Clearly the situation is more complicated than it at first appears. A great deal will depend on the exact temperature levels of the environment and on the amount of direct sunshine. Even if we suppose that the climate was suitable for hair loss—that is, moderately hot, but not intensely hot—we still have to explain the striking difference in coat condition between the naked ape and the other open-country carnivores.
There is one way we can do this, and it may give the best answer yet to the whole problem of our nakedness. The essential difference between the hunting ape and his carnivore rivals was that he was not physically equipped to make lightning dashes after his prey or even to undertake long endurance pursuits. But this is nevertheless precisely what he had to do. He succeeded because of his better brain, leading to more intelligent manoeuvring and more lethal weapons, but despite this, such efforts must have put a huge strain on him in simple physical terms. The chase was so important to him that he would have to put up with this, but in the process he must have experienced considerable over-heating. There would be a strong selection pressure working to reduce this over-heating and any slight improvement would be favoured, even if it meant sacrifices in other directions. His very survival depended on it. This surely was the key factor operating in the conversion of a hairy hunting ape into a naked ape. With neoteny to help the process on its way, and with the added advantages of the minor secondary benefits already mentioned, it would become a viable proposition. By losing the heavy coat of hair and by increasing the number of sweat glands all over the body surface, considerable cooling could be achieved—not for minute by minute living, but for the supreme moment of the chase—with the production of a generous film of evaporating liquid over his air-exposed straining limbs and trunk.
This system would not succeed, of course, if the climate were too intensely hot, because of damage to the exposed skin; but in a moderately hot environment it would be acceptable. It is interesting that the trend was accompanied by the development of a subcutaneous fat layer, which indicates that there was a need to keep the body warm at other times. If this appears to counterbalance the loss of the hairy coat, it should be remembered that the fat layer helps to retain the body heat in cold conditions, without hindering the evaporation of sweat when over-heating takes place. The combination of reduced hair, increased sweat glands, and the fatty layer under the skin appears to have given our hard-working ancestors just what they needed, bearing in mind that hunting was one of the most important aspects of their new way of life.
So there he stands, our vertical, hunting, weapon-toting, territorial, neotenous, brainy, Naked Ape, a primate by ancestry and a carnivore by adoption, ready to conquer the world. But he is a very new and experimental departure, and new models frequently have defections. For him the main troubles will stem from the fact that his culturally operated advances will race ahead of any further genetic ones. His genes will lag behind, and he will be constantly reminded that, for all his environment-moulding achievements, he is still at heart a very naked ape.
At this point we can leave his past behind us and see how we find him faring today. How does the modern naked ape behave? How does he tackle the age-old problems of feeding, fighting, mating, and rearing his young? How much has his computer of a brain been able to reorganise his mammalian urges? Perhaps he has had to make more concessions than he likes to admit. We shall see.
SEXUALLY the naked ape finds himself today in a somewhat confusing situation. As a primate he is pulled one way, as a carnivore by adoption he is pulled another, and as a member of an elaborate civilised community he is pulled yet another.
To start with, he owes all his basic sexual qualities to his fruit-picking, forest-ape ancestors. These characteristics were then drastically modified to fit in with his open country, hunting way of life. This was difficult enough, but then they, in turn, had to be adapted to match the rapid development of an increasingly complex and culturally determined social structure. The first of these changes, from a sexual fruit-picker to a sexual hunter, was achieved over a comparatively long period of time and with reasonable success. The second change has been less successful. It has happened too quickly and has been forced to depend upon intelligence and the application of learned restraint rather than on biological modifications based on natural selection. It could be said that the advance of civilisation has not so much moulded modern sexual behaviour, as that sexual behaviour has moulded the shape of civilisation. If this seems to be a rather sweeping statement, let me first put my case and then we can return to the argument at the end of the chapter.
To begin with we must establish precisely how the naked ape does behave today when indulging in sexual behaviour. This is not as easy as it sounds, because of the great variability that exists, both between and within societies. The only solution is to take average results from large samples of the most successful societies. The small, backward, and unsuccessful societies can largely be ignored. They may have fascinating and bizarre sexual customs, but biologically speaking they no longer represent the mainstream of evolution. Indeed, it may very well be that their unusual sexual behaviour has helped to turn them into biological failures as social groups.
Most of the detailed information we have available stems from a number of painstaking studies carried out in recent years in North America and based largely on that culture. Fortunately it is biologically a very large and successful culture and can, without undue fear of distortion, be taken as representative of the modern naked ape.
Sexual behaviour in our species goes through three characteristic phases: pairformation, pre-copulatory activity, and copulation, usually but not always in that order. The pair-formation stage, usually referred to as courtship, is remarkably prolonged by animal standards, frequently lasting for weeks or even months. As with many other species it is characterised by tentative, ambivalent behaviour involving conflicts between fear, aggression and sexual attraction. The nervousness and hesitancy is slowly reduced if the mutual sexual signals are strong enough. These involve complex facial expressions, body postures and vocalisations. The latter involve the highly specialised and symbolised sound signals of speech, but equally importantly they present to the member of the opposite sex a distinctive vocalization tone. A courting couple is often referred to as ‘murmuring sweet nothings’ and this phrase sums up clearly the significance of the tone of voice as opposed to what is being spoken.
After the initial stages of visual and vocal display, simple body contacts are made. These usually accompany locomotion, which is now considerably increased when the pair are together, Hand-to-hand and arm-to-arm contacts are followed by mouth-to-face and mouth-to-mouth ones. Mutual embracing occurs, both statically and during locomotion. Sudden spontaneous outbursts of running, chasing, Jumping and dancing are commonly seen and juvenile play patterns may reappear.
