Our fourth inquiry is this: Are there any innate sex differences in affective or instinctive equipment that would naturally lead to a vocational differentiation of the sexes? Here we must acknowledge ourselves to be entirely without a literature of fact. The literature of opinion is very extensive on the subject, and it would be an interesting and no doubt an instructive task to collect and summarize the various and conflicting opinions of men as to the affective and instinctive differences between the sexes. Men and women as we see them in the world do differ in affective behavior, but no one can say whether these differences in behavior are original or acquired. There are different conventional standards of emotional behavior for men and for women, but no one would be justified in saying that such standards arose from inherent affective differences between the sexes. The very variety that characterizes the statements on this subject constitutes proof of the ignorance of mankind in regard to it.

Since exact data are entirely lacking, the discussion of this last question need not detain us. We may, however, glance at one instinct which has repeatedly been stated to characterize women, and to constitute in itself a natural justification for differentiating the sexes vocationally. This is the "maternal instinct." Since the period of helpless infancy is very prolonged in the human animal, and since the care of infants is an exacting and onerous labor, it would be natural for those who are not biologically attached to infants, to use all means at their disposal to fasten the whole burden of infant-tending upon those who are originally so attached. We should expect this to happen, and it does happen. There has been a continuous social effort to establish as a norm the woman whose vocational proclivities are completely and "naturally" satisfied by child-bearing and child-rearing.

In the absence of all data, it would seem most reasonable to suppose that if it were possible to obtain a quantitative measurement of "maternal instinct," we should find this trait distributed among women just as we have found all other traits distributed, which have yielded to quantitative measurement. It is most reasonable to assume that we should obtain a curve of distribution, varying from an extreme where individuals have a zero or negative interest in the care of infants, through a mode where there is a moderate amount of impulse to tend infants, to a second extreme where the only vocational interest lies in such activity. The bearing and rearing of children is in many respects analogous to the work of soldiers. It is necessary to national existence, it means great sacrifice of personal advantage, and it involves suffering and danger, and, in a certain percentage of cases, the actual loss of life. Thus, as in the case of soldiers, every effort is and must be made to establish as a norm the extreme end of the distribution curve, where there is an all-consuming interest in patriotism, in the one case, and in motherhood in the other. In the absence of all scientific data, we should, therefore, guard against accepting as an established fact about human nature a doctrine that we might expect to find in use as a means of social control. It is also fitting to raise the question as to just what is meant by the term, "maternal instinct." Does it mean desire for offspring which are as yet non-existent? Does it mean only the tendency to care for helpless offspring after they are actually in existence? Does it mean an interest in children as such, regardless of their origin? Or does it consist in a mingling of all these elements? Above all, does it involve, as an essential element, an interest in waiting personally upon infants? One certainly gains the impression from a perusal of the extensive literature of opinion that to most persons the term is quite unanalyzed, and that it calls for analysis.

We have now considered four of our inquiries in the light of experimental evidence. We have discovered that a great amount of work remains to be done before we can answer most of them conclusively, and that to one question, at least, no answer at all can be given from the literature of fact. We can only say that, so far, scientific experiment has revealed no sex differences in the original nature of intellect that would imply a necessary differentiation of vocations on the ground of sex. There exist no scientific data to show (1) differences in average intellect; (2) differences in mental variability; (3) special causes of intellectual inefficiency affecting one sex but not the other; (4) differences in affective or instinctive equipment, implying a "natural" division of labor.

The division of labor between the sexes, which has existed through historic times and still persists, originated, so far as we know, in physiological, not in psychological differences. The momentous physiological fact that women bear and nourish infants and men do not, is the great primary sex difference on which our economic and vocational organization has been built up. It might be supposed that natural selection would have evolved an intellectual (or unintellectual) type in women, which could find its complete natural satisfaction in the vocation of child-bearing and child-rearing. But such a selection could take place only if mental traits were sex-limited in inheritance, or existed as secondary sex characteristics. No mental trait has ever been proved to be sex-limited in inheritance, or to exist as a secondary sex character. So far as we know, daughters inherit mental traits from fathers as well as from mothers, and sons inherit them from mothers as well as from fathers. Under such circumstances the law of natural selection can never become operative to solve the vocational problems of women.

The fact that women have not in the past equaled men in "philosophy, science, art, invention and management" is frequently adduced as evidence of their innate unfitness for pursuits other than the domestic. From such evidence, however, we glean in reality no information whatever about the vocational aptitudes of women. We should not expect any notable achievement by women in the fields mentioned above, for the following reasons. Women must bear and nourish infants, and men cannot. The period of gestation and the period of infancy are very protracted in the human species, together covering, for each infant reared, about six years. Until very recently no scientific methods of controlling procreation have been generally known or utilized. Thus women have borne great numbers of infants, all their youth and maturity being consumed by bearing and rearing young. The small minority of women whose lives happened not to be so consumed would be very unlikely to make any contributions in extra-domestic vocational achievement for two reasons. In the first place, all women were expected to mate and thus to procreate and rear offspring, and no provision was made by society for their training in lines other than those they would be expected to use. In the second place, those women who did not meet the common fate failed to do so for some special reason, such as ill health, mental disease, or the necessity of caring for decrepit relatives. The very causes of their celibacy would operate also against any vocational achievement on their part.

In the irrational trial and error method by which our human institutions have been developed, the logical expectation would be that the great physiological sex difference in reproductive function would probably influence vocational activities just as it has done. We find in the traditional division of labor between the sexes exactly what we should expect to find, even though there were an identity of intellectual abilities and interests. It seems both psychologically and socially desirable that the one incontestable conditioning factor in the vocational differentiation of men and women be raised clearly to consciousness, rather than submerged, as in the past, by an elaborate system of defense mechanisms and traditional devices of social control. It would be going afield from the immediate purpose of this chapter to offer constructive suggestions for such changes in economic and domestic management as might be necessary to overcome this conditioning factor, and thus to give free vocational opportunity to both sexes alike. To effect these changes in such a way that the maximum social betterment may be achieved thereby will be a task not simple but complex. It will call for the best thought and the most enlightened effort of which we are capable, and will be accomplished only with the passing of years and decades.

The essential thing at present is to know whether any basis for future action may now be found in the established facts of human nature. In the present state of scientific knowledge it would be as dogmatic (and therefore as undesirable) to state that significant sex differences in intellect do not exist, as to state that such differences do exist. All we can say is that up to the present time experimental psychology has disclosed no sex differences in mental traits which would imply a division of labor on psychological grounds. The social gain would be very great if the public could be brought to recognize intelligently that to many of the questions regarding the vocational aptitudes of women no definite answers can at present be given, because the necessary data for the formulation of answers have never been collected. So far as is at present known, women are as competent intellectually as men are, to undertake any and all human vocations.

FOOTNOTES:

[15] There was published in the October (1914) issue of the Psychological Bulletin a summary of all important experimental work done on sex differences in recent years. Any reader wishing to take up the evidence greatly in detail will do well to consult all of the references there given.