the most economical methods of learning. Accordingly, the field of edu- cational psychology is divided into two large divisions which we may designate as:

I. The native equipment of human beings;

II. The psychology of learning.

Psychology and Teaching. Methods of teaching rest funda- mentally upon the psychology of learning. Since the experimental analysis of learning processes will have to reveal the principles ac- cording to which the human mind learns, and learns most economic- ally, it follows that the methods of teaching will have to be based upon these discoveries. This may be illustrated in the case of reading. If the child learns to read most economically by the word method, it follows that the most economical way of teaching read- ing would be ])y the word method. Likewise, if a child learns to spell homonyms more easily by studying them together, or memo- rizes prose or poetry more readily by wholes than by parts, it follows that these exercises should be taught accordingly. Evidently the fundamental principles of teaching must be based upon the psy- chological laws and principles of economic learning.

Waste in Education. Exact information concerning the proper procedure in educational matters is exceedingly rare. Definite, scientific knowledge of the proper methods of learning and teaching school subjects and of the efficient administration of our schools is surprisingly small, and the field of educational psychology in its broadest sense opens up endless problems for the future to solve. We know relatively little in a scientific way about the learning of any single school subject. For example, we do not know with any definite assurance what is the most economical amount of time to devote to any one of the school subjects. From such investigations as have been made, we may infer that there is an enormous waste in our educational practices which is indicated by such facts as the following: It has been found by recent tests and measurements

4 KDrcwrrowL psvcholoc.v

tlut some schools obtain just as gtXKl results by devoting on!

onc-hulf as much time to writing as other schtK>ls do. Similar fac ^^ have been brought out in the case of reading, arithmetic and oth(

'-* school subjects. Sch(H)Is which have devoted as much as ic

''^ minutes a week, or 20 minutes a day, have obtained no better r

^^ suits tlun other schools devoting 50 minutes a week, or 10 minuti

'' a day, to the s;mie subject. If these facts actually represent ll:

f^ rial |)ossibilities, it seems quite obvious thiit there is an enormoi

"^ wa>te in our schcM>ls and this waste is far greater than we reali;

"- until we nuike delinite calculations of the possible saving of tim

'" If by some means it were possible to save one minute a day k

al ever)' school day during the eight years of a child's school lif

*'' Wf would be able to save one entire week of school tinie. If \\

could s;ive four minutes a day for the same length of time, ^^ "^ would Ik- able- to save one month; if we were able to sa\e 18 mil

utts a day, wt- would be able to .save one-half of a school year; an

if by more t'coin)mical methods of learning and distribution <

time we were able to save 36 minutes a day for eight years, \\ ;jj would be ablr to save an entire school year. Such a .saving is m

imiK)ssibk-; indeed, by a better use of time and more elTecti\ ;i, methods of learning, it is highly probable. Eighteen minutes

day would mean a reduction of only ^yi minutes in each of foi , \ subjet Is; 3^ minutes a day would mean a reduction of only

minutes a day in each of four subjects. This time could be d<

voti-d with greater advantage to other and possil)ly more advance ** school subjects and school exercises.

"' The Specific Topics and Problems. In order that we may I

projR-rly oriintaled with reference to the problems tliiit will l " discussed under the two large divisions of educational ])sycholog}

'•^ the fuilowinL'ordi Tnf tuDJcs will be considered:

I. i he ii:iti\e ((luipiiienl of human beings.

a. What d(H'S it consist of?

b. To what extent does it N'an*?

1. Ajnong individuals. '" (a) In single traits.

^'' 0>) In combinations and relationships of traits.

2. At different times of life in the SiUne individual. I*" 3. Hetween the sexi*s.

*^ C. To what extent is it inherited? ,

: <l. How may it be measured?

PROBLEMS AND SCOPE 5

II. The Psychology of Learning.

a. The psychology of learning in general.

1. Observation and perception.

2. The rate and progress of learning.

3. Transference of training.

b. The psychology of learning school subjects in particular.

1. The psychological processes involved in each subject.

2. The measurement of ability and progress in learning

each subject.

3. The most economical methods of learning the material

of each subject.

a* d

M Ol

U ti fr tl <1

PART I THE NATIVE EQUIPMENT OF HUMAN BEINGS

CHAPTER II

THE INSTINCTIVE ELEMENTS OF NATIVE EQUIPMENT

Reflexes, Instincts, and Capacities. The equipment with which human beings start in hfe may be divided into three types of inherited responses and abihties: Reflexes, instincts, and capaci- ties. The distinction among these three is primarily one of definite- ness and degree of complexity. An instinct may be defined from the neurological side as an inborn neural connection between sense organ and muscle. It may be defined from the functional side as an inborn capacity of responding in definite ways under definite circumstances. These responses are prior to experience and train- ing, and need not be learned. To close the eyes when an object suddenly approaches them, to get food when hungry, to strike when struck, and to be afraid of thunder and of the dark, are illus- trations of instinctive responses. The reflexive and instinctive responses are inherited in the sense that there is present in the nervous system, either at the time of birth or later on as a result of growth, a set of nervous connections already formed for the carrying out of a particular action in response to a given situation. If the child closes his eyes when an object suddenly approaches, it means that the motor impulses travel from the retina to the visual center of the brain, from there to the motor center which controls the movement of the eyelids, and from there out to the muscles of the eyelids to cause the contraction. In the case of inherited responses, the connection from the sensory to the motor centers is already present and ready to operate in carrying out the action. In the case of acquired responses, such as habits, these nervous connections must be formed as a result of effort and trial on the part of the individual.

The difference between reflexes and instincts is largely a differ- ence of complexity. Both are inherited types of responses. Re- flexes are simpler forms of reaction usually involving a limited set of muscles and occvu-ring in response to precise stimuli. The contraction or expansion of the iris, the closing of the eyelids, the knee jerk, are illustrations of reflexes. Instincts are complex re-

lO KDUCATIONAL PSYCHOLOGY

actions involvin;:; tlu- use of large groups of muscles or, in many instances, the entire muscular system of the body. They may he aroused either by external stimuli or situations or possibly by internal stimulation. To make movements in the direction of getting f(MKl when hungry, to seek shelter when cold, to offer re- sistance when hemmed in, to s])it out what tastes bad, and the like, are instinctive reactions. Capacities are distinguished from reflexes and instincts in being general mental abilities rather than specific motor responses and in referring primarily to the native mental e(juipmcnt, such as the powers of sensation, j)ercei)tion, retention, attention, imagination, and all the varied complex I)sychic processes.

Classification of Instinctive Responses, The older classifica- tions of instincts usual!}' dixided thcni into three or four large groups of responses, such as individual, racial, and social, and re- garded them rather as general tendencies than as specific responses. The present conception of instincts is to regard them as specific responses with inherited neural mechanisms which will be set into action by specific stimuli or situations. On this basis the classification consists of an enumeration of as many definite, identi- fiable, unlearned reactions to specific situations as can be observed and as can be recognized in human beings prior to training and habituation in each particular ty]>e of activity. Accordingly, Thonidike ('14, I) enumerates forty or more different tyjx's of in- stinctive reactions as follows:

1. Food getting and j)rotective responses.

1. Eating.

2. Reaching, grasping, and putting objects into the

mouth.

3. Acquisiti(jn and possession.

4. Hunting.

5. Collecting and hoarding.

6. Avoidance and repulsion.

7. Rivalry and cooperation.

8. Habitation.

9. Response to confinement.

10. Migration and domesticity.

11. Fear.

12. Fighting. I J. Anger.

INSTINCTIVE ELEMENTS OF NATIVE EQUIPMENT 1 1

II. Responses to behavior of other human beings.

14. Motherly behavior.

15. Gregariousness.

16. Responses of attention to other human beings.

17. Attention getting.

18. Responses to approving and to scornful behavior.

19. Responses by approving and scornful behavior.

20. Mastering and submissive behavior.

21. Display.

22. Shyness.

23. Self-conscious behavior.

24. Sex behavior.

25. Secret! veness.

26. Rivalry.

27. Cooperation.

28. Suggestibility and opposition.

29. Envious and jealous behavior.

30. Greed.

31. Ownership.

32. Kindliness.

^^. Teasing, tormenting, and bullying.

34. Imitation.

III. Minor bodily movements and cerebral connections.

35. Vocalizations.

36. Visual exploration.

37. Manipulation.

38. CleanHness.

39. Curiosity.

40. Multiform mental activities.

41. Multiform physical activities.

42. Play.

Relation of Education to Native Endowment. The inherited equipment of the human being is the foundation upon which educa- tion must build; it consists of the faculties and capacities which the child has for reacting to his environment. It is the utilization, the training or the curbing of these endowments which education attempts to accomplish. In much of the writing and thinking con- cerning educational problems, there has been a relative overem- phasis, in space and time, upon instincts and an underemphasis upon the mental capacities. Education in the sense of schooling has as

12 EDUCATIONAL PSYCHOLOGY

much if not more to do with the latter than with the former. The direct appeal to, and use of, instinctive reactions in actual concrete instances in school work are not as frecjuent and specific as is com- monly implied. The number of instincts enumerated in the pre- ceding list which may be directly and concretely appealed to in the learning of a school subject is relatively small. The best way to be convinced on this j)oint is to take the various instincts one by one, and to determine to what extent each one may be aj)pealed to or used in teaching the various sxibjects. The number of specific applications is much smaller than one is likely to anticipate. Two- thirds or three-fourths of them are probalily never immediately but only indirectly concerned in school exercises, and most of the remaining ones, such as rivalry, cooperation, collecting and hoard- ing, are serviceable chiefly as general motives. As such they are, to be sure, highly important.

We must, of course, not minimize the j)lace and importance of instinctive reactions in behavior as a whole. They furnish the general motives and mechanisms for doing and learning, but the mental capacities are more directly and concretely involved in the acquisition of knowledge and skill in school subjects.

The instinctive elements in learning any school subject are for the most part simple reflex actions or undeveloped connections. Take learning to read as an illustration. The chief instinctive elements ])robably are the reflexes in the control of the eyes, the neural mechanism for receiving and transmitting \isual impulses to the brain, the capacities for attentiveness and retentiveness, and partial motor control of the speech organs. The process of learning to read assumes these and uses them; but, what is more important from the practical side of getting the meaning of the printed word is the establishment of countless new con- nections.

Perhaps the most important role of instinct in education lies in motivating and energizing the learning processes. There can be no education except through the activity of the child himself; and no activity can take place which does not ultimately depend ujjon native tendencies. They are the origin of effort, the springs of action. The skillful teacher j^lays upon them and aj^peals to them in countless ways. The ability to do this is an art which is not rasily learned from books; it is acquired rather by jxitient practice and by sympathetic contact with children.

The energizing power of instinct makes itself felt largely through

INSTINCTIVE ELEMENTS OF NATIVE EQUIPMENT 13

its control of the attention processes. Owing to the peculiarities of our inherited nervous organization, certain impressions have a potency over others in attracting the attention and interest of the child. A flash of lightning, a hoHday parade, one's name in the newspaper, or a moving picture make certain instinctive appeals to the attention of a young girl which the study-lamp, the doing of errands for mother, the seeing of a stranger's name in the newspaper, or the reading of the history lesson do not make. The great im- portance of attention for the learning process lies in the fact that associations, analyses, and indeed all mental processes are carried out much more effectively when they occupy the focus of attention. Ebbinghaus found that, after inattentively reading over nonsense syllables until many successive persons had learned them per- fectly, he himself could repeat very few of them. Impressions must occupy the focus of consciousness in order to be retained effectively.

Considering the three main t)^es of attention, passive, active, and secondary passive, the most simple and the one most directly related to the instinctive life is probably the first. Passive atten- tion is such as one gives spontaneously to any curious or interesting sight or sound. Active attention is such as one gives perhaps to an inherently distasteful task which requires an efifort of will to keep the mind upon it. While such a task itself does not supply the stimulus for vigorous instinctive reaction, it is in some direct way connected with one that does. A little girl will apply herself to the disagreeable task of learning a spelling lesson, not because the words in themselves have any charm for her but because she has the instinctive craving for the approval of her teacher. The third type of attention, secondary passive or derived attention, is at- tention which has become passive only after having passed through an initial active stage. It is illustrated by the common experience of becoming absorbed in a task which at first required a distinct effort. In the beginning the motivation lay outside the task, say in a sense of duty or social obligation; but after a time an adequate stimulus for activity was encountered in the work itself.

Apparently back of every act of attention lies somewhere a more or less primitive, innate tendency to action. To focus the atten- tion of a class upon various associations involved in learning the multiplication table, a skillful teacher may on one day appeal to curiosity in the novelty of the combinations; on another day she may appeal to the native pleasure in rhythm by making the table

14 EDUCATIOXAL PSYCHOLOGY

into u rhyme or sonp;. Or the tendency to play will he utilized by making the number combinations into a game. More than likely the game itself will dejiend upon instinctive rivalry and emulation. The love of social ai)proval is appealed to by giving distinctions, murks, gilt stars, and the like. Future ad\'antage may be used as an intlucement for present api)lication. The instinct of pugnacity may be utilized in wanting to succeed in a hard task. The teacher herself, in standing position with face and body in animated attitudes, may api)eal to the fundamental interest in change and action. Lastly may be mentioned the more doubtful negative moti\es of deprivation from coveted privileges and, biologically l)erhaps the most fundamental and powerful of all motives, physical pain. It may be worth noting that animal psychologists have found pain in some cases a more potent motive to learning than ])leasure. Hoge and Stocking ('12) found that rats when rewarded b\- food alone had by no means learned j^erfectly certain sensory habits in 610 trials; when they were punished for failures they learned the habits jjcrfectly in this number of trials, but when they were both rewarded for successes and punished for failures they learned the habits perfectly in 530 trials.

Educational Doctrines Based upon Instincts. Some very far- reaching s])ecu!ations and theories with regard to the nature and value of instincts for education have been spun out, some of which an' largely imaginary and questionable, and are based upon analogy rather than fact. For the most part these educational doctrines have centered around three concepts.

The first is that instincts are the great dynamic forces of human nature which determine the actions, desires, and achievements in an indivitlual's life. Hence the injunction to the school has been to work with nature rather than against her or apart from her. We shall call this the dynamic theory of instincts.

The second is that these instincts are highly transitory; that they burst out at certain times in the growth of the individual with more or less dramatic force and suddenness, and that if they are not allowed to manifest themselves, they will disaj^pear never to be revived again. From this assumption has been derived the peda- gogiail application of the ma.xim, ''strike while the iron is hot.'' 'ihis is the theor}' of the transitorincss of instincts.

The third is that instincts appear in the growth of the child in t he order in which they appeared in the evolution of the race. From thi^ assumption has been derived the jjcdagogical maxim, "teach

INSTINCTIVE ELEMENTS OF NATIVE EQUIPMENT 15

the child his activities in the order in which the interests for them appear." This is known as the recapitulation theory of instincts.

Critique of the Dynamic Theory of Instincts. To work with nature rather than against her is undoubtedly a sound principle. The fundamental instincts of man are the driving forces of human life that determine ultimately the motives and causes of behavior. They are so deep-seated in the human psychophysical organism that we may almost say that to work apart from, or against, nature is a futile task. If, through the instinct of multifonn activities, a child manifests a tendency to draw, the school should take ad- vantage of this original impulse and build upon it. All the original manifestations of a child's nature should be used in the acquisi- tion and training of those exercises which education considers valuable.

This dynamic theory of instincts, however, involves on the one hand a difficulty and on the other a questionable assumption. The difficulty is that the principle is general and as such does not point out the particular ways in which the school may cooperate with the inborn forces of child nature. It is easy enough to say "work with nature," but just how is that to be done in teaching a pupil how to make the letter "a," or to learn the reading of a printed word, or to acquire correct speech, or to learn the grammatical rules of a foreign language? Ultimately, the concrete use of the principle must be determined experimentally. Our definite knowledge of the tech- nique of learning in the case of school subjects is appalUngly limited. Only by careful and painstaking experimentation can this principle be made useful in the concrete work of the school in anything more than an offhand impressionistic manner.

The questionable assumption is that the instincts are infallible guides of human life. It may be argued that since instincts are such powerful springs to action as to have maintained the individual and the race for numberless generations, they must necessarily be dependable in producing action and interest of the right sort. But the question may fairly be raised: Are the native tendencies always right so that we should always cooperate with them and never coun- teract or curb them? The theory of the infallibility of instincts is based on the belief that for countless ages nature has found by ex- perimentation and natural selection what is best for the individual. Whatever the child is inclined to do by virtue of his natural pro- clivities is right and good for him; or, if apparently not useful, it is a

1 6 EDUCATIONAL PSYCHOLOGY

necessary precursor or a necessary accompaniment of useful tenden- cies. On the theory of immunization or catharsis, the undesirable tendencies prepare the ground for the proper development and growth of the desirable ones. However, the theory of catharsis is highly questionable and runs counter to the law of use and disuse which in general operates to the effect of making permanent the functions exercised. The belief is that if a boy has proclivities toward thieving or lying or dishonesty, and is allowed to exercise these unconstrained, he will purge himself of these tendencies and he the more honest and truthful later on in life. Concrete data, however, in addition to the general principle of use and disuse, seem to point in the opposite direction. Experimental and statistical inquiries show that the relative strength of the various traits remains fairly constant throughout life; that if a child manifests certain abilities and tendencies even during childhood, these abili- ties and tendencies will remain relatively dominant during his adult life. Early interests and intellectual capacities are very certain, on the whole, of being prophecies of similar interests and intellectual abilities later in life. As will be pointed out in a succeeding chapter, scholastic ability remains fairly constant in any given child all through his educational career.

Furthermore, we must remember that nature, in the develop- ment of instincts and in securing adaptation to environment, works on the whole in a very slow and prodigal manner; and that conditions of life may change long before the organism through its behavior appropriately adapts itself to the surroundings by fur- nishing the necessary native equipment within the organism. On this account a great deal of our native equipment is out of date and has adapted man to primitive conditions of uncivilized life. As a result of this, we manifest many tendencies which are not par- ticularly useful at the present time. We would be better off if in l)Iace of them we had instinctive capacities for meeting situations with which we are to-day confronted in civilized life. As Thoni- dike has pointed out:

"The imperfections and misleadings of original nature arc in fact many and momentous. The common good requires that each child karn countless new lessons and unlearn a large fraction of his natural birthright. The main reason for this is that original equipment is archaic, a(!ai)ting the human animal for the life that might be led by a family group of wild men in the woods, amongst the brute forces of land, water, wind, rain, plants, animals, and other groups of wild men. Tiic life to

INSTINCTIVE ELEMENTS OF NATIVE EQUIPMENT 17

which original nature adapts man is probably far more like the life of the wolf or ape, than like the life that now is, as a result of human art, habit and reasoning, perpetuating themselves in language, tools, build- ings, books and customs." ('14, 1, p. 280.)

That these primitive tendencies persist with great strength is shown by the ready manner in which the veneer of civilization comes off and by the fact that men and women in strained circumstances will easily revert to their primitive, brutal instincts. The chief ad- vocate of the theory of infallibility and catharsis of instincts has been G. Stanley Hall, who has said:

"In education, don't cut off the tadpole's tail."

