by Robin Baker
It is a week since they had sex – last Saturday, in fact. Four years ago, when they first met, they had sex at least once a day (except during her menstrual periods, when neither of them was particularly keen). In those early days they would have ridiculed the possibility of intercourse only once in a whole week. Now, once a week had become more and more common, even though their usual routine was still to have sex twice a week. Until, that is, two months ago when they had given up using contraception.
Not that they were in any rush to have children. They hadn’t yet contemplated the earnest nightly conception campaigns that some of their thirty-something friends had delighted in describing to them. Rather, they preferred to leave it to fate (and so far fate had decreed ‘no conception’). They had both found mild sexual excitement in the possibility of conception and for a while their rate had returned to three or four times a week. This week, however, had been different. A couple of separate nights out and, if they were honest, an unexplained coolness between them had conspired against their ever quite getting round to sex. The usual warmth of their relationship had not fully returned until this Saturday morning as they drove on a pre-arranged visit to her sister. Even now, as they eventually got into bed, they could both still feel the legacy of the week’s coolness. It was with some tentativeness that the man made his first faltering contacts with his partner’s bare body. Once started, however, they quickly slipped into their usual routine.
He begins by gently kissing her face and stroking her breasts. Then they kiss deeply. He strokes her legs to her knees. After a while, he moves down and sucks her nipples. All this time, she cursorily strokes his back and buttocks. Tonight, as is often the case, she cannot concentrate and her mind keeps slipping back to conversations with her sister earlier in the day. She is jolted back to the present when he places his hand between her legs, moves her longest pubic hairs, opens her lips and inserts a finger to check if she is wet. He thinks she is ready. She knows she is not and winces at the prospect of unlubricated penetration. She moves her hand, finds his penis and gently squeezes, in part to see how ready he is but primarily to delay his moving into position. Briefly, her ploy works. He pauses to savour the sensation and responds with half-hearted massage of her genitals. Even though his massage misses her clitoris by a centimetre, he detects (or imagines) an increase in wetness on his finger inside her vagina. He moves his hand and begins to shift his body into the missionary position. She keeps her hand on his penis, and when the moment comes helps to guide its swollen tip into position. She leaves her hand between them for a few seconds to stop him pushing too hard, too soon (she is still nowhere near moist enough). Then, she has no alternative but to abandon the act to him. It takes a while before his gentle working backwards and forwards makes her lubricants really start to flow and his penis is able to enter fully.
Until she was lubricated, the woman had focused her mind on his and her genitals and the mechanics of penetration. But once she is lubricated and he begins the routine of thrusting, her mind drifts back to her sister. Her attention returns to the present only when he makes an uncomfortable movement. Despite her abstractedness, years of practice allow her to time the quiet noises in her throat to the man’s thrusts. Then, suddenly, her mind jumps back to Wednesday night and the man who had flirted with her when she was out with a group of her female friends. Now, in her mind, it is him on top of her. Her heart speeds up, her breathing quickens, and her noises get louder. But just as her fantasy begins to take shape and she feels she might even come, her partner makes a particularly awkward thrust. Her fantasy disappears. The moment has gone, and the next second she realises he is ejaculating. She makes a sound for each of his contractions, then relaxes with him as his penis shrinks inside her. Impatient for him to remove his now dead weight, she coughs, gently. His limp appendage is ejected, he moves off her and they slip into their usual post-coital embrace. Both feel guilty at not having made more effort for their partner’s sake and both feel depressed. Briefly, they exchange untruths over how pleasurable everything had been before eventually drifting into post-coital sleep.
For most people, the commonest situation in which they have sexual intercourse is at home and with a long-term partner. Rapidly, such intercourse becomes a matter of routine within the relationship; but, routine as it may be, it plays a surprisingly important role in the man’s and the woman’s pursuit of reproductive success.
This chapter consists of Scenes 2 to 5, each of which explores one or more facets of intercourse within a long-term relationship. Whereas most of the scenes in the book will involve different characters in different situations, these first few (Scenes 2 to 7) follow a single couple. We stay with them and follow their routine sex until the woman conceives and we have unravelled the full story behind her conception.
While interpreting these first scenes, I take the opportunity to explain some of the basics of human sexuality. Many of these will be well known to readers, but I guarantee a few surprises. Some of the descriptions may seem a little detailed, but this detail will help later when we discuss some of the more interesting aspects of human sexual behaviour – such as male and female masturbation and the female orgasm.
Anyone who has ever lived in a sexual relationship for a few years should find familiar elements in the scene we have just witnessed. In fact, it is so familiar that there is a danger of missing the subtlety of both people’s behaviour. Here we meet a couple who have had penetrative sex perhaps five hundred times in the four years of their relationship. Yet not one of those inseminations has led to pregnancy. Of course, they have been using contraceptives, but from time to time they will have been careless and the woman could have become pregnant, but she didn’t. Now they have stopped taking contraceptives, but she still hasn’t conceived.
