The Naked Ape

by Desmond Morris

  So it seems plausible to consider that face-to-face copulation is basic to our species. There are, of course, a number of variations that do not eliminate the frontal element: male above, female above, side by side, squatting, standing, and so on, but the most efficient and commonly used one is with both partners horizontal, the male above the female. American investigators have estimated that in their culture 70 per cent of the population employ only this position. Even those who vary their postures still use the basic one for much of the time. Fewer than ten per cent experiment with rear-entry positions. In a massive cross-cultural survey involving nearly two hundred different societies scattered all over the world, the conclusion was that copulation with the male entering the female from the rear does not occur as the usual practice in any of the communities studied.

  If we can now accept this fact, we can return from this slight digression to the original question concerning sexual self-mimicry. If the female of our species was going to successfully shift the interest of the male round to the front, evolution would have to do something to make the frontal region more stimulating. At some point, back in our ancestry, we must have been using the rear approach. Supposing we had reached the stage where the female signalled sexually to the male from behind with a pair of fleshy, hemispherical buttocks (not, incidentally, found elsewhere amongst the primates) and a pair of bright red genital lips, or labia. Supposing the male had evolved a powerful sexual responsiveness to these specific signals. Supposing that, at this point in evolution, the species became increasingly vertical and frontally orientated in its social contacts. Given this situation, one might very well expect to find some sort of frontal self-mimicry of the type seen in the gelada baboon. Can we, if we look at the frontal regions of the females of our species, see any structures that might possibly be mimics of the ancient genital display of hemispherical buttocks and red labia? The answer stands out as clearly as the female bosom itself. The protuberant, hemispherical breasts of the female must surely be copies of the fleshy buttocks, and the sharply defined red lips around the mouth must be copies of the red labia. (You may recall that, during intense sexual arousal, both the lips of the mouth and the genital labia become swollen and deeper in colour, so that they not only look alike, but also change in the same way in sexual excitement.) If the male of our species was already primed to respond sexually to these signals when they emanated posteriorly from the genital region, then he would have a built-in susceptibility to them if they could be reproduced in that form on the front of the female’s body. And this, it would seem, is precisely what has happened, with the females carrying a duplicate set of buttocks and labia on their chests and mouths respectively. (The use of lipsticks and brassières immediately springs to mind, but these must be left until later, when we are dealing with the special sexual techniques of modern civilization.)

  In addition to the all-important visual signals, there are certain odour stimuli that play a sexual role. Our sense of smell has been considerably reduced during evolution, but it is reasonably efficient and is more operative during sexual activities than we normally realize. We know that there are sex differences in body odours and it has been suggested that part of the process of pair-formation – falling in love – involves a kind of olfactory imprinting, a fixation on the specific individual odour of the partner’s body. Connected with this is the intriguing discovery that at puberty there is a marked change in odour preferences. Before puberty there are strong preferences for sweet and fruity odours, but with the arrival of sexual maturity this response falls off and there is a dramatic shift in favour of flowery, oily and musky odours. This applies to both sexes, but the increase in musk responsiveness is stronger in males than females. It is claimed that as adults we can detect the presence of musk even when it is diluted down to one part in eight million parts of air, and it is significant that this substance plays a dominant role in the scent-signalling of many mammalian species, being produced in specialized scent-glands. Although we ourselves do not possess any large scent glands, we do have a large number of small ones – the apocrine glands. These are similar to ordinary sweat glands, but their secretions contain a higher proportion of solids. They occur on a number of parts of the body, but there are specially high concentrations of them in the regions of the armpits and the genitals. The localized hair-tufts that grow in these areas undoubtedly function as important scent-traps. It has been claimed that scent production in these areas is heightened during sexual arousal, but no detailed analysis of this phenomenon has yet been made. We do, however, know that there are 75 per cent more apocrine glands in the female of our species than in the male, and it is interesting to recall that in lower mammals during sexual encounters the male sniffs the female more than she sniffs him.

  The location of our specialized odour-producing areas appears to be yet another adaptation to our frontal approach to sexual contact. There is nothing unusual about the genital centre, this we have in common with many other mammals, but the armpit concentration is a more unexpected feature. It appears to relate to the general tendency in our species to add new sexual stimulation centres to the front end of the body, in connection with the great increase in face-to-face sexual contacts. In this particular case it would result in the partner’s nose being kept in close proximity with a major scent-producing area throughout much of the pre-copulatory and copulatory activity.