"Rousseau would leave prepubescent years to nature and to these primal hereditary impulsions and allow the fundamental traits of savagery their fling till twelve. Biological psychology finds many and cogent reasons to confirm this view if only a proper environment could be pro- vided. The child revels in savagery; and if its tribal, predatory, hunting, fishing, fighting, roving, idle, playing proclivities could be indulged in the country and under conditions that now, alas! seem hopelessly ideal, they could conceivably be so organized and directed as to be far more truly humanistic and liberal than all that the best modern school can provide. Rudimentary organs of the soul, now suppressed, perverted, or delayed, to crop out in menacing forms later, would be developed in their season so that we should be immune to them in maturer years, on the principle of the Aristotelian catharsis for which I have tried to sug- gest a far broader application than the Stagirite could see in his day." (Hall, '08, p. 2.)

"He should have fought, whipped and been whipped, used language offensive to the prude and to the prim precisian, been in some scrapes, had something to do with bad, if more with good, associates, and been exposed to and already recovering from as many forms of ethical mumps and measles as, by having in mild form now he can be rendered immune to later when they become far more dangerous, because his moral and religious as well as his rational nature is normally rudimentary." ('08, P- 23S-)

The Theory of the Transitoriness of Instincts. This concep- tion of instincts contains two elements: First, the suddenness of the appearance of instincts, and second, the unrevivable disappearance of instincts. The most conspicuous advocate of the former idea in this country, has been G. Stanley Hall, who states it as follows:

"But with the teens all this begins to be changed and many of these precepts must be gradually reversed. There is an outburst of growth

i8

p:i)Ucational psychoix>gy

tlial iiL'cds ;i large pari of the total kinetic incrgy of the IxkIv. There is a new interest in adults, a passion to be treated like ones elders, to

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Fig. I. — Height of boys and girls measured in centimeters, based on measure- ments of 45,151 lx)ys and 43,298 girls. After Boas Cgb-'gy).

make plans for the future, a new sensitiveness to adult praise or blame. The large muscles have their innings and there is a new clumsiness of body and mind. The blood-vessels expand and blushing is increased, new sensiilions and feelings arise, the imaginatit)n lilossoms, love of

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12 13 Ages

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Fir,. 2. — Rale of tap|)ing. Number of taps made with right hand in 30 seconds. Based on tests with 395 boys and 495 girls. After Smedley ('00- 01).

nature is born, music is felt in a new, more inward way, fatigue comes easier and sooner; and if heredity and environment enable the individual

INSTINCTIVE ELEMENTS OF NATIVE EQUIPMENT 19

to cross this bridge successfully, there is sometimes almost a break of continuity, and a new being emerges." ('08, p. 236.)

The correctness of the theory of sudden appearance is primarily a question of fact. Thus Hall describes the social instincts at the time of adolescence as follows:

"The social instincts undergo sudden unfoldment and the new life of love awakens. It is the age of sentiment and of religion, of rapid fluctua- tion of mood, and the world seems strange and new. Interest in adult life and in vocations develops. Youth awakes to a new world and under- stands neither it nor himself." ('04, Preface p. XV.)

The advocates of this viewpoint maintain, therefore, that there is a nascent period for motor activity, for memory and habituation, for reason and logical thinking and the hke; that the school should seize these opportunities to teach those activities which will exer- cise the particular capacities that occupy the stage of youth at that period; and that more can be accomplished at those periods in a given length of time than can be accomplished in several fold as much time later on.

The facts do not seem to warrant an interpretation of such marked suddenness but indicate rather a gradual waxing of in- stincts. There appears to be no special time during which the child suddenly begins to reason or to reason very much more than he had done theretofore. The same description seems to be true of memory, motor ability, the collecting instinct, and other capaci- ties, as indicated in the accompanying graphs.

A great deal of the dramatic bursting forth of instincts is chiefly a dramatic bursting forth of descriptive words. The actual facts seem to justify more nearly an interpretation of gradual unfold- ment instead of a sudden bursting forth. Growth in height and weight proceeds by a very uniform increase even diu-ing the adoles- cent period. Motor capacity grows steadily and uniformly without particularly sudden leaps or bounds. Memory ability increases steadily for both rote and logical material up to adulthood, during which it probably remains fairly constant mitil senility sets in. There is no memory period diu-ing which the child memorizes very much more readily than he did before or than he ever will later. The memory of the average adult for both mechanical and logical material and for either immediate or permanent retention is superior to the memory of the average child at any age. Even reasoning

20

EUUCATIONAL PSYCHOLOGY

ability, which is usually described as appearing suddenly at the dawn of adolescence, is a matter of gradual development . To argue

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Fig. 3. — Memiiry for diRils based upon tests of 9,^7 |>upils. After Smedley ('cx)-'oi).

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Fir.. 4.- Development in arillimetical reasoning as measured by llie Courtis test No. 8, Series ;\. The verlica.1 a.xis shows the number of problems done cor- rectly in si.\ minutes.

INSTINCTIVE ELEMENTS OF NATIVE EQUIPMENT 21

that school exercises which consist mainly of memorizing should be placed at the "memory age" on the ground that the pupil will learn them more readily at that time than at a later time in life, is fallacious. It may be advisable to begin the study of foreign languages earlier than is customary, but not for any reason of more rapid memorizing at an earlier age. If rapidity of tapping, Figure 2, is any indication at all of endurance or of quickness of becoming fatigued, it does not seem to be true that "fatigue comes easier and sooner" during the adolescent stage. The graphs for tapping

11 10 w 7 6 6					/
			J	/
			/
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4 5 6 7 8

Grade

Fig. 5. — Development in arithmetical reasoning as measured by the arith- metical scale A. After Starch ('16). The vertical axis represents the scale step or the number of problems done correctly.

do not drop but tend to rise gradually even during the years from eleven to fifteen. There is practically a level at the age of eleven but no drop.

The unrevivability of instincts through disuse has been advocated chiefly by James as follows:

"This leads us to the law of transitorincss which is this: Many in- stincts ripen at a certain age and then fade away. A consequence of this law is that if, during the time of such an instinct's vivacity, objects adequate to arouse it are met with, a habit of acting on them is formed, which remains when the original instinct has passed away; but that if

22

EDUCATIONAL PSYCHOLOC;\

no such objects are met with, then no habit will be formed; and, later on in life, when the animal meets the objects, he will altogether fail to react, as at the earlier epoch he would instinctively have done." ('90, II, p. 398.)

"Leaving lower animals aside, and turning to human instincts, we see the law of transiency corroborated on the widest scale by the altera- tion of different interests and passions as huniiin life goes on. With the child, life is all play and fairy-talcs and learning the external properties of 'things'; with the youth, it is bodily exercises of a more systematic sort, novels of the real world, boon-fellowship and song, friendship and love, nature, travel and adventure, science and i)hilosophy; with the

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0 7 S U 10 11 1-' 13 U 15 16 17 Ages

Fig. 6. — The number of collections made by children at various ages. After C. V. Burk ('00;.

man, ambition and policy, acquisitiveness, responsibility to others, and the selfish zest of the battle of life. If a boy grows up alone at the age of games and sports, and learns neither to play ball, nor row, nor sail, nor ride, nor skate, nor fish, nor shoot, probably he will be sedentary to the end of his days; and, though the best of opportunities be afforded him for learning these things later, it is a hundred to one but he will pass them by and shrink back from the effort of taking those necessar>' first steps the prospect of which, at an earlier age, would have filled him with eager fielight. The sexual passion expires after a protracted reign; but it is well known that its peculiar manifestations in a given individual dejK'ud almost entirely on the habits he may form during the early IH'rio<l of its activity. Kxposure to bad company then makes him a lo*»sf livL-r all his days; thastity kept at first makes the s;ime easy later

INSTINCTIVE ELEMENTS OF NATIVE EQUIPMENT 23

on. In all pedagogy the great thing is to strike the iron while hot, and to seize the wave of the pupil's interest in each successive subject before its ebb has come, so that knowledge may be got and a habit of skill acquired — a headway of interest, in short secured, on which afterward the individual may float. There is a happy moment for fixing skill in drawing, for making boys collectors in natural history, and presently dissectors and botanists; then for initiating them into the harmonies of mechanics and the wonders of physical and chemical law. Later, intro- spective psychology and the metaphysical and religious mysteries take their turn; and, last of aU, the drama of human affairs and worldly wisdom in the widest sense of the term." ('90, II, pp. 400-401.)

Facts seem to support this aspect of the nature of instincts more than the theory of the sudden appearance. The law of disuse of functions is necessarily in general support of the theory. Any fiinctions will, as a rule, be strengthened through exercise. The assumption, however, that instincts, if not exercised when they first manifest themselves, will become dormant beyond the possibility of reawakening, or that they actually become dormant, is question- able. James gives isolated instances in favor of his viewpoint. Experimental and comprehensive observations are missing at the present time. Isolated illustrations of the opposite viewpoint, however, also are to be found. Thus it frequently happens that through the change of circumstances of life, instincts apparently long dormant or never given opportunity to manifest themselves, will quickly appear for action. For example, the writer has a friend who as a boy had never developed the instinctive tendencies in- volved in fishing. About the age of thirty, through the opportuni- ties of a new environment, the instinct appeared so strongly that he will go to great lengths at any time of day or night to follow this sport. But isolated instances are dangerous bases on which to generalize, and future inquiries will have to solve the problem. Many instincts apparently are dormant only because no opportu- nity of expressing themselves are at hand, or because other more dominant interests prevail, but may, when appropriate circum- stances arise, rapidly appear for action.

The Recapitulation Theory of Instincts. The principle of re- capitulation was formulated by biologists to account for the develop- ment of animal organisms in the early stages of their growth. The theory of recapitulation holds that the individual retraces in its growth the successive stages of development of the entire animal series. Thus Hall says:

24 EDUCATIONAL PSYCHOLOGY

"Holding that the child and the race are each keys to the other. I have constantly suggested phyletic explanations. ..." ('04, I, p. \'III.)

"The best index anil guide to the staled activities of adults in past ages is found in the instinctive, untaught, and non-imitative plays of children. ... In play every mood and movement is instinct with heredity. Thus we rehearse the activities of our ancestors, back we know not how far, and repeat their life work in summative and adumbrated ways. It is reminiscent, albeit unconsciously of our line of descent, and each is the key to the other. . . . Thus stage by stage we enact their (our ancestors') lives. Once in the phylon many of these activities were elaborated in the life and death struggle for existence. Now the elements and combinations oldest in the muscle history of the race arc re-presented earliest in the individual, and those later follow in order." ('04, I, pp. 202-203.)

And Puffer says: "We are by turns vertebrates, gill-breathing verte- brates, lung-breathing vertebrates (we make the great change at birth), little monkeys, Uttle savages, and finally civilized men and women." ('12, p. 77)

The e\'i<U'Tices ;:jiven for the principle of recapitulation are largely embrj-olo^^ical and structural. Vestigial organs such as the vemai- form appendix, gill slits, etc., are further cited as evidences of the remainder of structures once useful. The facts seem to be that such recai)itulation as takes ])Iace is very brief and confined almost wholly to the prenatal ])eriod of an individual's develo])ment. Davidson, after a comprehensive review of the biological evidence for the theory, concludes thus:

"The history of recapitulation is an instructive one. A principle of limited application within the field of its origin was elevated to a position of wide generality, and so gave rise to a conception in the main mislead- ing. Carried into a new territory without a sufikient examination of its merits, it was applied broadly as an explanatory principle and thus distributed its misleading influence beyond its own borders." ('14, p. 99.)

"A more thorough consideration of the facts has led to a view of de- velopment essentially contradictory to this recapitulatory one. Ontogeny represents the ancient life-cycle which as such has been transmitted from the beginning. The chronological secjuence from egg to maturity is not a rehearsal of a like historical series of events throughout the i)hylogeny of species; it is but the recurrence of an order which has been repealed in the lifetime of each individvial from the beginning. In general, the effect of the modifications induced by germinal mutations and selection in the successive ontogenies, to make them over, and to destroy the resemblance of later ones to their predecessors."

INSTINCTIVE ELEMENTS OF NATIVE EQUIPMENT 25

The recapitulation theory with its pedagogical corollate, the culture epochs theory, has been developed largely as an analogy with many of the analogues missing. Its usefulness for educational thinking seems to the writer to be greatly exaggerated. It has built pedagogical mountains out of biological molehills. It is primarily an anatomical principle proposed to account for the embryological development of biological organisms, and has been brought over into human behavior to explain on the one hand, the order and dates of appearances of instincts, and to furnish on the other hand, a basis for the order and dates of teaching subjects in the school curriculum. The former assumption is more or less dubious, since most, if not all, of the demonstrable recapitulation occurs before birth; and the latter assumption is quite certainly dubious, since the anatomical and probably also the functional recapitulation has long ceased when the child begins his definite education.

CHAPTER III

VARIATION IN HUMAN CAPACITIES

How May They be Measured and Represented? Differences among human beings are quantitative rather than qualitative. That is, all human beings have the same reflexes, instincts, and capacities; all have the powers of perception, discrimination, at- tentiveness, retentiveness, reasoning, and so forth. Ail persons, consequently, have the same general qualitative make-up. The variations from person to person are, therefore, primarily differ- ences in the strength of the various abilities that each individual possesses, and in the manner in which amounts of the various

Fig. 7. — Distrihiilion of numory ability of 173 University students. The test consisted in diiliilin^ ten monosyllaljic nouns. The [K-rsons then recorded the words that they remembered. The horiz<jntal axis indicates the numlx-r of words and the vertical a.xis indic;ites the number of persons ha\ ing each memory ability.

36

->

40

50

60 70 80

Letters per Minute

90

Fig. 8.— Distribution of ability in the A-test. Based on 164 University stu- dents. The horizontal axis represents the number of A's canceled in one minute; the vertical axis represents the number of persons of each ability.

3 4

13

5 6 7 8 9 10 IL Eigures per Minute

Fig. 9. — Distribution of ability in canceling a certain geometrical figure in a page of figures. Time allowed, one minute. Based on 164 persons.

a8

EDUCATIONAL PSYCHOLOGY

trails combine in the same [)erson. The ditTerences are quaUtative only in the sense that combinations of \arying amounts of diverse traits occur.

The most convenient manner in which to rej)resent and deter- mine the amount of variation in a given trait is by means of the dis- tril)ution curve, or the surface of fret|uency. The distribution cur\'e is a curve designed to represent how fre(|uently each amount

20 30 40 50

Associations per 15 Seconds

Fjc. io. — Distribution of ability in K'i^'nk' associations in response to a stimulus word. The horizontal axis f^ises the number of words >jiven in 15 sec- onds. The vertical a.\is gives the number of persons of each ability. Based on 13s i)crsons.

or strength of a given trait occurs in a given group of persons. The range of abihty fron\ a small amount to a large amount is repre- sented along the base line, or .\ axis, from left to right, and the number of times each ])articular ability occurs is rejiresentcd ver- tically along the ordiiiates, or y axis. (.See Figures 7, S, 0, and 10.)

How Wide are the Differences? The investigation of this problem in recent years has brought out the fact tiiat the differ- ences among human beings are very much greater than has com- monly been thought. If we measure a group of jjupils in a given

VARIATION IN HUMAN CAPACITIES

29

class or grade, we find that on the average the best pupil is able to do from two to twenty-five times as much as the poorest pupil, or is able to do the same task from two to twenty-five times as well as the poorest pupil. The accompanying table shows the range of differences between the highest and the lowest in a series of tests made upon fifty university students.

TABLE I

Range of differences between the best and the poorest in a series of mental tests. Based upon the writer s Experiments in Educational Psychology, page 8, which may be consulted for the nature of the tests.

Best Record

Poorest Record

Ratio

Memory span Memorizing. .

E Test

Er Test

Opposites. . . . Genus-species

Addition

Subtraction. .

Average

8 words I min.

25 sec. I min. 30 sec.

30 sec. 45 sec.

31 sec. 20 sec.

4 words 4 min.

I min. 30 sec. 3 min. 25 sec.

1 min. 50 sec.

2 min. 5 sec. 2 min.

I min. 30 sec.

I : 3-35

What is the Nature of the Variation? From the general ap- pearance and form of the distribution curves of mental traits, we note that abilities range without break from the lowest to the highest. Our common terminology of dividing groups of persons into various classes as dull, mediocre, and bright, on the assumption that they may be divided into distinct classes with gaps between them, is psychologically incorrect. The fact rather is that all grades of ability, varying by infinitesimally small amounts from the lowest to the highest, are found in the human species.

The next conspicuous feature about the nature of the distribu- tion of mental abilities is the general shape of the curve. This indicates that the large majority of individuals cluster about the center. In the accompanying illustration it will be noticed that if the entire range of abilities is divided along the base Hne into three equal sections so that we may designate the one at the right as the superior section, the one in the middle as the medium sec- tion, and the one at the left as the inferior section, we find that

30

i:i )l tA riONAL rSYCHOLOGY

approximately two-thirds, or db'/'o of all persons fall into the middle third; one-sixth or if'o fall into the superior one-third, and the remaining one-sLxth, or if/i fall into the inferior one-third of the range of abilities. In other words, the normal distribution curve is a symmetrical, bell-shaped figure, having its mode in the center and dropping at first rather gradually, then very rai)idly and finally \ery slowly. The statement attributed to Lincoln that "God must have loved the common people because He made so many of them" is i)sychologically true. If the middle third of the entire range of abilities represents the common people, then two-thirds of all persons are common people.

32 to 40 45 48

Inches

Fig. II. — Distribution of chest measurements of English soldiers.

The third interesting fact to be noted is that psychological and bi(jlogical traits vary universally in the same manner in conforniity with the normal, bell-shai)ed curve. Note for exam|)le the dis- tril)ution of such biological traits as chest measurement, height, girth of head, and so forth, as represented in the accompanying graphs, Figures ii, 12, and i,^. The number of men who are ex- tremely tall or extremely short is very small, and the number less tall or less short is larger and larger as the median is being ap- proached. 'I'his uniformitN throughout organic nature is an in- teresting and significant fact. Ai)parently nowhere are there traits

VARIATION IN HUMAN CAPACITIES

31

which are discontinuous so that gaps would exist within the ranges of the traits, nor do we find that, on the whole, traits are distributed

55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70" Inches

Fig. 12. — Distribution of the height of 1,052 women.

in a skewed manner, so that the great majority of individuals would lie either in the upper or lower range of abilities.

51 52 53 54 55 56 57 58 59 60 61 Head Girths in Centimeters

62

Fig. 13. — Distribution of the head girth of 1,071 boys, 16-19 years of age.

