It is irrelevant to our generation whether people in the past wanted many children and grandchildren or whether it just happened. The only factor to shape our characteristics is who in the past had children (and how many) and who did not. (p.4)
We have already mentioned that a woman is slightly more likely to have routine sex with her partner during the infertile postovulatory phase of her cycle. The same is not true for infidelity. A woman is much more likely to have penetrative sex with a man other than her partner during her fertile phase. Moreover, she is much less likely to use or insist on the man using contraception on such occasions. (p.42)
What her conscious mind will not realize, though, is that having collected sperm from her ex-boyfriend, her body is now very keen also to collect sperm from her partner.Her body hall already decided that, on balance, her ex-boyfriend would make a better genetic father than her partner. The one thing it doesn't know is how their ejaculates compare. She wants to have hell egg fertilized by her ex-boyfriend only if his ejaculate is also the more fertile and competitive. The way for her to discover this is to pit one ejaculate against the other. In other words, her body wants to promote sperm warfare between the two men, and this is probably her only chance ever to do so. (p.44)
Humans are not, of course, the only animals to indulge in oral sex. Most male mammals, from rats and dogs to elephants and monkeys, nuzzle, smell and lick the female's vulva during foreplay. Monkeys also touch a female's genitals, sometimes inserting their fingers in to her vagina, then smelling and licking them on withdrawal. What all these males are doing is collecting information. They are seeking the answer to three questions. Is the female healthy? Is she fertile? And has she recently had sex with another male? A man is doing exactly the same — and the information he collects can be a big help in his pursuit of reproductive success. (p.72)
Surveys of many cultures around the world consistently show that,in looking for a long-term partner, women prefer men who have, or have the potential of, wealth, status, stability and durability. In the past, in all cultures, the children of women paired to men at the top of the scale for these qualities had a far greater chance of survival,health and subsequent fecundity. The same holds true even in today's industrialised societies. (p.139)
Moreover, when we look at which children are most likely to belong to their partner, women show a clear pattern. (...) the child most likely to have been sired by a woman's partner is the second; the children least likely are the first, and particularly the last. The reasons, though, are slightly different for first and last. (141)
Even so, not only is the average woman less likely to have a boy than a woman paired to a high-status male, but women paired to low-status males and women without a partner at all are more likely to produce a daughter. Why?
The answer is that a son is a much more precarious reproductive option than a daughter. Despite his potential to produce large numbers, he is more likely to die before he begins to reproduce, and he has much more chance of not reproducing at all, even when he tries. If they are not reproductively competitive, sons are a poor option. (p.145)
There are two ways in which a daughter is the safer option: first, although relatively few daughters produce large numbers of grandchildren for their mothers, relatively few fail to produce any; second, a mother can be certain that all of the grandchildren produced through a daughter are hers. She cannot be so certain about the grandchildren apparently produced by a son.
Thus, only when there is a very good chance that a son will not only survive but will also be reproductively competitive against other males is it worth producing a boy. So, in principle, we should not be surprised to find that women without long-term partners and women paired to lower-status males produce an excess of daughters — or to find that those paired to higher-status males produce an excess of sons. Nor should we be surprised that, in between these two extremes, most women compromise and show no bias towards either sex. (p.146)
The female orgasm is pleasurable because it has a function. A woman feels like an orgasm whenever her body judges it will enhance her reproductive success. When her body judges it will reduce her reproductive success, she feels no such urge. (p.188)
The functions of nocturnal orgasms seem to be identical to those of masturbatory ones. (...) It is probably because nocturnals are more cryptic than masturbation that they are also more closely linked to the menstrual cycle. Given that both types of orgasm are advantageous if they occur at the beginning of the fertile phase, nocturnals are probably the better option — being less likely to betray the woman's fertile phase to her partner. It is probably also because nocturnals are cryptic that women, unlike men, are more likely to have them as they age and obtain a partner, not less. (p.196-197)
But there is a limit to how much time and effort it is worth him putting into getting a woman to climax during intercourse. First, if her body is not interested in an intercourse orgasm, he cannot force her to climax, no matter how hard he tries. Secondly, the cervical sperm filter which he can sometimes try so hard to bypass may on some occasions not actually exist. If the woman has retained very few sperm from her previous insemination, if she has neither masturbated nor had a nocturnal since that insemination, and if any even older sperm or menstrual debris have been cleared, the filter in her cervix will be as weak as it can be anyway. In this case, the man gains little if anything from making a great effort to encourage her to climax during intercourse. (p.212)