  Up to this point we have been considering ways in which the appetitive sexual behaviour of our species has been improved and extended, so that contacts between the members of a mated pair have become increasingly rewarding, and their pair-bond therefore strengthened and maintained. But appetitive behaviour leads to a consummatory act and some improvements have been needed here too. Consider for a moment the old primate system. The adult males are sexually active all the time, except when they have just ejaculated. A consummatory orgasm is valuable for them because the relief from sexual tension that it brings damps down their sexual urges long enough for their sperm supplies to be replenished. The females, on the other hand, are sexually active only for a limited period centred around their ovulation time. During this period they are ready to receive the males at any time. The more copulations they experience, the greater the insurance that successful fertilization will be achieved. For them, there is no sexual satiation, no moment of copulatory climax that would pacify and tame their sexual urges. While they are on heat, there is no time to lose, they must keep going at all costs. If they experienced intense orgasms, they would then waste valuable potential mating time. At the end of a copulation, when the male ejaculates and dismounts, the female monkey shows little sign of emotional upheaval and usually wanders off as if nothing had happened.

  With our own pair-bonding species the situation is entirely different. In the first place, as there is only a single male involved, there is no particular advantage in the female being sexually responsive at the point where he is sexually spent. So there is nothing working against the existence of a female orgasm. There are, however, two things working very much in its favour. One is the immense behavioural reward it brings to the act of sexual co-operation with the mated partner. Like all the other improvements in sexuality this will serve to strengthen the pair-bond and maintain the family unit. The other is that it considerably increases the chances of fertilization. It does this in a rather special way that applies only to our own peculiar species. Again, to understand this, we must look back at our primate relatives. When a female monkey has been inseminated by a male, she can wander away without any fear of losing the seminal fluid that now lies in the innermost part of her vaginal tract. She walks on all fours. The angle of her vaginal passage is still more or less horizontal. If a female of our own species were so unmoved by the experience of copulation that she too was likely to get up and wander off immediately afterwards, the situation would be different, for she walks bipe-dally and the angle of her vaginal passage during normal locomotion is almost vertical. Under the simple influence of gravity the
seminal fluid would flow back down the vaginal tract and much of it would be lost. There is therefore a great advantage in any reaction that tends to keep the female horizontal when the male ejaculates and stops copulating. The violent response of female orgasm, leaving the female sexually satiated and exhausted, has precisely this effect. It is therefore doubly valuable.1

  The fact that the female orgasm in our species is unique amongst primates, combined with the fact that it is physiologically almost identical with the orgasmic pattern of the male, suggests that perhaps it is in an evolutionary sense a ‘pseudo-male’ response. In the make-up of both males and females there are latent properties belonging to the opposite sex. We know from comparative studies of other groups of animals that evolution can, if necessary, call up one of these latent qualities and bring it into the front line (in the ‘wrong’ sex, as it were). In this particular instance we know that the female of our species has developed a particular susceptibility to sexual stimulation of the clitoris. When we remember that this organ is the female homologue, or counterpart, of the male penis, this does seem to point to the fact that, in origin at any rate, the female orgasm is a ‘borrowed’ male pattern.

  This may also explain why the male has the largest penis of any primate. It is not only extremely long when fully erect, but also very thick when compared with the penises of other species. (The chimpanzee’s is a mere spike by comparison.) This broadening of the penis results in the female’s external genitals being subjected to much more pulling and pushing during the performance of pelvic thrusts. With each inward thrust of the penis, the clitoral region is pulled downwards and then, with each withdrawal, it moves up again. Add to this the rhythmic pressure being exerted on to the clitoral region by the pubic region of the frontally copulating male, and you have a repeated massaging of the clitoris that – were she a male – would virtually be masturbatory.

  So we can sum up by saying that with both appetitive and consummatory behaviour, everything possible has been done to increase the sexuality of the naked ape and to ensure the successful evolution of a pattern as basic as pair-formation, in a mammalian group where it is elsewhere virtually unknown. But the difficulties of introducing this new trend are not over yet. If we look at our naked ape couple, still successfully together and helping one another to rear the infants, all appears to be well. But the infants are growing now and soon they will have reached puberty, and then what? If the old primate patterns are left unmodified, the adult male will soon drive out the young males and mate with the young females. These will then become part of the family unit as additional breeding females along with their mother, and we shall be right back where we started. Also, if the young males are driven out into an inferior status on the edge of society, as in many primate species, then the co-operative nature of the all-male hunting group will suffer.

  Clearly some additional modification to the breeding system is needed here, some kind of exogamy or out-breeding device. For the pair-bond system to survive, both the daughters and the sons will have to find mates of their own. This is not an unusual demand for pair-forming species and many examples of it can be found amongst the lower mammals, but the social nature of most primates makes it a more difficult proposition. In most pair-forming species the family splits up and spreads out when the young grow up. Because of its co-operative social behaviour the naked ape cannot afford to scatter in this way. The problem is therefore kept much more on the doorstep, but it is solved in basically the same way. As with all pair-bonded animals, the parents are possessive of one another. The mother ‘owns’ the father sexually and vice versa. As soon as the offspring begin to develop their sexual signals at puberty, they become sexual rivals, the sons of the father and the daughters of the mother. There will be a tendency to drive them both out. The offspring will also begin to develop a need for a home-based ‘territory’ of their own. The urge to do this must obviously have been present in the parents for them to have set up a breeding home in the first place, and the pattern will simply be repeated. The parental home-base, dominated and ‘owned’ by the mother and father, will not have the right properties. Both the place itself and the individuals living in it will be heavily loaded with both primary and associative parental signals. The adolescent will automatically reject this and set off to establish a new breeding base. This is typical of young territorial carnivores, but not of young primates, and this is one more basic behavioural change that is going to be demanded of the naked ape.

