INDIVIDUAL DIFFERENCES
THE MEANING OF INDIVIDUAL DIFFERENCES. The major part of
this volume has been devoted to a consideration of those
traits, interests, and capacities which all individuals share, and
which may in general be described as the "original nature of
man." These distinctive inborn tendencies were treated, for
purposes of analysis, in the most general terms, and, on the
whole, as if they appeared in the same strength and variety in
all individuals. When we thus stand off and abstract those
characteristics which appear universally in all individuals,
human nature appears constant. But there are marked variations
in the specific content of human nature with which
each individual is at birth endowed. Put in another way, one
might say that to be a human being means to be by nature
pugnacious, curious, subject to fatigue, responsive to praise
and blame, etc., and susceptible to training in all these
respects. By virtue of the fact that we are all members of the
human race, we have common characteristics; by virtue that
we are _individuals_, we all display specific variations in specific
human capacities. There is, save abstractly, no such thing as
a standard human being. We may intellectually set up a
norm or standard, but it will be a norm or standard from
which every individual is bound to vary.
The fact that individuals do differ, and in specific and definable
respects, has most serious consequences for social life.
It means, briefly, that while general inferences may be drawn
from wide and accurate observations of the workings of human
nature, these inferences remain general and tentative,
and if taken as rigid rules are sure to be misleading. Theories
of education and social reform certainly gain from the general
laws that can be formulated about original human traits,
fatigue, memory, learning capacity, and the like. But they
must, if they are to be applicable, take account also, in a
precise and systematic way, of the variety of men's interests and
capacities. To this fact of variety in the original nature of
different men social institutions and educational methods
must be adapted. Arbitrary rules that apply to human nature
in general do not apply to the specific cases and specific
types of talent and desires. Educational and social organizations
can mould these, but the result of these environmental
influences will vary with individual differences in original
capacities. We can waste an enormous amount of time and
energy trying to train a person without mechanical or mathematical
gifts to be an engineer. We not only save energy and
time, but promote happiness, if we can train individuals so
that their specific gifts will be capitalized at one hundred per
cent. They will be at once more useful to society and more
content with themselves, when they are using to the full their
own capacities. They will at once be unproductive and unhappy
when they find themselves in activities or social situations
where their genuine talents are given no opportunity
and where their defects put them at a conspicuous handicap.
Individuals differ, it must further be noted, not only in
specific traits, but in that complex of traits which is commonly
called "intelligence." In the broadest terms, we mean by an
individual's intelligence his competence and facility in dealing
with his environment, physical, social, and intellectual. This
competence and facility, in so far as it is a native endowment,
consists of a number of traits present in a more or less high
degree, traits, for example, such as curiosity, flexibility of
native and acquired reactions, sociability, sympathy, and the
like. In a sense an individual possesses not a single intelligence,
but many, as many as there are types of activity in
which he engages. But one may classify intelligence under
three heads, as does Thorndike:[1] mechanical intelligence,
involved in dealing with things; social intelligence, involved in
dealing with other persons; and abstract intelligence, involved
in dealing with the relations between ideas. Each of
these types of intelligence involves the presence in a high degree
of a group of different traits. Thus, in social intelligence,
a high degree of sympathy, sensitivity to praise and blame,
leadership, and the like, are more requisite than they are for
intelligent behavior in the realm of mechanical operations or
of mathematical theory. A person may be highly intelligent
in one of these three spheres and mentally helpless in the
others. Thus, a brilliant philosopher may be nonplused by a
stalled motor; a successful executive may be a babe in the
realm of abstract ideas. But what we rate as a person's general
intelligence is a kind of average struck between his various
competences, an estimate of his general ability to control
himself in the miscellaneous variety of situations of which
his experience consists.
[Footnote 1: "Measuring Intelligence," _Harper's Magazine_, March, 1920.]
There have been a number of tests devised for the purpose
of estimating an individual's general intelligence.[1] On a
rating scale such as is used in these examinations most
individuals will come up to a certain standard that may be
called average or normal. There will be a certain number so
far below the normal rating in a complex of traits that go to
produce intelligent (competent and facile) behavior that they
will have to be classed as subnormal, ranging from
feeblemindedness to idiocy. A certain number will be found so
extraordinarily gifted in general traits and in specific
abilities--in given subject-matters, as, for example, in
mathematics and music--that they will be marked out as geniuses.
Following the laws of probability, the greater the inferiority
or superiority, the more exceptional it will be.
[Footnote 1: These, in large part, deal with words and ideas and
are, therefore, weighted in favor of abstract intelligence, and
put at a discount individuals whose experience and whose intelligence
are predominantly social or mechanical in character. Some of the
tests are fairly adequate for mechanical intelligence, but no good
tests have been devised for social intelligence. These tests,
however, as used in the army and for appraising college entrants,
as at Columbia University, have been demonstrated to be fairly
good indices of general intelligence.]
Individual differences are, therefore, seen to be not simply
differences with respect to given mental traits, but differences
with respect to general mental capacity. Experimental
investigation points to a graded difference in mental capacity,
ranging from idiocy to genius, the largest group being normal
or average, the size of the group diminishing with further
deviation from the average in either direction.
Certain important correlations, furthermore, have been
found between the level of intelligence and the level of character.
The great in mind, it may be said briefly, are also great
in spirit. "General moral defect commonly involves intellectual
inferiority. Woods and Pearson find the correlation between
intellect and character to be about .5.... General
moral defect is due in part to a generally inferior nervous
organization."[1]
[Footnote 1: Thorndike: _Educational Psychology_ (1910), p. 224.]
One other important correlation must be noted. While
gifts and capacities are specific, superiority in a given trait
commonly involves superiority in most others. Exceptional
talent in one direction in most cases involves exceptionality
in many other respects. While talents are not indiscriminately
transferable from one field to another, the same complex
of traits which makes a person stand out preëminently in
a given field, say law, would make him stand out in any one of
half a dozen different fields into which he might have gone.