Much of this pair-formation phase may take place in public, but when it passes over into the pre-copulatory phase, privacy is sought and the subsequent patterns of behaviour are performed in isolation from other members of the species as far as is possible. With the pre-copulatory stage there is a striking increase in the adoption of a horizontal posture. Body-to-body contacts are increased in both force and duration. Low intensity side-by-side postures repeatedly give way to high-intensity face-to-face contacts. These positions may be maintained for many minutes and even for several hours, during which vocal and visual signals become gradually less important and tactile signals increasingly frequent. These involve small movements and varying pressures from all parts of the body, but in particular from the fingers, hands, lips and tongue. Clothing is partially or totally removed and skin-to-skin tactile stimulation is increased over as wide, an area as possible.
Mouth-to-mouth contacts reach their highest frequency and their longest duration during this phase, the pressure exerted by the lips varying from extreme gentleness to extreme violence. During the higher-intensity responses the lips are parted and the tongue is inserted into the partner’s mouth. Active movements of the tongue are ten used to stimulate the sensitive skin of the mouth interior. The lips and tongue are also applied to many other areas of the partner’s body, especially the ear-lobes, the neck and the genitals. The male pays particular attention to the breasts and nipples of the female, and the lip and tongue contact here becomes extended into more elaborate licking and sucking. Once contacted, the partner’s genitals may also become the target for repeated actions of this kind. When this occurs, the male concentrates largely on the female’s clitoris, the female on the male’s penis, although other areas are also involved in both cases.
In addition to kissing, licking and sucking, the mouth is also applied to various regions of the Partner’s body in a biting action of varying intensities. Typically this involves no more than soft nibbling of the skin, or gentle nipping, but it can sometimes develop into forceful or even painful biting.
Interspersed between bouts of oral stimulation of the partner’s body, and frequently accompanying it, there is a great deal of skin manipulation. The hands and fingers explore the whole body surface, concentrating especially on the face and, at higher intensities, on the buttocks and genital region. As in oral contacts, the male pays particular attention to the female’s breasts and nipples. Wherever they move, the fingers repeatedly stroke and caress. From time to time they grasp with great force and the fingernails may be dug deeply into the flesh. The female may grasp the penis of the male, or stroke it rhythmically, simulating the movements of copulation, and the male stimulates the female genitals, especially the clitoris, in a similar way, again frequently with rhythmic movements.
In addition to these mouth, hand and general body contacts, there is also a tendency at high intensities of pre-copulatory activity to rub the genitals rhythmically against the partner’s body. There is also a considerable amount of twining and intertwining of the arms and legs, with occasional powerful muscle contractions, so that the body is thrown into a state of clinging tension, followed by relaxation.
These, then, are the sexual stimuli that are given to the partner during bouts of precopulatory activity, and which produce sufficient physiological sexual arousal for copulation to occur. Copulation starts with the insertion of the male’s penis into the female’s vagina. This is most commonly performed with the couple face-to-face, the male over the female, both in a horizontal position, with the female’s legs apart. There are many variations of this position, as we shall be discussing later, but this is the simplest and most typical one. The male then begins a series of rhythmical pelvic thrusts. These can vary considerably in strength and speed, but in an uninhibited situation they are usually rather rapid and deeply penetrating. As copulation progresses there is a tendency to reduce the amount of oral and manual contact, or at least to reduce its subtlety and complexity. Nevertheless these now subsidiary forms of mutual stimulation do still continue to some extent throughout most copulatory sequences.
The copulatory phase is typically much briefer than the pre-copulatory phase. The male reaches the consummatory act of sperm ejaculation within a few minutes in most cases, unless deliberate delaying tactics are employed. Other female primates do not appear to experience a climax to their sexual sequences, but the naked ape is unusual in this respect. If the male continues to copulate for a longer period of time, the female also eventually reaches a consummatory moment, an explosive orgasmic experience, as violent and tension-releasing as the male’s, and physiologically identical with it in every way except for the single obvious exception of sperm ejaculation. Some females may reach this point very quickly, others not at all, but on the average it is attained between ten and twenty minutes after the start of copulation.
It is strange that there is this discrepancy between the male and female as regards the time taken to reach sexual climax and relief from tension. This is a matter that will have to be discussed in detail later when the functional significance of the various sexual patterns are being considered. Suffice it to say at this point that the male can overcome the time factor and arouse the female to orgasm either by prolonging and heightening the pre-copulatory stimulation, so that she is already strongly aroused before penis insertion takes place, or he can employ self-inhibitory tactics during copulation to delay his own climax, or he can continue to copulate immediately after ejaculation and before he loses his erection, or he can rest briefly and then copulate for a second time. In the latter case, his reduced sex drive will automatically ensure that he takes much longer to reach his next climax and this will give the female sufficient time on this occasion to reach hers.
After both partners have experienced orgasm, there normally follows a considerable period of exhaustion, relaxation, rest, and frequently sleep. From the sexual stimuli we must now turn to the sexual responses. How does the body respond to all this intensive stimulation? In both sexes there are marked increases in pulse rate, blood pressure and respiration. These changes begin during pre-copulatory activities and rise to a peak at the copulatory climax. Pulse rates which, at normal level, stand at 70 to 80 per minute, rise to go to 100 during the earlier phases of sexual arousal, then climb to 130 during intense arousal and attain a peak of about 140 at orgasm. Blood pressure that starts at about 120 rises to 200 or even 250 at the sexual climax. Breathing becomes deeper and more rapid as arousal develops and then, as orgasm approaches, develops into prolonged gasping often accompanied by rhythmic moaning or grunting. At climax the face may be contorted, with mouth wide open and nostrils expanded, in a manner similar to that seen in an athlete in extremis, or someone fighting for air.