<< Individual Variation >>

It is obvious, but it needs to be pointed out again, that no population of variant individuals can ever have their behavior characterized by any simple description. It is more nearly possible to write anatomic descriptions which cover a whole group of individuals, but physiologic functions are usually more variable than anatomic structures, and behavioral characters are still more variable than physiologic functions.

While approximately 3.3 is the mean frequency of total outlet for younger males, no mean nor median, nor any other sort of average, can be significant unless one keeps in mind the range of the individual variation and the distribution of these variants in the population as a whole. This is particularly true in regard to human sexual behavior, because differences in behavior, even in a small group, are much greater than the variation in physical or physiologic characters (Table 40, Figure 32). There are a few males who have gone for long periods of years without ejaculating: there is one male who, although apparently sound physically, had ejaculated only once in thirty years. There are others who have maintained average frequencies of 10, 20, or more per week for long periods of time: one male (a scholarly and skilled lawyer) has averaged over 30 per week for thirty years (Table 43). This is a difference of several thousand times.

Table 40. Individual variation in frequency of total sexual outlet

Fre-
quencies
Per
Week		 Individual Variation in Total Sexual Outlet
Younger Ages:
Adolescent to 30		 All Ages:
Adolescent to 85
Cases Sample
Population
%		 U. S.
Population
%		 Cases Sample
Population
%		 U. S.
Population
%
0.0 232 2.0 1.7 291 2.1 1.3
— 192 1.7 1.2 260 1.8 1.3
0.5 1136 9.9 8.3 1491 10.6 12.1
1.0 1397 12.2 11.3 1852 13.2 14.8
1.5 1235 10.8 11.2 1579 11.2 11.4
2.0 1240 10.8 10.4 1606 11.4 13.3
2.5 1066 9.3 9.6 1299 9.2 9.6
3.0 979 8.5 7.6 1194 8.5 7.7
3.5 910 7.9 8.1 1049 7.4 6.2
4.0 622 5.4 5.2 717 5.1 4.3
4.5 455 4.0 4.1 529 3.8 3.1
5.0 411 3.6 3.5 446 3.2 2.3
5.5 267 2.3 2.2 298 2.1 1.7
6.0 249 2.2 2.5 279 2.0 2.3
6.5 158 1.4 1.5 169 1.2 1.0
7.0 189 1.6 1.9 208 1.5 1.2
7.5 122 1.1 1.2 127 0.9 0.7
8.0 99 0.9 1.4 105 0.7 0.7
8.5 65 0.6 0.7 69 0.5 0.4
9.0 33 0.3 0.2 44 0.3 0.2
9.5 40 0.3 0.3 46 0.3 0.3
10.0 68 0.6 0.8 71 0.5 0.6
11.0 61 0.5 0.9 67 0.5 0.5
12.0 43 0.4 0.5 49 0.3 0.3
13.0 30 0.3 0.6 39 0.3 0.4
14.0 31 0.3 0.5 36 0.3 0.4
15.0 25 0.2 0.4 33 0.2 0.3
16.0 19 0.2 0.3 23 0.2 0.5
17.0 18 0.2 0.4 20 0.1 0.2
18.0 10 0.1 0.1 12 0.1 0.1
19.0 10 0.1 0.2 12 0.1 0.1
20.0 9 0.1 0.2 11 0.1 0.2
21.0 5 — 0.2 6 0.1 0.1
22.0 8 0.1 0.1 10 0.1 0.1
23.0 6 — 0.1 6 — —
24.0 2 — — 2 — —
25.0 6 — 0.1 6 — 0.1
26.0 4 — 0.2 5 — 0.1
27.0 3 — 0.1 3 — —
28.0 0 0 — 0 0 —
29 + 12 0.1 0.2 14 0.1 0.1
Total 11467 100.0 100.0 14083 100.0 100.0
Mean 2.88 ± 0.027 3.27 2.74 ± 0.024 2.34
Median 2.14  1.99 

Raw data, based on the available sample, are corrected for a population of the same age,
marital status, and educational level as that shown for the total population in the U. S. Census
of 1940.