There seems to be no evidence that extraordinary capacity in
one direction is balanced by extraordinary incapacity and
stupidity in others. The fact that individuals differ not only
in specific traits but in general mental capacity has, also,
certain obvious practical consequences. It means that there are
present in society, in the light of recent tests in the army, an
unexpectedly large number of individuals below the level of
normal intelligence. One in five hundred, Thorndike estimates,
is the "frequency of intellectual ability so defective as
to disturb the home, resist school influence, and excite popular
derision." These are clearly liabilities in the social order.
On the other hand, there is a large number above the level of
average intelligence. The importance of this group for human
progress can hardly be overestimated. As we have seen
in other connections, progress is contingent upon variation
from the "normal" or the accustomed, and such variation
from the normal is initiated in the majority of cases by members
of this comparatively small super-normal group. If
civilization is to advance it must capitalize its intelligence;
that is, educate up to the highest point of native ability. But
in any case, its chief guarantee of progress lies in the
comparatively small group in whom native ability is exceptionally
high. For it is among this group that original thinking,
invention, and discovery almost exclusively occur.
CAUSES OF INDIVIDUAL DIFFERENCES. Among the chief causes
of individual differences may, in general, be set down the following:
(1) Sex, (2) Race, (3) Near Ancestry or Family,
(4) Environment. The particular fund of human nature
which an individual displays, that is, his specific native
endowments, as they appear in practice, will be a resultant of
these various causes. In the study of each of these characteristics,
we should be able ideally to eliminate all the others
and to consider them each in isolation.
THE INFLUENCE OF SEX. In the case of sex, for example, we
should not confuse individual differences due to the fact of sex
with individual differences due to divergent training given to
each of the sexes. In scientific experiments to determine sex
differences in mental traits, there have been careful attempts
to eliminate everything but the factor of sex itself. Thus in
Karl Pearson's studies of fifty twin brothers and sisters, the
factors of ancestry and difference of training and age were
practically eliminated.
In so far as allowance can be made for other contributing
factors, studies of individual differences due to sex have
revealed, roughly speaking, the following results. There have
been, in the field of sensory discrimination and accuracy of
motor response, slight--and negligible--differences of responses
made by male and female. The subjects stated were,
in most cases, selected so far as possible from the same social
strata, social and intellectual interest, and background.[1]
[Footnote 1: As, for example, the members of the graduating and junior
classes of the co-educational college at the University of Chicago,
studied by Dr. Thompson.]
Thorndike reports the general results of such tests as follows:
The percentages of males reaching or exceeding the median ability
of females in such traits as have been subjected to exact investigation
are roughly as follows:
In speed of naming colors and sorting cards by color and
discriminating colors as in a test for color blindness 24
In finding and checking small visual details such as letters 33
In spelling 33
In school "marks" in English 35
In school "marks" in foreign languages 40
In memorizing for immediate recall 42
In lowness of sensory thresholds 43
In retentiveness 47
In tests of speed and accuracy of association 48
In tests of general information 50
In school "marks" in mathematics 50
In school "marks" (total average) 50
In tests of discrimination (other than for color) 51
In range of sensitivity 52
In school "marks" in history 55
In tests of ingenuity 63
In accuracy of arm movements 66
In school "marks" in physics and chemistry 68
In reaction time 70
In speed of finger and arm movement 71
The most important characteristic of these differences is their
small amount. The individual differences within one sex so enormously
outweigh the differences between the sexes in these intellectual
and semi-intellectual traits that for practical purposes the sex
difference may be disregarded. So far as ability goes, there could
hardly be a stupider way to get two groups alike within each group
but differing between the groups than to take the two sexes. As is
well known, the experiments of the past generation in educating
women have shown their equal competence in school work of elementary,
secondary, and collegiate grade. The present generation's experience
is showing the same fact for professional education and business
service. The psychologists' measurements lead to the conclusion
that this equality of achievement comes from an equality of natural
gifts, not from an overstraining of the lesser talents of women.[1]
[Footnote 1: Thorndike: _Educational Psychology_, briefer course, pp. 345-46.]
That is, so far as experiments upon objectively measurable
traits have been conducted, the specific differences that
individuals display have comparatively nothing to do with the
fact that an individual happens to be a man or a woman.
These experiments have been conducted with boys and girls
as young as seven, and with men and women ranging up to the
age of twenty-five.[2]
[Footnote 2: There seems, as might be expected to be, a slightly
higher differentiation between the two sexes after adolescence
than before.]
These experiments have been conducted to test sensory
discrimination, precision of motor response and some of the
simpler types of judgment, such as those involved in the solution
of simple puzzles with blocks, matches, etc. The fact
of the negligibility of sex difference with regard to certain
minor measurable traits has been adequately demonstrated
by a wide variety of experiments. The fact of sex equality or
mental capacity has been less accurately but fairly universally
noted by popular consensus of observation and opinion of the
work of women in the various trades and professions. There
are differences between men and women in physical strength
and in consequent susceptibility to fatigue. These are
important considerations in qualifying the amount of work a
woman can do as compared with that of a man, and have
justly resulted in the regulation of hours for women, as a
special class. But there do not seem to be, on the average,
significant original differences in mental capacity.[3]
[Footnote 3: On this subject there has been collected a large
amount of accurate experimental data. See Goldmark: _Fatigue
and Efficiency_, part II, pp. 1-22. These refer to
physiological differences.]
There do exist, as a matter of practical fact, some of the
special attributes commonly ascribed to the masculine and
feminine mental life, but it is generally agreed by investigators
that these are to be accounted for by the different environment
and standards socially established for men and for
women. There are radical and subtle differences in training
to which boys and girls are subjected from early childhood.