Clearly, they have not repeated this particular act five hundred times in order to have children. Nor are they unusual in this. The average man and woman, no matter whether they live in the bush of the Kalahari desert or in a multi-bedroomed executive house, will have penetrative sex about two to three thousand times in their lifetime. Yet, even without modern contraception, most people have fewer than seven children. This works out at about five hundred inseminations to produce each child, though the precise figure is unimportant. Whatever the fine details of the arithmetic, the conclusion is inescapable. From the viewpoint of reproductive success, people do not have routine sex primarily to produce children.
Nor are humans unique in this respect. In fact, compared to other primates, we are probably fairly average in terms of the number of inseminations per offspring. We pale into insignificance compared with pygmy chimps, who seem always to be having sex. Outside of primates, the lion, which takes three thousand inseminations to produce another lion, also beats us fairly easily. Some birds may mate only a handful of times for each nestling, but others are about the same as us and mate hundreds of times to produce each young bird. So why do we, and all these other animals, mate so often if not to procreate? How does routine sex help both men and women in their pursuit of reproductive success?
The explanation usually trotted out is that we (and presumably, therefore, all of these other animals) have sex because we enjoy it, because it brings pleasure. But is that really true? Look at the couple in our scene again. Of course, in those first few weeks of their relationship when they were having sex every day, the penetration, the contact and even the prospect of just being naked together was exciting to both of them. Also, of course, even since that first flush of excitement, one, the other or both of them will occasionally have gained real pleasure from an intercourse. But recently, our couple have experienced such pleasure less often. In the scene we have just witnessed, neither partner was particularly looking forward to sex and, if they had both been honest, neither of them actually gained that much pleasure from their intercourse.
The woman certainly didn’t. The whole process was uncomfortable, even marginally painful, and almost totally unrewarding. She had experienced
far more sexual excitement from simply flirting with another man the previous Wednesday than she did from full sex with her partner this Saturday. As for the man, he was bored during foreplay, irritated at having to insert himself into an unlubricated vagina, and both bored and irritated waiting for her to become aroused while he was thrusting. He had a brief pleasurable sensation in the seconds before ejaculation, but almost immediately afterwards sank into a guilt-ridden depression. Moreover, not only had the pair gained little pleasure from their union, they had both known they wouldn’t even before they started.
So why did this couple have sex this particular Saturday night, and why will they do it again and again over the weeks, months and even years to come?
In its most general sense, the explanation for routine sex is tautological. Men’s and women’s bodies are programmed by their genes to seek sex with their partners at intervals, as a matter of routine, whether their brains can see a good reason for it or not. Why? Because routine sex can actually make a difference to the number and quality of children, grandchildren, great-grandchildren and so on that men and women might have. It can do so despite leading to conception on only one out of every five hundred or so occasions. Moreover, it does so without the conscious brain knowing and, most often, without it actually caring.
So what is the big benefit of routine sex within relationships that needs no involvement from the conscious brain? The precise answer depends on whether you are male or female, and introduces us to the first example of a theme that runs throughout this book: what is best for one partner is very often not best for the other. In this case, what men’s bodies are trying to do is maintain a population of sperm inside their partner. What women’s bodies are trying to do is confuse the man so he never knows, either consciously or subconsciously, the best time to inseminate her.
Some female primates, such as chimpanzees and baboons, actually advertise when they are most fertile each month by developing large and conspicuous red, crusty swellings around the anus and vulva and sometimes red skin on the chest as well. Male baboons and chimpanzees get turned on by these signals, and are much more interested in sex with the female when she is at this peak of beauty! The males compete for a female most strongly during the few days when she is most fertile, and each male does his very best to prevent her from mating with other males. Often he gives up doing other things, like feeding, just so that he can keep a close eye on her.
In contrast, many other primates, particularly those which, like humans, form monogamous relationships (gibbons, for example), hide rather than advertise their fertility. Why? Well, if the male doesn’t know when the female is most fertile, he can’t guard her so intensively. After all, he can’t give up eating and sleeping indefinitely. So, by hiding her fertility, a female primate gives herself much more control over when and by whom she conceives. In particular, she makes it easier for herself to be unfaithful to her partner if she ever wants or needs to be. This works for women just as well as it does for gibbons.
The elegance and effectiveness of a woman’s ability to hide her fertility from men is breath-taking. On the one hand, her body creates an environment in which conception is relatively easy but only if the timing is absolutely right. On the other hand, her body gives absolutely nothing away to the male that could help him to get that timing right. The details of this strategy for confusion are fascinating.
First, as a general rule, a woman’s body allows sperm to remain fertile for no more than five days after being deposited inside her. Secondly, sperm seem to need about two days inside the female to reach peak fertility. Thirdly, women produce just one egg per menstrual cycle, but this egg dies within a day of being produced by her ovary. What all this means is that for a man to have any chance of fertilising a woman, he has to inseminate her at least once during the period from five days before she ovulates to about twelve hours afterwards. To have the best chance, which still isn’t very high (about one in three), he must inseminate her about two days before she ovulates. A day or so either side of this optimum time and his chances decrease dramatically.
