Chapter 2: Sex Differences
§1. Anatomical and physiological differences between the sexes
While it is obvious that psychological sex differences are of the very highest importance in determining the social relations and functions of men and women, it may seem at first that the purely anatomical differences, and many of the physiological differences, are of slight importance, and that social psychology would have very little concern with these differences. That, on the contrary, it is especially important to consider these differences in detail, will be shown in this chapter. Not only are the psychological differences closely related to the physiological and the anatomical differences, but in the present state of our knowledge it is impossible to evaluate properly in the field of psychological differences without a consideration of these others. Furthermore, the very specificity and definiteness of the anatomical and physiological differences, and the dependence of the development of these upon certain functions which also control mental development, render it necessary that we consider these anatomical and physiological characters in detail.
The most fundamental differences between men and women are in the sex organs. Included in these sex organs are characteristic glands: the pair of ovaries in the female, and the pair of testes in the male. Certain groups of cells in the ovaries produce the eggs, or ova, and certain groups of cells in the testes produce the spermatozoa, whose function is to fertilize the ova. But in both the male and female glands there are other cells (the interstitial cells) which secrete substances called sex hormones directly into the blood stream; and these sex hormones produce far-reaching effects upon the organism.
( 26) The ovaries and testes, together with the other genitalia or sex organs which are essential to procreation, are customarily designated the primary sex characters. The greater development and lacteal function of the female breasts are sometimes classed as primary sex characters, but more usually are not so included.
In addition to the primary sex characters, there are a large number of differential features of the male and female, some of which are universal, and some of which vary in different races, which are not absolutely essential to the process of reproduction, and which are hence called secondary sex characters. We shall consider these secondary characters before discussing the primary characters further.
In general details of form and structure, the adult human being stands between the human child and the ape, the woman nearer the child than is the man, and therefore farther from the ape. The child has a long body, short limbs, large head and brain, and rounded bodily contour. The ape has a short body, long limbs (especially the fore limbs), small head and brain, and prominent skeletal and muscular development. In the proportions of the main parts of the brain, and the relative sizes of the viscera, the same relation of babe, woman, man, and ape holds to a certain extent. In the external structure of the cranium, between the ridged skull of the ape and the smooth skull of the babe stand the skulls of the adults, the man's more like the ape's.
In one important proportion the woman deviates markedly in most races from the man and the babe and the ape, namely, in the width of the hips. In woman the hips are wide, often wider than the shoulders; but in man, as in the babe and ape, the hips are relatively narrow. In greater size of buttocks woman is again different from man and the ape, but not so different from the babe.
The larynx is larger in men than in women, and situated lower in the throat. The vocal cords are larger and thicker and these differences are responsible for the differences in pitch and timbre of the adult male and female voices. The protuberance of the male larynx known as the "Adam's apple" is not developed in the female.
In many minor details of bodily structure women differ from men. The thigh bone is shorter than in men; the proportions of the chest, and of the spinal column are different; the arm is flatter; the index finger is larger, and the thumb shorter; the thigh is greater in diameter
( 27) and more conical in shape; the pelvis is, of course, larger; the legs slant inward more from hip to knee; many joints are differently formed; and there are various other characteristic differences.
These differences, however, vary from race to race, and many of them are practically absent in some races. Among the Tamils, for example, the body form of the woman is so close to that of the man that they are not easily distinguishable if the genitals are concealed.
In absolute height and weight, and in size of skull, man surpasses woman on the average in most races. The average height of adult English males is about 67.5 inches; of females 62.7. The differences between these measurements correspond closely to differences in other European countries, and of certain special groups in the United States. Sargent found from several thousand Harvard students and students in American women's colleges, average statures of 68 and 63 inches. On account of the great variety of races in the United States no representative means are available for the general population. The European norms, moreover, are based on measurements of groups which may not be fairly representative, and are, therefore, only approximate.
No figures are available for the average weight of the English male and female adults. Among the American college groups, Sargent found an average male weight of 138 pounds, and an average female weight of 114 pounds.
The proportion of fat to other tissue is greater in women than in men, in which respect again women resemble babes more than do men, and resemble apes less. The excess female fat is distributed in the breasts and buttocks, and in the tissue just beneath the skin; and it is the subcutaneous fat which gives the softness and roundness to the female figure.
In respect to absolute brain weight, men rank higher than women as might be expected from the larger male skull. The brain measurements so far made have not been numerous enough, or fairly enough selected, to have much statistical value. Obviously, measurements can be made only on such brains as are available in the dissecting room, or which are donated by their erstwhile owners. But it is evident that
( 28) the adult female brain of European races is somewhere near 10 per cent smaller in weight than the male brain. Various average weights which have been observed for females have ranged from 1200 to 1250 grams, and the corresponding averages for males are from 1350 to 1400 grams. But the average weight of the woman's body is from 15 to 18 per cent less than that of the man's, so that her relative brain weight is actually greater than the man's. Furthermore, when we consider that fat constitutes a greater per cent of the woman's total weight than it does of the man's, we see that the relative brain weight is still more in favor of the woman. For, of course, the function of the brain is to "control" the muscles and glands, and the reserve of fat does not enter into the mechanism directly: In ratio of brain weight to body weight woman is again closer than man to the babe, and farther from the ape.
Attempts have been made to show that woman's brain is inferior to man's in depth of convolutions, in number of nerve cells, and in the proportions of the frontal lobes and other portions of the cerebrum, and in the proportions of cerebellum and brain stem to cerebrum. More careful and recent investigations show, however, that there are no discernable sex differences in these respects.
The blood of women has been found to contain more water, and fewer red corpuscles than that of man; in which again she would be nearer the babe than is man. The approximate number of red blood corpuscles has been estimated as 5,000,000 per cubic millimeter in men and 4,500,000 in women. But since the blood-count for women varies with the menstrual cycle, the estimates which have been made are not final. No difference in number of white corpuscles has been discovered.