There are deeply fixed traditions as to the standards of action,
feeling, and demeanor to which boys and girls are respectively
trained and to which they are expected to conform. If a boy
should not live up to this training and expectation, he may be
marked out as "effeminate." If a girl does not conform, she
is defined as a "hoyden" or a "tomboy."
These social distinctions, which are emphasized even in the
behavior of young boys and young girls, grow more pronounced
as individuals grow older. One need hardly call attention
to actions regarded as perfectly legitimate for men
which provoke disapproval if practiced by women. Rigid
training in these different codes of behavior may cause
acquired characteristics to seem inborn. But whether these
general features commonly held to distinguish the mental life
of man or woman are or are not intrinsic and original, they
have been marked out by certain investigators as socially
fundamental. Thus Heymans and Wiersma, two German
investigators, set down as the differentia of feminine mental
life (1) greater activity, (2) greater emotionality, (3) greater
unselfishness of the female.[1]
[Footnote 1: See Thorndike's _Educational Psychology_ (1910), p. 136.]
There are some general differences noted by both layman
and psychologist, which, though not subject to quantitative
determination, yet seem to differentiate somewhat definitely
between feminine and masculine mental activity. These
may be set down in general as occurring in the field of
emotional susceptibility. Thorndike traces them back to the
varying intensity of two human traits earlier discussed: the
fighting instinct, relatively much stronger in the male, and
the nursing or mothering instinct, much stronger in the
female. With this fact are associated important differences in
the conduct of men and women in social relations. The maternal
instinct is held by some writers, for instance, to be in
large measure the basis of altruism, and is closely associated
with sensitivity to the needs and desires of others. Thorndike
writes:
It has been common to talk of women's dependence. This is, I am
sure, only an awkward name for less resentment at mastery. The
actual nursing of the young seems likewise to involve equally
unreasoning tendencies to pet, coddle, and "do for" others. The
existence of these two instincts has been long recognized by
literature and common knowledge, but their importance in causing
differences in the general activities of the two sexes has not.
The fighting instinct is in fact the cause of a very large amount
of the world's intellectual endeavor. The financier does not
think merely for money, nor the scientist for truth, nor the
theologian to save souls. Their intellectual efforts are aimed in
great measure to outdo the other man, to subdue nature, to
conquer assent. The maternal instinct in its turn is the chief
source of woman's superiorities in the moral life. The virtues
in which she excels are not so much due to either any general
moral superiority or any set of special moral talents as to her
original impulses to relieve, comfort, and console.[1]
[Footnote 1: Thorndike: _loc. cit._, pp. 48-49.]
Ordinary observation reveals, as literature has in general
recorded, what Havelock Ellis has called the "greater affectability
of the female mind." There is evidenced in many
women a singular and immediate responsiveness to other
people's emotions, a quick intuition, a precise though non-logical
discrimination, which, though shared to some extent
by all individuals gifted with sympathy and affection, is a
peculiarly feminine quality. Indeed when a man possesses
it, it is common to speak of him as possessing "almost a
woman's intuition." Such emotional susceptibility is manifested
in the higher frequency of emotional instability and
emotional outbreaks among women than among men, and the
decreased power of inhibition which women have over
instinctive and emotional reactions. Further than this, women
more than men may be said to qualify their judgments of persons
and situations by their emotional reactions to them.
The common suspicion that in general women's abilities
are less than those of men has seemed to gain strength from
the greater number of geniuses and eminent persons there
have been among men than among women. Professor Cattell
writes in this connection:
I have spoken throughout of eminent men as we lack in English
words including both men and women, but as a matter of fact women
do not have an important place on the list. They have in all thirty-two
representatives in the thousand. Of these eleven are hereditary
sovereigns, and eight are eminent through misfortunes, beauty, or
other circumstances. Belles-lettres and fiction--the only department
in which woman has accomplished much--give ten names as
compared with seventy-two men. Sappho and Joan d'Arc are the
only other women on the list. It is noticeable that with the
exception of Sappho--a name associated with certain fine fragments--women
have not excelled in poetry or art. Yet these are the departments
least dependent on environment, and at the same time those
in which the environment has been perhaps as favorable to women
as to men. Women depart less from the normal than men--a fact
that usually holds for the female throughout the animal series; in
many closely related species only the male can be readily
distinguished.[1]
[Footnote 1: Cattell: "A Statistical Study of Eminent Men,"
_Popular Science Monthly_, vol. LXII. pp. 375-77.]
In the facts of higher variability among males, and the
hitherto restricted social opportunities provided for women
are to be found the chief reasons for the comparatively high
achievement of the male sex as compared with the female.
But on the average the difference between the two sexes with
respect to mental capacity is slight.
THE INFLUENCE OF RACE. A second factor in determining
individual differences in mental traits is race. There are
certain popular presuppositions as to the inherent differences in
the mental activity of different races. The Irishman's wit,
the negro's joyousness, the emotionality of the Latin races,
the stolidity of the Chinese, are all supposed to be fundamental.
And in a sense they are. That is, in the life and
culture of these groups, such traits may stand out distinctively.
But most psychologists and anthropologists question
seriously whether these traits are to be traced to radical differences
in racial inheritance. For the most part they seem
rather to be the result of radical differences in environment.
"Many of the mental similarities of an Indian to Indians and
of his differences from Anglo-Saxons disappear, if he happens
to be adopted and brought up as an Anglo-Saxon."[1]
[Footnote 1: Thorndike _loc. cit._, p. 52.]
There have been various experimental studies made to
determine how much divergences in the mental activity of
different races are determined by differences in racial
inheritance. Such experiments have been conducted chiefly
upon very simple traits and capacities. The accuracy of
sensory response among different races has, for example, been
examined. There have proved to be, in regard to these, slight
differences in the effectiveness and accuracy of response.
