The actual evidence that has been gathered on this question is still uncertain and fragmentary. While it does not yet establish anything definitely, it points to rather surprising conclusions. In all cases investigated the discovered differences in variability have been very slight, and if they balance either way tend to prove a greater variability among women. Neither sex need have a monopoly of either imbeciles or geniuses, but women may yet be found to be slightly more favored with both!
The first painstaking investigation in this field was made by Dr. Karl Pearson who published his interesting results as one essay in his Chances of Death and Other Studies in Evolution in 1897. Under the heading “Variation in Man and Woman” (Vol. I, pp. 256-377), written as a polemical attack upon Havelock Ellis’s stand in this theory, he set forth results of measurements upon men and women in seventeen anatomical characteristics. He obtained his data from statistics already collected, from measurements of living men and women, and from post-mortem and archeological examinations. Female variability (coefficients of variation) proved greater in eleven of these seventeen characteristics, male in six. He concluded among other things that “there is ... no evidence of greater male variability, but rather of a slightly greater female variability. Accordingly the principle that man is more variable than woman must be put on one side as a pseudo-scientific superstition until it has been demonstrated in a more scientific manner than has hitherto been attempted.”
To round out this evidence Doctors Leta Hollingworth and Helen Montague measured 20,000 infants at their birth in the maternity wards of the New York Infirmary for Women and Children. They sought to discover whether environmental influences played any determining rôle in producing the results obtained by Pearson from measurements upon adults. From the ten anatomical measurements made upon these babies they found that “in all cases the differences in variability are very slight. In only two cases does the percentile variation differ in the first decimal place. In these two cases the variability is once greater for males and once greater for females.” (“The Comparative Variability of the Sexes at Birth,” American Journal of Sociology, Vol. XX, 1914-1915, pp. 335-370.)
The findings on anatomical variability do not, of course, necessarily prove anything about differences in the range of mental ability. They do, however, suggest the probability of parallel results and such studies as have been made tend, on the whole, to bear this out. All the recent work in this field (and it is still fragmentary) seems to point at least to equal mental variability among men and women. In 1917, Terman and others in their “Stanford Revision of the Binet-Simon Scale for Measuring Intelligence” investigated this problem among school children from five to fourteen years old. They obtained the Intelligence Quotients of 457 boys and 448 girls and compared these I.Q.’s with teachers’ estimates and judgments of intelligence and work and with the age grade distribution of the sexes for the ages of 7 to 14. After making all necessary qualifications, they concluded that the tests revealed a small superiority in the intelligence of the girls that “probably rests upon a real superiority in intelligence, age for age.” But “apart from the small superiority of the girls, the distribution of intelligence shows no significant differences in the sexes. The data offer no support to the wide-spread belief that girls group themselves more closely about the median or that extremes of intelligence are more common among boys” (p. 83).
Dr. Hollingworth, again, has made a study of mental differences for adults. She has summarized the results of recent studies in sex differences in mental variability and in tastes, perceptions, interests, etc. Her conclusions on this score are interesting: “(1) The greater variability of males in anatomical traits is not established, but is debated by authorities of perhaps equal competence. (2) But even if it were established, it would only suggest, not prove, that men are more variable in mental traits also. The empirical data at present available on this point are inadequate and contradictory, and if they point either way, actually indicate greater female variability....” (“Variability as Related to Sex Differences in Achievement,” American Journal of Sociology, Vol. XIX, pp. 510-530, Jan., 1914.)
It seems hardly safe scientifically, therefore, to restrict women to the average levels in education and work and profession on the ground that eminence is beyond their range. But if the female geniuses have not been cut off by a comparatively narrowed range of mental ability, where are they? Certainly history does not reveal them in anything like satisfactory number. And it is now that women may bring forward their third weapon of attack. The female geniuses may have been missing not because of an inherent lack in the make-up of the sex, but because of the oppressive, restrictive cultural conditions under which women have been forced to live.
The important rôle played by cultural conditions in the cultural achievement of various nations and races has been noted with increasing emphasis by the newer schools of sociology and anthropology. No scholar can now defend unchallenged a thesis of “lower or higher races” by urging the achievements of any race as an index of its range of mental ability. Culture grows by its own laws and the high position of the white race may be as much a product of favorable circumstances as of exceptional innate capacities. Similarly the expression taken by the genius of various nations appears to vary strikingly. This is especially impressive in the realm of music. The Anglo-Saxon peoples are singularly lacking in great musical composers. Neither Britain nor America, nor indeed any of the northern countries have contributed one composer worthy of mention beside the Beethovens and Wagners and Chopins of this art. Indeed the great names in music are generally of German, Latin or Slavic origin. Yet no one thinks of urging this fact as evidence of an Anglo-Saxon failure of major creativeness. Instead we point to achievements in other fields or at most attempt to explain this peculiar lack by some external causation. Similarly all our impatience with the un-artistic approaches of the American people does not lead us to frame a theory of their lack of genius. There are many cultural factors to be considered first.
But as soon as we approach the problem of female genius, too many of us are apt to bring forward an entirely different kind of interpretation. We pass over the undoubted female geniuses lightly—granting Sappho and Bonheur and Brunn and Eliot and Brontë and Amster and Madame Curie and Caroline Herschel and perhaps even Chaminade and Clara Schumann and several others. We admit the undoubtedly significant parts women are playing in modern literature. But the question always remains.
Yet in no national or racial group have cultural influences exercised so restrictive an influence as among the entire female sex. Not only has the larger world been closed to them, not only has popular opinion assumed that “no woman has it in her,” but the bearing and rearing of children has carried with it in the past the inescapable drudgery of housework. And this is “a field,” as Dr. Hollingworth points out, “where eminence is not possible.”
It was Prudhon who sneered in response to a similar argument that “women could not even invent their distaff.” But we now know enough about the laws of invention to realize how unfair such sneering is. Professor Franz Boas and his school have long demonstrated that cultural achievement and mental ability are not necessarily correlated. For material culture, once it begins, tends to grow by accumulation and diffusion. Each generation adds to the existing stock of knowledge, and as the stock grows the harvests necessarily become greater. Modern man need have no greater mental ability than the men of the ice ages to explain why his improvements upon the myriad machines and tools that are his yield so much larger a harvest than the Paleolithic hunters’ improvements upon their few flint weapons and industrial processes. For, as Professor Ogburn has well shown (in “Social Change,” Part III) all invention contains two elements—a growing cultural base and inventive genius to work with the materials it furnishes. The number of new inventions necessarily grows with the cultural base. Even 50 times 100 make only 5000, but 2 times 1,000,000 make 2,000,000. Countless generations have added their share to the total material culture which is ours and which we shall hand down still more enriched to posterity.