Figure 32. Individual variation in frequency of total sexual outlet.

In considering structural characters of plants and animals, such as total height in the human, or length of wings, legs or other parts in other animals, a maximum that was two or three times the size of the minimum would command considerable attention (Bateson 1894, Wechsler 1935, Thorndike 1940). One of us has published data (Kinsey 1942) on individual variation in populations of insects. The populations represented individuals of single species, from single localities. There were many characters which varied. Extreme wing lengths, for instance, varied between 10 and 180 micrometer units. This difference of 18 times probably represents as extreme a linear variation as is known in any population of adults of any species of plant or animal. But differences between the extreme frequencies of sexual outlet in the human (Figure 32) range far beyond these morphologic differences. Calculation will show that the difference between one ejaculation in thirty years and mean frequencies of, say, 30 ejaculations per week throughout the whole of thirty years, is a matter of 45,000 times. This is the order of the variation which may occur between two individuals who live in the same town and who are neighbors, meeting in the same place of business, and coming together in common social activities. These sexually extreme individuals may be of equal significance, or insignificance, in the societal organization. They may be considered as very similar sorts of persons by their close friends who do not know their sexual histories. It has been notable throughout our field collections that a sample of as few as a hundred histories is likely to show a considerable portion of this full range of variation.

These differences in frequency of sexual activity are of great social importance. The publicly pretended code of morals, our social organization, our marriage customs, our sex laws, and our educational and religious systems are based upon an assumption that individuals are much alike sexually, and that it is an equally simple matter for all of them to confine their behavior to the single pattern which the mores dictate. Even in such an obviously sexual situation as marriage, there is little consideration, under our present custom, of the possibility that the two persons who have mated may be far apart in their sexual inclinations, backgrounds, and capacities. Persons interested in sex education look for a program which will satisfy children — meaning all the children — at some particular educational level, overlooking the fact that one individual may be adapted to a particular, perhaps relatively inactive, sort of sexual adjustment, while the next would find it practically impossible to confine himself to such a low level of activity. In institutional management, there has been almost complete unawareness of these possible differences between inmates. The problems of sexual adjustment for persons committed to penal, mental, or other institutions, the problems of sexual adjustment for men and women in the army, the navy, or other armed forces, are a thousand different problems for any thousand of the persons involved.

While the curve shows three-quarters (77.7%) of the males with a range of variation that lies between 1.0 and 6.5 per week, there is still nearly a quarter (22.3%) of the males who fall into extreme ranges (total population, U. S. Correction). There are, for instance, 7.6 per cent of all the males whose outlets may average 7 or more per week for periods of at least five years in some part of their lives. Daily and more than daily arousal and sexual activity to the point of complete orgasm must occur among some of the friends and acquaintances which any person has. The data on the female show that there is even a wider range of variation there, although a larger number of the females are in the lower portion of the curve.

The range of variation that occurs in the sexual behavior of the female far exceeds the range of variation in the male. Consequently, it would be unfortunate if any of the comparisons made in the present volume should be taken to indicate that there are sexual qualities which are found only in one or the other sex. The record will have misled the reader if he fails to note this emphasis on the range of variation, and fails to realize that he or she probably does not fit any calculated median or mean, and may in actuality depart to a considerable degree from all of the averages which have been presented. The difficulty lies in the fact that one has to deal with averages in order to compare the most characteristic aspects of two different groups, but such averages do not adequately emphasize the individual variation which is the most persistent reality in human sexual behavior.

