But all these observations notwithstanding, the fact remains well established that even in childhood notable sexual differences make their appearance. Other observations, too, confirm this notion of sexual differentiation—for example, pathological experiences.
There are some diseases to which women are especially liable, others which occur by preference in men. To some extent, indeed, this is explained by the special exposure of one sex or the other to certain noxious influences. The neuroses that appear as the sequelæ of injuries are especially common in the male sex, because the occupations of men expose them more than women to injuries of all kinds. Of such cases, of course, we do not speak here. But there are some unquestionably hereditary morbid tendencies which manifest themselves by preference in one sex or the other, and such sexual predisposition shows itself even in childhood. I propose to give instances of this; some quoted from Möbius,[18] some from other authors, and some taken from my own personal experience.
Chlorosis is a disease of feminine youth, but very often makes its appearance in childhood, especially towards the end of the second period of childhood, at this earlier age, also, attacking girls in preference to boys. Hæmophilia, on the other hand, and also certain hereditary forms of muscular atrophy, occur chiefly in males, and this in early childhood. Diabetes is principally a disease of adults, but occasionally it is met with in children also; among adults, there is a considerable preponderance of males affected with this disease when diabetes occurs in childhood, the disease also exhibits a preference for the male sex, although at this time the peculiar sex-incidence is less marked than in later life. Congenital defects of the heart are commoner in boys, the proportion obtained from a very large number of cases of this kind being 61.6 boys: 38.4 girls. Chorea (St. Vitus's dance) affects girls more often than boys, the ratio in this case being 2.5 girls: 1 boy. In the case of whooping cough, we find that two girls suffer for every one boy. As regards circumscribed facial atrophy, which usually begins during childhood, a preponderance of the disease in the female sex is also noticeable. Hysteria was formerly regarded as a typically feminine disease, and although this view has now been shown to be erroneous, the fact remains that girls and women are far more often affected than boys and men. As regards hysteria in childhood, Bruns[19] states that the ratio of girls affected is to boys affected as 2:1. It is interesting to note that in the earlier years of childhood, prior, that is to say, to the age of nine years or thereabouts, no marked difference exists in the sex incidence of hysteria, the cases being distributed in the proportion, 55 per cent. girls, 45 per cent. boys; but after the age of nine, the proportion of girls affected with hysteria increases, while that of boys diminishes. Eulenburg,[20] indeed, records 17 cases of hysteria, affecting children at ages nine to fourteen years; of these nine were boys, and eight girls. Clopatt, on the other hand, collected from the literature of the subject 272 cases of hysteria in young children, 96 being boys, and 176 girls. Typhoid is commoner in males; and Möbius lays stress on the fact, which he regards as especially striking, that the difference in the sex-incidence of this disease is manifest even in childhood. As regards colour-blindness, there is a notable preponderance among males, and since we here have to do with a congenital affection, this preponderance is as marked among children as among adults. Many defects of speech also exhibit a notable difference in their sex-incidence. Hermann Gutzmann[21] has shown that in the case of stammerers we find 71 per cent. boys and 29 per cent. girls. I take this opportunity of referring briefly to the fact that, as Max Marcuse[22] reports, certain diseases of the skin exhibit sexual differentiation of type even during childhood. The disseminated cutaneous gangrene of children is far more frequent in girls than it is in boys; Broker, among twelve cases, found ten girls. Alopecia areata, on the other hand, affects both sexes with equal frequency, but affects them at different ages. Whereas during the first years of life girls are more frequently attacked; when the age of twenty is passed, the relation between the sexes in this respect are reversed.
Criminological experiences appear also to confirm the notion of an inherited sexual differentiation, in children as well as in adults. According to various statistics, embracing not only the period of childhood, but including as well the period of youth, we learn that girls constitute one-fifth only of the total number of youthful criminals. A number of different explanations have been offered to account for this disproportion. Thus, for instance, attention has been drawn to the fact that a girl's physical weakness renders her incapable of attempting violent assaults upon the person, and this would suffice to explain why it is that girls so rarely commit such crimes. In the case of offences for which bodily strength is less requisite, such as fraud, theft, &c., the number of youthful female offenders is proportionately larger, although here also they are less numerous than males of corresponding age charged with the like offences. It has been asserted that in the law courts girls find more sympathy than boys, and that for this reason the former receive milder sentences than the latter; hence it results that in appearance merely the criminality of girls is less than that of boys. Others, again, refer the differences in respect of criminality between the youthful members of the two sexes to the influences of education and general environment. Morrison,[23] however, maintains that all these influences combined are yet insufficient to account for the great disproportion between the sexes, and insists that there exists in youth as well as in adult life a specific sexual differentiation, based, for the most part, upon biological differences of a mental and physical character. I have referred to these criminological data for the sake of completeness, but I feel it necessary to add that their importance in relation to our subject of study is comparatively trifling, since most of the cases in question are offences committed by persons who can no longer properly be regarded as children.
As we have seen, during childhood, and especially during the second period of childhood, there exists a larger number of sexual differences both mental and physical. Some of these are obviously discernible when we compare isolated individuals; others only become apparent when we institute a statistical comparison. And when such differences appear in childhood, we find that they are quantitatively less extensive than the sexual differences of adults. For the sexual life is in the child less developed than it is in the adult. We shall learn that in the matter of the sexual impulse, the child exhibits an imperfect differentiation. A similarly imperfect differentiation is found in childhood in respect of a number of other qualities. Thus, there are many diseases which later in life manifest a sexual differentiation, but in childhood are undifferentiated. We observe a similar age-distinction in respect of suicide, which occurs in Europe far more frequently in men than in women, the ratio among suicides being three or four men to one woman. Among child-suicides there is far less disproportion between the sexes. According to Havelock Ellis, indeed, the suicidal tendency makes its appearance in girls at an earlier age than in boys.
Such a marked differentiation as there is between the adult man and the adult woman certainly does not exist in childhood. Similarly in respect of many other qualities, alike bodily and mental, in respect of many inclinations and numerous activities, we find that in childhood sexual differentiation is less marked than it is in adult life. None the less, we have learned in this chapter, a number of sexual differences can be shown to exist even in childhood; and as regards many other differences, though they are not yet apparent, we are nevertheless compelled to assume that they already exist potentially in the organs of the child.