Finally, the variation in both psychological and biological traits occurs apparently according to the law of chance, that is, according

32

EDUCATK )\ \l. PSYCHOLOGY

lo the frecjuency of occurri-iuc- of ;i c haiur tvint. Consequently, on this assumption, the statistical treatment of the distribution of mental abilities becomes subject to the mathematical j)ro[)erties of the probability integral. What we mean by the statement that the variation occurs according to the law of chance may be illustrated in the following manner: If we toss up ten pennies at one time, count the numi)er of heads up and keep a record of it, then repeat the tossing a thousand times and keep a record each time, it will be found that the number of times no heads are up will occur very

Fio. 14. — Distribulion of the nunihorof heads u[) in tossing; ten pennies i.ooo times. The horizontal axis >,'ives the number of |)ossil)le heads up in each tossing; the vertical axis gives the number of times each number of heads was U|).

rarely, likewise, the number of limes all ten heads are uji will occur very rarely, the number of times one head is up or nine heads are up will t)ccur less rarely, and as you ai)j)roach from either side toward four, five, and six, the occurrences will be more and more frequent. The actual records of a thousand such tossings are represented in Figure 14. It would seem as though nature, in the production of her creatures, aimed at a target. The largest num])er of trials strikes somewhere near the bull's-eye, a smaller numl)er strikes within the ne.xt circle, and a still smaller number within the next circle, and so on. The corresjumdence between the actual tlistribution of abilities and the values of the i)robabilily integral is exceedingly useful in permitting statistical treatment of series of

VARIATION IN HUMAN CAPACITIES

33

measurements of any trait. Figure 15 gives the mathematical or theoretical probability curve.

Variation in Abilities in School Subjects. The differences in

Fig. 15. — The theoretical probability curve.

abilities in school subjects are fully as wide as in special psycho- logical capacities. They are probably due primarily to native

Grade 8		• • • •	• • • • •	• •«• •
Grade 7	•	• • •••	• • •	^ ,	•
Grade 6	• •	.: :	.:.:	• ••	• • •
Grade 5		• ,	• • • • • •	• • •	«• •	• •
Grade 4		• • « ••		.
Grade 3	. .	• • I •
Grade 2	• .	•• ••••	• •

1.0

3.0

4.0

5.0

6.0

7.0

8.D

Fig. i6. — Distribution of pupils (in one school) in grades 2 to 8 in reading ability as measured by the author's tests. The horizontal axis represents speed and comprehension combined in terms of speed, i. e., words read per second.

ability rather than to differences in opportunity, training, or en- vironment. Table 2 shows the range of difference in ability

Grade 8					.:•:!	... I • • •• ••	• •• •	••	•
Grade 7		•		.. :	. t ••• ••	•••••	••• •••	• •	• ••
Grade 6			••	• • •	•• •	• • •••	•«•	•
Grade 6		•	• ••	• • •	• • • •• •	• •
Grade 4			•• ••••	• • • • • • ••• ••••	• • •	•
Grade 3	• •••••• •	:.	•
Grade 2	•	. :.	•

90

100 110 120

writiii;,'. S[)cc(l and

20 yO 40 50 60 70 80

T-'iG. 17. — Dislrihution anrl overlap[)ing of puf)il quiilit}' combined into one score as explained in tlie author's Educational Measurements. The numbers along the horizontal axis represent speed and C|ualit_\' in terms of speed, i. c., letters per minute. Quality was measured by the Thorndike scale.

Grade 8				•		. . :	. i . .
Grade 7			•		•	• •	. : • • •	:» . :	•
Grade 6				• ••	•:	••••• ••	•• • »	1.: .:	: .
Grades				• • • •	••••••• a	• •	• •• •• •	•
Grade 4		• •	••• •	• 1 • • • • • •	•	..:.!?:	•	•
Grades	• • • •	•:• •:	• • • • • ••	1 :. ..	• •	•
Grade 2 • • ••	• • • • •	•ff •• ••	' • •	• • •

0 10 20 aO 10 00 60 7Q tft) W 100

Fig. 18. — Distribution and ovcrlapi)inK of [)upils in spelling as measure*! by the author's test. The numbers along the horizontal a.\is are the numbers of words sfKlled out of a list of 100.

VARIATION IN HUMAN CAPACITIES

35

in various school subjects as found in a class of 36 eighth-grade pupils. Abilities in reading, arithmetical reasoning, spelling, grammar, and history were measured by the author's tests ('16).

	Grade 8 •	• • • • • • • • •	' • • • • • • • • • • I • • • •
	Grade 7	• • • • • • • • • • • • • • • •	' • • • • • • •
	Grade 6	• • • • • • • • • • •	• • • • •
	Grade 5 • • •	• • • • • • • • • • • • • • • • • • • •
	Grade 4
	Grade 3	• • •

10

15

Fig. iq. — Distribution and overlapping of pupils in ability to solve arith- metical problems as measured by the author's Scale A. The numbers along the horizontal axis are the steps on the scale.

Quality of writing was measured by the Ayres scale, the four fundamental operations in arithmetic by the Courtis tests (series B), and composition by the Hillegas scale ('12.)

36

EDUCATIONAL PSYCHOLOGY

TABLE 2

Ranp;es of difference between tlic IkjsI and the poorest in a class of .^6 eighth

grade pupils.

Best

Poorest Ratio

Reading — Sjx-cd

Reading — Comprehension

Writing — Speed

\\" riling — Quality

Arithmetic — Reasoning

Arithmetic — Addition (Rights)

Arithmetic — Subtraction (Rights) Arithmetic — Multiplication (Rights) Arithmetic — Division (Rights) ....

Spelling

Composition

Grammar (Scale A)

History

Average

6.

76. io«. 90 15 15 17 17 16 90 70

13 104

I	8 1:3.7
22	1:35
57	1:1 6
60	':i 5
2	17-5
I	1:15
2	1:8.5
I	1:17.
2	1:8.
45	i;2.
30	1:2.3
6	1:2.2
4	1:26.

1 :7.6

In the accompanying diagrams, Figures 16-26, the complete distril)Ution of the abilities of the puj)ils in each grade in the sub- jects of reading, Avriting, spelling, etc., are shown as determined by methods of measurement described else^vhere. These graphs show that the range from the lowest to the highest ability in any given subject within any given grade, is aj)pro.\imately as great as that found for special mental functions referred to in a ])receding section. The best j)upil in reading or spelling or any school subject is from one and a half to twenty-five times as capable as the poorest pupil. As a result of this wide range of abilities, there appears an enormous amount of overlapi)ing of the abilities ])ossessed In- the pupils in other grades in the same school. Thus it will be noted that the best pupil in arithmetical reasoning in the third grade is as capable as the poorest i)upil in the eighth grade. All j^upils had been tested l)y the same set of problems. The Siime statement a})plies with practically identical details to any school subject. Putting the situation in a little different statement, it has been shown that 60% of the best pui)ils in any given grade could be e.xchanged with the 60% of the poorest pupils in the ne.xt higher grade, with the result that there would be no change in average ability of the two grades.

VARIATION IN HUMAN CAPACITIES

37

The question next arising is this: Granting that the range of ability in any one subject is as large as the results of the tests show it to be, may, however, a given pupil not be two or three years ahead of his grade in arithmetic, two or three years behind his grade in spelling, up to the average of his class in reading, etc., and may he not be placed correctly, after all? The facts, however,

• • i • • • • •	I • • < • • • • 1 • • • I • • • •	Grade • •	8 1
• • • • • • • • • • • • • < • • • • « • • • • <	( e 1 • • •	Grade • • •	7
• • • • • • • •	• • • •	Grade •	6
• • • • • • • • • • • • •	•	Grade •	5
	> • • •
a-CA^		Grade	4
t I I I I \	> •
« O 9 • • <	> e •

0 5 10 15

Fig. 20. — Distribution and overlapping in addition as measured by the Courtis test. Ttie numbers along the horizontal axis represent the number of examples done correctly.

seem to be as represented in the accompanying illustration, Figure 27, in which a combined score was obtained for each pupil as fol- lows: In reading and writing in grade i; in reading, writing, and spelling in grade 2; in reading, writing, spelling, and arithmetic in grades 3 and 4; and in reading, writing, spelling, arithmetic, language, and composition in grades 5 to 8. Even when the varia- tions in abilities in different subjects possessed by the same pupil

38

EDUCATIONAL PSYCHOLOCY

arc- C()uiitt'rl);ilaiuc{l aiul avi-ragcd, the range of abilities and tin overlappitij^ is ]tra(li(ally as large. It Avill he noticed, for e.\- amjjle, that the hist i)U])ils in the second and third grades in these three subjects coiiihined, are almost U|) to the abiiit)' of the poorest pupils in the eighth grade. The fact is that in every eighth grade

Grade 8	• * •
• • • •	* • •
* • • •	• * *
Grade 7			• • • • • •
	• • %
Grade 6	• • • • • • 4		• •
Grade 5	• • •		•

0 b 10 15

Fig. 21. I )i^tril)iiti()n and ovcrlapjjinK in use of correct Knglish as measured by the author's (irammalual Scale A. The numbers along the baseline are the steps on that scale.

one pu|)ii in nine is fully ef|ual in ability to the average ability of the pu|)ils in the second year of high school and could do the work e(|ually well if he had been allowed to go on rai)idly enough to be in thi- second year of high school. Two pu|)ils in every nine are equal in ability to the average pupil in the first year of high schot)l, three of tin- nine pupils are correctly placed in the eighth grade,

VARIATION IN HUMAN CAPACITIES

39

two are equal only to the average seventh grader, and one is equal only to the average sixth grader. Thus by proper promotion or classification, one pupil in every nine could save two years in eight, and two pupils in every nine could save one year in eight.

Expressing the same facts in a different form for the school population as a whole, we may say that:

I pupil in loo could finish the 8 grades in 4 yrs. or at 10 yrs. of age.

2 pupils
9 21 "	C (
33 "■ 21 "
9 "
2 "
I pupil

II
12
I.S
14
15
16
17
18

Grade 7	« • • «	• • ••	• • • ••• •	• •• •••		• •
Grade 6		• • • •• • •	•	• • • •		• • •• •
Grade 5	: ::::	• • •

0 10 20 30 40 50 60 70 80 90 100

Fig. 22. — Distribution and overlapping in geography as measured by the author's geography test. The numbers along the horizontal axis are the scores in the test. The situation in the case of history is very similar.

The last two groups are composed of pupils so retarded that they probably never would or could complete the elementary school. The variation in ability is so great that the children of any given age are spread out over about nine years of maturity. For example, children ten years old range in ability all the way from fourteen-year-olds to six-year-olds or less, and the numbers of pupils at each age of mentality are approximately those given above. These facts are further borne out by recent tests of in- telligence, (See Chapter VII.)

This enormous range of ability and the resulting overlapping of successive grades, is probably the most important single fact discovered with reference to education in the last decade. The import of it is so significant of the situation as it exists in our schools to-day and of the possibilities in the direction of the proper reclassification or

40

EDUCATIONAL PSYCHOLOGY

	Uradc s		1 M U ^ • mi •	•
	Grade 7		• •	1 •
	Grade C	• • 1	• '	• • • • • • •■	• • • • • • •	• •
	Grade 5 •	•		• • •	• • • •	•

;X)

40

60

80

Fio. 23. — Distribution and ovcrlappinp in ability to write a coni|)osition as rated by the Hillegas scale. The numbers along the base are values on that scale.

Grade 8
Grade 7 • • • •	: . : • • • • • ■ : :.: :.	! ■ • • •
Grade 6	• • : : • • • • •••••••	• • • •
Grade 5	• • • • • • • • • • • • . : ::;	• • • • •
Grade 4	: .:: :	:: • • > • • •
Grade 8 • : • : : • • •	• *
Grade 2 • • • • • • X : :	I : : .

0 i) 10 lb

Fig. 24. — Distribution and overlappinR in drawinR ability. The numbers along the horizontal .i.\is arc the units of Thorndike's drawing scale.

VARIATION IN HUMAN CAPACITIES 41

readjustment of pupils according to ability that we have scarcely begun to realize how great the differences are or in what manner the readjustments may be made.

Provisions Made in the School for the Variations in Abilities. Experimental work has drawn renewed attention to the possibilities of taking account of the enormous ranges of abilities such as are

	Year 4 • • • • • •
m 6	Year 3 \ \ • • • • • • •
CO § 2 (U	Year 2 \\ , , • • • • • •
	• • • Year ll ,\ *,\\ ', • ••••••• • ••••••••• • • 1 1* .1

0

20

40' 60

Scale Values

100

Fig. 25. — Distribution and overlapping of pupils in a high school in ability to write an English composition. The numbers along the horizontal axis are values on the Hillegas scale.

found even in an ordinary class of supposedly homogeneous pupils. To keep an ordinary class of pupils together is no doubt very wasteful in time both for the gifted as well as for the stupid pupils. The gifted must listen to questions and explanations designed chiefly for the benefit of the dull pupils, but which the bright pupils already understand. The dull pupils, on the other hand, waste time by being dragged along too rapidly in the endeavor to keep the bright pupils occupied.

4-^

EDUCATIONAL PSYCHOLOGY

Tlu- plans which havr bt-en proposed for meeting the varjing abilities of pupils fall into two general classes: First, those which attempt to keep the pupils of a gi\en class together but vary the manner of instruction for the i)upils of difTerent capacities; second, those which keep the manner of instruction uniform but promote or retard pupils according to their achicxcments.

IB	-
10	High School Seniors
m S 6 D .5	-					• • • •
I'm ^ 0			•			• • •
^16	High	School
lU	Fre	shmen
6	-
		•				• •
fi	1 1					• • I 1 1 I 1

1 -' 3 4 5 6 7 8 <J 10 11 12 la 11 15 Steps -Grammatical Scale A

Fin. 2Ct. — Distribution and ovcriuppinj; of pupils in a lii^;li school in ability in flis^riminati^^,' iHlwcen a)rrcct and incorrect Kn);lish. The- numbers along tlie horizontal axis arc the steps on the author s CJraniniatical Saile A.

The princi])al schemes of the first general method which have been tried in various schools are known as the individual instruc- tion or Pueblo plan, the monitorial group plan, the extra-work j)lan, and the sujjervised study or Bataxia ])lan. The individual instruction plan was en\ployed by Suj)erintendent P. W. Search in Pueblo, Colorado, and consisted in the abolition of all class instruction and the substitution of indi\idual teaching according to the needs of the pupils. The monitorial group j^lan is carried out by dividing a class into several groups, usually three, according

VARIATION IN HUMAN CAPACITY

43

to the abilities of the pupils, and by appointing a monitor for each group from among the members of the class. The extra-work plan consists in having recitation and class instruction chiefly for those who need it, and in assigning additional work to the capable pupils to be done at their desks. The supervised study plan de-

Grade	8				•	• * •	• • • • • • i	.:..	• • •
	• • • • 1	• • •	• • •
Grade	7					•			•	•
• • •	' • •	• • • •	• •
Grade	6			• •	• • • • •	• • • • • • • •	« « •	< • • •	•
Grade	5			•	* • • • •	• • • • • • • • •	• • • • • •
Grade	4	•	• '	• • • • • •	• • • • • • • • • • • •	• • • •
Grade	3		• 1 • • • • 1 • • • • 1 • • • • '	• • • • • • • • '	•	» • •
Grade	2		•	• •
• • •	• • • • (	• •
Grade	1 • • • 1	• ( • • < • • • • <	• • • < • •••	• •	•

0.5

1.0

1.5

2.0 2.5 3.0 3.5 Average Scores

4.0

4.5

50 5.5

Fig. 27. — Distribution and overlapping of pupils when their attainments in different subjects are averaged. Reported in a thesis by Helen Craig in the library of the University of Wisconsin, 1918.

votes a part of the class period to the usual recitation and instruc- tional work, and the remainder to study done under the supervision of the teacher. Sometimes the class period is considerably length- ened and no home study is done; at other times, the class period is kept at the usual length with some assignments for home study. These plans have been in operation in various schools during

44 KUUCATIONAL rSVCFIOI.OdV

the ])asl thirty years witli \arying amounts of success or failure. Most of them have been successful ^vhen carried out under the immediate sui)er\ision of the persons uho devised them. The difikulty, however, has usually been that when others have at- tempted to use them they have not been so satisfactory. Some of the schenu'S ha\e been objectionable on other grounds also. For example, the individual instruction i)lan is in part unsatisfac- tory because it removes a larj^e share of the social stimulus and interaction that is derived from class instruction.

The one tv])e of pkm ^vhich is being adopted on an extensisc .scale and is ])roving to be generally applical)le, is some form of the supervised study plan. The methods with which this plan is carried out differ considerably and great care must be taken to avoid formality in the di\ision of the time between recitation and study during the class jjeriod and in the order and nianner in whidi the super\ision is carried out. A more detailed discu.ssion will be given in the chapter on "How to Study" where this subject ])roperly belongs.

The dilTerent schemes coming under the second general proposi- tion, namely, that of keeping the manner of instruction constant and varying the rate of promotion, have been applied widely, and many dilTerent plans designed to produce greater flexi- bility in the rate of ])romotion have been worked out in \arious school systems. As illustrations, two ])lans will be mentioned because they have been in successful operation for many years. In Cambridge, Mas.sachu.setts, there has been in operation a plan for some twenty years, in which the work of grades three to eight is laid out in three dilTerent courses of study. Pursuit of course A pennits the completion of the remaining six grades in six years; pursuit of cour.se B permits the completion of the work in five years; and the ])ursuit of course C makes jiossible the completion of the six grades in four years. Transfer from one course to another may take place at any time.

In the St. Louis schools a method of |)romolion has been in force for a great many years which consists in dividing the school year into four quarters of ten weeks each. Promotion can be made at the end of each f|uarter. Pupils who have made a grade of excellent may be promoted to the next higher class at the end of any ten-week period, and pujjils who l)a\e made very low grades or practically failed, must repeat tluir work beginning with the various ten-week periods.

\'ARIATION IN HUMAN CAPACITIES 45

The effect of this plan in shortening the time of a considerable proportion of pupils is shown in a study made by W. J. Stevens. 1 This investigation shows the length of time required by each of 1,439 pupils in four elementary schools in St. Louis to complete the eight grades.

TABLE 3

The average attendance per grade of 1,439 pupils, graduates, required to com- plete each of the eight grades. Forty weeks is assigned in the course of study for each grade.

Number of Average Ntjmber of Number of Average Number of Pupils Weeks to Complete Pupils Weeks to Complete

Each Grade Each Grade

1 17 33 4i

2 18 49 42 I 20 29 43 I 21 27 44 8 22 19 45 8 23 20 46

13 24 IS 47

17 25 9 48

19 26 5 49

25 27 4 50

46 28 4 51

43 29 2 52

52 30 2 53

83 31 2 54

103 32 I 55 99 33 2 56 .

109 34 2 57

92 35 2 58

no 36 I 59

87 37 I 60

104 38 2 62 95 39 I 63 87 40 2 70

Median 35 weeks

Total average time of attendance 288 .weeks

Xo do 320 weeks' work

Double promotions 17%

Normal promotions 67%

Repeaters 16%

It will be noticed from this table that thirteen pupils completed the eight grades in an average of twenty weeks to do forty weeks

1 Reported in a thesis (1914) in the library of the University of Wisconsin. The study was carried out under the direction of Professor E. C. Elliott.