There are racial differences in hearing, as tested by the ticking
of a watch or clock artificially made. In this test, Papuans,
to take an instance, were inferior to Europeans. The sense
of touch has been similarly tested, and comparatively negligible
differences have been found. In regard to the five senses,
their efficiency seems to be about equal in all the races of
mankind. The proverbial keenness of vision of the Indian, for
example, is found to be due to a superior training in its use, a
training made imperative by the conditions of Indian life. In
reaction time tests--that is, tests in the speed of simple mental
and motor performances--the time consumed in response
has been found to be about the same for all races tested. The
results have been similar with regard to certain simple processes
of judgment or inference:
There are a number of illusions and constant errors of judgment
which are well known in the psychological laboratory, and which
seem to depend, not on peculiarities of the sense organs, but on
quirks and twists in the process of judgment. A few of these have
been made the matter of comparative tests, with the result that
peoples of widely different cultures are subject to the same errors,
and in about the same degree. There is an illusion which occurs
when an object, which looks heavier than it is, is lifted by the hand;
it then feels, not only lighter than it looks, but even lighter than it
really is. The contrast between the look and the feel of the thing
plays havoc with the judgment. Women are, on the average, more
subject to this illusion than men. The amount of this illusion has
been measured in several peoples, and found to be, with one or two
exceptions, about the same in all. Certain visual illusions, in which
the apparent length or direction of a line is greatly altered by the
neighborhood of other lines, have similarly been found present in all
races tested, and to about the same degree. As far as they go, these
results tend to show that simple sorts of judgment, being subject
to the same disturbances, proceed in the same manner among various
peoples; so that the similarity of the races in mental processes
extends at least one step beyond sensation.[1]
[Footnote 1: Woodworth: "Racial Differences in Mental Traits,"
_Science_, New Series, vol. 31, pp. 179-81.]
Professor Woodworth also points out that these simple
tests are not adequate to measure general intelligence.
A good test for intelligence would be much appreciated by the
comparative psychologist, since, in spite of equal standing in such
rudimentary matters as the senses and bodily movement, attention
and the simpler sorts of judgment, it might still be that great
differences in mental efficiency existed between different groups of men.
Probably no single test could do justice to so complex a trait as
intelligence. Two important features of intelligent action are
quickness in seizing the key to a novel situation, and firmness in limiting
activity to the right direction, and suppressing acts which are
obviously useless for the purpose in hand. A simple test which calls for
these qualities is the so-called "form test." There are a number of
blocks of different shapes, and a board with holes to match the
blocks. The blocks and board are placed before a person, and he is
told to put the blocks in the holes in the shortest possible time. The
key to the situation is here the matching of blocks and holes by their
shape; and the part of intelligence is to hold firmly to this obvious
necessity, wasting no time in trying to force a round block into a
square hole. The demand on intelligence certainly seems slight
enough; and the test would probably not differentiate between a
Newton and you or me; but it does suffice to catch the feeble-minded,
the young child, or the chimpanzee, as any of these is likely to fail
altogether, or at least to waste much time in random moves and
vain efforts. This test was tried on representatives of several races
and considerable differences appeared. As between whites, Indians,
Eskimos, Ainus, Filipinos, and Singhalese, the average differences
were small, and much overlapping occurred. As between these
groups, however, and the Igorot and Negrito from the Philippines
and a few reputed Pygmies from the Congo, the average differences
were great, and the overlapping small.[1]
[Footnote 1: Woodworth: _loc. cit._, pp. 171-86.]
Equality among races in the various traits that have been
measured by psychologists does not imply that common
observation is wrong in counting one race as intellectually
superior to another. There have, as yet, been no measurements
of such general features of social life as energy, self-reliance,
inventiveness, and the like. But from indications of
experiments already made, these so-called (and for practical
purposes genuine) intellectual differences between the
individuals of different races must be attributed to differences in
environment. Races _as_ races seem to be equally gifted.
Professor Boas points out that civilized investigators traveling
among savage tribes commit one serious fallacy in insisting
on the inferiority of these primitive peoples. They
are said to be irrational, for example, when they are quite
logical in their way of dealing with the material which is at
their disposal. Without any scientific information available,
for example, anthropomorphism, or the tendency to interpret
cosmic phenomena in human terms is quite natural and reasonable.
Again:
The difference in the mode of thought of primitive man and that
of civilized man seems to consist largely in the difference of character
of the traditional material with which the new perception associates
itself. The instruction given to the child of primitive man is not
based on centuries of experimentation, but consists of the crude
experience of generations. When a new experience enters the mind of
primitive man, the same process which we observe among civilized
man brings about an entirely different series of associations, and
therefore results in a different type of explanation. A sudden
explosion will associate itself in his mind, perhaps, with the tales he has
heard in regard to the mythical history of the world, and consequently
will be accompanied by superstitious fear. When we recognize
that neither among civilized men nor among primitive men the
average individual carries to completion the attempt at causal
explanation of phenomena, but carries it only so far as to amalgamate
it with other previously known facts, we recognize that the
result of the whole process depends entirely upon the character of
the traditional material.[1]
[Footnote 1: Boas: _Mind of Primitive Man_, pp. 203-04.]
This may be illustrated by our immediate reactions of pleasure
or disgust at customs or ideas that provoke directly opposite
reactions among races reared in another tradition.
Again primitive races have been accused of lacking self-control.
The fact is that they exhibit self-control about
matters which they regard as important, and lack of it in
respect to matters which they regard as trivial. "When an
Eskimo community is on the point of starvation, and their
religious proscriptions forbid them to make use of the seals
that are basking on the ice, the amount of self-control of the
whole community which restrains them from killing those
seals is certainly very great."[2] The case is similar with
regard to nearly all the alleged inferiorities of primitive man, his
improvidence, unreliability, and the like. In nearly every
instance, it has been found that we are holding him to account
for not being able to persist in courses of action which do not
seem to him, with his training and education, worth persisting
in, and for not conforming to standards which, given his
background, are meaningless.