Interestingly enough, we may predict that the persons who will be most often incapable of accepting our description of American females will be some of the promiscuous males who have had the largest amount of sexual contact with females. Most of these males do not realize that it is only a select group of females, and usually the more responsive females, who will accept pre-marital or extra-marital relationships. Some of these males will find it difficult to believe that the incidences of extra-marital coitus are as low as our data indicate; some of them will not easily be persuaded that there is such a percentage of females who fail to reach orgasm in their coitus; some of them will find it difficult to believe that there is such a large proportion of the female population which is not aroused in anticipation of a sexual relationship, and which is not dependent upon having a regular sexual outlet. They will fail to take into account the large number of females who never make socio-sexual contacts, and never become involved in the sort of non-marital relationships from which these males have acquired most of their information about females.

Because there is such wide variation in the sexual responsiveness and frequencies of overt activity among females, many females are incapable of understanding other females. There are fewer males who are incapable of understanding other males. Even the sexually least responsive of the males can comprehend something of the meaning of the frequent and continuous arousal which some other males experience. But the female who goes through life or for any long period of years with little or no experience in orgasm, finds it very difficult to comprehend the female who is capable of several orgasms every time she has sexual contact, and who may, on occasion, have a score or more orgasms in an hour. To the third or more of the females who have rarely been aroused by psychologic stimuli, it may seem fantastic to believe that there are females who come to orgasm as the result of sexual fantasy, without any physical stimulation of their genitalia or of any other part of their body. Sensing something of this variation in capacities and experience, many females—although not all—hesitate to discuss their sexual histories with other females, and may prefer to carry their sexual problems to male clinicians. Because they fail to comprehend this variation in female sexual capacities, some of the females in positions of authority in schools and penal and other institutions may be more harsh than males are in their judgments of other females. There are many social problems which cannot be understood unless one comprehends the tremendous range of variation which is to be found in sexual behavior among both females and males, but particularly among females.
Cases of females who fail to comprehend the sexuality of other females are frequently noted in psychiatric and sociologic literature, as in: Burgess and Cottrell 1939:230 (female at twenty-one shocked to find there are women who desire coitus). Kroger and Freed 1951:382 (female of forty-three asks if women “actually enjoyed sex or were just talking”). Two contrasting statements may be found in: Gray 1951:193, 195-196 (a female author who states “There is no such thing, in a women at least, as ‘sex starvation.’. . . There is no hunger for sex in the sense that there is hunger for food. . . . lack of a sex life will not hurt you no matter how young you are”). English and Pearson 1945:364 (male authors who state that when coitus occurs only once or twice a month, “if the wife is sexually normal, she is bound to find incompatibility in such a marriage” ).

Since sexual matters are less frequently discussed among females than other aspects of their lives, most females have little knowledge of the sexual habits of any large number of other females. Only clinicians who have seen a considerable variety of sexual histories, and are able to think in terms of statistical averages, can have foreseen the sort of record which we have presented here.

The possibility of any individual engaging in sexual activity at a rate that is remarkably different from one’s own, is one of the most difficult things for even professionally trained persons to understand. Meetings of educators who are discussing sex instruction and policies to be followed in the administration of educational institutions, may bring out extreme differences of opinion which range from recommendations for the teaching of complete abstinence to recommendations for frank acceptance of almost any type of sexual activity. No other subject will start such open dissension in a group, and it is difficult for an observer to comprehend how objective reasoning can lead to such different conclusions among intelligent men and women. If, however, one has the histories of the educators involved, it may be found that there are persons in the group who are not ejaculating more than once or twice a year, while there may be others in the same group who are experiencing orgasm as often as ten or twenty times per week, and regularly. There is, inevitably, some correlation between these rates and the positions which these persons take in a public debate. On both sides of the argument, the extreme individuals may be totally unaware of the possibility of others in the group having histories that are so remote from their own. In the same fashion, we have listened to discussions of juvenile delinquency, of law enforcement, and of recommendations for legislative action on the sex laws, knowing that the policies that ultimately come out of such meetings would reflect the attitudes and sexual experience of the most vocal members of the group, rather than an intelligently thought-out program established on objectively accumulated data.