46 EDUCATIONAL PSYCHOLOGY

of work, that is, in half of the prescribed amount of time. In other words, about i^^ of the pupils required approximately four years, 6.3% five years, 22.8% six years, 34.6% seven years, 24.9% eight years, 7.6% nine years, 1.7% ten years, and 1.3% eleven to thirteen years to complete the eight grades. These results agree quite closely with the figures suggested on i)age 39.

Promotion by subjects is a i)lan adopted in various schools. The ])rogram must be arranged so that all grades recite in the same subject at the same ])criod in order that a pupil may do his work with the ]>articul;ir class to which he belongs. For example, a fifth- grade pupil might recite in spelling with a seventh-grade class, in reading with a sixth-grade class, in arithmetic with a fourth-grade cla.ss, and so on.

In high school work there is equal need for flexibility in progress. Plans should be dc\ised whereby a class could be divided into three sections, a rapid, a normal, and a slow section. For example, an algebra class, after some early tests, could be divided into three divisions. Section A could easily do the year's work in two-thirds of the year and then pass on to geometry or more ad\'anced algebra or even some other subject. Section B could do the normal work in the year, and Section C could take a year and a third to do the normal year's work, or could cover only two-thirds of the ground in the year and receive only two-thirds credit. Differences in ability are sufliciently great to make ])Ossible as much dif- ference in progress as is here indicated. The more capable ] )upils could easily shorten their high school course by half a year or a year.

A plan of flexible promotion that can be administered success- fully has in niany respects distinct advantages over any plan which merely varies the instruction for the reason that it allows the capable pupil really to gain the advantage of his ability; because he is able to shorten his elementary school period, which is one of the aims striven for at the present time. The elementary school ( ourse is considered too long. Any plan which varies the method of instruction so as to require more work of the cajnible jiupil no doubt occui)ies the time of these pupils and gives them the benefit of the additional work achieved, but it does not give the pupil the full benefit that lie de.servi'S in accordance with his capacities. In practical life the capable man performs several tinies as much work or makes several times as rapid |>rogress in the same perio<l of time as the incapable man, both having equal opj)ortunities.

VARIATION IN HUMAN CAPACITIES 47

Why should not the schools permit progress according to ability and achievement? Greater flexibility in promotion or retardation is an advantage both to the more gifted and to the less gifted pu- pils. The former will be able to step forward whenever they are ready and the latter will not need to step back so far whenever a part of the work must be gone over again. Promotion once a year works to the disadvantage of both types of pupils. The bright pupils cannot well jump an entire year and so will not be able to progress as rapidly as their abiUties warrant, while the slower pupils will have to repeat an entire year when a quarter or half of a year would be sufficient. School progress is determined too much by the calendar and not enough by capacity. The most capable one-third of pupils are advanced too slowly, and the least capable one-third are advanced too rapidly. A saving of half a year or a year on the part of a fourth or a third of the pupils would be of inestimable value to the pupils themselves and to the com- munity at large, either in getting an earlier start in their life work, or, preferably, in securing more advanced and thorough training.

Finally, one of the most important, if not the most important aspect of the principle of progress according to performance, is its appeal to the individual to do the best he can. Few incentives are as strong as the personal impulse of going forward as rapidly as possible and of putting forth the best that is in one. If a child knows that, if he can spell as well as the pupils in the grade above him, he will be put with them, he will be stimulated as he would be in no other way to reach that degree of attainment. Likewise, if he knows that he is likely to be put back to recite in speUing with the pupils of a lower grade if he falls behind, he will put forth his best efforts to hold his own. Dawdling could hardly be en- couraged more than it is in many of our schools. Rewards in adult life are more nearly according to ability and performance. The same conditions would work to the advantage of school life.

The schools have given special attention to the backward pupils by organizing separate classes for them and by giving them extra help, but they have given little or no attention to the advanced pupils. Society would be compensated far more for paying at least equal attention to the gifted pupils since they primarily will determine the future progress of mankind. The leaders of society will come from the right end rather than from the left end of the

48 EDUCATIONAL PSYCHOLOGY

ilistrihution ciirvr. Wi-^doni would dictate thai \vc tlcxoU- at Irast as much care and ihou^dil to thi-in, that we surround thcni with an atmosphere of hij,'h asi)iratioii and achievement and stim- ulate to the full their powers of originaHty and discovery. This would make for maximum i)rogress based upon ability and per- formance, not upon birth or social caste.

CHAPTER IV CORRELATION AMONG HUMAN CAPACITIES

Problem. Any given single trait varies over an enormously wide range among the members of the human race as a whole. The problem, however, before us now is: To what extent is a given amount of any capacity accomi)anied in general in the same person by equal, larger or smaller amounts of any other ability? To what extent is a good memory in the same person accompanied by an equally good capacity for reasoning or attention or perception or judgment? To what extent is poor or mediocre ability in memory accompanied by poor or mediocre ability in other directions? If all mental abilities were measured on a scale of o to lo, the con- crete problem would be: To what extent would a memory ability of 7 be accompanied in the same person by a perception ability of 7, or a judgment ability of 7? If it is not accompanied by the same amount of other abilities, by how large or small an amount of any other ability is it accompanied?

Educationally the problem is important and takes the following form: To what extent may we expect pupils, who are excellent, mediocre, or poor in one subject to be excellent, mediocre or poor in other subjects? To what extent is a statement such as the following true in general: "I simply cannot learn languages or mathematics, although I get along very well in my other studies" ? To what extent is freedom of electives in studies justifiable on the basis of variation in the combination of capacities in the same individual? To what extent are mental and physical traits correlated? To what extent are abilities similar at different times of life in the same individual? To what extent is ability in childhood or youth a forerunner of ability in adulthood?

Methods of Measuring Combinations of Traits. The extent to which various amounts of abilities accompany one another is measured or expressed definitely by the coefficient of correlation. The value of the coefficient of correlation ranges from i.oo through o to -1.00. A coefficient of correlation of i.oo means a complete agreement. If the coefficient of correlation between ability in

49

50 EDUCATIONAL PSYCHOLOGY

Latin and ability in German were i.oo, it would mean that the best pupil in Latin would be also the best pupil in German, the second best pu[)il in Latin would be the second best pupil in Ger- man, etc., dowTi to the poorest pupil in Latin who would also be the poorest in German. As the correlation drops farther and farther belo\v i.oo toward o, the closenos of this agreement be- comes correspondingly less until o is reached. If the coefficient of correlation between ability in Latin and ability in German were —I.oo, it would mean that the best pupil in Latin would be the poorest pupil in German, the second best pupil in Latin would be the second poorest in German, etc. As the correlation rises above —i.oo toward o the reversal becomes less and less until o is reached. A coefficient of o means that no relationship exists. A pupil might have any amount of ability in one subject and any other amount c)f aljility in the othiT subjcrt.'

The Correlation Among Specific Mental Abilities. The early investigations in this field found surjirisingly small correlations even among apparently vcv}' similar or closely related capacities. Thus it was thought that a person might ha\e a good memory' for words but not for numbers or faces; he might ha%-e a keen percep- tion of words but not of letters or geometrical figures and the like. As typical of the earlier results on correlations we may cite a few from Wissler ('oi) as follows:

Auditory memory of figures and visual mcmor>- of figures .:() lo .39

" " " " " auditor}' '" " pas.>iagc .04

" " " " " memory of length of line .00 "passage" " " " " " -.07

" " " " " quickness in naming colors .03

" " " " " reaction time .12

" figures " " " .17

The significance of these coefficients may be interjireted approxi- niately as follows: A coefficient of o means that no correlation exists, and roughly speaking, a coefficient of .30 or less is small and practically means very little agreement. Correspondingly, a coefficient lying between .,^0 and .50 nuans a moderate amount of agrcLinent, a coefficient between .50 and .75 means a considerable correlation, while a coefficient above .75 indicates a ver>' close

' For mcthofLs of rompiitinrr the cocfTK-icnt of correlation, consult the author's Fx- perimnUs in Educalional Psychology, (1017 Edition) Chapter I\': Whipple, MdniuU of Menial and Phyui'il Tfsls. ('h.i|)iiT III: Thorndikr. Stmlal and Social Measure menu, (hapttr XI; and Rugg, II. O., Stalislical Methods Applied to liducalion, Chapter IX.

CORRELATION AMONG HUMAN CAPACITIES 51

relationship and, as it approaches i.oo, indicates practically perfect agreement. From the table, it appears that many coefficients are very low and imply little or no agreement. The coefficients so low as to indicate practically very little correlation are stated to exist between auditory memory of figures and visual memory of figures. This would mean that a person might have a very good memory for figures seen but a poor memory for figures heard.

The difficulty with these coefficients is that they are based upon unreliable and incomplete measurements of the traits concerned. Many of the measurements of the early investigations of correla- tions were derived from group tests which had been made but once. Measurements thus obtained have been shown by subse- quent investigations to be rather uncertain indications of the real amount of a given trait possessed by the individual. In order to obtain a fairly accurate measurement of a given capacity, it is necessary to repeat several times under favorable circmnstances the measurement of the trait in question. You cannot obtain anything like an accurate measure of any amount or quantity by a single measurement made under distracting conditions. If we should wish to measure the memory capacity of a given in- dividual, we should not consider the result very trustworthy if a single test were given consisting of eight lines of poetry learned in three or four minutes. We ought at least to repeat the test with several similar passages, preferably on different days, and derive therefrom an average. This is, in fact, the sort of procedure that has been followed in subsequent researches. Inaccurate measurements, as indicated by recent analyses of correlations, tend to reduce very materially the computed coefficients below the actual amounts of correlation.

Recent researches have shown that among many traits qmte close, and among other traits very close, correlations exist. An investigation by J. A. Stevenson ('18) showed remarkably close correlations between various types of sensory discrimination. The plan of the investigation consisted in making extensive and repeated measurements of discrimination in lengths of lines, in intensities of sound, in degrees of brightness, in shades of gray and in pressures on the end of the first finger. The correlations com- puted on the basis of these measurements with ten persons were as follows:

52

EDUCATIONAL PSYCHOLOGY

TABLF 4 After Stevenson ('i8).

Lines and intensity of sound go

Brightness and intensity of sound 90

Pressure and intensity of sound 36

Pressure and lines 3Q

Lines and hrij,'htness 92

Pressure and brightness 41

A similar investigation in the field of memory, conducted hy Miss N. F. Bennett ('16), showed on the basis of numerous and repeated tests with nine subjects fairly close correlations among the capacities to remember various kinds of material such as syllables, numbers, nouns, prose, and faces, between visual and auditor}' presentations of the material, and between mediate and immediate learning. Her conclusions are stated thus:

" I. There is a high correlation between mediate and immediate re- tention if a siiflicicnt number and variety of measurements for each l3pe of menior)' are taken, and the results amalgamated to determine ranks.

"2. There is a high correlation between the memory span, or imme- diate retention for disconnected materials, and the ability to learn the siime."

Holling\vorth made a study to determine the increase in the coefhcients of correlation among six dilTercnt capacities with the increase in the number of measurements made uj^on each aipacity. His results are set forth in the following table. They indicate a ver)' marked rise in the coeflicients with the increase in the number of tests.

TABLE 5

The average correlation of each test with all others at various |>oints in the curve of practice. After llollingworth ('12).

Trial	Addi.nc	Opposites	Color NxyiNG	DlSCRtMI- NATtON	Co-ordina- tion	Tapplsc	Final Average
I	10	. 10	•15	-.07	- 15	• ' 7	• 06s
5	4"	.26	15	•35	.21	•32	.2S0
25	SO	•35	4.S	• 27	•03	35	320
80	■ sa	4i	.V?	.st	.iS	•34	• 3QO
205	.48	.62	61	• "	.M	■52	.490

CORRELATION AMONG HUMAN CAPACITIES

53

As an illustration of a series of correlations among special mental functions based upon measurements repeated several times but not as frequently as those in the preceding tables, we may cite the coefficients obtained by Simpson. These coefficients are unusually high because they are based upon tests performed on two ex- treme groups of subjects, the one a highly intelhgent group and the other distinctly unintelligent.

TABLE 6 Correlations among certain mental abilities. After Simpson ('12).

1 . Ebbinghaus test . . . .

2. Hard opposites

3. Memory of words. .

4. Easy opposites

5. A-Test

6. Memory of passages

7. Adding

8. Geometrical forms. .

9. Learning pairs

10. Completing words . .

11. Drawing lines

12. Estimating lengths . .

					cr
a H	H	Q 0	H		0 < <		OS 0	a	Q a: 0
< u 0 S	i 0	> 0 a	0 0. 0. 0 >		0 > a 0 a	0 z Q	H W a 0	Pn 0 z z	0 g H Id h) a
W	X	S	<	<	§	^	w 0	1-1	0 u
I	2	3	4	5	6	_7_	8	9	10
92
92	92
75	81	68
68	76	70	71
91	86	89	69	60
71	74	56	70	67	66
54	64	67	54	94	60	44
72	72	82	43	44	63	46	40
50	70	51	50	84	38	77	61	34
26	25	06	53	27	12	27	30	04	17
52	55	59	56	57	5«	17	35	54	22

22 55

Burt obtained the following correlations (Table 7) from a va- riety of tests of specialized mental functions made upon forty-three pupils. The test designated as dotting was regarded as a measure of voluntary attention; the tests designated as spot pattern, mirror and memory were designed to measure memorial and associative capacities; the tests called alphabet and sorting referred to sensori- motor capacities; dealing and tapping to motor functions; and the remainder to sensory discrimination.

54

EDUCATIONAL PSYCHOLOGY

Dotting

S[Kit pattern.

Mirror

Memory. . . . Alphabet. . . .

Sorting

Dealing

Tapping

Sound

Lines

Touch

Weight

TABLE 7 After Burt ('09).

•38 •63 .67 •05 •74 .66

•55 •3S 30

•73 58 .12 .40

• 23 .16 .06

• 14

•57 • 17 .26 -.08 . I

.09

29

•23 .00

49

The import of the researches up to the present time seems quite certainly to prove that the higher mental capacities are on the whole rather closely correlated. The coefficients lie for the most part above .50, and some of them reach uj) to .So and .90. The same statement holds approximately for sensory cai)acities among themselves and also probably for motor capacities among them- selves. The cross-correlations among traits from these three levels is, so far as we can judge at the present stage of our knowledge, lower than among the traits within a given level. This seems to be particularly true of the correlation of motor cajiacities with hitellectual capacities.

Correlations Among Abilities in School Subjects. The develop- ment of knowledge concerning this aspect of our problem has had a history similar to that of the special mental functions. The early correlations among abilities in school subjects were computed upon relatively uncertain data. About 1903, coefficients obtained by various investigators, were as follows:

CORRELATION AMONG HUMAN CAPACITIES

55

TABLE 8

Summary of coefBcients of correlation between abilities in high school subjects as reported up to about 1903. (Thorndike '03, pp. 26, 30-31).

B = After Burris, based on nearly 1,000 pupils.

P = After Parker, based on 245 pupils.

Br = After Brinckerhoff, Morris, and Thorndike.

History B .

P.

Br Science B .

P.

Br Algebra B .

P.

Br Drawing B .

P.

Br German B .

P.

Br French B .

P.

Br Latin B .

P.

Br Mathematics B .

P.

Br

.40 .62
■41
■41	.40
.58	.56
.26	.61

•55

15 .20

•65 •30

•49

.62

•SO •39

.09

•38

.16

•49 .42

•58

.43 •43 •44 •33

.26

.40

■33 ■30

.62 •58

.44 •54 •35 .41

.07

■52

•54

.06

•30

.40

■33

•38

.48

.40 ■31

In the case of grammar school subjects, A. G. Smith (Thorn- dike '03 p. 13), computed the following correlations:

English and Mathematics 39

" " Geography 43

" " Drawing 15

Mathematics and Geography 36

" " Drawing 14

Geography " " 12

56 EDUCATIONAL PSYCHOLOGY

These coefficients for the most part indicate only a moderate amount of correlation. Thus Thorndike interpreted them in 1903 by the following statement: "For our purpose the most striking thing about these figures is their small amount. It is safe to say that in a grammar or high school student a deviation from the average ability in any one subject implies by and large a deviation in any other not more than half as great. The most talented scholar in one field will be less than half as talented in any other, The most hopeless scholar in one field will in another be not so very far l)elow mediocrity." ('o.^, pp. 37-38).

The coelVicients here quoted were based usually upon marks of a single teacher in any given subject. Recent studies have called attention to the unreliability of marks and the difTerences in stand- ards of marking employed by dilTercnt teachere. Sec Chapter XXII. This necessarily produces a considerable reduction in co- efficients based upon them.

A computation based upon the average mark of each pupil in each subject in grades five to eight yielded the following coefficients (Table 9):

TABLE 9

Correlations among abilities in school subjects. After Starch ('13).

Arithmetic and languapc S5

" geography 83

" " history 73

" " reading 67

" spelling 55

Language and gcograi)hy S5

" " history 77

" reading 83

" spclHng 71

Geography and history 81

" " reading 80

" spelling 52

History and reading 67

" " spelling 37

Reading and spelling 58

These coefficients are almost twice as high as those previously quoted and represent very close correlations. They would warrant the interi)retation that the pupil who is g(X)d, mediocre, or poor in a given subject, is good, mediocre, or pcwr to very nearly the same, but not equal, degree in all other subjects so far as his abili-

CORRELATION AMONG HUMAN CAPACITIES 57

ties are concerned. Such lack of agreement as does exist is due probably to a difiference of interest and industry on the part of the pupil in different subjects at different times and to a real difference in abilities in the various fields. Thus spelling ability correlates apparently less closely with ability in other subjects than abihties in these other subjects correlate among themselves. The up-shot of the whole problem concerning the variation in the combination of traits, or the extent to which different amounts of mental traits accompany one another, may fairly be stated as follows:

First, no negative correlations exist either among the abilities involved in school subjects or among the special mental functions measured by special tests. Popular and "short-story" psychology is false in the assumption and description of antagonisms of mental traits. They apparently do not exist among desirable and useful traits. Advice, given to prospective wives, such as "if he is good- natured, he may be lazy; if he is scholarly, he may be cold; if he is thrifty, he may be sting}^; if he is generous he may be wasteful," may produce caution, but it is not true psychology. Good-natured men are probably on the whole no more lazy than ill-natured men are, and scholarly men are probably on the whole no more cold- hearted than stupid men are. In fact the opposite is more likely to be true. And such statements as "Johnny is very bright in read- ing, but he simply cannot get arithmetic" is a soothing salve for the feelings of parents, but not apt to be sound psychology.

