with t the sharp primary distinction of maleness and femaleness, is also of importance indirectly, for it will have to be kept in mind at a later stage of the discussion, when the question of predisposing factors in the 'castration-complex' has to be raised. We may content ourselves at this point with suggesting that some of the psychological differences actually to be observed between grown men and women must be, not so much secondary sex characters, as tertiary, the offspring of the self-consciousness of sex, of the intense primitive awareness of the primary sex distinction. We are here in contact with the problem which most students of sex differences have kept in mind, viz. how far the observable differences are innate and how far acquired, being in the latter case the result of suggestion, custom and tradition, and, psycho-analysts may add, an expression of the 'castration-complex.' To take an example, how far the generally acknowledged imitativeness of women, their readiness to follow a plan laid down for them, their comparative lack of initiative and originality, are innate, or due to the effect of a tradition of sexual modesty and submissiveness. This is an obscure issue, and one which experimental methods have so far been unable to decide. Neither is the psycho-analytic method yet able to give a full answer. It does, however, throw some valuable new light upon the problem; and that, mainly because this question of sex differences is essentially a genetic problem, and must in the end be approached from the standpoint of a genetic psychology. In this respect there is a striking parallel between the history of this study and that of criminology. Not so very long ago, criminology was a mere accumulation of facts about adult criminals. It was what one might call a fortuitous concourse of atomic facts; and it was this condition which made the Lombrosian theory possible, the theory being an attempt to substitute a speculative evolutionary dynamics for a concrete individual history. The science did not begin to move until it shifted its attention from the adult to the child, and the individual genesis of the criminal was studied. So with our present problem; a static enumeration of mental differences between the adult man and woman has only limited scientific value. What is needed is a genetic study of the individual boy and girl. And the psycho-analytic method is essentially genetic. The time would thus seem ripe for a brief review of the new facts as to sex differences which psycho-analysis has been able to bring together in the pursuit of its individual studies.

There is a further reason for looking to psycho-analysis for important contributions to this problem. It is becoming increasingly clear to students of sex differences that those differences are greatest in the

region of emotional and temperamental characteristics, and that the factor of interest is the key to such intellectual differences as are found in practical life. The experimental studies of sex differences1 in the cognitive processes, while scantier than one could wish, and sometimes based upon too few or too unrepresentative cases, are on the whole convergent in tendency. That tendency is to minimise the extent and significance of sex differences. There appears to be little or no difference in the mean level of general intelligence and the higher mental functions; where any has been shown, it has been negligible in comparison with the extent of individual variations. Differences with regard to specific mental functions, particularly those on the lower mental levels, appear to be somewhat greater in degree and general significance; but even here the range of individual variation is too wide to allow the sex group difference any great weight. (The range of individual variability itself appears to be the most striking sex group difference found, being, on all counts and with regard to most measurable qualities, greater in the male than in the female.)

It is, however, in those tests in which the detailed nature of the task to be performed is prescribed by the conditions of the experiment, those designed to measure quantitative differences in one or two determined qualitative processes, as for instance tests of controlled association, memory, and reasoning, that the sex differences turn out to be minimal. Where the task given is less rigidly fixed by the conditions of the experiment, and subjective factors have free play, as in experiments on free association, positive and significant sex differences appear, in the form of divergent 'interests.' And interest is the bridge between the cognitive processes and the emotional and temperamental aspects of the personality. Following on this hint, and led by the recent general development of the psychology of emotion and instinct, the student of sex differences has seen the focus of attention shift from the intellectual processes to the conative and affective. It is in this field however that the psycho-analytic method is an indispensable instrument of research, and we must therefore turn to it for any specific contributions it has to offer to the problem of sex differences.

1 See, for instance: (1) Thorndike, Educational Psychology, I (Columbia University, 1914). (2) Burt and Moore, "The Mental Differences between the Sexes' (J. Exp. Pedagogy, 1911). (3) Burt, Mental and Scholastic Tests (King and Son, 1921). (4) Burt, 'The Development of Reasoning in School Children' (J. Exp. Pedagogy, v). (5) Jastrow, in Psychological Review, III. (6) Thompson, The Mental Traits of Sex (University of Chicago Press, 1903). (7) Report on Differentiation of Curriculum between the Sexes (H.M. Stationery Office, 1923).

It is not hoped to do more in this brief note than to state the nature of the problem from the psycho-analytic point of view, and to hint at possible specific lines of inquiry.

II. Analysis of genetic problem.

An analysis, from the genetic point of view, of the problem of sex differences leads to the following necessary lines of inquiry: (a) What are the primitive and specific differences between male and female in the nature of the sex impulse itself? (b) Are there any differences as regards the relation of the sex impulse to the ego trends? (c) Are there any psychological mechanisms characteristic of male and female? (d) What differences are there in the external relations of the male and female child, and in the problems of adjustment set for each by these external relations? (e) Finally, what are the relations between all the foregoing factors and the observable differences in the general mental life of adult men and women? It is important to distinguish these aspects of the problem, although it is hardly practicable to keep them quite separate in the discussion, since they are so closely interwoven in the facts.