A striking difference between adult men and women is found in the hair. The hair on the man's face tends to grow rapidly, and to become dark and coarse, forming a beard. The same tendency is shown by the male body-hair also, notably on the chest, abdomen, arms, and legs, sometimes forming an ape-like fur over considerable areas. The face and body-hair of the woman, on the other hand, retains its infantile fineness and colorlessness in the great majority of cases. The pubic hair on the woman, however, is characteristically more luxuriant than that of the man.
With regard to the hair or the scalp, there is some doubt. It has
( 29) been maintained that the cranial hair does not on the average grow as fast or attain as great length in the male as in the female, but this has not been adequately demonstrated. Certainly, women are not as subject to baldness as are men, although the masculine hat and the patronage of barber shop have been held responsible for the prevalence of male baldness.
It has been maintained that women are fairer of skin than men of the same race, but it is not certain that such is the case when both are equally exposed to the weather. The same uncertainty applies to the observation that the hair of women is darker than that of men, since the sun demonstrably bleaches hair. There is more reliable evidence that the eyes of women are darker than those of men of the same race, but this cannot be said to be an established fact.
The thyroid gland is not only relatively but also absolutely larger in women than in men, and diseases of the gland are far more common among girls and women than among boys and men. This gland is closely associated with the life of sex. Concerning the other glands, the information available indicates that the stomach and kidneys are relatively larger in women, and possibly the liver also; these again being infantile characteristics. The bladder also is larger, or rather more distensible; but in this respect woman is farther from the infant than is man, for the infantile bladder is relatively small.
Among the functional or physiological characteristics of women as compared with men, the menstrual cycle is most conspicuous. This occurs with remarkable regularity, and with an interval of from two weeks to eight weeks according to the individual. In the great majority of cases it approximates a lunar month, or four weeks, hence the name "menstrual" and hence also the identification of the cyclically changing moon as the virgin goddess. The menstrual cycle is not a mere recurrent episode, but involves, in many women at least, a complicated series of changes in vascular and motor functions, involving very serious emotional modifications, which extend through-out the month. In man, certain observers have thought that cyclic changes occur, but these observations have not as yet been generally accepted, and there is reasonable doubt that a male periodicity similar to the menstrual cycle exists.
The female adult heart beats faster than the male; approximately 8 to 10 beats per minute faster under the same conditions.
Among civilized races, men are muscularly stronger than women, both absolutely and in relation to body-weight, and have greater physical endurance than women. This is apparently not the case among primitive races, although we have not very reliable evidence concerning them. The weakness and rapid fatigability of civilized women may be due to their environment, training, and methods of life. At any rate, it is interesting to note that year by year, as girls and young women go in more and more for athletics, sports, and out-door life, the track, field, and strength test records for women approach nearer and nearer to those for men. Laboratory records will probably show that the resistance to fatigue of these hardier women approaches male standards. No one can say confidently that in a few years women will not measure up to male standards in resistance and in strength-weight ratio.
The secondary characteristics of sex are not present in early infancy, but begin to develop just before, or during puberty, which occurs normally between the ages of ten and sixteen. Puberty is the functional development of the primary sexual characters, especially of the ovaries and the testes; and the development of those glands exercises a powerful influence upon the development of the secondary sex characters. If the testes are congenitally absent in the male, or if he is castrated in infancy, many of the male secondary characters do not develop at all. The voice does not "change," but becomes feminine; and the beard does not grow; the body develops in form somewhat (but not greatly) like that of the female, and acquires the feminine superfluous layer of fat. Many observations have been made on eunuchs (i.e., males who have been castrated) so that we have a considerable degree of certainty on these points.
We have no direct data on the effects of ovariotomy (removal of the ovaries) from female infants; but judging from experiments which have been conducted on animals, and from the effects of ovarian degeneracy, one may safely conclude that such removal would have little effect in female structural development, although it might have a profound effect on functions. Where the ovaries have been removed from adults, menstruation ceases, and the general cyclic changes connected with the menstrual phases are also abolished. Castration or ovariotomy of the adult does not abolish sex desire or sex sensitiv-
( 31) -ity, but this desire and sensitivity do not develop in the eunuch castrated in infancy, and probably would not develop in the female if ovariotomy were performed in infancy.
Experimental castration and ovariotomy have been performed on many animals, and such experiments are adding to our knowledge of human sexual developments. The most striking experiments have been the transplanting of ovaries to the castrated male, and testes to the ovariotomized female. In such cases, the animals take on many of the anatomical characteristics of the other sex, and some of the important psychological characteristics.
Pubertal development in the female is considered to be complete when the menstrual flow first appears, but the girl at this time has not reached full development either anatomically or physiologically. Many of the characteristic body changes, such as the broadening of the hips, the full development of pubic hair, and the development of the breasts, are not completed for some years after the first menstruation. Full stature and strength are, of course, attained still later, and full emotional and intellectual maturity is probably not reached until about the age of twenty-five. The chief significance of the first menstruation is that ovulation (the ripening of an egg) has occurred, which means, of course, that the girl has become able to conceive. It is by no means certain that eggs are not produced a number of months before menstruation appears in some cases, especially those in which monthly nose bleeding has preceded the first menstruation.
In the case of the boy, there have not been demonstrated symptoms of the development of mature spermatozoa comparable to the girl's menstruation, hence, it is apparently impossible to compare these phases of maturity in the two sexes. It is popularly believed, and taught by many texts, that girls as a rule "mature" earlier than boys, but the significance of such statements is as yet conjectural. Even if it is true that as a rule, mature ova in the female appear at an earlier age than that at which mature spermatozoa appear in the male (and we do not yet know this to be true), the fact means little. "Maturity," or the more limited "sexual maturity," is a complex matter of which we know little. Girls may "mature" in some details earlier than boys; and boys may "mature" in some details earlier than girls. Emotionally, it is possible that men mature earlier than women; but even of this we cannot be certain as yet.