Most of the opinions of students who state that they "simply can- not get" mathematics or language or history are in part probably due to a relatively small discrepancy in abilities, that is, to some- what less ability in mathematics, language or whatever the sub- ject may be; but to a larger extent they are illusory, because, when the actual facts are obtained or when more careful measurements of the abilities in various directions are made, the abilities corre- late much more closely than the student's statements would lead one to believe. As a concrete example the following case of a col- lege freshman, brought to the author's attention, may be cited: The student claimed that he had always had great difficulty in learning foreign languages but that other subjects were easy for him. He stated that in high school he never was able to obtain a grade in languages higher than about 75 but that in other subjects his grades were always high, as high as 95. Since his trouble seemed to be language it was thought that he might have a defective memory

58 EDUCATIONAL PSYCHOLOGY

or an abnormal type of imagery. Some memorj- and imagery tests revealed the fact that he had normal memory and imagery of average ability. This at once led to an inquiry into his actual high sch(X)l record to ascertain his grades. The various grades for any given subject are final grades in dilTerent courses as follows: Knglish, Sj, 80, 78, 81; History, 88, 75, 83; mathematics, 80, 87, 77; science, 87, 87; Latin, 77, 79, 75; German, 75, 75. When these marks are compared there is little or nothing to ex])lain. His marks in Latin and German were somewhat lower than in other subjects, which is probal)ly largely e.\])hiined by his o\m statement that he "hated" languages, but they were not much lower on the whole. The highest grade in any subject was in the first year of history, 88, but he also had a grade of 75 in the second year of history and 77 in the 3rd course in mathematics. There was no grade of 95 in the entire list. This record was corroborated by the grades which he received at the end of the first eight weeks of his freshman year in college: Spanish, Fair; Geolog}', Fair; English, Fair; Mathematics, Fair; History, Poor. His abilities are pretty uniformly mediocre in all respects.

Excejjtions do occur such as that of a boy seventeen years of age in the second year of the high school who was able to carrj' his work satisfactorily, but was able to read no more fluently, either orally or silently, than the average ])uy)il can at the end of the first grade. He was a normally intelligent boy. Such cases occur perhaps once among one or two hundred pupils, and may be regarded as ab- normal.

Second, intellectual and scholastic abilities are for the most part closely correlated. Barring certain e.xceptions, which are rarer than is generally suj)posed, abilities are combined in fairly similar amounts. Intercorrelations between the different levels, intellectual, sensory, and motor, seem to be smaller and in some traits, jiractically zero. Some of the motor abilities, such as hand- writing, ha\-e practically no correlation with intelligence or general mental abilities.

The wider bearing of the facts about the combinations of mentid capacities, together with the distribution of mental traits according to a continuous, bell-shaped curve discussed in the ])rece(ling chapter, are deeply significant for the j)rol)lem as to whether there are distinct mental t)pes. Mankind apparently cannot be divided into three or four separate tjix'S. The ancient cla.ssification of tenii)eranunts into sanguine, choleric, melancholic.

CORRELATION AMONG HUMAN CAPACITIES 59

and phlegmatic, may be conveniently analogous to the four seasons of the year, spring, summer, autumn, and winter respectively, but there are no mental types that correspond to such superficial characteristics and none that are marked off sharply or even vaguely from one another. If all members of the human race were to be exhibited in a distribution curve whose base line represented from left to right different amounts of "sanguine-melancholic, or choleric- phlegmatic" natures, the curves would in all probability not be a series of four distinct curves separated from one another, nor even possess four modes with depressions between them, but would very likely be single continuous distribution surfaces of the usual normal form with one mode. The human beings who even remotely ap- proach any one type are very rare. The rule is that each person possesses more or less of all different traits, and within certain limits, roughly similar amounts of the various traits. Persons in whom the divergences are large are the exceptions rather than the rule.

Correlation between Special Mental Capacities and General Intelligence. So far as definite data are available on this point, the inference may be drawn that many special mental functions are correlated anywhere from moderately to very closely with general intelligence. Men of intelligence have, on the whole, keen powers of perception, observation, and attention, remarkable re- tentiveness, exceptionally rapid and varied association processes, as well as unusually incisive powers of analysis and soundness of judgment. We may note here in passing, by turning to Chapter VII, the amounts of correlation of certain capacities with general estimated intelligence as found by Simpson, Burt, and others.

The usefulness of the facts that many specific mental capacities are reliable symptoms or essential constituents of general intelli- gence will be particularly important in the future in the develop- ment of tests and methods of measuring intelligence. The value of this to mankind, not only in education but in all fields of human endeavor, can hardly be foretold at the present time. Further con- sideration will be given to it in a later chapter.

Correlations between Mental and Physical Traits. In the case of adults, the correlations between mental abilities and such physi- cal characteristics as height, weight, size of head, lung capacity, or strength of grip, are either very low or zero. In the case of children, the situation is somewhat different, B. T. Baldwin made an elabo- rate study of 861 boys and 1,063 S^^^^ i^ the University of Chicago elementary and high school, the F. W. Parker school of Chicago,

6o EDUCATION.\L PSYCHOLOGY

and the Horace Mann School of Columbia University. Measure- ments of various physical characteristics were obtained at yearly and half-yearly intervals on two proups of pupils. One group was followed continuously through the ages from six to twelve, and the other from twelve to eighteen. A parallel comparison between the physical measurements and the school records of the same pupils was then made. From these results, Baldwin has deri\ed the following conclusion:

Taller, heavier children mature physically in advance of the shorter, lighter ones. Those whose physiological age is accelerated complete the last grade of the elementary s( hool at 12 years, 9 5/6 months of age with an average of 84.39c, and those below average or of retarded phys- iological development, complete the elementary school work at 13 years 7 4/13 months of age, with an average of 81.7%. (Bulletin of Bureau of Education No. 5S1, 1914. Page 82.)

Correlations Between Early and Later Mental Abilities. The

jirobiem here is, to what extent will a given pupil maintain his record of excellence, mediocrity, or stupidity all through his educa- tional career or all through his life? Will the puj^il who has high, medium, or low ability in the clementar}- school also have high, medium, or low ability in high school and in college? The first extensive study in this field was made by W. F. Dearborn (09) who traced through the high school and through the university the scholastic records of various groups of students, varj-ing in size from 92 to 472, and coming from eight large and four small high schools in Wisconsin. He divided the pujiils into four quartilcs according to their marks in high school, and then ascertained to what extent the pupils remained in the same riuartiles during their university course. His records showed that the pupils maintained the same records with remarkable consistency. He states his con- clusion in the following words:

We may say then, on the basis of the results secured in this group (472 pupils) which is sufllcicntly large to be representative, that if a puj)!! has stood in the first quarter of a large class through high school, the chances are four out of five that he will not fall below the first half of his class in the university. . . . The chancer arc but about one in five that the student who has ilonc poorly in high school — who has been in the lowest quarter of his class — will rise above the median or average of the freshman class at the university, and the chances that he will prove a superior studciU at the university are ver)' slim indeed. . . . The

CORRELATION AMONG HUMAN CAPACITIES 6 1

Pearson coefficient of correlation of the standings in the high schools and in the freshman year, for this group of 472 pupils is .80. ... A little over 80% of those who were found in the lowest or the highest quarter of the group in high school are found in their respective halves of the group throughout the university. . . . Three-fourths of the students who enter the university from these high schools will maintain through- out the university approximately the same rank which they held in high school.

F. 0. Smith made a similar study of 120 students entering the College of Liberal Arts at the University of Iowa. He traced their records from high school through the entire university course and found almost the same situation. Expressed in terms of coefficients of correlations, the results were as follows:

TABLE 10 Correlations. After Smith. ('12.) H. S. average and Univ. Freshman Average

H. S. Average and Univ. Sophomore Average . H. S. Average and Univ. Junior Average .... H. S. Average and Univ. Senior Average ....

ist and 2nd Year High School

ist and 3rd Year High School

ist and 4th Year High School

University Freshman and Sophomore

University Freshmen and Junior

University Freshmen and Senior

T. L. Kelley compared the marks of 59 pupils as they passed from grade five up into the first year of the high school. The extent of the agreement of their records in successive years is shown in the following coefficients of correlation:

TABLE II. After Kelley. ('14)-

Correlation between marks in the grades and marks in the first high school

year.

First Year of High School and 7th Grade 72

First Year of High School and 6th Grade 73

First Year of High School and 5th Grade 53

First Year of High School and 4th Grade 62

He then states:

"The net conclusion which may be drawn from these coefficients of correlation is that it is possible to estimate a person's general ability in the first year (H. S.) class from the marks he has received in the last four

62 EDUCATIONAL PSVCHOLX)GY

years of elementary school with accuracy represented by a coefficient of correlation of .jSq, and that individual idiosyncrasies may be estimated, in the case of mathematics and English, with an accuracy represented by a coeflicient of correlation of .515. . . . Indeed, it seems that an estimate of a pupil's ability to carry high school work when the pupil is in the fourth grade may be nearly as accurate as a judgment given when the pupil is in the seventh grade."

A study of the permanency of interests was made by Thorndike ('12) by comparing the relative strength of interests and abilities during each of three periods of a person's school aireer, during the elementary school, high school, and college. These comparisons were made by asking one hundred individuals to estimate in ret- rospect, their relative interests and abilities in mathematics, history, literature, science, music, drawing, and manual work. Such data are necessarily subject to the errors of memory and judgment, but they are practically the only results available so far as strength of interests is concerned. Thorndike inferred from these estimates that early interests are not passing whims, but rather prophetic, with a fair degree of certainty, of later interests and abilities. He concludes that "A correlation of .60 or .70 seems to be appro.ximately the true degree of resemblance between the relative degree of an interest in a child of from ten to fourteen and the same person at twenty-one." "Interests are shown to be not only permanent but also symptomatic to a very great extent, of present and future capacity or ability. Either because one likes what he can do well, or because one gives zeal and effort to what he likes, or because interest and ability arc both SNTiiptoms of some fundamental feature of the individual's original nature, or because of the combined action of all three of these factors, interest and ability are bound very closely together. The bond is so close that either may be used as a sym[)tom for the other almost as well as for itself. The importance of these facts for the whole field of j)ractice with re.spcct to early diagnosis, vocational guidance, the work of social secretaries, deans, advi.ser, and others who direct students' choices of schools, studies and careers is obvious."

The impression gained from all these investigations is that human nature is not a medley of capricious ca])acities which vary from year to year, but rather a fairly consistent combination of abilities throughout lifi .

CHAPTER V

SEX DIFFERENCES

Educational Significance of Sex Differences. If we may judge fairly at the present time concerning the nature and amounts of differences between the sexes in mental characteristics, it would seem that the differences are so small in native intellectual abili- ties that they are almost wholly negligible in the education of boys and girls. That boys and girls ought to be educated differ- ently may very probably be desirable, but for reasons other than differences in ability. The professional, business, and domestic life of men and women makes it necessary to have different train- ing for boys and girls. But so far as the native abilities involved in school work are concerned, boys and girls might as well pursue the same courses from the first day of school to the last.

Popular vs. Scientific View of Sex Differences. Probably more fallacious psychology of sex has been spread abroad by novelists and journalists than has been disseminated on any psychological question of popular interest. Occasional and extreme differences in individuals of either sex have been seized upon and exaggerated by descriptive phraseology and represented as though they were the normal divergences between men and women. Up to less than two decades ago, there was practically no scientific knowledge of the nature of sex differences available, and the statements of popular beliefs about such differences were hardly exaggerated by the sort of differences implied in the Sanscrit myth of the creation of woman.

"In the beginning, when Twashtrai came to the creation of woman, he found that he had exhausted his materials in the making of man, and that no soUd elements were left. In this dilemna, after profound medita- tion, he did as foUows: He took the rotundity of the moon, and the curves of the creepers, and the clinging of tendrils, and the trembling of grass, and the slenderness of the reed, and the bloom of flowers, and the Ughtness of leaves, and the timidity of the hare, and the vanity of the peacock, and the clustering of rows of bees, and the joyous gaiety of sun- beams, and the weeping of clouds, and the fickleness of the winds, and the softness of the parrot's bosom, and the hardness of adamant, and the sweetness of honey, and the cruelty of the tiger, and the warm glow of

63

64 EDUCATIONAL PS^'CHOLOGY

fire, and the coldness of snow, and the chattering of jays, and the cooing of the kokila, and the hyixicrisy of the crane, and the fidelity of iht- chakrawiika, and then coniiH)unding all these together, he made woman and gave her to man. But after one wtck, man came to him and s;iid: Ix)rd, this creature that you have given me makes my life miserable. She chatters incessiintly and teases me beyond endurance, never leaving me alone; and she requires incess;int attention, and takes all my time up, and cries about nothing, and is always idle; and so I have come to give her back again, as I cannot live with her. So Twashlrai said: Very well; and he took her back. Then after another week, man came again to him and siiid: I>ord, 1 find that my life is very lonely since I gave you back that creature. I remember how she used to dance and sing to me, and look at me out of the corner of her eye, and play with me, and cling to me; and her laughter was music, and she was beautiful to look at, and soft to touch; so give her back to me again. So Twashtrai said: Very well, and gave her back again. Then after only three days, man came back to him again and said: Lord, I know not how it is; but after all I have come to the conclusion that she is more of a trouble than a pleasure to me; so please take her back again. But Twashtrai said : Out with you, Be off. I will have no more of this. You must manage how you can. Then man said: But I cannot live with her. And Twashlrai replied: Neither could you live without her, and he turned his back on man, and went on with his work. Then man said: What is to be done? For I cannot live either with or without her. (Thomas, Source Book of Social Origins, p. 512.)

Such )X)]iular beliefs have been in part justified by the pro])ability that many ()]>vi()us difTerences are clue to the work, and the result- ing variation in experience and environment, of women as con- trasted with those of men. Thus men know more about business, ])olitics, current events and machines because their occupations bring them much more in contact with these things; but it does not follow that women could not, or would not, know us much about them if their occujiations were as much concerned with them. Women know more about cooking, social events, and household utensils because their occupations bring them much more in con- tact with thiin; but it does not follow that men could not, or would not, aCfjuire as much knowledge or skill in these directions if their occupations required it.

The difTerences between the sexes are probal)Iy quantitative rather than (|ualilative. Both men and women have the same re- flexes, instincts, and capacities with the exce])lion of certain as- pects of the sex instinct. Tliese are probably similar in the main

SEX DIFFERENCES 65

and differ chiefly in their manner of expression. The differences due to sex life and the rearing of children, with the consequent differences in occupations and experiences, will account for many of the superficially observable differences between men and women.

What are the differences that have been scientifically measured and compared? In order to produce a complete picture of mental differences between men and women it would be necessary to measure each trait in a very large number of persons and to com- pare the measurements with regard to both the averages of the abilities and the manner of the distribution of each ability. This has been done in part only with a few traits and only upon small groups of persons.

Differences in Average Amounts of Mental Abilities. There are two methods by which abilities of two groups may be compared. Either we may state the actual average or median of each group, or we may state how many members of one group reach or exceed the average or median of the oth6r group. The latter method is preferable in many respects to the former in that it makes possible a comparison of groups of various sizes and indicates the relative differences more nearly true to fact. The two methods may be illustrated in the case of a memory test consisting of the oral pres- entation of ten words at the rate of one word per second and of asking the subjects to record immediately the number of words remembered. He ma), then state that the number of words remembered on the average by men was 6.9 and by women 7.2. Or we may state that 43.6% of men reached or exceeded the me- dian of the women. The latter method of comparison represents probably more true to life the amount and kind of difference or similarity that actually exist. The differences, hastily inferred from a comparison of averages only, would lead to the conclusion that in regard to memory women are distinctly superior to men. The implication would be that all women have a memory superior to that of men, whereas the fact is that the number of women having a memory superior to that of men is really small and that, in these few women, memory is better only by a very small shade. If 43% of men reach or exceed the median of women, it means that if the 7% of women having a slightly superior memory were omitted, the remaining 93% of the women would have a memory ability identical with that of the men. A difference of 7% in the distributions between two groups is represented by the curves in

66

EDUCATIONAL PSYCHOLOGY

Figure 28. The difference is so small that the groups could hardly be distinguished.

By the method of amounts of overlapping in the distrihntion of one grouj) over the other, the following results have been ol> tained from students in the University of Wisconsin in a series of tests on memory as just stated, on perception consisting in the cancellation within one minute of as many of a certain geometrical figure as possible, on motor ability consisting in tapping with a pencil upon a card as rapidly as possible for thirty seconds, and on mental addition as described elsewhere.'

Fk;. 28. — Distribution cun'cs representing a difference of 7% between the medians of the two groups.

TABLE I-' Percentage of men reaching or exceeding the median of women.

Perception of geometrical forms .

Memor\' of words

Motor ability

Mental addition

193 men	200 women	54-5%
55 men	77 women	43-6%
25 men	50 women	72 0%
21 men	46 women	66.7%

In the interpretation of these percentages of overlapping it must be remembered that if 50% of one group reaches or exceeds the median of the other, it means of course that the two groups are identical in ability and distribution. If the percentage of men reaching or exceeding the median of the women is over 50% it means that the men are superior by the number exceeding 50%.

Helen Thompson Woolley made a series of tests as indicated in the following table upon twenty-five men and women at the Uni- versity of Chicago, on the basis of which Thonulike has computed the followiivj ixrc cnfaL'es of men reailiiiii: or i \i itiiiiiir the median for women:

' Ejcp<rinu:nU in Uiudiumal J'iyckjliisy, rcvi.-A:J edition, chapter 16.

SEX DIFFERENCES

67

TABLE 13

Percentages of men reaching or exceeding the median of the women. After Woolley as computed by Thorndike ('14, III, p. 178).

Reaction time 68%

Tapping 81%

Sorting cards, speed 14%

Sorting cards, accuracy 44%

Thrusting at target 60%

•Drawing Hnes 72%

Threshold of pain 46%

Threshold of taste 34% (22)

Threshold of smell 43%

Lifting weights 66%

Two-point discrimination 18% (43)

Memory (syllables and learning) 32% (46)

Ingenuity 63%

In a similar comparison made on the basis of 100 boys and 100 girls from results obtained by Gilbert, the percentage of boys reaching or exceeding the median of girls was as follows:

TABLE 14

Percentages of boys reaching or exceeding the median of the girls. After Gilbert ('94) as computed by Thorndike ('14, III, p. 182).

to 14 years 15 to 17 years

Discrimination of weights 48% 58%

"colors 39% 58%

Reaction time 57% 76%

Resistance to size-weight illusion 55% 68%

Rate of tapping 64% 73%

Thorndike ('14, III, p. 183) reports measurements in which the comparison of the percentages of boys reaching or exceeding the median of girls for persons 8 to 14 years old, were as follows:

TABLE IS

Associative tests, opposites, addition, multiplication, etc 48%

Perception, A-test, etc ^^%

Memory of words 40%

The writer has made comparisons in the case of school subjects on the basis of abilities measured by means of tests and scales. Speed of writing was measured in terms of letters written per minute. Quality was rated by the Thorndike scale. Attainments

68 EDUCATIONAL PSYCHOLOOV

in the remaiiniij^ subjects were measured by the author's tests in these fields. The following percentages of boys, reaching or ex- ceeding the median of the girls, were obtained:

TABLt: 10

Speed of handwriting, about i loo boys and i loo girls 47%

(^)uality of handwriting, " 1100 " " 1100 " 39%

Arithmetical reasoning, " 1250 " " 1250 " 60%

History, " 429 " " 526 " 72%

( icograpiiy, ' " 447 " " 472 " 48%

Figures of a similar sort computed by Thomdike ('14, III, p. 183) on the basis of teachers' marks showed the following percent- ages of boys reaching or exceeding the median of girls:

TABLE 17

High school pupils

English 41%

Mathematics 57%

Liitin 57%

History 60%

College students

English 35%

Mathematics 45%

History and economics 56%

Natural sciences 50%

Modern languages 40%

The difficulty with many of the measurements is that they are based on too small a number of j^ersons. Comparisons based on twenty-five ])ersons from either sex may be indicative but not final. Sunmiarizing, we may say that women and girls are supe- rior in sensibility, in memory, in most forms of perception, in C|uality of handwriting, and linguistic fluency. It is interesting to note in this connection that in the survey of mental-test results • the women excel in tweh'c out of fourteen tests which de- pend chiefly upon linguistic fluency. Thus the females excel in speed of reading, both oral and silent, in amount of information given in describing an object or in making a rept)rt, in the genus- species test, in the number of words thought of and written per minute, in the ])art-whole test, in the opposites test, in memory span for words, in memory for K)gical-verbal material, in the word-

' (iivin in the various chapters of Wliipplc's Manual of Mental and Physical Trsls.