[Footnote 2: _Ibid_. p. 108.]
But if differences in racial attainments are due to differences
in environment, it might be said that this itself is testimony
to the superiority of the race that has the more complex
and exacting environment. This is not by any means clearly
the case. The "culture" or civilization which a race exhibits
is a very uncertain index of its gifts or its capacities. The
culture found in a race is, it may be said without exaggeration,
largely a matter of accident or circumstance rather than
of heredity.
Some of the environmental causes for differences in culture
may he explicitly noted. Any modern culture is the result
of interminglings of many different cross-streams and cross-borrowings.
Races that have long been isolated as, for example
the African negroes, have no possibility of picking up
all the acquisitions to which races that intermingle have
access. Progress in the developments of arts, sciences, and
institutions depends on fortunate individual variations. The
smaller the race the less the number of variations possible,
including those on the side of what we call genius. Again
fortunate variations depend not so much on the general average
intellectual capacities of the race as on its variability.
So one race may possess a relative superiority of achievement
because of its high variability, just as, as we have already
pointed out, the greater preëminence of the male sex with
regard to intellectual accomplishment is due to the greater
number of variations both above and below the norm which
it displays. The reasons for variability are again, according
to Professor Boas, largely environmental. "We have seen,
when a people is descended from a small uniform group, that
then its variability will decrease; while on the other hand,
when a group has a much-varied origin or when the ancestors
belong to entirely distinct types the variability may be
considerably increased."[1]
[Footnote 1: Boas; _loc. cit._, p. 93.]
Again a race may be placed in such geographical conditions
that a fortuitous variation on the part of one individual may
prove of enormous value in the development of its civilization.
Or fortunate geographical conditions may stimulate
types of activity that lie dormant, although possible, among
other races. Thus by some investigators the flexibility and
emancipation of the Greek genius were attributed to their
access to the sea and their constant intermingling with other
cultures, especially the Egyptian.
On the subject of the fundamental equality of races despite
their seeming disparity, as that at present, let us say, between
whites and negroes, Professor Boas writes:
Much has been said of the hereditary characteristics of the Jews,
of the Gypsies, of the French and Irish, but I do not see that the
external and social causes which have moulded the character of
members of these people have ever been eliminated satisfactorily;
and, moreover, I do not see how this can be accomplished. A number
of external factors that influence body and mind may easily be
named--climate, nutrition, occupation--but as soon as we enter
into a consideration of social factors and mental conditions we are
unable to tell definitely what is cause and what is effect.
* * * * *
The conclusions reached are therefore, on the whole, negative. We
are not inclined to consider the mental organization of different races
of man as differing in fundamental points. Although, therefore, the
distribution of faculty among the races of man is far from being
known, we can say this much: the average faculty of the white race
is found to the same degree in a large proportion of individuals
of all other races, and although it is probable that some of these
races may not produce as large a proportion of great men as our own
race, there is no reason to suppose that they are unable to
reach the level of civilization represented by the bulk of our own
people.[1]
[Footnote 1: Boas; _loc. cit._, pp. 116, 123.]
In contrast must be cited the opinions of a large class of
psychologists and anthropologists who are inclined to regard
racial differences as intrinsic and original. Of such, for example,
is Francis Galton, who claims in his _Hereditary Genius_,
that taking negroes on their own ground they still are inferior
to Europeans by about one eighth the difference, say, between
Aristotle and the lowest idiot. Recent psychological
experiments in the army reveal, again, certain fundamental
intellectual inferiorities of negroes, though whether this is
environmental or to be traced to hereditary causes is open to
question.
The fact remains that there are, despite the lack of evidence
for hereditary mental differences, practical differences in the
mental activity of different races that are of social importance.
These differences, which seem so fundamental, have been
explained primarily by the powerful control exercised over the
individual by the habits which he acquires even before the
age of five years. These, though unconscious, may be, as the
Freudian psychologists maintain, all the more important for
that reason. This would appear to be the only explanation of
significant racial differences. Cultural differences cannot,
biologists are generally agreed, be transmitted in the germs
that pass from generation to generation. One may say, in
effect, that an individual is differentiated in his mental traits
by early association with a certain race, and by his immediate
ancestry or family, rather than by the fact of belonging
physically to a certain race.
THE INFLUENCE OF IMMEDIATE ANCESTRY OR FAMILY. A factor
that is, on experimental evidence, rated to be of high importance
in the determination of the differences of the mental
make-up of human beings, is "immediate ancestry" or family.
Stated in the most simple and general terms this means
that children of the same parents tend to display marked
likenesses in mental traits, and to exhibit less variation among
themselves than is exhibited in the same number of individuals
chosen at random. A great number of experiments have
been conducted to determine how far resemblances in mental
traits are due to common parentage. The correlation between
membership in the same family and resemblances of
social traits has been found to be uniformly high.
The inference was made that children of the same family
would show great resemblances in mental traits, when accurate
experiments showed marked similarity in physical traits
under the same conditions. The coefficient of correlation
between brothers in the color of the eye, is, according to the
results obtained by Karl Pearson, .52.[1] The coefficient of
fraternal correlation in the case of the cephalic index (ratio
of width to length of head) is .40. The correlation of hair
color is found to be .55. The fact of high correlation between
resemblance of physical traits and membership in the
same family is of crucial importance, because these traits
are clearly due to ancestry, and not to environmental
differences. If physical traits show such a correlation, it is likely
that mental traits will also, mental traits being ultimately
dependent on the brain and the nervous system, which are both
affected by ancestry.
[Footnote 1: These facts are based on the reports of Karl Pearson
in his _On the Laws of Inheritance in Man_. What is meant by
coefficient of correlation may be explained as follows: If the
coefficient of correlation between father and son is .3 and the
coefficient of correlation between brother and brother is .5 we
may say: a son on the average deviates from the general trend of
the population by .3 of the amount of his father's deviation, a
brother by .5 of the amount of his brother.]