The physical growth of boys does not keep pace with that of girls. Although male infants are on the average larger and heavier than girls, girls exceed boys in absolute stature and weight during the pubertal period, and are again exceeded by boys from sixteen on. In relation to the norms for the adults of both sexes, however, females are taller and heavier than males during both infancy and the pubertal period. Adult stature is attained by females at about twenty, by males at about twenty-three. The increase in weight, however, is said to continue until the age of forty in men, and fifty in women, although this difference may be due to accumulation of fat by the woman between forty and fifty.
It has been very commonly supposed that males are more vulnerable to diseases than women, but this now seems to be doubtful, although it has been claimed that women recover from injuries, wounds, and surgical operations better than men do. The formerly assumed greater variability of males in respect to stature, form, and other anatomical and physiological characteristics, is no longer accepted.
§2. Psychological sex differences
Because the mind is a function of the organism, we might reasonably expect to find that men and women should show psychological differences, since they show such well marked organic differences. Certain important psychological differences we do indeed find: differences in sex desire, sex interest, and sexual sensitivity, which may well be called primary psychological characters. There are undoubtedly also important secondary psychological differences, but we must admit that at present we know little about them, and we must look with great suspicion on the extensive mass of allegations in popular literature concerning the secondary psychological differences of sex. We shall discuss the putative secondary differences first.
In surveying psychological functions it is useful to distinguish between capacities and performances. High capacity for discrimina-
( 33) -tive judgment, for example, does not necessarily imply that the individual will use this capacity with a high degree of efficiency: emotional tendencies, desires, and general integrative tendencies, as well as environmental conditions, cooperate to determine the actual performance. Especially in the field of specific mental functions must we avoid the easy confusion of capacity and performance. Moreover, since tests measure performance only, the evaluation of capacities is a very difficult matter.
In attempting to evaluate mental capacities it is useful to distinguish (a) sensory capacities, (b) intellectual capacities, (c) capacities for sensory and intellectual discriminations, (d) capacities for learning, (e) capacities for recall, (f) affective (feeling and emotional) capacities and tendencies, (g) capacity for accuracy of reaction, (h) capacity for speed of reaction, (i) capacities and tendencies of desire, and (j), general integrative tendencies. These divisions are not strictly coordinate, and they overlap somewhat, but they are practically justifiable.
In respect to sensory capacity, few sex differences have been made out. The probability is established by the fragmentary experimental work so far done, that, except for "pain," male sensitivity is slightly higher on the average than female sensitivity. These findings are complicated by the fact that in smell, taste, and sight, sensitivity differs individually according to the quality of the stimulus, and perhaps these are sex differences in this respect. It is probable that for certain odors and certain tastes, the males are more sensitive, and for certain others, the females; but this has not been made out with certainty.
There are apparently more "color blind" and "color defective" males than females. Aside from color blindness, men are in general more color sensitive, although it seems possible, in view of recent tests, that women average lower in sensitivity to blue, and men in sensitivity to red. Such an indication appears, for example, in the cases of men to whom a very dark red appears "black," and the cases of women
( 34) when a very dark blue appears black. Color deficiency and color blindness are not entirely a matter of sensitivity, for some of the individuals who are most defective in discrimination of colors, are at the same time exceptionally sensitive to the stimulus.
Blindness (other than color blindness which is not really "blindness" at all) is more frequent among men than women; but since the greater part of blindness is due to venereal diseases, or to injuries received in industry or war, the comparisons here do not have significance for our purposes. Dioptic defects of vision, especially myopia, are much more frequently reported among women and girls than among men and boys.
In respect to "cutaneous pain" aroused by pressure on the skin, women and children are more sensitive than men, so far as observations go. In how far the thinness of the skin and the softness of the subcutaneous connective tissue and the fascia, more effectively transmitting the pressure to receptors in deeper tissue, is responsible for this difference, we cannot say. Comparative experiments upon men, and upon women who have been toughened by manual labor or athletics, have not yet been performed. When electricity and other forms of pain stimulation are applied, no definite sex differences are found.
In regard to sensory discrimination (such as pitch discrimination, weight discrimination, etc.) males are superior to females except in respect to tactual acuity (measured by the normal perceptible separation of two points applied to the skin), in which women excel. These conclusions are tentative only, since measurements have not been made upon large groups in ways which would exclude differences due to the toughening of the skin by exposure to the weather and contact with rough objects and differences due to practice; and practice effects are large in the field of sensory discrimination. In regard to intellectual discrimination we have no evidence bearing conclusively upon the point.
In learning by simple association, girls and women seem to be quicker than boys and young men. Such learning is tested by "immediate memory" (that is, immediate repetition of the words,
( 35) numbers, or other material learned). For this reason, girls excel in "substitution" and "cancellation" tests (which are both tests of simple associative learning). Curiously enough, girls excel also in the avoiding of forming associations, as in the "color-naming" test. In retention of what has been learned over short periods of time, (one or two days), females are also superior to males. But for longer periods of retention, the sex differences seem to disappear.
In logical memory (as distinguished from rote memory), where the significance of what has been studied is to be retained, regardless of form, there is no clear differentiation of the sexes; although it is sometimes assumed that males are superior in this. Women may be relatively deficient in the application of what has been learned; if this were true it would explain their inferiority to men in the solving of problems, in arithmetic as in other matters, which has been reported by some experimenters. Girls are said to find geometry relatively harder than algebra (as compared with boys), presumably for this reason. In schools and colleges, women seem to do best in linguistic, literary, and historical subjects, where memory (not necessarily rote memory) is the important factor; and they are said to be at a disadvantage in mathematics and scientific topics in which problem-solving is involved. The fact that in coeducational schools and colleges girls and women have in certain cases made better average grades than boys and men, has been said to be due in part to the pre-dominant selection of languages, literature, and history by the females, and in part to their more serious application to the curriculum. It is probably true that until recently the male students have been more distracted by school and college "life" and by other extraneous activities, although the female students are rapidly growing toward the same neglect of the curriculum as has been characteristic of the males, and perhaps in some institutions have outstripped the male students in this respect.
