I
The mind is a very wonderful thing, but it is questionable whether it
is more wonderful than some of the instinctive modes of behavior of
lower forms of life. If mind is viewed as an adjustment to external
conditions for the purpose of securing control, the human mind is no
more wonderful in its way than the homing and migratory instincts of
birds; the tropic quality of the male butterfly which leads it to the
female though she is imprisoned in a cigar-box in a dark room; or the
peculiar sensitivity of the bat which enables it, though blinded, to
thread its way through a maze of obstructions hung about a room.
The fact of sensitivity, in short, or the quality of response to
stimulation, is more wonderful than its particular formulation in
the human brain. Mind simply represents a special development of the
quality of sensitivity common to organic nature, and analogous to the
sensitivity of the photographic plate. The brain receives impressions,
records them, remembers them, compares new experiences with old, and
modifies behavior, in the presence of a new or recurrent stimulation,
in view of the pleasure-pain connotation of similar situations in the
past.
In very low forms of life, as is well known, there is no development
of brain or special organs of sense; but the organism is pushed and
pulled about by light, heat, gravity, and acid and other chemical
forces, and is unable to decline to act on any stimulus reaching it.
It reacts in certain characteristic, habitual, and adequate ways,
because it responds uniformly to the same stimulation; but it has
no choice, and is controlled by the environment. The object of brain
development is to reverse these conditions and control the actions of
the organism, and of the outside world as well, from within. With the
development of the special organs of sense, memory, and consequent
ability to compare present experiences with past, with inhibition
or the ability to decline to act on a stimulus, and, finally, with
abstraction or the power of separating general from particular
aspects, we have a condition where the organism sits still, as it
were, and picks and chooses its reactions to the outer world; and, by
working in certain lines to the exclusion of others, it gains in its
turn control of the environment, and begins to reshape it.
All the higher animals possess in some degree the powers of memory,
judgment, and choice; but in man nature followed the plan of
developing enormously the memory, on which depend abstraction, or
the power of general ideas, and the reason. In order to secure this
result, the brain, or surface for recording experience, was developed
out of all proportion with the body. In the average European the brain
weighs about 1,360 grams, or 3 per cent. of the body weight, while
the average brain weight of some of the great anthropoid apes is only
about 360 grams, or, in the orangoutang, one-half of 1 per cent. of
the body weight. In point of fact, nature seems to have reached the
limit of her materials in creating the human species. The development
of hands freed from locomotion and a brain out of proportion to bodily
weight are _tours de force_, and, so to speak, an afterthought, which
put the heaviest strain possible on the materials employed, and even
diverted some organs from their original design. A number of ailments
like hernia, appendicitis, and uterine displacement, are due to the
fact that the erect posture assumed when the hands were diverted from
locomotion to prehensile uses put a strain not originally contemplated
on certain tissues and organs. Similarly, the proportion of idiocy and
insanity in the human species shows that nature had reached the limit
of elasticity in her materials and began to take great risks. The
brain is a delicate and elaborate organ on the structural side, and
in these cases it is not put together properly, or it gets hopelessly
out of order. This strain on the materials is evident in all races
and in both sexes, and indicates that the same general structural
ground-pattern has been followed in all members of the species.
Viewed from the standpoint of brain weight, all races are, broadly
speaking, in the same class. For while the relatively small series of
brains from the black race examined by anthropologists shows a slight
inferiority in weight--about 45 grams in negroes--when compared
with white brains, the yellow race shows more than a corresponding
superiority to the white; in the Chinese about 70 grams. There is
also apparently no superiority in brain weight in modern over ancient
times. The cranial capacity of Europeans between the eleventh and
eighteenth centuries, as shown by the cemeteries of Paris, is not
appreciably different from that of Frenchmen of today, and the
Egyptian mummies show larger cranial capacity than the modern
Egyptians. Furthermore, the limits of variation between individuals in
the same race are wider than the average difference between races.
In a series of 500 white brains, the lowest and highest brains will
differ, in fact, as much as 650 grams in weight.
There is also no ground for the assumption that the brain of woman
is inferior to that of man; for, while the average brain of woman is
smaller, the average body weight is also smaller, and it is open
to question whether the average brain weight of woman is smaller in
proportion to body weight.[257] The importance of brain weight in
relation to intelligence, moreover, has usually been much exaggerated
by anthropologists; for intelligence depends on the rapidity and range
of the acts of associative memory, and this in turn on the complexity
of the neural processes. Brains are, in fact, like timepieces in this
respect, that the small ones work "excellent well" if they are good
material and well put together. Although brains occasionally run above
2,000 grams in weight (that of the Russian novelist Turgenieff weighed
2,012), the brains of many eminent men are not distinguished for their
great size. That of the French statesman Gambetta weighed only 1,160
grams. It must be borne in mind also that there are many individuals
among the lower races and among women having brain weight much in
excess of that of that of the average male white.
Of all the possible ways of treating the brain for the purpose of
testing its intelligence, that of weighing is the least satisfactory,
and has been most indefatigably practiced. A better method, that of
counting the nerve cells, has been lately introduced, but to treat a
single brain in this way is a work of years, and no series of results
exists. In the meantime Miss Thompson, in co-operation with Professor
Angell, has completed a study of the mental traits of men and women
on what is perhaps the best available principle--that of a series
of laboratory tests which eliminate or take into consideration
differences due to the characteristic habits of the two sexes. Her
findings are probably the most important contribution in this field,
and her general conclusion on differences of sex will, I think, hold
also for differences of race:
The point to be emphasized as the outcome of this study
is that, according to our present light, the psychological
differences of sex seem to be largely due, not to difference
of average capacity, nor to difference in type of mental
activity, but to differences in the social influences brought
to bear on the developing individual from early infancy to
adult years. The question of the future development of the
intellectual life of women is one of social necessities and
ideals rather than of the inborn psychological characteristics
of sex.[258]
There is certainly great difference in the mental ability of
individuals, and there are probably less marked differences in the
average ability of different races; but difference in natural ability
is, in the main, a characteristic of the individual, not of race or
of sex. It is probable that brain efficiency (speaking from the
biological standpoint) has been, on the average, approximately the
same in all races and in both sexes since nature first made up a good
working-model, and that differences in intellectual expression are
mainly social rather than biological, dependent on the fact that
different stages of culture present different experiences to the
mind, and adventitious circumstances direct the attention to different
fields of interest.