Women also change their likelihood of having an intercourse orgasm during infidelity. On average, they are more likely to climax during or after intercourse with a lover (33 per cent of occasions) than they are during or after routine intercourse with their partner (22 per cent of occasions). Thus a lover's army receives assistance in entering the battlefield more often than does a partner's. (p.224)
It is probably for these reasons that, as in many scenes in this book, most men would prefer to enter a woman and begin intercourse without trying to help her climax during foreplay. But because women often have much to gain from a foreplay orgasm and frequently seek a man's cooperation in achieving one, the level and length of stimulation during foreplay is one of the major areas of conflict between men and women during their sexual encounters. (p.226)
Basically, a woman uses a man's approach to foreplay and intercourse to gain information about him. A man who is able to arouse a woman and stimulate her to orgasm signals that he does have past experience of other females. This tells her that other women have also found him attractive enough to allow intercourse. The more effectively he stimulates her the more experienced he should be — and hence the greater the number of women who have so far found him to be attractive. Mixing her genes with his, therefore, may produce sons or grandsons who are also attractive to women, hence increasing her reproductive success. (p.235)
In a study of American students published in 1982, it was found that girls who were exposed to an attempt at date rape were three times more likely to resume their relationship with the man concerned if his attempt succeeded than if it failed. (250)
On average, men who are physically able to overcome the final defenses of a female and achieve insemination leave more offspring than those who are not. So women whose sons and grandsons also have this ability will enjoy greater reproductive success. (p.254)
A common pattern, shown by the girl in the scene, is for a woman to stay in a homosexual relationship for one to three years before moving on to a heterosexual relationship. Also as in the scene, older women often 'fit in' a stable homo-sexual relationship between successive heterosexual ones. (p.291)
When women live together, they often synchronize their periods. Not only lesbians, but mothers and daughters, nuns, prisoners, nurses and students also often synchronise when they live together. In a fascinating series of experiments carried out in the USA in the early 1980s, each woman in a group of volunteers agreed to have the underarm secretions from another woman rubbed under her nose every other day for a few months. Each woman who received the secretion adjusted her menstrual cycle to synchronise with that of the woman who had provided it — which implies that chemicals are present in a woman's underarm secretions which enable groups who spend a lot of time together to synchronize their menstrual cycles. (p.296)
It is estimated that in some of the world's major industrial cities nearly half of women experience an attempted rape in their lifetime, and a quarter are actually raped. Such estimates are, of course, very approximate and confounded not least by the fact that, as in our scene, very few rapes are actually reported. The current estimate is that only about one rape in ten is made known to the authorities. So widespread is rape and so often do children result from rape that all of us could probably find a rapist among the past five generations of our ancestors.(p.313-314)
However, trauma may not be the only factor. Although a woman is more likely to conceive from rape than she is from routine intercourse with her partner, there are other, less traumatic, situations in which she is equally likely to conceive. One is when she has sex with a partner whom she has not seen for a long time and whom she sees only briefly — as when a soldier comes home on a short leave. Another is during snatched moments of infidelity. What these two situations have in common with rape is not trauma but a limited opportunity to collect a particular man's genes. The physiological mechanism for conception is also likely to be the same in all three situations — ovulation in response to intercourse. (p.317)
As we have seen on many occasions in this book, the genes of males who have an above-average reproductive success are desirable targets for a woman's body.
If she can collect such genes, she will increase her reproductive success via male descendants who inherit the same potential for success. Since we decided for rapists that, on balance, they do indeed have above-average potential, it should be no surprise to find that when a woman's body has a one-off opportunity to collect a rapist's genes, it often does so.
This conclusion does not mean, as people often assume, that a woman should therefore seek to be raped. On the contrary, it is reproductively important to the woman that her body collect genes from only the most successful of rapists. If she conceives to an inept rapist, doomed quickly to be caught and to suffer social retribution and incarceration, her male descendants would inherit unsuccessful characteristics. (...) The result is that only a minority of women are ever raped, but those who are may then respond by conceiving.(p.317-318)
Not only primates but many other groups of animals have been shown to have testes of a size appropriate to the risk of sperm warfare. From butterflies to birds and from mice to men, the more likely a male's sperm are to engage in conflict, the larger his testes relative to the size of his body. (p.338)
(Robin Baker - Sperm Wars, - Infidelity, Sexual Conflict and Other Bedroom Battles)