Measurements of measurable traits and observations of less
objectively measurable ones, have revealed that immediate
ancestry is in itself an influential factor in producing likenesses
and differences among men with respect to mental traits.
One interesting case, interesting because it was a test of a
capacity that might be expected to be largely environmental
in its origins, was that of the spelling abilities of children in
the St. Xavier School in New York. Thorndike thus reports the test:
As the children of this school commonly enter at a very early age,
and as the staff and the methods of teaching remain very constant,
we have in the case of the 180 brothers and sisters included in the 600
children closely similar school training. Mr. Earle measured the
ability of any individual by his deviation from the average for his
grade and sex, and found the co-efficient of correlation between
children of the same family to be .50. That is, any individual is on the
average fifty per cent as much above or below the average for his age
and sex as his brother or sister.
Similarities in home training might theoretically account for this,
but any one experienced in teaching will hesitate to attribute much
efficacy to such similarities. Bad spellers remain bad spellers though
their teachers change. Moreover, Dr. J. M. Rice in his exhaustive
study of spelling ability found little or no relationship between good
spelling and any one of the popular methods, and little or none
between poor spelling and foreign parentage. Yet the training of a
home where parents do not read or spell the language well must be a
home of relatively poor training for spelling. Cornman's more careful
study of spelling supports the view that ability to spell is little
influenced by such differences in school or home training as commonly
exist.[1]
[Footnote 1: Thorndike: _loc. cit._, p. 78.]
In general the influence of heredity may be said far to outweigh
the influence of home training. In all the cases
reported, the resemblances were about the same in traits subject
to training, and in those not subject to training. Thus industry
and conscientiousness and public spirit, which are clearly
affected by environment, show no greater resemblance than
such practically unmodifiable traits as memory, original
sensitiveness to colors, sounds, and distances.
The influence of parentage, it must be added, consists in the
transmission of specific traits, not of a certain "nature" as a
whole. There are in the germ and the ovum which constitute
the inheritance of each individual, certain determinant elements.
The elements that determine the original traits with
which each individual will be born vary, of course, in the
germs produced by a single parent less than among individuals
chosen at random, but they vary none the less. In this
variation of the determining elements in the germs of the
same individual is to be found the cause of the variation in
the physical and mental traits among children of the same
parents.
Since the determining elements, the unit characters that
appear in the sperm or ovum of each individual, do not appear
uniformly even in children of the same parents, brother
and sister may resemble each other in certain mental traits,
and differ in others. "A pair of twins may be indistinguishable
in eye color and stature, but be notably different in hair
color and tests of intellect."
Mental inheritance, as well as physical, is, then, organized
in detail. It is not the inheritance of gross total natures, but
of particular "mental traits." If we had sufficient data, we
should be able to analyze out the unit characters of an
individual's mental equipment, so as to be able to predict with
some accuracy the mental inheritance of the children of any
two parents. In the case of physical inheritance, the laws of
the hereditary transmission of any given traits are known in
considerable detail. The detailed quantitative investigations
of inheritance, following the general lines set by Mendel, have
given striking results.
Physical traits have been found to be analyzable into unit-characters
(that is, traits hereditarily transmitted as units),
such as "curliness of hair," "blue eyes," and the like. Mental
traits, however, do not seem analyzable into the fixed
unit-characters prescribed by the Mendelian laws of inheritance.
The success which breeders have had in the control of the
reproduction of plants and animals, in the perpetuation of a
stock of desirable characteristics and the elimination of the
undesirable, has given rise to a somewhat analogous ideal in
human reproduction. That eugenics has at least its theoretical
possibilities with regard to physical traits, few biologists
will question. However difficult it may be in practice
to regulate human matings on the exclusive basis of the kind
of offspring desired, it is a genuine biological possibility. In a
negative way, it has already in part been initiated in the
prevention of the marriage of some extreme types of the physically
unfit, by the so-called eugenic marriage laws in some
states in this country.[1]
[Footnote 1: There have been laws, as there is a fairly decided
public opinion, adverse to reproduction by the feeble-minded and
the morally defective. But (see Richardson: _The Etiology of
Arrested Mental Development_, p. 9) there have been a number
of cases of feeble-minded parents producing normal children.]
But whether scientific regulation of marriages for the
production of eugenic offspring is feasible, even apart from the
personal and emotional questions involved, is open to question.
No mental trait such as vivacity, musical ability,
mathematical talent, or artistic sense, has been analyzed into
such definitely transmissible unit-characters as "blue eyes"
and "curliness of hair." So many unit-characters seem to be
involved in any single mental trait that it will be long before
a complete analysis of the hereditary invariable determinants
of any single trait can be made.
It is thus impossible to tell as yet with any security or precision
the biological components of any single mental trait.
The evidence at our disposal, however, does confirm us in the
belief that one of the most significant and certain causes of
individual differences, whether physical or mental, is immediate
ancestry or family. Individuals are made by what they
are initially, and, as we shall presently see, therefore largely
by their inheritance. With the latter, environment can do
just so much, and no more. And the most significant and
effective part of an individual's inheritance is his family for
some generations back, rather than the race to which he belongs.
THE INFLUENCE OF THE ENVIRONMENT. Those factors so far
discussed which determine individual differences are independent
of the particular conditions of life in which an individual
happens to be placed. An individual's race, sex, family
are beyond modification by anything that happens to him
after birth. Maturity, in so far as it is mere growth independent
of training, is also largely a fixed and unmodifiable
condition.
The original nature, determined by race, sex, and immediate
ancestry, with which a man starts life is subject to modification
by his social environment, by the ideas, customs, companions,
beliefs, by which he is surrounded, and with which
he comes continuously in contact. Commonly the influence
of environment is held to be very high. It is difficult, however,
accurately to distinguish between effects which are due
to original nature and effects which are due to environment.