Even the scientific discussions of sex show little understanding of the range of variation in human behavior. More often the conclusions are limited by the personal experience of the author. Psychologic and psychiatric literature is loaded with terms which evaluate frequencies of sexual outlet. But such designations as infantile, frigid, sexually under-developed, under-active, excessively active, over-developed, over-sexed, hypersexual, or sexually over-active, and the attempts to recognize such states as nymphomania and satyriasis as discrete entities, can, in any objective analysis, refer to nothing more than a position on a curve which is continuous. Normal and abnormal, one sometimes suspects, are terms which a particular author employs with reference to his own position on that curve.

The most significant thing about this curve (Figure 32) is its continuity. It is not symmetrical, with a particular portion of the population set off as “normal,” “modal,” “typical,” or discretely different. No individual has a sexual frequency which differs in anything but a slight degree from the frequencies of those placed next on the curve. Such a continuous and widely spread series raises a question as to whether the terms “normal” and “abnormal” belong in a scientific vocabulary. At the best, abnormal may designate certain individuals whose rates of activity are less frequent, or whose sources of sexual outlet are not as usual in the population as a whole; but in that case, it is preferable to refer to such persons as rare, rather than abnormal. Moreover, many items in human sexual behavior which are labelled abnormal, or perversions, in textbooks, prove, upon statistical examination, to occur in as many as 30 or 60 or 75 per cent of certain populations. It is difficult to maintain that such types of behavior are abnormal because they are rare.

The term ‘‘abnormal” is applied in medical pathology to conditions which interfere with the physical well-being of a living body. In a social sense, the term might apply to sexual activities which cause social maladjustment. Such an application, however, involves subjective determinations of what is good personal living, or good social adjustment; and these things are not as readily determined as physiologic well-being in an organic body. It is not possible to insist that any departure from the sexual mores, or any participation in socially taboo activities, always, or even usually, involves a neurosis or psychosis, for the case histories abundantly demonstrate that most individuals who engage in taboo activities make satisfactory social adjustments. There are, in actuality, few adult males who are particularly disturbed over their sexual histories. Psychiatrists, clinical psychologists, and others who deal with cases of maladjustment, sometimes come to feel that most people find difficulty in adjusting their sexual lives; but a clinic is no place to secure incidence figures. The incidence of tuberculosis in a tuberculosis sanitarium is no measure of the incidence of tuberculosis in the population as a whole; and the incidence of disturbance over sexual activities, among the persons who come to a clinic, is no measure of the frequency of similar disturbances outside of clinics. The impression that such “sexual irregularities” as “excessive” masturbation, pre-marital intercourse, responsibility for a pre-marital pregnancy, extramarital intercourse, mouth-genital contacts, homosexual activity, or animal intercourse, always produce psychoses and abnormal personalities is based upon the fact that the persons who do go to professional sources for advice are upset by these things.

It is unwarranted to believe that particular types of sexual behavior are always expressions of psychoses or neuroses. In actuality, they are more often expressions of what is biologically basic in mammalian and anthropoid behavior, and of a deliberate disregard for social convention. Many of the socially and intellectually most significant persons in our histories, successful scientists, educators, physicians, clergymen, business men, and persons of high position in governmental affairs, have socially taboo items in their sexual histories, and among them they have accepted nearly the whole range of so-called sexual abnormalities. Among the socially most successful and personally best adjusted persons who have contributed to the present study, there are some whose rates of outlet are as high as those in any case labelled nymphomania or satyriasis in the literature, or recognized as such in the clinic.

