Decoding Love - Andrew Trees [24]
Although by no means settled, there is one school of thought I find persuasive. It appears that female orgasm might function as a highly sensitive sexual selection device—and one that sticks a dagger into the heart of the romantic story line. Researchers conducted a study of when women had orgasms. The surprising finding was that the level of a woman’s romantic attachment did not increase the frequency of her orgasm, nor did it depend on the man’s sexual skill. That’s right. Despite hundreds of books on how to be a better lover, women’s orgasms have little to do with a man’s abilities or even the love the woman has for a man. What did increase the likelihood of female orgasm? How symmetrical a woman’s partner was—in other words, how much a man’s left and right sides mirrored each other. I know that sounds preposterous, but symmetricality is actually a pretty good indicator of health, i.e., genetic fitness. The more disease and illness, the less symmetrical someone tends to be (studies have also found that less symmetrical men tend to have lower IQs). Think Quasimodo, and you will have an extreme version of someone who is asymmetrical. And researchers have found that women orgasm more with symmetrical men. Simply put, female orgasms appear to be largely predicated on a subconscious evaluation of a man’s genetic merit.
So what does all that have to do with the orgasm as a sexual selection device? Robin Baker and Mark Ellis studied whether or not a woman’s orgasm had an effect on the amount of sperm her body retained, and what they found was that a woman’s orgasm has an enormous effect. If a woman doesn’t orgasm or has an orgasm more than a minute before the man ejaculates, she retains very little of the sperm. But if she has an orgasm less than a minute before he does or up to forty-five minutes afterward, she retains most of the sperm, which vastly increases the chances that her egg will be fertilized (they measured the “flowback”—the amount of ejaculate discharged from the vagina shortly after sex—from more than three hundred copulations, by having the women squat over a beaker). So, a man who can make a woman orgasm (i.e., a symmetrical man) has a much better chance of impregnating a woman. Scientists call this sort of hidden mechanism that helps a woman’s body choose sperm from a particular male “cryptic female choice.”
All of this takes an even more disturbing turn when you bring infidelity into the equation. Remember the theory that wives are unfaithful in order to go after genetically superior sperm? It appears that the female orgasm may be actively aiding in this strategy. Another study revealed that wives who were having affairs tended to have adulterous sex at their most fertile times and that 70 percent of those copulations resulted in an orgasm (as opposed to only 40 percent of the copulations with their husbands). In other words, not only were unfaithful wives more likely to have sex with their lovers during their most fertile period, they were also more likely to orgasm and to retain a larger amount of sperm. When the researchers did the math, they discovered that a wife could have sex twice as often with her husband as with her lover but still be more likely to conceive with her lover (studies have also shown that women with regular partners fake orgasms more often, likely as a way of diverting suspicion about their fidelity).
How likely is it that this sort of hidden sexual selection occurs? A lot more likely than any of us would like to believe. In one study, researchers estimated that 4-12 percent of children born in Great Britain were conceived in an environment of sperm competition, which basically means that sperm from multiple men were in the woman’s vaginal tract at the same time and competing to fertilize the same egg. The same study suggested that the majority of men and women in Western societies have at one time or another engaged in sperm competition. Another recent survey found that one in eight female respondents had sex with two