Differences in training are important, but the results vary
with the natures trained. Precisely the same environment
will not have the same consequences for two different natures.
Two approximately same natures will show something like
the same effects in dissimilar environments. Human beings
are certainly differentiated by the customs, laws, ideals,
friends, and occupations to which they are exposed. But
what the net result will be in a specific case, depends on the
individual's equipment to start with, an equipment that is
fixed before the environment has had a chance to act at all.
The kindliness and indulgence that save some children
demoralize others. In some people a soft answer turneth away
wrath; in others it will kindle it. Andrew Carnegie starts as a
bobbin boy, and becomes a millionaire; but there were many
other bobbin boys. The sunset that stirs in one man a lyric,
leaves another cold. The same course in biology arouses in
one student a passion for a life of science; it leaves another
hoping never to see a microscope again. On the other hand,
the same types of original capacity thrown into different
environments will yet attain somewhat comparable results, in
the way of character and achievement. The biographies of
a few poets, painters, philosophers, and scientists chosen at
random, show the most diverse antecedents.[1]
[Footnote 1: Taking the social and professional status of a
distinguished man's father as some index of the social environment
to which he was subjected during his youth, we find some
interesting examples: The father of John Keats was a livery
stable-keep; his mother the daughter of one. Byron's father
was a captain in the Royal Guards; his mother a Scottish heiress.
Newton's father was a tanner; Pasteur's, a tanner; Darwin's, a
doctor of considerable means. Francis Bacon's father was Lord
Keeper of the Great Seal; Newton's was a farmer and the headmaster
of a school; Turner was the son of a barber.]
An individual, again, to a certain extent, makes his own
environment. What kind of an environment he will make
depends on the kinds of capacities and interests he has to
start with. Similarity of original tendencies and interests
brings men together as differences among these keep them
apart. The libraries, the theaters, and the baseball parks
are all equally possible and accessible features of their
environment to individuals of a given economic or social class.
Yet a hundred individuals with the same education and
social opportunities will make themselves by choice a hundred
different environments. They will select, even from
the same physical environment, different aspects. The
Grand Cañon is a different environment to the artist and to
the geologist; a crowd of people at an amusement park
constitutes a different environment to the man who has come
out to make psychological observations, and the man who
has come out for a day's fun. A dozen men, teachers and
students, selected at random on a university campus, might
well be expected to note largely different though overlapping
facts, as the most significant features of the life of the
university.
The environment is the less important in the moulding of
character, the less fixed and unavoidable it becomes. If an
individual has the chance to change his environment to suit
his own original demands and interests, these are the less
likely to undergo modification. This is illustrated in the animal
world by the migratory birds, which change their habitations
with the seasons. Similarly human beings, to suit the
original mental traits with which they are endowed, can and
do exchange one environment for another. There are a very
large number of individuals living in New York City, in the
twentieth century, for example, for whom a multiplicity of
environments are possible. The one that becomes habitual
with an individual is a matter of his own free choice. That is,
it is choice, in the sense that it is independent of the
circumstances of the individual's life. But an individual's choice of
his environment must be within the limited number of alternatives
made possible by the original nature with which he
is endowed. As pointed out in connection with our discussion
of "Instinctive Behavior," we do originally what gives
satisfaction to our native impulses, and avoid what irritates
and frustrates them. We may be trained to find satisfactions
in acquired activities, but there is a strong tendency to
acquire habits that "chime in," as it were, with the tendencies
we have to start with.
There is, for example, to certain individuals, intrinsic
satisfaction in form and color; to others in sound. To the
former, pictures and paintings will tend to be the environment
selected; to the latter the hearing and the playing of
music. To those gifted with sensitivity in neither of these
directions, pictures may be through all their lives a bore, and
a piano a positive nuisance.
These facts of original nature, therefore, determine initially,
and consequently in large part, what our environment is
going to be. Once we get into, or select through instinctive
desires, a certain kind of environment, those desires become
strengthened through habit, and that environment becomes
fixed through fulfilling those habitual desires. A man may,
in the first place, choose artists or scholars as companions
because his own gifts and interests are similar. But such an
environment will become the more indispensable for him
when it has the reinforcement of habit to confirm what is
already initially strong in him by birth. "To him who hath
shall be given" is most distinctly true of the opportunities and
environment open to those with native gifts to begin with.
Original nature thus sets the scope and the limits of an
individual's character and achievement. It tells "how
much" and, in the most general way, "what" his capacities
are. Thus a man born with a normal vocal apparatus can
speak; a man born with normal vision can see. But what
language he shall speak, and what sights he shall see, depend
on the social and geographical situation in which he happens
to be placed. Again, if a man is born with a "high general
intelligence," that is, with keen sensory discriminations and
motor responses, precise and accurate powers of analysis of
judgment, a capacity for the quick and effective acquisition
and modification of habits, we can safely predict that he will
excel in some direction. But whether he will stand out as a
lawyer, doctor, philosopher, poet, or executive, it is almost
impossible from original nature to tell.[1]
[Footnote 1: The psychological tests used in the army, and being
used now with modifications in the admission of students to
Columbia College, are "general intelligence" tests. That is, they
show general alertness and intellectual promise, but are not
prophetic of any specialized talents or capacities.]
INDIVIDUAL DIFFERENCES--DEMOCRACY AND EDUCATION. The
fact that individuals differ in ability and interest has important
consequences for education and social progress. It
means, in the first place, that while current optimistic
doctrines about the modifiability of human nature are true, they
are true within limits--limits that vary with the individual.
Whether or not we shall ever succeed, through the science or
the practice of eugenics, in eliminating low ability and
perpetuating high exclusively, the fact remains that there are in
contemporary society the widest variations both in the kinds
of interest and ability displayed, and in their relative efficacy
under present social and industrial conditions.