In regard to comparative speed of reaction we have no data of statistical importance. Such data as have been obtained seem to show that women are quicker, provided the reaction is one that has been thoroughly learned, but that they fatigue more rapidly than men. In speed of tapping, for example, women are found to be faster than men on short records, but slower on long or repeated records. Where choice or discrimination is involved in the reaction, it is possible that
( 36) the males are speedier, but data on this point are insufficient. Concerning accuracy of reaction requiring fine coördination we have no reliable evidence, although this is a very important topic.
In considering the affective characteristics of the sexes we must revert to a consideration of primary psychological sex differences, since these are found in the fields of feeling, emotion, and desire. The profound changes which take place at puberty, and which significantly differentiate the male from the female in so many anatomical details and in important physiological respects, are controlled by the hormones of the testes and ovaries. This control is exercised in part through other glands; the thyroid, pituitary, and adrenal, and perhaps others; upon the functions of which the products of the genital glands exercise an influence. It is possible that the whole glandular life is influenced by the sex glands, and it is at least certain that the important endocrine glands above named are affected. Further, we know that endocrine glands in general, and especially the ones named, exercise a powerful effect on the general emotional life of the individual. It is, therefore, extremely probable that along with the differentiation of growth and function controlled directly and indirectly by the sex glands, there is also a differentiation in the emotional life of man and woman; but our experimental knowledge is at present not sufficient to indicate the details of this differentiation, hence we must depend on more general information, which is, frankly, more suggestive than reliable.
We have reason to assume that the sexual desires and emotions and the sexual sensitivity of the man and woman (the primary psychological characters of sex) are different. Aside from their intrinsic characters, the sex desires and emotions differ in their excitability, and in their temporal courses; and these are highly significant differences.
In discussing sex desire, it must be understood that while we here use the term in a very literal sense (and in fact, because of that literal-ism), we do not restrict it to the narrow application to desire for sexual stimulation or for the activities which we will below designate as "specific." Just as we uniformly designate all characteristics which are peculiar to the female, or to the male, as sex characteristics, whether they are characteristic of the sex organs, or secondary characteristics such as differences in stature, in form, and in bony development, so also, and for the same reasons, we designate any desire which is
( 37) determined as to its object by the differentiation of the sexes, as sex desire. If the man at any time desires feminine society, in a way in which he does not desire masculine society, that desire is literally a form of sex desire, since it is determined by the sex of the object, as well as by his own sex. The sex desire in such a case may be simply for association with women at the tea table. This is really a common sense usage of the term sex; and it is fully justified by the fact that such desires are intimately associated with the primary life of sex, and controlled thereby. When a man has such social sex desires, it is because he is male in the full sense of the term; he would not have the mental characteristics of the male any more than he would have the secondary anatomical characters if he had not the primary sex characters. When, on the other hand, the effeminate boy prefers to associate with girls rather than boys because of his effeminacies, his desire for feminine society is not truly sexual.
These considerations must be understood, or the whole intent of the discussion below will be seriously misapprehended. The definitions to be given for the several types of sex desire must be carefully considered, and further references to those types always understood in the light of the definition.
Among the forms of sexual desire we may distinguish: a. Generalized personal desire. A man or woman may be "interested" in individuals of the other sex, without the selection of a particular individual who is desired above all others. The desire in this stage is for the society of individuals of the other sex, that is, the desire may be said to be "social" in the narrow sense of the term. Analytically, the desire is for general stimulation by individuals of that sex: visual, auditory, and olfactory stimulation as well as tactual and kinaesthetic. There is desire also for common stimulation and common activity, and these are very important parts of the total desire. ,The man desires not only to see and hear the woman, and to touch her, but also
( 38) to engage in the same activities in which she engages. In walking, playing games, and dancing with a woman, the man satisfies desires of various of these types. He is not only stimulated by her, visually, acoustically, and tactually; but he is also stimulated by the same stimulus which stimulates her, and he acts with her. Moreover, a very important factor is added in the knowledge that the stimulation arising from her is intentionally directed toward him. Yet in many cases, there is minor satisfaction in the stimulations when he is merely with her in the society of others, and she is neither talking directly to him, nor displaying herself visually for his particular benefit. A man's satisfaction in viewing a beautiful woman on the street or on the stage, or in listening to a beautiful voice, or in viewing a statue or painting may be of this generalized sexual sort; and the same holds true for the woman. There is no thought of specific sexual relations in this plane of desire.
b. A higher state of desire tending to a higher form of satisfaction, (or more serious dissatisfaction as the outcome may be), involves a particular person, and may be designated as particularized personal desire. In this case, we say the individual is "in love." The personal desires of the lover are toward the loved one, and it is her society (or his society), her stimulation, and common stimuli and common activity with her, which are preeminently desired. Sometimes love excludes the generalized desire entirely, and the man in love has no more and no different kind of desire for the society of other women than for the society of other men. Sometimes, however, the generalized desire coexists with the particularized; or rather, the tendencies coexist; for the man really in love does not desire woman while he is desiring the woman; and the converse holds true for women.
c. In the form of sex desire which may be called specific, the act of coitus is in the forefront of consciousness, or details directly connected with coitus are focal; the desire is primarily for the act itself; and the stimulus desires and common activity desires are merely such as con-duce most effectively to the completion of the act.
These three types of sex desire grade into one another through many stages. The individual whose personal desire is generalized, particularizes, of course, during the time when an individual of the other sex is available; but the particularization endures only while he or she is stimulated by that individual, and any one of a large class of indivi-
( 39) -duals may be substituted one for another. He desires to dance with, talk to, or otherwise associate with the particular woman who is available, but would be just as desirous of and just as well satisfied with any one of a number of women of the same general type, and sometimes of a wide range of types. In some cases where there is actual particularization of a more personal sort, the particular desire is little stronger than the general: the man, for example, is somewhat in love with one woman; desires her more strongly than other women, and derives more satisfaction from her society; yet his desire for any other woman of the same general type may be nearly as strong.
Finally, the personal desire shades gradually into the specific and vice versa in a temporal way; and there is a gradation of blends of the two at definite times. Very often, the particularized desire begins in the personal form, and grows in time into the specific; and frequently that which commences as relatively specific desire for a given individual grows in time into a comprehensive personal desire.