SEX DIFFERENCES 69

building test and in the Ebbinghaus completion test; while the males excel in the rate of association and in the sentence building test. Apparently the popular belief in the greater linguistic fluency of women is not without foundation. Men and boys are superior in motor capacities, such as tapping, quickness of reaction, in arithmetical reasoning, and in resistance to suggestions as indi- cated by the size-weight illusion and the use of suggestive ques- tions in testimony. The two sexes seem to be approximately equal in associative processes and in most school subjects. The amounts of difference, however, are very small. This is particu- larly true of all the traits that have been measured in a sufficiently

1.20 1.00

.80

.60

.40 -

.20

.00

Girls

9 10 Years

12

13

14

Fig. 29. — Comparison of general intelligence of boys and girls as measured by the Stanford revision of the Binet-Simon tests. After Terman ('16, p. 72). The numbers along the vertical axis are intelligence quotients as explained in Chapter VII.

large number of persons to make the comparisons safe. Any differences lying between 40% and 60% of the number of either sex reaching or exceeding the median of the other are practically negligible. If 60% of one sex reach or exceed the median of the other, it means that 10 persons in a hundred of the one sex, are by a small amount superior to the other. Differences larger than this have been established with a fair degree of certainty practically only in the case of one large field of capacities, namely, that of motor abilities. Differences in nearly all other respects in which comparisons have been made on large numbers of persons are almost entirely within the limits of 40% to 60%. Terman found in measuring the general intelligence of nearly 1,000 boys and girls

70

EDUCATIOXAL PSYCHOLOGY

by means of his revision of the Binet-Simon tests that for the ages of five to fourteen j,'irls tend to be very slightly sui)crior to boys and that after fourticn they are practically equal. His results are set forth in Figure 2S.

It seems a likely interpretation that motor superiority has been carried over to include intellectual sui>eriority as well. For centu- ries women have been considered intellectually inferior to men. They were thought to be incapable of acquiring anything more than an elementary education. It has been only since the middle of the 19th centur>' that co-education and women's colleges have been generally established. Intellectual inferiority has probably

Fig. 30. Range of ability of men a.nd women in color discrimination. After Henmon ('10).

been inferred chiefly from niotor and mu.scular inferiorit}- and from the conditions of a narrower environment and dependency due to the bearing and rearing of children. The inference and belief of intellectual inferiority is apparently unfounded. This conclu- sion may be fairly dra\\ii both from the sjjeoific psychological tests that have been cited and also from the recent successes of women in the acquisition of higher education.

Diflference in the Range of Variations in Abilities. Besides C()m|);iring the average amounts of any gi\en ability in the two se.xes, we may compare also the range of abilities from the lowest to the highest in the two se.xes. Such comj)arisons have been made in a few traits and the general inference has been that the range of abilities is wider among men than among women. The distribution of the abilities in the geometrical perception test made upon 193

SEX DIFFERENCES 7 1

men and 200 women mentioned in a preceding paragraph, was as follows:

Scores: , 2-3 4-5 6-7 8-9 lo-ii 12-13 14-1S

193 Men 4.5% 15.4% 33-9% 21.9% 15.4% 5.6% 2.8%

200 Women 3.2% 20.8% 38.9% 21.6% 10.7% 3.9% 0.8%

Thus in the extremely high ability of canceling 14 to 15 geo- metrical figm"es in one minute, there were 2% more men than women, and in the lowest ability of canceling only two to three geometrical figures, there were 1.3% more men than women. Comparisons of this sort can be made safely only on large numbers of individuals, and consequently there is as yet little reliable material available.

The ratio of female to male variability has been computed by Thorndike ('14, III, p. 194) on the basis of tests of memory, re- action-time, discrimination of length, opposites, and cancellation made by Gilbert ('94) upon 100 boys and 100 girls of each age from 6 to 17. The average ratio in all tests for the ages of 9 to 12 was found to be .92, for the ages 13 to 14 1.025, and for the age of 15, .97. Girls were slightly less variable at all ages except 13 and 14. In a test of color discrimination Henmon ('10) also found a slightly larger variability among men than among women as shown in Figure 30.

The author made a comparison of the range of abilities in history and geography as measured by his tests in these subjects, and found the following distributions:

History, 8th Grade Percentages of boys and girls attaining the various scores

Scores: o-io 11-20 21-30 31-40 41-50 51-60 61-70

Boys 4-2% 9-3% i5-3% 170% 13.2% 12.2% 11.5%

Girls 6.2% 22.7% 22.7% 16.4% 12.8% 9.4% 6.0%

Scores (continued) : 71-80 81-90 91-100 loo-iio Total

Boys (continued) 9.3% 6.6% 2.1% 0.4% 288

Girls (continued) 2.3% 2.6% 0.9% 0.0% 352

Geography, 7 th Grade

Scores: o-io 11-20 21-30 31-40 41-5° 51-60 61-70 71-80

Boys 06% 2.8% 4-7% 8.4% 5-3% 12.2% 14.7% 14-7%

Girls 03% 16% 56% 10.0% 10.0% 12.5% 18.7% 18.7%

Scores (continued) : 81-90 gi-ioo loi-iio 111-120 1 21-130 Total

Boys (continued) 10.3% 8.1% 9-i% 6.9% 2.8% 320

Girls (continued) 10.0% 8.7% 7-2% 5-9% 3-i% 322

72 EDUCATIONAL PSYCHOLOGY

The varial)ility of boys in the case of history is somewhat larger than that of the girls, ^\hereas in the case of geography it is sub- stantially the same.

ThomJike ('14, III, p. 195) has given the range of ages of boys and girls in the third year of high schools in Chicago, Philackli)hia, New \'ork, Detroit, Fall River, Los Angeles, Lowell, and Worcester as follows:

Afjc 13 14 15 16 17 i8 19 20 and over Total

Boys 7 02 504 1246 1203 57-' 1 93 67 3974

Girls 4 73 562 1351 1289 554 120 34 3987

There are about twice as many boys as girls at either 13 or 20 or over.

In support of the general iH-Iief that the range of general abilities is wider in men than in women may also be cited the fact that in the history of the world most of the great geniuses have been men, and also the statistical fact that male idiots and criminals at the other extreme of the distribution curve consideraljly outnum- ber the female. The fact that the great geniuses of the world have been men rather than women would accordingly be ex-jjlained, not on the basis of lack of opportunity, but mainly on the basis of greater exceptional ability. The theory seems plausible but has been ]iroposed rather in ad\'ance of a con\'incingly wide range of e.\])erimental data. If it is true, it would mean that according to the perception test the one or two per cent most gifted individu- als are men and the i or 2% least gifted individuals arc also men, that of the next 10 or 12% of most gifted indi\'iduals aj^proximately two-thirds would be men and one-third women, and likewise of the next 10 or 12'^ i least gifted individuals at the other extreme, about two-thirds would be men and one-third women. For the remainder of the distribution the number would be practically identical. The facts should not be interi)reted as im])lying that men as a rule are superior to women, but would mean simply that only the one or two exceptional jiersons in a hundred would be superior to the most gifted women. The remaining 96 or 98% would be largely identical.

CHAPTER VI THE INHERITANCE OF MENTAL TRAITS

Problem. In a certain obvious sense, the entire native equip- ment of any human being is inherited. The various capacities and the relative amounts of them with which a person starts in Hfe are derived from the cells from which the individual originates. The dififerences among these original cells, even when derived from the same parent, are assumed to vary with regard to any potentiality according to the normal distribution curve about the central tendency of that particular parent. Stalks of corn growm from seed taken from the same ear will vary considerably from one another because the seeds themselves, even from the same ear, are different, but yet they will vary around the general type of the parent stalk. It is therefore obvious that children of the same parents will not be absolutely alike but that they will vary about the central tendency of their ancestors. The specific problem is not: Are mental traits inherited? but rather: How much do children of the same parents or ancestors resemble one another in the amounts of different traits possessed, and in the manner in which the various traits combine? To what extent are abilities in school work inherited? To what extent are the wide ranges of abilities, noticed in Chapter III, due to native equipment or to opportunity and environment? To what extent does a person make of himself what he does by virtue of his opportunities or by virtue of his inherent make-up? What part of the future adult individual is really determined by the school as an agency of his environment and what part is beyond the control of the school?

Methods of Studying Heredity. Any individual is the resultant of the interplay between his inherited equipment and the stimuli from his environment. Hence, theoretically, there are two general methods of studying the problem: First, by keeping the environ- ment constant and varying the ancestry, so to speak; or second, by keeping the ancestry constant and varying the environment. That is, according to the former plan we would place children of entirely different ancestry into the same environment from birth

73

74 KDUCATIONAL PSYCHOLOGY

up to a given puint in life, and then measure the amount of simi- larity or dilTerence; or according to tlie latter plan, we would place children of the same ancestry into entire!}' dilTerent environments from birth to a given point in life, and then measure the amount of similarity or dilTerence. Such ideally scientific conditions are I)ractically impossible to obtain. The best we can do is to measure the resemblances or difTerences of children of the same ancestry and compare them with the resemblances or difTerences of children of dilTerent ancestry, both groups living in appro.vimately the same enxironnicnt.

General Views Concerning Mental Heredity. Two extreme views concerning heredity are possible according to our conception of the relative roles ])layed by heredity and environment in the production of adult individuals. We may assume on the one hand that v.hat a person l:)ecomes is absolutely and entirely determined by heredity, and that environment makes no dilTerence whatever; or we may assume on the other hand that what a person becomes is Completely and entirely determined by his en\ironmcnt, and that heredity jjlays no ])art. Neither \iew has been held by any serious student of heredity in recent times. Views very closely ajjproach- ing these e.xtremes, have, howe\'cr, been held by prominent writers and thinkers in times jxist; whereas various views between these extremes arc generally being held at the jiresent time, de])ending ui)on the conception as to whether the larger, smaller, or ecjual share is contributed by heredity or by environment. The ^•iew held by most scientific students of the i)roblem to-day gives weight to both elements with perhaps the major emphasis upon heredity.

The Similarity of Abilities among Related Eminent Persons. This particular method of attacking the probleni was historically the first means of approaching the study of the inheritance of mental traits. Two extensi\e investigations on this aspect of the subject ha VI' been made. The first was carried out by Sir Francis Galton and i)ul)iished in iSoc;. Galton made a study of 977 emi- nent men, each of whom was the most eminent among 4,000 ]>ersons. He i)roceeded to determine how many relati\'es of ec|ual eminence and of var\ ing degrees of relationship each ]urson possessi'd. In this manner he found that the.se 077 men had the following relatives of a like degree of en\inence: 89 fathers, 114 brothers, 129 sons, 52 grandfathirs, 37 grandsons, 5.^ uncles, and 61 nephews, or a total of 5;;5. (lailon further jjointed out that 977 ordinary men

THE INHERITANCE OF MENTAL TRAITS 75

selected by chance from the population at large would have only four such eminent relatives. He concluded as follows:

"i. That men who are gifted with high abilities — even men of class I E — easily rise through all the obstacles caused by inferiority of social rank.

" 2. Countries where there are fewer hindrances than in England, to a poor man rising in life, produce a much larger proportion of persons of culture, but not of what I call eminent men. (England and America are taken as illustration.)

"3. Men who are largely aided by social advantages are unable to achieve eminence, unless they are endowed with high natural gifts."

More recently an extensive study was made by Woods ('06) on mental and moral heredity in royalty. Woods made a com- parison of 671 members of royal families in Europe by giving each person a rating on a scale of i to 10 in which 10 signified excep- tionally high ability or genius, and i represented exceedingly low ability or imbecility. These ratings were made by the judgment of Woods himself according to the reports of these persons in histories and biographies. On the basis of these estimates, a tabulation was then made of the relationship of persons of various degrees of ability. He found that most of the eminent persons were grouped about four stocks or families out of fifteen, namely, the families of Frederick the Great, Queen Isabella of Spain, William the Silent, and Gustavus Adolphus. Likewise, he found that most of the persons of lowest ability were grouped around certain families in Spain and Russia, and the persons of mediocre ratings, four to seven, centered about some half dozen royal families including the houses of Hanover, Saxe-Coburg-Gotha, Reuss, Mecklenburg, Hapsburg in Austria, Holstein, Denmark, Saxony, Savoy, Orleans and modern Portugal. The ratings, of course, were not absolutely correct measurements of their abilities, but they, no doubt, represented greater validity than general impres- sions would. He further computed coefl&cients of resemblance in intellect and morals as follows:

I. In intellect :

Offspring and father 30

" " grandfather .16

" " great-grandfather 15

II. In morals:

Offspring and father 30

" " grandfather 175

76 KDUCATIONAL I'SYCHOLOCiV

I >r. Woods then altcniplcd to determine whether (^r not thtfact of accession to the throne by virtue of birth gave an individual greater opix)rtunity for eminence. This he states in the following nianner:

"There is one peculiar way in which a lilllc more than half of all males have had a consi(lcral)le advantage over the others in gaining distinction as inifxjrtanl historical characters. The eldest sons, or if not the eldest, those sons to whom the succession has devolved, have un- doubtedly had greater op[M)rlunilies to become illustrious than those to whom the succession did not fall by right to jjrimogeniture. I think every one must feel that perhaps much of the greatness of Irederick II of Prussia, Clustavus Adolphus, and William the Silent, was due to their oflicial positions; but an actual mathematical count is entirely opposed to this view. The inheritors of the succession are no more plentiful in the higher grades than in the lower. The figures show the number in each grade who came into power by inheriting the throne."

Grades i 23456789 lo

Total No. in each j; rude 7 Ji 41 49 71 70 68 43 18 7

Succession inheritors 5 14 26 31 49 38 45 23 12 4

Percent 71 07 O3 64 69 54 07 54 67 57

"It is thus seen that from 54 to 71*^ inherited the succession in the different grades. The upper grades are in no way composed of men whose opportunities were enhanced by virtue of this high position. Thus we see that a certain very decided difference in outward circumstances — namely, the right of succession — can be proved to have no etTect on intellectual distinction, or at least so small as to be unmeasurable without much greater data. The younger sons have made neither a poorer nor a better showing. ('06, pp. 285-2S6.)"

"The ujjshot of it all is, that as regards intellectual life, environment is a totally inadequate explanation. If it explains certain characters in certain instances, it always fails to explain as many more; while heredity not only e.xplains all (or at least Qo^t ) of the intellectual side of character in practically every instance, but does so best when questions of en- vironment arc left out of the discussion. Therefore, it would seem that we arc forced lo the conclusion that all these rough differences in in- tellectual activity which are susceptible of grading on a scale of ten are due to predetermined differences in the primary germ-cells." ('06, p. 286.)

WTiile heredity no doubt plays an important part in the prmluc- tion of intellect and character the |)art attributed to it by VV'chkIs that it explains " at least QO% of the intellectual side of character in every case " is hardly warranted either by the findings of other investigators or by the results of Woods himself. His corrrelation between father and offspring is only .30.

THE INHERITANCE OF MENTAL TRAITS 77

Similarities of Abilities Among Related Defective and Low Grade Persons. Quite a number of studies have been made in recent years concerning the frequency with which defective persons are either distantly or closely related. One of the first studies w^as that of the Jukes reported by R. G. Dugdale in 1877. Max Juke, born in 1720, was a shiftless truant, who married an equally worthless woman. Up to 1S77 there had been five generations with approximately 1,200 descendants among whom have been traced the following types of persons: 310 paupers, 7 murderers, 60 habit- ual thieves, 50 prostitutes, 130 convicted of crime, 300 died in infancy, 440 physical wrecks from debauchery, only 20 learned a trade, and 10 of these learned it in prison. The estimated cost to the State of New York has been put at approximately $1,000 a person. In contrast with this lineage, a comparison has been suggested with the Jonathan Edwards family, which had approxi- mately 1,400 descendants in the same period of time. Among them there have been 120 graduates of Yale alone, 14 college presidents, over 100 professors, 135 books of merit have been written by various members of the family, and 118 journals have been edited by them. Aaron Burr was the only black sheep among them and he can certainly not be classed as an intellectually de- fective person. (Winship '00).

Poellman of Bonn (Guyer '16^ p. 271) made a study of a family called the Zeros in which 800 descendants were traced through six generations back to a female drunkard. Among them were found 102 professional beggars, 107 illegitimate offspring, 181 prostitutes, 54 inmates of almshouses, 76 convicted of crime, and 7 murderers. The cost to the state was placed at $1,206,000.

More recently a very interesting study was conducted by Dr. Goddard of the Training School at Vineland, New Jersey. Dr. Goddard ('12) traced the ancestry of a young girl who had been brought to his institution. It was found that the lineage went back to a man, Martin Kallikak, a soldier in the Revolutionary War, who was the progenitor of two lines of descendants. (See Figure 31.) He had an illegitimate son whose mother was feeble- minded. This was the establishment of line — A — which had, down to the time of the study, 480 direct descendants among whom were found the following: 143 feeble-minded, 292 unknown, 36 illegitimates, 33 prostitutes, 24 alcoholics, 3 epileptics, 82 died in infancy, 3 criminals, 8 keepers of disreputable houses, and only 46 normal individuals. Apparently human nature does not gather

78

EDUCATIONAL PSVCIK )L( K i V

grapes of thorns or figs of thistles. After his return from the war, Martin married a woman of normal intelligence and from this lineage — B — there had come during the same period of time, 4g6 direct descendants, of whom all were normal individuals with the

THE LAWFUL WIFE

©-

MAATII KALLIXAK SR.

I THE MMELESS

FEEBLEUmOEO 6IRL

liil

[§ (N) (N) (N) (N) [N] ®

-®

RHODA 2ABETH

(Sw-lli-r-O ^ ^^^' ' '4 (S) (N) d)

$S<h^^6666

TAKEN IH D. D,

GOOD 9 VRS. 4 mt. HOME

D.K TRS.