There are, it must be noted at the outset, a not inconsiderable
number of individuals who must be set down as absolute
social liabilities. Even if existing social and educational
arrangements were perfect, these would remain unaffected
and unavailable for any useful purpose. They would have to
be endowed, cared for, or confined. There is the quite
considerable class, who, while normal with respect to sensory and
motor discrimination, seem to be seriously and irremediably
defective in their powers of judgment. These also seem to
offer invulnerable resistance to education, and their original
natures would not be subject to modification even by an
education perfectly adapted to the needs of normal people.
But the more significant fact, more significant because it
affects so many, is the fact that within the ranks of the great
class of normal people, there are fundamental inherited differences
in ability and interest. Next in importance to the fact
that an individual is human is the fact that he is an individual,
with very specific initial capacities and desires. For education
the implications are serious. Education aims, among
other things, to give the individual habits that will enable
him to deal most effectively with his environment. But an
individual can be trained best, it goes without saying, in the
capacities and interests he has to begin with. Education cannot,
therefore, be wholesale in its methods. It must be so adjusted
as to utilize and make the most of the multifarious
variety of native abilities and interests which individuals
display. If it does not utilize these, and instead sets up
arbitrary moulds to which individuals must conform, it will be
crushing and distorting the specific native activities which
are the only raw material it has to work upon.
There have not as yet been many detailed quantitative
studies of individual differences that would enable educators,
if they were free to do so, scientifically to adapt education to
specific needs and possibilities. Beginnings in this direction
are being made, though rather in advanced than in more
elementary education. Professional and trade schools, and
group-electives in college courses are attempts in this direction.
Any attempt, of course, to adapt education to specific
needs and interests, instead of crushing them into _a priori_
moulds, requires, of course, a wider social recognition and
support of education than is at present common. For individual
differences require attention. And where millions are
to be educated, individual attention requires an immense
investment in teaching personnel.
But in this utilization of original interests and capacities
lies the only possibility of genuinely effective education.[1]
In the first place to try in education to give individuals habits
for which they have no special innate tendencies to begin with,
is costly. Secondly, to train individuals for types of life or
work for which their gifts and desires are ill adapted is to
promote at once inefficiency and unhappiness. One reason
why the chance to identify one's life with one's work (as is the
case with the artist and the scholar) is so universally recognized
as good fortune, is because it is so rare. A general and
indiscriminate training of men, as if they were all fitted with
the same talents and the same longings, does as much as
underpayment or overwork to impair the quality of the work
done and the satisfaction derived from it.
[Footnote 1: A beginning in the application of this principle has
been made by the vocational guidance and employment management work
which is being done with increasing scientific accuracy throughout
the United States. Individual differences and interests are studied
with a view to putting "the right man in the right place." This
slogan is borrowed from the Committee on Classification and Personnel,
which during the Great War, through its trade tests and other
machinery of differentiation, utilized for the national welfare
the specific abilities of thousands of drafted men.]
It has latterly been recognized that industry offers the
crucial opportunity to utilize to the fullest individual differences.
By "getting the right man in the right place," we at
once get the work done better and make the man better satisfied.
If adequate attention is given to "placement," to the
specific demands put upon men by specific types of work, and
to the specific capacities of individuals for fulfilling those
demands, we will be capitalizing variations among men instead
of being handicapped by them. As it is, specific differences
do exist, and men enter occupations and professions ignoring
them. As a result both the job and the man suffer; the
former is done poorly, and the latter is unsuccessful and unhappy.
It must be noted that the existence of specific differences
between individuals does not altogether, or often even in part,
imply superiority or inferiority. It implies in each case
inferiority or superiority with respect to the performance of a
particular type of work. Whether scientific insight and
accuracy is better than musical skill, whether a gift for
salesmanship surpasses a gift for mathematics, depends on the
social situation and the standards that happen to be current
among the group. An intensely disagreeable person may be
the best man for a particular job. All scientific observation
can do is to note individual differences, to note what work
makes demands upon what capacities, and try to bring the
man and the job together.
It must be emphasized that, while individual capacities
determine what an individual can do, social ideals and
traditions determine what he will do, because they determine what
he will be rewarded and encouraged to do. There is no
question but that in our industrial civilization certain types
of ability, that of the organizer, for example, have a high
social value. There is no question but that there are other
abilities, which under our present customs and ideals we
reward possibly beyond their merit, as, to take an extreme
case, that of a championship prize fighter. We can through
education and vocational guidance utilize all native capacities.
To make provision for the utilization of all native
capacities is to have an efficient social life. But to what end
our efficient human machinery shall be used depends on the
ideals and customs and purposes that happen to be current in
the social order at any given time.
In the words of Professor Thorndike, "we can invest in
profitable enterprises the capital nature provides." But
what profiteth a man or a society, is a matter for reflective
determination; it is not settled for us, as are our limitations,
at birth.
The net result of scientific observation in this field is the
discovery, in increasingly precise and specific form, that men
are most diverse and unequal in interest and capacity. The
ideal of equality comes to mean, under scientific analysis,
equality of opportunity, leveling all social inequalities; the
fact of natural inequalities and divergences remains incontestable.
There may even be, as recent psychological tests seem to
indicate, a certain proportion of individuals who are not
competent to take an intelligent part in democratic government,
who, having too little intellectual ability to follow the
simplest problem needing coöperative and collective decision,
must eternally be governed by others. If these facts come to
be authenticated by further data, it merely emphasizes the
fact that in a country professedly democratic it is essential
to devise an education that will, in the case of each individual,
educate up to the highest point of native ability.
Where a country is ostensibly democratic, a few informed
citizens will govern the many uninformed, unless the latter
are educated to an intelligent knowledge and appreciation of
their political duties and obligations. Furthermore, the citizens
of a community who are prevented from using their native
gifts will be both useless and unhappy. Certainly this is
an undesirable condition in a society where all individuals are
expected, so far as possible, to be ends in themselves and not
merely means for the ends of others.