The most important sex difference in desire is that in the man it is more uniform in type, in woman more diverse. The difference may best be brought out by describing male desire.
In man, sex desire is frequently present in a highly specific form without any particularization, and with a minimum of even generalized personal desire. In such cases the desire may be ideationally vague, with no thought of definite object or means of satisfaction, although affectively vivid, and is usually called sex excitement. More-over, personal sex desire in man passes very easily and quickly into the specific form, without requiring intermediate activities, such as caressing. Furthermore, man seldom loses the general desire for long periods of time, but is during most of his life, no matter how definitely he particularizes, "susceptible" to women generally. There are, of course, individual variations in these respects; and a few individuals may differ widely from the general type; but the overwhelming majority of men differ only mildly in type of desire, however much they may differ in respect to its gratification. Finally, the liability to sex desire of the several types is constantly present, subject to no times or seasons, although it is possibly a little greater in the spring and early summer than at other times.
In women, on the other hand, there is a wider range of types, and the great majority of cases differ markedly from the male type. In
( 40) these cases, specific desire is less apt to arise except from the particularized personal form; in many cases it seldom or never arises except in this way, and is less apt to occur in the vague specific form. More-over, personal desire does not pass so automatically into specific but requires the intermediate stimulation of caressing. The woman, in many cases, must have personal desire for the man, involving finally the desire to be tactually and kinaesthetically stimulated by him; and these stimulations arouse the specific desire.
When the woman's personal desire becomes particularized, although the general desire is seldom completely lost, it lessens or decreases more markedly than it does in man; to a degree so small usually that it precludes her particularization upon another man until she loses her particularization upon the first man.
The preceding description applies to a certain range of types of women only, although that range probably includes the majority. There are others who are in type like the average man; and still others who go to the other extreme of never having any specific desire: an extreme which is seldom if ever approximated by any man except he be mentally or physically defective, or seriously diseased. Between these two wide extremes all gradations in feminine type are represented.
In many women, and perhaps in all, sex desire is dependent upon and varies with the menstrual cycle. At a certain phase of the cycle, it is less easily aroused, and at another phase is much more easily aroused, or occurs spontaneously in the specific form. In other words, there is in the human female an oestrous cycle, like that of the lower animal female, and with the same period as the menstrual cycle.
It must not be supposed that on the average the sexual desires of the man are any stronger than those of the woman, although the conditions of arousal may be different. It is even possible that the reverse is true; and it is certainly true that in very many women the desires, when fully aroused, have a violence far surpassing that of the average man. This is a point which it is especially important that the woman should know for her protection.
The development of sexual desire in the woman is far more a matter of education, through sexual stimulation and sexual experience, than is the case with the man. In many women the desire is very slight
( 41) until developed by repeated stimulations and experiences, and may thereafter be powerful and easily aroused. In many others the desire is never developed to a very high level, even though they may be married for years, and to some of them sexual intercourse eventually becomes intensely repugnant. In most of these cases, the conditions off intercourse have been abnormal through absence of the appropriate psychological details, frequently because of the dense ignorance of the husband.
As regards sexual emotion and feelings aside from desire, there are definite differences between man and woman which it is not important to discuss here. There are also definite differences in sexual sensitivity, which are tied up with the differences in desire and emotion. We have gone far enough into the subject to show that extreme and important affective differences probably exist; and exist in a realm which we know to be of great consequence for the entire emotional life. For we know that changes in the sexual affective life influence profoundly the whole emotional life: witness the changes in moods, in excitability, and in general emotional responses which occur conspicuously in the menstrual cycle of some women, and probably of many.
If the total emotional life of man differs profoundly from the total emotional life of woman, then, in spite of equality in perceptual, intellectual, associative, and reflective capacities, it cannot be expected that the two sexes will perform alike. Their interests will be different, and their distribution and fixation of attention will perhaps be different. And if such were not the case, it would seem that the family, the most important of all social groups, and the most coherent, would not be possible.
The cyclic variability of woman's emotional life (which is true on the average although it may not be true of all cases), and its greater personalization, are the most important points in which it differs from that of the man. The variability undoubtedly interferes severely with the success of many women in vocations in which initiative and self direction are required, and may be the basis for her lesser aptitude for problem solving. Business and professional life offer their opportunities and make their demands without regard to the lunar month, and the woman is sometimes in the mood to respond to them, some-times not. Hence, "woman's work" has been predominantly along
( 42) those lines which offer no progress, and which, like house work, can be periodically neglected, or which like stenography, are so standardized that the routine requirements are definite, and have to be met, moods or no moods. For, where there is an objective requirement which must be met, and is not too severe, the individual will by extra effort measure up to it for a short time regardless of mood and lowered vitality. The woman can force her work, just as the drunken man, or the asphyxiated or drugged man, can make for a short time as good a record on many mental and physical tests as he can normally, because the task is mechanical and he feels the need of accomplishing it. Yet, it is probable that just as tests have been designed in which the deficiencies of those individuals can be shown, so tests can eventually be applied to the woman which will show her cyclic variations in initiative due to the emotional cycles.
The personal tendency of woman's emotion has also its effects in her performances. It has many times been said that woman fails as a surgeon and succeeds as a nurse, because of her personal solicitude and sympathy for the patient; and this impression is doubtless correct as far as it goes. The successful surgeon must remove the appendix from his patient as impersonally as he cuts a bone out of his steak. But, of course, in view of the extreme variability of woman, we may expect to find some who are as impersonal in their affective life as the most impersonal man.
Qualitative or intensive affective differences between men and women are hard to find. Woman, on the average, has not been shown to be gentler or sterner, more optimistic or more pessimistic, more irritable or more placid, than man. She seems to hate, love, fear, worry, rejoice, no more or less deeply than does man. We cannot say that maternal emotions are more intense than are paternal. In some of these respects, moreover, although the individual variations in women may be no greater than those in men the distributions may be different. A recent investigation on the likes and dislikes of men and women has brought out the indication that woman is relatively stronger in her dislikings, man in his likings. These are matters of secondary desires and aversions, of course, and it is not certain yet that it is generally true. Yet certain commonplace observations, especially in regard to foods, seem to bear out this conclusion. The results of wider experimental work on this point will be important.