Clinical subjects who have such unusual items in their histories often do present psychopathologies — that is why they have gone to the clinics. But the presence of particular behavior, or the existence of a high rate, is not the abnormality which needs explanation. The real clinical problem is the discovery and treatment of the personality defects, the mental difficulties, the compulsions, and the schizophrenic conflicts which lead particular individuals to crack up whenever they depart from averages or socially accepted custom, while millions of other persons embrace the very same behavior, and may have as high rates of activity, without personal or social disturbance. It has been too simple a solution to discover the sexual items in a patient’s history, to consider them symptoms of a neurosis, and to diagnose the disturbance as the outcome of the departure from the established mores. It is much more difficult to discover the bases of the unstable personalities that are upset by such sexual departures, and to treat the basic defects rather than to patch up the particular issues over which the disturbances occur. Clinicians would have more incentive for using such an approach if they were better acquainted with the normal frequencies of the so-called abnormal types of activity, and if, at least as far as sex is concerned, they could acquire a wider acquaintance with the sexual histories of well-adjusted individuals.

Most of the complications which are observable in sexual histories are the result of society’s reactions when it obtains knowledge of an individual’s behavior, or the individual’s fear of how society would react if he were discovered. In various societies, under various circumstances, and (as we shall later show) even at various social levels of the population living in a particular town, the sex mores are fundamentally different. The way in which each group reacts to a particular sort of history determines the “normality” or “abnormality” of the individual’s behavior — in that particular group (Benedict 1934). Whatever the moral interpretation (as in Moore 1943), there is no scientific reason for considering particular types of sexual activity as intrinsically, in their biologic origins, normal or abnormal. Yet scientific classifications have been nearly identical with theologic classifications and with the moral pronouncements of the English common law of the fifteenth century. This, in turn, as far as sex is concerned, was based on the medieval ecclesiastic law which was only a minor variant of the tenets of ancient Greek and Roman cults, and of the Talmudic law (Angus 1925, May 1931). Present-day legal determinations of sexual acts which are acceptable, or “natural,” and those which are “contrary to nature” are not based on data obtained from biologists, nor from nature herself. On the contrary, the ancient codes have been accepted by laymen, jurists, and scientists alike as the ultimate sources of moral evaluations, of present-day legal procedure, and of the list of subjects that may go into a textbook of abnormal psychology. In no other field of science have scientists been satisfied to accept the biologic notions of ancient jurists and theologians, or the analyses made by the mystics of two or three thousand years ago. Either the ancient philosophers were remarkably well-trained psychologists, or modern psychologists have contributed little in defining abnormal sexual behavior.

The reactions of our social organization to these various types of behavior are the things that need study and classification. The mores, whether they concern food, clothing, sex, or religious rituals, originate neither in accumulated experience nor in scientific examinations of objectively gathered data. The sociologist and anthropologist find the origins of such customs in ignorance and superstition, and in the attempt of each group to set itself apart from its neighbors. Psychologists have been too much concerned with the individuals who depart from the group custom. It would be more important to know why so many individuals conform as they do to such ancient custom, and what psychology is involved in the preservation of these customs by a society whose individual members would, in most cases, not attempt to defend all of the specific items in that custom. Too often the study of behavior has been little more than a rationalization of the mores masquerading under the guise of objective science.

While this problem will be met again in other places, the present discussion of frequencies of total sexual outlet provides a good opportunity for understanding the futility of classifying individuals as normal or abnormal, or well-adjusted or poorly adjusted, when in reality they may be nothing more than frequent or rare, or conformists or non-conformists with the socially pretended custom.

As a conclusion to this section, it seems appropriate, therefore, to summarize the record of individual variation which has thus far been presented in the sample of the females.

1.    Incidences and Frequencies of Erotic Response. We have noted that there were 2 per cent of the females in the sample who had never been aroused erotically. There were some who had been aroused only once or twice or a very few times in their lives. At the other extreme there were females who had been aroused almost daily, and sometimes many times per day, for long periods of years. There was, of course, every gradation between those extremes.

2.    Intensity of Erotic Response. The same degree of tactile or psychologic stimulation had brought very different responses from different females. There were individuals who had responded mildly, with only mild physiologic reactions and without reaching orgasm; but there were other females who had responded instantaneously to a wide variety of stimuli, with intense physiologic reactions which had quickly led to orgasm.