(a) With regard to the nature of the sex impulse, it is clear that we must take into account not only the normal sex reactions of the adult, but infantile forms of sexuality also, since we are making a genetic study. The classic writers on the subject of sex differences, and all pre-psychoanalytic students have dealt only with the mature sex impulse. Speaking of this first, there can be no doubt as to a specific difference between male and female in the nature of the impulse, as regards the essential sex act and the fore-pleasures preparatory to it. The male impulse is from the nature of the case relatively active, the female relatively passive; and this complementary activity and passivity are in part an expression of the sadistic-masochistic components of the impulse, and in part of the greater freedom of the object-libido in the male, and the greater narcissism of the female. This distinction as to activity and passivity is not, of course, an absolute one, and it refers to the form or aim of the impulse, rather than to its inner character, since the libido, as Freud points out1, is in one sense always active. It is, however, a sufficiently deep distinction to justify us in speaking of the male sex impulse as predominantly active, and of the female as predominantly passive, as far as the act of coitus and the immediate preparatory stages are concerned. These are not the whole of the sex reactions of the 1 Freud, Three Contributions to the Theory of Sex, p. 79.

adult; but as soon as we leave them for the region of what we may usefully call the courting phase (using this term not in the narrow sense of a specific social custom, but in the biological sense, as covering all the phenomena of the preliminary stages of sex attraction), we find ourselves. already very far from pure impulse, and at the point where the question of innate and acquired' differences arises. We already have here what we described as tertiary sex differences, which are not so much the direct spontaneous expression of the essential metabolisms of male and female, as of the interplay of these with the self-consciousness of sex. Moreover, we are not here dealing with the sexual trends alone, but with complex psychical formations in which the ego-ideal is a considerable determining element. The whole ground is so complex and obscure that I shall not attempt to cover it, but will content myself with a brief reference to some of the factors entering into female modesty, as illustrative of the difficulty of disentangling inherent differences between male and female from conscious and unconscious sophistications.

We cannot doubt that there is an organic element in female modesty, that in so far as it is what we may call a relative sex inertia, a passive waiting for stimulation by the active approach of the male, it is a secondary sex character, and is intimately bound up with the profound cycle of the reproductive processes in the female, contrasted with the biological freedom of the male. And even where modesty passes over into actual coyness, into a withdrawal at the first signs of pursuit by the male, it may still be regarded as a simple secondary sex character, because of its obvious biological values, serving to heighten the excitement and efficiency of the male in the sexual act. These aspects of modesty in the human female are shared with infra-human creatures, and we must regard them as direct expressions of innate sex difference.

This organic core of sexual inertia and reticence is liable, however, in the human female, to undergo various degrees of reinforcement and exaggeration, until, as we know, it may even reach to an entire unawareness of sexual desire and an entire ignorance of the facts of intercourse and reproduction, in otherwise highly informed women. But, apart from such pathological exaggeration, a more normal modesty and reticence still appears, on psycho-analytic evidence, to be in part an expression of what we have called the self-consciousness of sex, acting through the familiar 'castration-complex.' The shame of having no penis, of bearing only the wound which is itself a sign of having been despoiled of the phallus, and of enduring the menstrual flow, which is in turn for unconscious fantasy a confirmation of the wound theory

of the female genitalia, this shame is a powerful element in female modesty. It receives further reinforcement from the disgust arising from the proximity of the excretory apertures to the sexual centre, a disgust attaching itself also to the menstrual flow, which commonly tends to be thought of as an excretion. This disgust is, of course, itself a reaction barrier to primitive excretory and 'perverse' interests, the strength of which reaction is the outcome of human self-awareness. Since, however, the excretory processes occur in the same relation to the organs of sexual pleasure in men, this cannot be the differentiating element in female modesty, save that there is the additional source of disgust in the menstrual flow in women. The main differentiating factor would undoubtedly appear to be the castration shame. And in the castration shame the ego trends, or at least the libidinous components of the ego, are inextricably interwoven with the more strictly sexual elements. The pride of possession and the pride of power on the male side, envy and chagrin at the supposed loss of these on the female side, are unmistakeably egoistic trends, and indeed, from one point of view, the castration-complex might well be said to be an expression of the instinct of self-preservation. The prototypes of castration, the loss of faeces and deprivation of the nipple, undoubtedly have both libidinous and egoistic values, and the genitalia themselves must lie at the very heart of the bodily and social self. I shall presently raise more fully the question of the relation of the sex impulse in male and female to the ego trends, and at the moment am only concerned to point out the egoistic elements in female modesty, which will have some bearing on that further discussion.

Turning now to infantile sexuality, it would not appear that the normal differences in reaction between male and female are here so marked. In the pregenital phases, oral and anal conditions would appear to be the same in boy and girl. The one important difference is with regard to urination. The differences in structure must from the beginning carry with them corresponding differences in organic sensation, characteristic of each type of urinary experience; and we have ample evidence of the great personal significance assumed by the process of urination as soon as visual attention and comparison can be directed to it. Urination, in its characteristic form in the two sexes, is of importance not only because of its direct libidinous value, and its direct organic contribution to the primitive ego, but also because of its role in infantile fantasies of love and power. Moreover, it introduces a difference in the earliest phase of genital sexuality, since the genital zone and the urethral