Fir,. 31. — Dcsrcndants of tin: Kallikak ramily. Squares = males, drrles = females, hiac k sfjiiares or cinlcs = feeMeminded, open scjuarcs or cinles = normal persons. Ihe lineage was traced back from Deborah. After Goddanl.

exception of five, one of whom was reported as mentally defective, two as alcoholics, one as sexually immoral, and one as a case of religious mania. There were no epili-ptics or criminals, and only 15 died in infancy. The remainder were good citizens, including doctors, lawyers, educators, judges, and business men.

One thing seems to stand out very conspicuously from the

THE INHERITANCE OF MENTAL TRAITS 79

numerous facts of family histories that have been unravelled in recent years, namely, that much defective mentality, degeneracy, and crime is a m.atter of ancestry. General opinion among persons in charge of institutions for defectives is that two-thirds of all cases are due to heredity and one-third to environmental or un- known causes. Thus Dr. Alfred Wilmarth, Superintendent of the Wisconsin Home for Feeble-minded, says:

"My own observations, and those of others in this country and Europe, would indicate that at least two-thirds of the feeble-minded have defec- tive relatives. This is significant. Mental accident may occur in any family, but it is rarely a second case occurs unless there is a tendency to nerve degeneracy. (Quoted by Guyer,'i6, p. 245.)

"I present to you the results of compiling the histories on 1,000 appli- cations, where our information is most thorough; but I am confident that these do not tell the whole story. In 3 1 1 of these any neurotic taint in the family history is absolutely denied. In 365 cases at least one near relative suffers from one of the graver forms of nervous or mental trouble; in 170, two relatives were found; in 73 cases, three relatives, and in 81 cases four or more. These figures agree very accurately with the results of other observers in this country and abroad. It is safe to say that less than one-third of the defective classes are the results of disease or trau- matism in families capable of transmitting a healthy, well developed nervous system."

Dr. Goddard of the Training School, Vineland, New Jersey, states in connection with his tests of 2,000 children:

"But we now know that 65% of these children have inherited the condition, and that if they grow up and marry they will transmit the same condition to their oft'spring. Indeed, we know that this class of people is increasing at an enormous rate in every community and unless we do something to stop this great stream of bad protoplasm we shall some day be swamped in a sea of degeneracy."

Likewise Dr. A. C. Rogers of the Minnesota School for Feeble- minded, at Faribault, says:

"We have no survey of mentality in this country except in very small areas, but probably about 65% of the feeble-minded children that we know of are feeble-minded from heredity; that is, they come from families in which there is much feeble-mindedness, usually associated with various neuroses or psychoses. There are about 35% approximately that are acquired cases. These cases develop from various things. Full develop- ment may be prevented during gestation, or early childhood, or early adolescence, but these acquired cases are entirely distinct from the hereditary ones." (Guyer '16, p. 246.)

8o EDUCATIONAL PSYCHOIX)GY

Likewise, Dr. Martin W. Barr of the Pennsylvania Training School for Feeble-minded Children states:

"In my individual study of 4,050 cuscs of imbecility, I tind 2,631 or 65.34%, caused l)y malign heredities; and of these 1,030, or 25.43%, are due to direct inheritance of idiocy; and 280, or 6.91%, to insanity."

To one who wishes to argue in favor of environment as the chief determining element in ability and character, such data as have been presented from family histories and relationships are not en- tirely convincing. It might be argued that a given family has so many individuals of high or low intelligence and achievement because its members were born in circumstances which did or did not afford opportunities for development and training and for achieving higher success. It might be said that the descendants of the Edwards family were born and reared among favorable cir- cumstances of educational and financial advantages and conse- quently were fitted for greater tasks and lived in an environment in which larger opportunities offered themselves, whereas the members of such a lineage as the Jukes family would have just the opposite environment of birth, education, and opportunity in life. In answer to all this, we must remember, however, that abihty very largely determines the sort of environment in which a person is satisfied to live, that a really capable person is quite likely to push forward and to find a way out of the en\ironment in which he may hapi)en to have been born, or to improve it if he cannot leave it, and finally, we must remember that the persons of low ability were born in circumstances of a correspondingly low nature because of the hereditary stock of the families from which they came. Their jxircnts were content to live under the circumstances under which they did live because their abilities and desires sought for nothing better.

Similarities between Brothers and Sisters in Special Mental Traits. Pearson has shown that the resemhlaiue in physical characteristics among brothers and sisters is approximately .50. He gives the following coefficients of correlaiitui for various physical traits.

Brother aiui sister

Hair color 55

Cephalic index 4Q

IleiRht SO

Eye color . . .52

THE INHERITANCE OF MENTAL TRAITS

8l

What, however, is the degree of resemblance in mental traits? The general argument is that mental traits are dependent upon anatomical and neurological structures, and hence, if these are inherited, mental traits must also be inherited. What is the evi- dence from experimental and statistical facts?

In a study made by the writer ('17) a series of tests of capacities directly affected by school work and another series of tests of capac- ities not directly affected by school work were applied to 18 pairs of brothers and sisters in the University of Wisconsin. Each test was given twice on two different occasions in order to obtain a fairly accurate measurement of the capacities concerned. The pur- pose of giving the two types of tests was to ascertain whether brothers and sisters were more alike in the traits affected by train- ing than in the traits not directly affected by school training. The following were the tests and the correlations obtained between pairs of children of the same family :

TABLE 18 Correlations between abilities of brothers and sisters. After Starch ('17)

Reading — speed

Reading — comprehension . .

Writing — speed

Writing — quaHty

Size of reading vocabulary .

Spelling

Arithmetical reasoning. . . .

Addition attempts

Addition — rights

Subtraction — attempts. . . .

Subtraction — rights

Multiplication — attempts . Multiplication — rights. . . .

Division — attempts

Division — rights

Average .

Memory

A-test

Geometrical form test . Tapping

Average

Coefl&cients based on ranks in all tests combined

82 EDUCATIONAL PSYCHOLOGY

In order to grasp the full import of these figures, it is necessary to remember that the coefTicient of correlation between mental abilities of pairs of unrelated individuals selected by chance would be zero, and that any coefficient above zero between pairs of brolJiers and sisters means a corresponding amount of resemblance.

"From the above (able several interesting results appear, (i) The resemblance of siblings is apparently no greater in those mental traits which are directly affected by school work than in those which arc not so affected. The average correlation in the former group of tests is .42 and in the latter .38. This seems to indicate that the mental similarities of children of the s;ime parents arc due primarily to heredity rather than to similarity of environment since the resemblance is no greater in those traits which are more directly affected by environment.

"(2) The resenil)lance of siblings is approximately as great in menial traits as in physical traits. Pearson found the correlation between brother and t)rother in height to be .50 and in cephalic index (ratio of length to width of head) .40. These correlations for physical traits are a. Uttle larger than the ones found here for mental traits taken separately. The correlation, however, calculated on the basis of a combined rank for each person in all mental tests together was found to be .73. This greater correlation for all tests combined as compared with the correlation for single trails is due partly to the variation of the correlations among the single traits and partly due to the imperfections in the separate tests, which arc counterbalanced to some extent in a combined ranking." (Starch '17, p. 237.)

Pearson ('04) made a comparison of 2,000 brothers and sisters who were rated by their teachers in such traits as vivacity, self- assertion, introspection, popularity, conscientiousness, temper, ability, and handwriting. On the basis of these ratings he found coefficients of correlation ranging from .4 :; to ,64 with an average of .52. These results are interesting and indicative of the resem- blance of more general traits of character, but they are probably rendered more or less uncertain l)y the unreliability of one person's ratings of such elements of character. The likelihood is that the teachers would be more inclined to estimate alike the children from the same families, rather than to estimate them more different than they really were.

Similarities of Brothers and Sisters in Abilities in School Sub- jects. In a study made s<.\eral years ago, Earle (03) found a correlation of .50 between the spelling abilities of 180 pairs of brothers and sisters. The writer ('15) made a study of the scho-

THE INHERITANCE OF MENTAL TRAITS 83

lastic records of children from 63 families. The average grade in all school subjects was obtained for each pupil and used as the measure of his academic ability. The correlations based upon these averages were as follows:

First and second child in a family, 63 pairs 58

Second and third child in a family, 24 pairs 64

First and third child in a family, 24 pairs 34

Average 52

Further comparisons were made for abilities in specific school subjects which yielded the following correlations:

Spelling, 57 pairs of children from the same parents 21

Reading, 57 pairs of children from the same parents 49

Writing (speed) 24 pairs of children from the same parents 18

Writing (quality) 24 pairs of children from the same parents 06

Another study was made of 38 children from 11 families. All the marks that each pupil had received in each study in grades three to eight were averaged. From these averages the following coefficients of correlation were obtained.

Arithmetic, 54 pairs 32

Spelling, 54 pairs 21

Reading, 54 pairs 31

Language, 54 pairs 24

"No importance, I believe, can be attached to the differences in cor- relation between the various studies. The correlation for individual studies is lower than that for scholarship in general based on the average performance in all studies combined. This is probably due chiefly to the fact that the inaccuracies of teachers' marks in individual subjects are partly ehminated in the averages derived from all studies.

"Abilities in special subjects are inherited, apparently, to no greater extent in one subject than in another. What is probably inherited is either general scholarship or else more specialized traits than ability in arithmetic, or ability in language. Each study involves many mental faculties and nearly all studies involve the same faculties with varying emphasis.

"In corroboration of this point we may notice the following table of average marks for each of nine families in each study.

"In this table, we must examine the ranks, rather than the marks, of the different families in each subject, so as to eliminate the variation in -Standards of marking. These famiUes rank very nearly the same in the

84

EDUCATIONAL PSNTTTOI^OCV

various studies. For example, family C is first in every study except arithmetic and there it is third. Family (1 is second in every subject except arithmetic and there it is fourth. Family I is either third or fourth in every subject but one, and family H is last in every subject except one.

TABLE u) .Averages for each f;unily in each subject.

FVMII.Y	No. OP
	Children
A	3
B	5
C	4
D	6 4
E
1*
G	3 3
H
I	3

Akitp-

MtTlC

Grade

Rank

72.3 75-1 80.2 80.4

77-4 73.6 8 77.6 4 76.1 4 Si. 8 I

Spellinc.

Grade

Rank

85.1 76. I 89.1 85 9 78.5 80.8 86.6 2 78.4 8 8SS 4

Reading

Grade

R.ink

73-2 86. 7 81. 1

74-4

76.1

84.4 So. 5 82 I

Lanou.m-.e
Grade
	R.ank
80	7	5
74	6	9
83	6	I
81	6	4
76	I	7
76	0	8
S3	2	2
So	0	6
82	5	3

Geog-

RAPBY

Grade

Rank

76.7 8

75-3 9 84.6 I 78.6 6

79 3 4 78.6 6

83.8 2 78.6 6 81.6 3

History

Grade

Rank

77.9 8

76.1 9 84.0 I

78.5 6 78 7 5

78.2 7

83.8 2

79.6 4

81.9 3

"There i.s no evidence, at least from these figures, for the notion that special abilities in certain studies run in families. ^Mental trails running in families are very likely more specialized than abilities in school studies which involve large groups of mental functions. The children of any given family are on the average equally good or equally poor in all studies. Ability in school work is apparently inherited to the s;ime extent as jihysical features since the coeflicients of correlation for children of the same parents are ai)proximalely the s;ime for both physical and mental traits." (Starch, '15, pp. 609-610.)

Schuster and IMdcrtoii (07) calculated the resemblance in scholarship between brother and brother and between father and son among the Oxford honor men and found a coclTicient of correla- tion of .40 for the former and .^^i ior the latter. Miss Eldcrton further determined the correlations between cousins from records of about 300 families and found a coelTicient of .27.

Miss Emily S. Dexter ' made a study of the scholarship records (^f 185 pairs of brotJiers, sisters, brothers anrl sisters, graduates of the University of Wi.sconsin, and of 69 similar pairs who were gradu- ates of the high school at .Ashland, Wisconsin. She reports the following coelTicienls:

' The study was r.nrrird ntif under the <lircction of Profes.s«)r Henirmn and reported ill a thc»ii in the liljrury uf the UiiivcrMty of Wiscuiuuii, 1915.

THE INHERITANCE OF MENTAL TRAITS

85

TABLE 20

	Number OF Pairs	General Scholar- ship IN all Sub- jects	English	Lan- guage	Mathe- matics	History	Science
University: All pairs Bro. and bro . . . Sis. and sis. . . . Bro. and sis. . . . High School: All pairs Bro. and bro . . . Sis. and sis ... . Bro. and sis ... .	185 44 71 66 69 10 26 23	.69 ■47 53 .62 .64 ■38 39 36	.64 .58	.63	■55	.62 ■63	.60 .61

Miss Dexter concludes "that inheritance, to a much greater extent than training is responsible for the degree of resemblance found."

"If it were largely training, we would expect to find the resemblance greater between brother and brother, and sister and sister, than between brother and sister, but such is not the case. In the high school the cor- relations for the three groups are much the same, but, as has been pointed out, that may be due to a great extent to chance, for the groups are small. However, in the case of the university, where the groups average nearly three times as large as in the other school, we find the resemblance be- tween brother and sister to be greater than between brother and brother, or sister and sister.

"Again, there is the question as to specialized abilities, and also that of general mental ability rather than specialized abilities as a basis of ex- planation for the close resemblance found. Thorndike, as has been said, finds that heredity is highly specialized. This study, however, seems to show a stronger tendency toward general mental ability, if by that we mean approximately equal ability in all subjects. It seems, also, to give almost no evidence of alternate inheritance; that is, of one individual's inheriting ability in one line while his brother inherits ability in another. In other words, a student who is above the average, either of his family or of the school, in one subject, is usually also above in most, and in many cases all, other subjects."

Similarities of Twins in Special Mental Traits. The two prin- cipal investigations on this phase of mental heredity were made by Galton and Thorndike. Galton made a general comparison of two groups of twins, one group of 35 pairs, which were reported as being very similar, in fact so similar that they were frequently reported

86 EDUCATIONAL PSYCHOLOGY

as indistinguishable, and another group of twenty pairs of dis- tinctly dissimilar twins. The conclusion formulated was to the effect that the former twins remained very similar all through life in spite of ditTerent environments, while the latter twins re- mained dilTerent all tlirough life in spite of similar environments. Concerning certain of the twins Gal ton reports:

"i. One parent says: 'They have had exactly the same nurture from their birth up to the present time; they are both perfectly healthy and strong, yet they are otherwise as dissimilar as two boys could be, phys- ically, mentally, and in their emotional nature.'

''2. T can answer most decidedly that the twins have been perfectly dissimilar in character, habits, and likeness from the moment of their birth to the present time, though they were nursed by the same woman, went to school together, and were never separated till the age of fifteen.'

"3. 'They have never been separated, never the least differently treated in food, clothing, or education; both teethed at the same time, both had measles, whooi)ing-cough. and scarlatina at the same time, and neither had any other serious illness. Both are and have been exceed- ingly healthy and have good abilities, yet they differ as much from each other in mental cast as any of my family differ from another.'

"5. 'They were never alike either in body or mind and their dissim- ilarity increases daily. The e.xteriial influences have been identical; they have never been separated.'

"9. 'The honie-traininp; and influence were precisely the same, and therefore I consider the dissimilarity to be accounted for almost entirely by innate disposition and by causes over which we ha\e no control.'" ('83, p. 170, Everyman's Library Edition.)

Gallon's general impression of his results is as follows:

"We may, therefore, broadly conclude that the only circumstance, within the range of those by which persons of similar conditions of life are affected, that is capable of j>roducing a marked effect on the char- acter of adults, is illness or some accident that causes physical infirm- ity. . . . The impression that all this leaves on the mind is one of some wonder whether nurture can do anything at all, beyond giving instruc- tion and professional training. There is no escape from the conclusion that nature prevails enormously ovx-r nurture when the differences of nurture do not exceed what is commonly to be found among persons of the same rank of society and in the same country." ('S3, pp. 168 and 1 7 J.)

Thorndike's investigation (05) was made by more accurate methods. He applied the tests, mentioned in the following table, to 50 pairs of twins and found the following correlations:

THE INHERITANCE OF MENTAL TRAITS

87

In the A-test R —

In the a-t and r-e test R —

In the misspelled word test R —

In addition R —

In multiplication R —

In the opposites test R —

"If now these resemblances are due to the fact that the two members of any twin pair are treated alike at home, have the same parental models, attend the same school and are subject in general to closely similar environments, then (i) twins should, to the age of leaving home, grow more and more alike, and in our measurements the twins 13 and 14 years old should be much more alike than those 9 and 10 years old. Again (2), if similarity in training is the cause of similarity in mental traits, ordinary fraternal pairs not over four or five years in age should show a resemblance somewhat nearly as great as twin pairs, for the home and school conditions of the former will not be much less similar than those of a pair of the latter. Again (3) if training is the cause, twins should show a greater resemblance in the case of traits much sub- ject to training, such as ability in addition or in multiplication, than in traits less subject to training, such as quickness in marking off the A's on a sheet of printed capitals, or in writing the opposites of words.

"On the other hand (i) the nearer the resemblance of young twins comes to equalling that of old, (2) the greater the superiority of twin resemblance to ordinary fraternal resemblance is, and (3) the nearer twin resemblance in relatively untrained capacities comes to equalling that in capacities at which the home and school direct their attention, the more must the resemblances found be attributed to inborn traits.

"The older twins show no closer resemblance than the younger twins, and the chances are surely four to one that with an infinite number of twins tested, the 12-14 year-olds would not show a resemblance ,15 greater than the 9-1 1 year-olds. The facts are: (Thorndike '14, III, pp. 248-249).

TABLE 21 The resemblances of young and old twins compared.

Twins, 12-14

1 . A-test

2. a-t and r-e tests. . . .

3. Misspelled word test

4. Addition

5k Multiplication

6. Opposites

Averages

8S

KDUCATIOXAI. rsVCHOLOr.V

The Influence of Uniform Environment Upon Different Original Abilities. All studies cited thus far have attempted to measure the amount of similarity in related persons as compared with un- related individuals on the assumption that the environment was roughly constant for all, that whatever resemblances existed be- tween pairs of brothers and sisters or between other types of rel- atives greater than that between any pairs of persons selected by chance from the population at large, is considered to represent the actual amount of similarity in the original inherited natures of the individuals springing from the same ancestry. The problem may, however, be pursued further from a dilTerent angle, namely, by specific control of the environment or some portion of it. Thus it is possible to keep some particular part of the environment uniform for a group of persons of widely ditTerent abilities and to measure to what extent the original ditTerences remain constant, increase, or decrease. If the differences remain constant, or increase, the in- ference would be that the ultimate dilTcrences of achievement would be primarily due to the inherited differences of capacities. If the differences decrease materially and finally disappear, the original differences would be mainly due to the elTect of environment and opportunity.

A number of such experiments have been carried out. An in- vestigation made by the writer ('ii) in which S persons multiplied mentally 50 3-place numbers by a i-place number each day for 14 successive days showed the following amounts of improvement:

T.MJLE 22

NUMBKR OF lOXAUI'I.KS IN 1st 10 .Mis.

NCMBER OF EXAMPLKS IN

Last 10 .Miv.

Gain in No. of Examples

Pkr Cent Gain

Three best persons . . Three poorest persons

39

51

45 26

104

Hence, both the greatest absolute and the greatest relative gain was made by the group with the highest initial records.