According to popular belief, woman differs from man in an import-ant affective respect, namely in type of esthetic feeling. It is sup-posed that esthetically, woman is more imitative, less creative than man. It may be that woman is less prone than man to distinguish what is intrinsically pleasant and appropriate from what is merely conventionally correct or d la mode. "Beauty,"aside from "style,"may be less real for woman, on the average, than for man. The habits of women in respect to decoration offer some support for this view. That which is in "style" is admired and enjoyed today, reprobated and condemned tomorrow when it is "out of style."This applies to form as well as to color.
In art, woman, it is said, to a greater extent than man, learns the rules and applies them, sometimes with great skill, but she never creates a new phase or type of art. It is believed by some extremists that the great majority of women have no intrinsic esthetic appreciation at all, but are merely appreciative of set standards. On these matters no conclusions can be reached until adequate experimental determinations have been made.
The fact that esthetic standards have been created almost exclusively by men, and adopted by women, may be in part responsible for the fact that, in so far as personal beauty is concerned, both men and women are predominantly interested in female beauty. But, in larger part at least, this striking fact is due in a more direct way to the primary psychological differences of sex.
Man needs but little stimulation of his sex interests, and this stimulation the normal aspects of woman's form and coloration and action is competent to supply. Woman, on the other hand, needs to be more directly stimulated and needs to have, therefore, the aspect of form and coloration and action which will incite the man to "make love" to her. Hence, man is abundantly interested in beauty qualifications in woman's form; and so is woman. To man they are direct sex excitants; to woman they are something to be imitated, or, if that be not possible, something to be wished for. The woman, therefore, in viewing the presentation of female characters or female activity on the stage, projects herself into the part: for the time being, she is dancing, posturing, or being kissed. Man has much less tendency to project himself into male parts. The direct enjoyment of the presentation is generally sufficient for him. This projective tendency
( 44) of woman broadens out into all dramatic fields, including those in which there is no question of "beauty;" but it has its basis in the primary sex attitude.
Of course, it is not to be denied that woman has her conception of "beauty" as applied to the male. Large stature, vigorous musculature, strength of movement, thick curly hair (to run her fingers through), and suggestions of virility; but these mean far less to the man himself than feminine charms do to the woman, and any deep consideration of them on the part of the male is commonly considered a matter for ridicule or contempt.
The sexual desires are not the only ones in which men and women .differ. The desire for conformity seems to be greater in women. Manof course has this desire strongly, but not so strongly nor so comprehensively, on the average, as has woman. Man conforms in many respects, because he must, or because he sees it is advantageous to be inconspicuous; but inwardly rebelling. Or, he conforms to an old order because change is troublesome or disagreeable. Woman, however, reaps keen satisfaction in conforming. This comes out clearly not only in the matter of styles and fashions, but also in the greater suggestibility of woman, which careful experiments have determined. Woman tends to perceive, to think, and to feel, that which is suggested to her, in so far as the actual environment or other pressing needs will let her. Woman has been called the "imitative sex" and "docile sex," and the evidence on suggestibility lends sup-port to this view. Here, also, woman would stand nearer the babe, and farther from-the ape, than man.
Yet, one must not forget that there are wide ranges of suggestibility in both sexes. Many women rival or exceed in independence of thinking the most original and unimitative of men; and that many men fall far below the average female level is easily shown by any street procession of a fraternal society. Female non-conformists are, however, more generally condemned or derided, especially by their own sex, than are men.
On the subject of general integration there is at present little data. As a matter of fact, adequate experimental methods for the determining of the ability to sustain and distribute the attention have but recently been devised, and have not yet been applied to this field. It may be that there are important sex differences here. If
( 45) there are differences they are certainly of high importance, but concerning such differences we could at present merely speculate.
What has been said already about the variability of anatomical and physiological characters in the sexes can be said even more positively in regard to mental characteristics. The old notion that woman is the "less variable"sex is without foundation. The most reliable experimental data on variability in mental characteristics shows very little difference between the sexes in sensory variation or variation in the higher mental processes; and that if there is any mental difference in this respect, woman is the more variable. This agrees with and confirms what we have said about the greater variability in feelings and in desires. Woman is really the "variable sex" both in regard to the temporal changes in the individual, and in regard to individual variations in respect to the average.
§3. The status and performances of men and women
It is obvious that woman as a sex can never be on a footing of economic equality with man, because of the handicap of women in the reproductive function. There is no reason why the class of women who do not bear children should not be on economic equality with men, unless they are hindered by the menstrual cycle (as some are) or prevented by the effects of the psychological differences we have pointed out. But for the majority of women the conditions are inescapable.
Economic inequality does not necessarily involve political or social inequality, but practically it contributes powerfully thereto. And even today, the women who are economically men's equals, so far as their capacities are concerned, are at an economic as well as social and political disadvantage because of the economic disadvantages of the larger class. The labor of the larger class of women is cheap labor because of their handicaps, which make them take what they can get; and the cheapness of their labor cheapens that of the others.
Nowhere, and in no time, have women been socially and politi-
( 46) -cally  the equals of men. As a sex, they have fallen pretty generally into two classes: private property and public property. Women as private property have been legally classified as wives, concubines, and slaves. Practically, however, they have been classified as drudges, mostly serving a double function of servile labor and of gratifying the lusts of their masters; and as playthings, ranging from the limits of "pampered mistresses" on the one hand to "adored divinities" on the other. The public women, a class peculiar to "civilized" society, not to savage or "primitive," have usually been held a public necessity, but despised and maltreated for their services. In some cases, however, the public women have been held high in personal esteem.