At first sight, it might seem that all a man has to do is note when his partner starts to menstruate, wait twelve days, and then inseminate her. That way, his sperm would reach peak fertility two days later on day 14 of her cycle. This is the day that many people assume marks the peak of a woman’s fertility. However, the woman’s body easily outsmarts such simple arithmetic: a predictable menstrual cycle is a rarity rather than the norm, and only occasionally does a woman ovulate on day 14. The key to her body’s strategy is variability, and hence unpredictability.
The total length of the menstrual cycle, from the beginning of one period to the beginning of the next, can be anything from about fourteen to forty-two days. This variation occurs not only from woman to woman but also from cycle to cycle for the same woman. Moreover, the part of the cycle that varies most is the part that would be most useful to the male – the number of days from the beginning of menstruation to ovulation. Far from being a predictable fourteen days, this phase can vary in length from about four to twenty-eight days in any normal, healthy woman. Neither the man nor the woman can predict the most fertile day of her cycle simply by counting forward from the beginning of her previous period.
Of course, confusing the partner requires a female to do more than vary the day of ovulation and avoid developing a tell-tale crusty bum and red vulval lips. Even without these attributes, a woman would still give the game away if she showed an interest in intercourse only when she was most fertile. She avoids this danger through a sophisticated veneer of subconscious changes in mood and behaviour. First, her body is prepared to allow her partner to inseminate her at any time during her menstrual cycle, both when fertile and when infertile. Secondly, her body shows an erratic succession of genuine, false and take-it-or-leave-it interests in sex throughout her cycle. If she does show a day or two of sexual interest when she is most fertile, it is well hidden among decoy phases of interest interspersed with genuine periods of coolness. Finally, and most sophisticated of all, she confuses her partner well because she also confuses herself. It is no accident that a woman is not naturally conscious of when she is most fertile. The uncoupling of her conscious mind from her body’s fertility is as important a part of her body’s strategy as all the other elements.
In the face of such a powerful and effective female strategy, the man has no chance of being able to predict the best time to inseminate. As a result, the only subconscious strategy open to him is to try to maintain a continuous sperm presence in his partner. Hence the advantage of routine sex to him as well as to her. If a man manages to routinely inseminate his partner about every two or three days, he should always have fertile sperm inside her – in which case, his chances of fertilising her egg in any given month will be about one in three. One missed insemination, however, could be critical, and in Scene 2 it was. The man failed to fertilise his partner’s egg.
When he ejaculated inside her that Saturday, it was a week since he had last done so, and his last sperm would have lost their fertility on Wednesday. His partner ovulated on Thursday night and, although a few sperm had still been alive inside her on Friday, when her egg was still alive, those sperm had been infertile. She did not conceive, and in two weeks’ time her next period will begin. Most likely she will begin to bleed on the Saturday of that week. We can predict this with some certainty because, unlike the number of days from the beginning of one period to ovulation, the number of days from ovulation to the beginning of the next period is a fairly predictable fourteen days, varying only from about thirteen to sixteen.
When she does begin to bleed, the couple will almost certainly see their failure to conceive this month as a joint one. However, there is an alternative interpretation – that the woman’s body actually engineered the situation to avoid conception this month, at least via her partner.
We saw earlier that women confuse men by seeking or allowing intercourse erratically throughout their
cycle. But this is not the whole truth. The incidence even of routine sex does vary a little during the menstrual cycle.
First, both women and men are less disposed to have sex while the woman is menstruating. Some human cultures even have a taboo against menstrual intercourse. We find the same reduction in rate of intercourse during menstruation in all primates that mate throughout the menstrual cycle – even in those, like marmosets, in which no blood flows to the outside. This reduction in sexual interest during menstruation should not be surprising, because menstruation is a time of slightly greater risk of infection to both males and females if they have penetrative sex.
Secondly, and perhaps this is surprising, a woman is more likely to have routine sex in the two weeks after she has ovulated, when she cannot conceive, than in the two or so weeks before, when she might conceive. The difference can be detected statistically, but is too slight to be noticeable to either the man or the woman. This subtle change in behaviour is not due to a conscious decision by couples to avoid conception. Women using reliable contraceptives, including the pill, show the same slight changes in behaviour. So, too, do other primates. The subtle change in a female’s willingness to have sex with her partner at different stages of her cycle is hormonal, not cerebral.
Engineering when and how often they have sex is only one of the ways in which a woman’s body manipulates the chances of her partner fertilising her egg. Another way is to get rid of some or all of his sperm. Most people will never have looked at the damp patch on their sheet after sex and marvelled at women’s power and sophistication. My hope, however, is that after reading the next scene, that damp patch will never seem the same again.
SCENE 3
The Wet Sheet