3.    Physical vs. Psychologic Sources of Arousal. Among those who had ever been aroused, there was no female who had been totally unresponsive to tactile stimulation, but there were females in the sample who appear to have never been aroused by any sort of psychosexual stimuli. At the other extreme there were females who had been aroused by a great variety of psychologic stimuli, and some who had responded to the point of orgasm from psychologic stimulation alone. There were females in the sample who had been more responsive to psychologic stimulation than any male we have known.

4.    Sources of Psychologic Stimulation. Among those females who had been aroused by psychologic stimuli, there were some who had responded to only a single sort of situation, and some who had responded to every conceivable sort of psychologic stimulation, including the observation of other persons, the observation of sexual objects or activity, fantasies of sexual objects or activity, recall of past experience, and the anticipation of new experience. There was every gradation between females who had responded only occasionally to a single sort of psychologic stimulus, and females who had responded regularly to every item of psychosexual stimulation.

5.    Age at First Erotic Response. We have reported female infants showing erotic responses at birth and specific responses by four months of age, we have reported the various ages at which other females first responded, and we have reported that there were some females who had not experienced their first erotic arousal until they were over thirty years of age .

6.    Age at First Response to Orgasm. We have recorded female infants reaching orgasm as early as four months of age, and we have indicated that there were some 9 per cent of the females in the sample who had lived into their late forties without reaching orgasm. There were females in the sample who had reached their first orgasm at every age between these extremes, including three who had not reached their first orgasm until they were between forty-eight and fifty years of age.

7.    Frequencies of Orgasm. Among the females who had responded to orgasm, there were some who had never responded more than once or twice in their lives. This was true even of some of the females who had been married for long periods of years. There were others who had responded in 1 or 2 per cent of their marital coitus, but there were many more who had responded much more often, including some 40 to 50 per cent who had responded to orgasm in nearly all of their coitus.

8.    Continuity of Response. We have shown that there were females who had been only occasionally aroused to the point of orgasm, with lapses of weeks or months and in some instances of some years between periods of arousal or orgasm. We have the record of one female who had gone for twenty-eight years between periods of coitus, with a masturbatory outlet of not more than one orgasm every two years in that long period. On the other hand, there were cases of females who had responded with high frequencies and great regularity throughout their lives, and there were cases with every conceivable pattern of discontinuity.

9.    Aging Effects. There were females in the sample who had responded earlier in their lives but who had ceased to experience orgasm and, in some instances, to be aroused erotically after their late thirties or forties. More of the females had responded until they were in their fifties or sixties, and we have recorded the case of one ninety-year-old female who was still responding regularly.

10. Sources of Outlet. There were females in the sample who had derived their entire sexual outlet from a single source, which was sometimes masturbation, or petting to climax, pre-marital coitus, marital coitus, or some homosexual contact. There were a few instances of females who had never experienced orgasm except in nocturnal dreams, and instances of married females who had never experienced orgasm except in extra-marital coitus. There were females in the sample who, in the course of their lives, had utilized all six of the possible sources of outlet, and some who were utilizing all six in a single five-year period. After the age of fifteen, something between 27 and 44 per cent of the females in the sample were depending upon a single source of outlet within each five-year period; something between 16 and 33 per cent were utilizing two sources of outlet more or less simultaneously; something between 6 and 16 per cent were utilizing three sources, and a smaller percentage was utilizing four to six sources within single age periods. There had been every conceivable combination of the possible types of sexual outlet.

11. The Combination of Variables. The sexual history of each individual represents a unique combination of these variables. There is little chance that such a combination has ever existed before, or ever will exist again. We have never found any individual who was a composite of all of the averages on all of the aspects of sexual response and overt activity which we have analyzed in the present volume. This is the most important fact which we can report on the sexual histories of the females who have contributed to the present study.

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