Within modern European society the beginning of a new era has been made. A new class of women has arisen who first achieved social equality, and showed that economic equality with men is possible for those who are willing to forbear child bearing; and then achieved a growing measure of political equality for women of all classes. It is beginning to be realized that woman has legal rights to her person, to her property, and her vote, and more right to her children than has their father. But these are great and radical innovations and are none of them fully conceded, even where legally guaranteed. Even so far, the change is the greatest revolution ever effected in social conditions. While men generally still look on women
( 47) as property, and large numbers of women are quite willing to be so regarded, the time is rapidly approaching when both these attitudes will completely disappear.
That the greatest handicap of woman is maternity, and the liability of maternity, and not her mental characteristics, has been shown by the fact that it has been the class of celibate women, or women otherwise free from the claims of motherhood, who have been able to organize and carry through this revolution.
Obviously, the environmental features are not yet such that we can see what the full performance of women will be. Girls are not trained either physically or mentally as boys are trained. They still look on a
fortunate marriage as an escape from work, and consider such a bar-gain commendable. Opportunities in professions, trades, and industries are not open to them as they are to men; and they still are treated with "chivalry" which is, to a large extent, an elaborate condescension to their assumed inferiority.
Hence, the fact that woman has accomplished little in the world does not mean a great deal. It may be true that in no profession has she yet made a high mark as a sex, although a few individuals have succeeded. Informal statistics have been gathered to show that in spite of the great number of girls studying music and arts, only a few pianists, composers, and artists, and those not of the first rank, have appeared. The extremely small number of women who have attained to moderate eminence in law, medicine, science, and literature has also been pointed out. And it has also been pointed out that even in those lines which in the Western world have long been considered woman's work, namely, cooking, dressmaking, and the care of children, men have taken first rank over women when they have gone into these lines. It is even said (and it may be true) that the dire inefficiency in European and American housekeeping is due to the fact that men have not yet taken it up and put it on a modern basis.
All these matters are really important; but even if the statements are true, arguments based on them are inconclusive. It would be rash indeed to predict what woman's achievements will or will not be after the social equality of the sexes shall be complete.
In spite of the revolution which has taken place, many changes remain to be made, among which are the abolition of prostitution,
( 48) with all that it entails upon the virtuous woman; the putting of "sex morality" on an ethical basis; the separation of sexual relations from a basis of financial compensation, within marriage, not merely outside it; the purification of marriage from its present degraded condition by the evolving of a reasonable divorce system; the education of women to broader views of life, and better coöperation with one another; all these must be done before the social power of the past will be swept away, and the conditions for the development of women be met. Yet, in spite of these considerations, of two things we may reasonably be sure, because they are based on physiological and psychological facts. First, that there will always be a large class of women who will devote themselves primarily to maternity, and whose achievement in the world will therefore be entirely incommensurate with those of men. Second, that whatever may be the achievement of the class of women who eschew maternity, they will not be on the whole the same as those of men. It is unthinkable that with the difference in emotional organization, and the difference in desire, they should sufficiently want to do the various things that men must do, and should have the emotional persistency in all these to reach success equal to that of men in all of them.
The real question is whether women will find some things which they so much want to do, and which their emotional nature will so dispose them to do, that they will do them better than men do, just as men will do some things better than women do. For one thing is certain: no one reaches major success in a profession or line of work when it is undertaken merely as a means. Potboilers are never master-pieces. The undertaking must be fascinating and desired in itself, and for its own success, or it will not reach the heights.
§4. The problems of sex education
The differential psychology of men and women presents a series of problems which are of importance for pure science, and which also are of serious practical consequence. The information to be gained by the solution of these problems is needed for the guidance of individual development of character, and for the harmonization of the interrelations of men and women in social progress, which depends so largely upon the improvement of marital relations and the complex social relations of the sexes which contribute to and depend upon mari-
( 49) - tal relations. Marriage is far more than a physiological pairing, and the development of its psychological possibilities requires training of the individuals in practical matters as well as the inculcation of ideals. Even physiological mating among the higher animals is far from being the simple "instinctive" process it has sometimes been supposed to be, and the more complex psychological adjustments of human mating require a definite, and sometimes lengthy learning process. Many cases of marriage failures come to the psychologist for adjustment: cases in which in spite of the real attachment of husband and wife, and the desires of both to realize a spiritual union, the union is not attained and the family has begun to disintegrate. In these cases, the one outstanding fact is ignorance of the psychology of sex; and the work of the psychologist in adjusting these families is largely the teaching of simple facts in regard to the mental sex life.
Unless both the man and the woman understand the essential emotional differences between them, the chances of successful marriage are small. Very often, both mates learn with sufficient rapidity during marriage; but very often also a family is wrecked before the knowledge has been attained, although in some cases both mates learn enough from the first marriage to make a second one successful. Disaster can often be prevented by giving proper instruction before marriage, or during its early stages, instead of leaving every-thing to the troublesome, and frequently unsuccessful, "trial and error" method. In many cases, errors learned by sex experience before marriage are the source of the marital failure, unless counter-acted by adequate knowledge later acquired; and many individuals are denied the chance of marriage because of earlier ignorance. Obviously, when fuller scientific information concerning the psychology of sex is available, including information concerning cognitive sex differences, vastly more can be done educationally; but it is important that the fundamental facts now known should be intelligently applied.
Much of the widespread misinformation concerning the psychology of women, and much of the injustice to which women are subjected is due to the failure to understand the difference between the development of sexual responsiveness and of sexual desires and emotions in the two sexes, and the greater rôle played by education in the woman. The man's desires and responsiveness develop more spontaneously;
( 50) that is to say, the internal stimulations and the common types of social stimulation to which men are rather uniformly subjected develop a responsiveness and type of desire which vary somewhat from man to man, but are sufficiently well developed in all but a very few individuals. On the other hand, although the variation in women is greater than in men, for the larger group of women, neither internal nor general social stimulations will develop either responsiveness or desire in its characteristic form without more specific types of stimulation supplied by the male. In such cases, the sexual responses are of the general personal type, and sex desire is limited to that category, until more specific desires and responses are aroused through cares-sing. Many women of profound passionate capacity live half of their lives without realizing the tendencies lying latent within them, and are astounded at the revelations which even these preliminary forms of sex experience bring about. Some women even do not develop their full capacities until several years after marriage has been entered. Whether this significant difference between men and women is really essential, or whether it is due to the differences in the training of boys and girls from childhood up, remains to be deter-mined. The important fact is that the differences exist at present, and must be taken into account. Many curious and conflicting misstatements concerning the differences in the sex desires of men and women have undoubtedly been based on data obtained from small numbers of women in one or the other of the stages of sexual development, in which mere chronological age plays a minor part. But undoubtedly also, the individual variations in women, under the same conditions of experience and training, are very great.