Similar results have been found in the practice experiments of sul)stiluting numbers for letters as described in the author's Ex- pert turn Is in luliualiottal Psyc/iolof^y, Chapter X. The follow- ing table gives the highest five and the lowest five records from aniong twenty persons. Each person practiced uo minutes.

THE INHERITANCE OF MENTAL TRAITS

89

TABLE 23 Average number of letters transcribed.

First 5 Min. Last 5 Min

Initial highest five persons . Initial lowest five persons .

139 100

310 239

171 139

Again the largest gain was made by the group having the greatest initial ability.

Results pointing in the same direction have been obtained by Thorndike, Whitley, and others. For example, Thorndike ('lo) found in the case of practice of nineteen persons in adding, the fol- lowing results:

TABLE 24

The effect of equal amounts of practice upon individual differences in column addition of one-place numbers. After Thorndike ('10).

•	Average Number of Additions per 5 Minutes Corrected for Errors	Average Time Spent in Practice FROM Mro-POINT OF First Test to Mid- point OF Last Test (in Minutes)
	First Test	Last Test	Gain
Initially highest 6 in- dividuals Initially next highest 6 individuals Initially lowest 7 in- dividuals	297 234 167-	437 345 220 -|-	140 III 54	40 49 46

The statistical studies of scholastic histories of pupils through various periods of school life, which were discussed in a preceding chapter under the heading of correlations of abilities at different times of life in the same individual, all tend to corroborate the ex- perimental facts here presented. The scholastic records show to a remarkable extent the uniformity with which each individual main- tains his position throughout his educational career. A very in- teresting tabulation was made by L. J. Coubal and E. VanLande- gend ^ to show the progress made by pupils in grades 4, 5, and 6 in one school in the four fundamental operations in arithmetic. Progress, was measured by the Courtis tests, Series B, month by

1 Under the direction of Professor Henmon, and reported in two theses in the library of the University of Wisconsin, 1917.

9©

EDUCATIONAL PSYCHOLOGY

month through an tntirc year. The records in the four opera- tions for each pupil were combined into a single score. Figures 32, eo

40

ao

20

10

						/
						' .'
				//y
=!^					\^'	/
^					/

,Bept. Oct. Nov. Dec. Jan. Feb. March April May, Fig. 2,2. — Progress in the four fundamental operations in arithmetic as measured by the Courtis tests, Series li, gi\en at monthly intervals. The heavy continuous line represents all the pupils of the 4th grade. The four broken lines represent these pupils divided into quartiles. TO

60

60

40

80

ao

					>		\
					• •	/y^'	-N
				/J	yy
	J	i^'''	'"^.	/^			\ \ \ \
—•— ■	yy	— " ^^

10 ~^^

S«pt. Oct. Nov. Dec. Jan.

Feb.

March April May

Fir.. 33. — Same as Fig. 32, for the 5th grade. Pupils divided into three groups instead of four.

3,^, ancl ;^4 give the curves of progress for the respective grades. The pupils in each grade were divided into groups according to their final performanc e. Thus the pupils in grade 4 were divided

THE INHERITANCE OF MENTAL TRAITS

91

into four groups while those in the other grades were divided into three groups. The results reveal the significant fact that the best groups in each grade made the greatest progress, the poorest groups made the least progress and the intermediate groups made average progress. The graphs for the various groups in any grade gradu- ally spread apart during the course of the year, indicating that the differences increase rather than decrease or remain constant. The more gifted pupils profit more by their school work than the less gifted.

All experimental results point in the direction that practice does

not equalize abilities; in fact, equal practice tends to increase differ-

70

60

60

40

30

20

10

Sept. Oct. Nov. Dec. Jan. Feb. March April May FiG. 34. — Same as Figs. 32 and S5, for 6th grade.

ences in achievement and skill rather than to decrease them. The more gifted individuals profit more, both relatively and absolutely, than the less gifted. This experimental fact is one of the most pro- found bits of evidence regarding the whole problem of heredity and environment. The talented men not only start with greater initial capacities but seem also to be capable of more intense application and more zealous desire to improve. "To him that hath shall be given" is psychologically true in the sphere of intellectual training as well as in the sphere of morality and religion. The man with ten intellectual talents will acquire far more than the man with one talent. If we may generalize for life as a whole, equal opportunities

							^^.•'
				,,--	' /	,y^ ^	'^
				— --	V\	—
■irrzTl		^	y		/
___^-	,^^^'	^	y

92 EDUCATIONAL PSYCIIOUXiY

for all do not produce equal abilities in all. Men may be born free politically, but they are not born equal mentally; they may be born equal in opportunities in a democratic society, but they cer- tainly are not equal in their ultimate achievements in life.

Influence of Different Environments upon Various Original Abilities. Iv\lensi\c inquiries into the effects of xarious enxiron- mental conditions upon the native ability of human beings have been made in other fields besides the experimental one which has been surveyed. Such investigation as the study made by Dr. Rice ('97 and 02) upon the effects of various factors in school life upon the attainments in spelling and in arithmetic, the studies of places of birth of American men of science made by Cattell ('06), or the study of the places of birth of eminent men of letters made by Odin, and similar investigations by I)e Candolle ('73), Jacoby ('81), and L^ilis, have ])een extensively referred to as bearing upon the problem of environmental forces in their inteq)lay with heredi- tary capacities. The real signilicance and argumentative weight of such data seem to the writer to be uncertain and duplex in their meaning. Cattell, for example, has pointed out that the number of eminent scientific men born about 1S60 in Massachusetts per one million population was very much greater than the number of eminent scientific men born in proportion to population in other states. To cite a few instances, he has com|)uted that per one million population there were bom eminent scientists as follows in various states:

Mass 108.8

Conn 86.9

R. 1 25.6

N. Y 47 o

Wis 450

111 24.0

Ala 2.0

Miss 1 .0

Similar figures are given for other states, and the inference made by Cattell is that the environment of Massiichusetts and similar states has been much more conducive to the development of scien- tific men and that the number of such men could be determined practically by the control of the i^roper educational stimuli.

Odin, in his study of 5,2.^3 noted French men t)f letters living during the period 1400 to 1S30, fi)un(l the following distribution according to places of Ijirth:

THE INHERITANCE OF MENTAL TRAITS 93

1,229 born in Paris

2.264 " " other large cities

1.265 " " small cities

93 " " country districts

From this it has been inferred that if France as a whole had been as fertile as Paris in the production of eminent men of letters there would have been approximately 54,000 great men of letters instead of less than 6,000. The difficulty, however, with both studies is that Paris and Massachusetts have been more productive of eminent men not necessarily on account of better educational and social environment, but possibly also because of the fact that eminent men of letters and science have by virtue of the location in them of educational institutions, scientific and other intellectual centers, necessarily been attracted to these places, and conse- quently their children were born in these localities. The facts as such may actually be used in the support of heredity as against enviromiient as much as they have been used in support of en- vironment as against heredity.

Likewise, the study of Rice with regard to the factors affecting efficiency in school subjects is uncertain. Rice, on the basis of extensive tests in spelling and arithmetic in various parts of the country, arrived at the general opinion that practically all external conditions of home and school such as foreign or American parent- age, home study, methods of teaching, size of class, and time devoted to study, made practically no difference whatever in the ultimate achievement of the pupils, and the implication is made that the final efficiency depends primarily upon heredity. The obvious uncertainty of such data as these is that while the facts in toto may imply such a situation, it is also quite certain that such a massing of data in this manner obliterates the effect of individual factors. Favorable conditions may be offset by unfavorable condi- tions and thus obscure the entire situation. To infer that good teaching and poor teaching make no difference in the ultimate results obtained, or that the amount of time given to study makes no difference in results, are conclusions that are quite likely to be unsound. The reason for the inference drawn by Rice is probably the fact that good teaching in some schools may be accompanied by other factors which tend to counteract its effect, whereas poor methods of teaching in other schools may be accompanied by favorable or unfavorable circumstances in other respects. The massing together of returns from many schools is bound to ob-

c;4 i;i)rr.\TION'AL psvciioL<onv

literati' the effects of the individual conditions. The only certain way to ascertain the effectiveness of one factor or another would he to control all conditions, or to be able to allow for theni definitely, with the exception of the one factor whose efBcacy is to be deter- mined. Thus in order to determine whether or not the different methods of teaching a given subject make a difference, it would be necessary to take a class of pupils in a given school and divide it up into two or more groups on the basis of equal initial capacities and to have each class taught, preferably by the same teacher and un- der the same general circumstances, by a different method. Then at stated intervals the two groups should be compared l)y reliable measures. In this manner definite results could be obtained as to the effectiveness of the various methods, conditions, or amounts of time devoted to a subject. Consequently, Rice's figures as they stand are of little worth so far as proving the forcefulness of dif- ferent environmental factors in the production of results is con- cerned.

A similar criticism applies to such studies as that made by Spill- man with regard to the place of birth of various men prominent in ])ublic and business life, such as presidents of the United States, governors, and railroad ])residents. Spillman ('09) has pointed out, for example, that 23 of the first 25 presidents of the United States were born in the country, that 41 out of 45 governors, and 47 out of 62 cabinet ofBcers were bom in the country. It is unsafe to argue that because a large percentage of the presidents of the United States or other jirominent persons were bom and reared in rural districts, that country life is more productive of ability and ambition. To argue with any certainty on the basis of such facts, it is necessary to know the ancestral antecedents of the ])ersons springing from various localities and sections of the popu- lation.

General Interpretation. The general impression from all e.\- ])erimental, statistical, and historical material thus far accumulated on the problems of mental heredity would seem to be somewhat as follows: Harring jraupers, invalids, and those suffering from want of food and shelter due to conditions beyond their personal control, and referring to all others living in the same community at the same time, the ultimate achievement of any gi\en individual is (\uv to his original ability, probably to the e.xtent of Oo to f)0%, and to actual differences in opportunity or e.xtemal circumstances only to the extent of 10 to 40%.

THE INHERITANCES OF MENTAL TRAITS 95

The facts of heredity bear down so heavily that the impression gained of the large part played by it leads one almost to a fatalistic philosophy. One is almost inclined to believe that persons become what they do largely on account of their hereditary capacities, and that they are not in the least responsible for their own outcome; that if a person is born with great capacities he will achieve high distinction, and if he is bom with mediocre or slender capacities, he will not achieve anything beyond his limits no matter what he may do. While it is certainly true that no one may achieve a position higher than his original capacities will permit, it does not follow that a mechanical, fatalistic view needs to be taken. Nature predominates enormously over nurture only in the relative and not in the absolute sense. This distinction must always be borne in mind in studies of heredity. In fact, in the absolute sense, nurture predominates enormously over nature. A Newton bom among Australian bushmen would no doubt have become a re- markable bushman, but never a world-renowned scientist. The necessary stimuli of environment must be at hand to train and develop original capacities. The difference between relative and absolute achievement may be illustrated in any of the experimental results concerning the effects of equal practice cited in a preceding section. The fact that all individuals improve by practice shows absolute gain in performance or skill. The fact that the gifted ones maintain their lead or even gain in their lead is relative achieve- ment. Before practice, no child can write; after practice, all normal children can write with more or less excellence. This is absolute gain. Before practice, some children have greater original capaci- ties for learning to write ; after practice, these same children main- tain the same superiority. This is relative gain. A Newton and an ordinary bushman born and reared among bushmen would probably be superior and ordinary bushman respectively. A Newton and an ordinary bushman born and reared in New York City at the beginning of the 20th century would probably become, respectively, the one a great scientific, professional or business man, and the other an ordinary person, able to get on, earn a living, and enjoy life within the ordinary Umits. The original abilities of ancient civilized peoples were probably very little different from the original abilities of modem civilized peoples. The differences are probably due to the transformation of the environment which is constantly being brought about through the efforts of man. A Newton bom in a modern civilized com-

96 EDUCATIONAL PSYCHOLOGY

munity would ha\'c ^cater and difTerent stimuli than one horn in an ancient or uncivilized community. His ultimate eminence woultl br dctfrniini-d l^y liis environment.

The jxissimi.siic air may further be dispelled by noting the fact that hardly one person in a thousand makes all the absolute gain possible for him even in a single ca|)acity. It has been proved over and over again in numerous abilities which ha\'e been used daily in one's occuj)ation that by a little special practice each day their efficiency may be enormously improved. Consequently, while the possibilities of each individual are limited by his original inherited ec|uipment, each one may develop his capacities far beyond the usual degree of attainment. While experimental evidence indicates emphatically that under equal opportunities the more gifted surpass the less gifted, yet rarely does anyone do his l^est or attain his limit even in a single capacity. Life is a matter of competition; let every- one compete to the fullest extent of his inherited abihty.

^7

CHAPTER VII

THE MEASUREMENT OF MENTAL CAPACITIES

Problem. Strictly speaking, it is impossible to measure directly the original equipment of a human being unmodified by environ- mental causes. The nearest approach would be the preparation of a complete inventory, and an exact measurement, of all the capac- ities that an individual possesses at birth. Even then, pre-natal conditions have entered into the growth of the organism. The next nearest approach would be a measurement of all capacities which are not directly or specifically trained by school, occupation, or special circumstances. In fact, no one can live and possess capac- ities without any modification of them from outside causes; hence the best that we can do is to measure as many capacities and abil- ities as possible which have been modified least by special exercise or training, and then to consider them as approximately represent- ing a person's original abilities, or, to make such allowances as we can for the influence of external causes. No human being up tc the present time has been measured in all respects at any given point in his growth by thoroughly accurate methods. A great many persons, however, have been partially measured in a great many capacities by more or less accurate or inaccurate methods at various stages of their growth.

General Value. John Stuart Mill has said the "greatest thing in the world is man, and the greatest thing in man is mind." To this statement we might possibly add that the greatest achieve- ment of science would be the measurement of the mind. The im- port and value of definite means for measuring the capacities of human beings would touch all phases of human life in which in- telligence is involved. If we had accurate means of describing a given person's capacities in all directions in terms that could be pre- cisely defined and understood, we would have an instrument for evaluating human beings far beyond our present possibilities. We would then be able to obtain a precise notion of the capacities of an individual. Consider for a moment what the advantages would be! In all sorts of human relations, men are called upon con- stantly to pass judgment upon their fellows concerning their fit-

97

98 EDUCATIONAL PSYCHOLOGY

ness, capacity, and promise of success for this or that particular line of work. The one tiling which is probably most important of all, aside from the special training in a given field, is the intelligence and native ability which a person possesses. What aptitudes does a person have for this or that type of work? Enormous waste in the energies of men are due to mal-adaptation of individual to task. The business world is rapidly turning toward psychology for help, and if psychology is to give the help it will have to be in the form of adequate measurements of the capacities of human beings. Sound vocational guidance, in which much interest has recently sprung uj), will have to be founded upon a sound vocational psychol- ogy whose development lies largely in the future. Courts are recognizing that responsibility for conduct rests upon mental maturity and intelligence, and that these must be determined first before proper adjudication may be made of an individual's behavior. Psychological laboratories have therefore been established in recent years in connection with juvenile courts. The immigration office finds it necessary to make intelligence examinations, even if crude, in order to exclude those distinctly unfit. In normal times a con- siderable number, So to 100 per month, are returned to the coun- tries whence they came on account of mental deficiency.

One of the large problems of the school is the proper adjustment of work and progress to the natural ability of the pupils and, in particular, the discovery of the morons and borderline individuals so that they may be taken care of in special classes or otherwise to the best advantage to themselves and to the other pupils in the school. Intelligence examinations would be useful not only in connection with the relatively small percentage of backward and defective pupils, but also in connection with the normal and supe- rior individuals. Such tests would be valuable in conjunction with the measurement of attainment in school subjects specifically, so that a child's progress and rate of advancement could be deter- mined on the basis of both types of measurements. Precise methods of evaluating the actual capacities of pupils would be of decided value in making possible a more accurate promotion or retardation of pupils according to their abilities, and a more accurate prescrij>- tion of work to be done and of the progress that can most profitably be made. The school has paid relatively more attention to the backward pupils by putting them into special classes than to the superior ones. And yet the latter will be the ones who will con- tribute most to the advancement of society as a whole. Why

THE MEASUREMENT OF MENTAL CAPACITIES 99

should there not be special classes for the gifted pupils so that they might be led to reach their fullest intellectual growth and thus return to society the most that they are capable of?

Methods of Measuring Original Capacities. In general two types of methods have been developed, at least in part, and used for determining the native ability of human beings. The term "native" of course, must be understood to signify not pure, native ability unmodified by experience, but native or original only in the sense of not being directly affected by specific training. The one method consists of a considerable variety of reactions to questions and situations which a child would be able to make as a result of normal growth in a normal environment. The tests developed on this principle are the Binet-Simon tests and the various modifica- tions of them.

The second general method has proceeded on the basis of meas- uring, by fairly precise methods, certain special mental functions from year to year, and of determining thereby the mental status and growth of the individual. Thus, for example, many capacities might be measured by a definite psychological technique from year to year, and certain norms might be established for each year so that we could say that a given individual's memory has been de- veloped to the norm or average of a child of ten. Similar tests and norms could be developed in as many different mental capacities as would seem to be necessary in order to obtain a fairly complete evaluation of an individual's natural abilities. This second general method has not as yet been developed to the same degree of com- pleteness as the Binet-Simon type ('05) with respect to either the selection of the particular capacities that should be tested, or the types of tests that ought to be used, or the technique by which they should be given. Brief consideration will be given to both plans of measurement.

The Binet-Simon Scale. This series of tests is arranged in groups according to years. Thus there is a series of tests for every year from age three up to twelve or fifteen, and in some of the revisions even to adult life. These tests were first prepared by the French psychologist, Binet, and the French physician, Simon, who collaborated for a period of twelve or fifteen years in the selection of tests and in assigning them to the proper years accord- ing to the growth and development of the child. These tests were first published in 1905 and since then were revised by the original authors in 1908 and in 191 1. A number of investigators have

lOO EDUCATIONAL PSYCHOLOGY

attempted to rt\ isc them and to adapt tliem to tlie conditions in their respective countries, and to improve them so that they would be more reUal)le and more accurately graded according to the growth of children from year to year. In this country, the chief revisions and imi)rovements have been made by Goddard, Kuhl- mann, Verkes, Tennan, and others. Prol)ably the most Siitis- factory and careful revision of the original Binet tests is the one recently j)repared by Terman and known as the Stanford Re\'ision. This revision consists in the elimination of some of the original tests, in the addition of a considerable numl)er of new tests, in the readjustment of other tests uj) or down the scale of years according to their difficulty, and particularly in the develoi)ment of a more precise technique for giving and evaluating the tests, so that ex- aminers may be guided specifically in the administration of them. The following is a complete list of the tests in the Stanford re- vision. The detailed directions for giving and scoring the tests together with extensive results, are given in Tcrman's The Meas- uremcnl of Intelligence.

The Stanford Revision and Extension

Ycur III. (6 tests, 2 months each.)

1. Points to parts of body. (3 of 4.)

Nose; eyes; mouth; hair.

2.