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.