After the psychological sex life of the woman has been once developed, she is a different person, and her personal problems, previously rather simple, become much more like those of the man. The woman, therefore, who achieves her sex education without marriage is in a peculiarly unfortunate position, a prey not only to the enormous force which has been liberated in her life, but a prey also to the large group of males who constantly seek to play upon these forces. The attitude which men frequently take towards the inexperienced woman, namely, that the responsibility for her actions rests upon her alone, if she consents to sex relations, can therefore have no palliation except on the assumption that such men are densely ignor
( 51) -ant of the psychology of woman, and the fact is that in few cases can she possibly know before hand the consequence of the step which she may contemplate. It is not necessary to assume anything essentially wrong in sex experience, or even in promiscuity; the serious ethical problem grows out of the psychological facts, together with the fixed definite conventions of the social system from which no individual can escape.
On the other hand, the more fully the woman or girl understands this situation, the more capable she is of protecting herself. Knowing that once having entered upon a new realm of experience, no return to the former security is possible, and that the complexities of the new life are such that she cannot evaluate them in advance; and that society is so organized that woman is put at every possible disadvantage in dealing with these complexities, she is not apt to entertain lightly an experimental attitude. Further, the young woman should know the awakening of her sex desire is a smoothly progressive process, beginning in details that may seem to her not in the least dangerous, but grading by small steps to a culmination in which she has no further control; and that she cannot foresee the point at which control will be lost.
It might seem, therefore, that while it is immensely important for the young woman to understand these matters as fully as possible, it is inadvisable to present the information to young men, lest it add to the advantage which the male has over the female. Unfortunately, at the present time there is better understanding of these points among the more unscrupulous men than among those whose justice would impel them to protect women. Practical safety is to be found in the education of both sexes, but special attention should be paid to the education of girls and young women.
The differences in the details of the temporal development of sex desire in the man and woman, even after the woman's sex training and development have been fully achieved, are of vital importance in married life. These differences are much better known to wives than to husbands, among whom, as a class, an astonishing amount of ignorance prevails on this subject. The better education of women in these details is, however, an important matter, in order that they may more effectively assist in the education of their husbands. Instruction in the details of sexual life which go beyond those it is pos-
( 52) -sible to present here should be given to unmarried women both as a preparation for marriage and for their protection before marriage.
For both men and women it is important that the emotional changes, other than changes in desire, which accompany the menstrual cycle should be understood as fully as possible. The woman should know that even if not ill at the menstrual flow, she is irritable, and tends to be unreasonable, in the few days just preceding it; and that the benefits of her kindness, generosity, and tenderness through-out the greater part of her life may be lost through failure to guard her expression and her judgments during these recurring brief periods. The man should know that she merits especial tenderness, consideration, and forbearance at these trying times. And this is true not only in the marital relation, but in every circumstance in which men and women are brought into social relations.
It is obvious that education is needed, not only in the physiology and biology of sex, but also in its psychology. The repression of the understanding of the laws of the sexual life not only leads to serious evils through ignorance and misinformation, but also by relegating sexual matters to the domain of the shady and furtive creates a realm of obscenity and of unduly heightened erotic values which has very serious detrimental effects. The realization of these facts has brought about a great improvement in frankness and seriousness in dealing with these topics—twenty years ago it would have been impossible to present this chapter to a college audience—and has brought about a change of attitude in regard to the education of young women; for it is no longer held that they should be kept in dense ignorance of the matters which men are allowed to know. But with these changes have come both benefits and damages.
There can be no doubt that preoccupation with sexual matters may in itself constitute sexual stimulation; and under modern social conditions increased stimulation is not needed. Not only the presentations of the stage and the screen, but the general conditions of social life contribute, if anything, too great sex stimulation of a general sort; and we need to lessen this if possible. Many of those who are seriously advocating the censorship of literature, the screen, and the stage, are quite correct in their general position, and wrong only because they do not see that the kind of censorship which they advocate, and
( 53) which is to some extent, unfortunately, put into practice, does not attain its object, and only increases the evil.
In the problem as it concerns printed materials, the books, articles, and pamphlets which presumably constitute serious educational material on the psychology of sex need serious consideration. It can be shown that to many readers these materials constitute stimulations of the sex tendencies and impulses which fan into flame the sexual passions in an undesirable way, and that both men and women have been impelled by these stimulations to free their impulses from control and embark upon paths of loose living of unfortunate consequences. The recognition of the need for sex education of children also has led to unfortunate consequences because some reckless per-sons have leaped in wildly where intelligent persons have trodden fearfully. There is especial need in this field for the consideration of Solomon's maxim that there is a time for all things.
To a large extent the flood of books for the young: "What a boy ought to know:" "What a girl ought to know:" etc., has been mere pornographic literature, in so far as they have not been mere frauds, purporting to reveal something erotic, and revealing nothing. And many of them are obviously written merely to sell on the advertising value of the subject. Verbal instruction has also been the medium for both charlatanry and mistaken zeal. Special lectures on sex are advisable for adults and for late adolescents, if these are accurate and authentic. But much that is presented on the topic of sex psychology is not well founded. For children, special lectures on sex are not justifiable, and are frequently bad in effect. Sex instruction of the young can be safely carried out only by two methods, first, by giving it as a normal, unemphasized part of biology and physiology and psychology; second, by answering truthfully any question the child may ask, but without impressing on the child information unasked and beyond the stage of his needs. There is a middle ground between the still too common practice of lying to the child on the one hand, and deliberately awakening and increasing his sexual curiosity on the other.