  It is perhaps unfortunate that this phenomenon of exogamy is so often referred to as indicating an ‘incest taboo’. This immediately implies that it is a comparatively recent, culturally controlled restriction, but it must have developed biologically at a much earlier stage, or the typical breeding system of the species could never have emerged from its primate background.

  Another related feature, and one that appears to be unique to our species, is the retention of the hymen or maidenhead in the female. In lower mammals it occurs as an embryonic stage in the development of the urogenital system, but as part of the naked ape’s neoteny it is retained. Its persistence means that the first copulation in the life of the female will meet with some difficulty. When evolution has gone to such lengths to render her as sexually responsive as possible, it is at first sight strange that she should also be equipped with what amounts to an anti-copulatory device. But the situation is not as contradictory as it may appear. By making the first copulation attempt difficult and even painful, the hymen ensures that it will not be indulged in lightly. Clearly, during the adolescent phase, there is going to be a period of sexual experimentation, of ‘playing the field’ in search of a suitable partner. Young males at this time will have no good reason for stopping short of full copulation. If a pair-bond does not form they have not committed themselves in any way and can move on until they find a suitable mate. But if young females were to go so far without pair-formation, they might very well find themselves pregnant and heading straight towards a parental situation with no partner to accompany them. By putting a partial brake on this trend in the female, the hymen demands that she shall have already developed a deep emotional involvement before taking the final step, an involvement strong enough to take the initial physical discomfort in its stride.

  A word must be added here on the question of monogamy and polygamy. The development of the pair-bond, which has occurred in the species as a whole, will naturally favour monogamy, but it does not absolutely demand it. If the violent hunting life results in adult males becoming scarcer than females, there will be a tendency for some of the surviving males to form pair-bonds with more than one female. This will then make it possible to increase the breeding rate without setting up dangerous tensions by creating ‘spare’ females. If the pair-formation process became so totally exclusive that it prevented this, it would be inefficient. This would not be an easy development, however, because of the possessiveness of the females concerned and the dangers of provoking serious sexual rivalries between them. Also working against it would be the basic economic pressures of maintaining the larger family group with all its offspring. A small degree of polygamy could exist, but it would be severely limited. It is interesting that although it still occurs in a number of minor cultures today, all the major societies (which account for the vast majority of the world population of the species) are monogamous. Even in those that permit polygamy, it is not usually practised by more than a small minority of the males concerned. It is intriguing to speculate as to whether its omission from almost all the larger cultures has, in fact, been a major factor in the attainment of their present successful status. We can, at any rate, sum up by saying that, whatever obscure, backward tribal units are doing today, the mainstream of our species expresses its pair-bonding character in its most extreme form, namely long-term monogamous matings.

  This, then, is the naked ape in all its erotic complexity: a highly sexed, pair-forming species with many unique features; a complicated blend of primate ancestry with extens
ive carnivore modifications. Now, to this we must add the third and final ingredient: modern civilization. The enlarged brain that accompanied the transformation of the simple forest-dweller into a co-operative hunter began to busy itself with technological improvements. The simple tribal dwelling places became great towns and cities. The axe age blossomed into the space age. But what effect did the acquisition of all this gloss and glitter have on the sexual system of the species? Very little, seems to be the answer. It has all been too quick, too sudden, for any fundamental biological advances to occur. Superficially they seem to have occurred, it is true, but this is largely make-believe. Behind the façade of modern city life there is the same old naked ape. Only the names have been changed: for ‘hunting’ read ‘working’, for ‘hunting grounds’ read ‘place of business’, for ‘home base’ read ‘house’, for ‘pair-bond’ read ‘marriage’, for ‘mate’ read ‘wife’, and so on. The American studies of contemporary sexual patterns, referred to earlier, have revealed that the physiological and anatomical equipment of the species is still being put to full use. The evidence of prehistoric remnants combined with comparative data from living carnivores and other living primates has given us a picture of how the naked ape must have used this sexual equipment in the distant past and how he must have organized his sex life. The contemporary evidence appears to give much the same basic picture, once one has cleaned away the dark varnish of public moralizing. As I said at the beginning of the chapter, it is the biological nature of the beast that has moulded the social structure of civilization, rather than the other way around.