The American Spectator

It turns out you can deny evolution and get published on the New York Times op-ed page. Dan Slater did just that, in a January piece called “Darwin Was Wrong About Dating.” Slater, author of a book about online dating, set out to debunk one aspect of a subspecialty known as evolutionary psychology, which, among other things, seeks to use Darwinism to explain behavioral differences between men and women.

Evolutionary psychology suggests that differences in sexual be­havior, which we tend to understand in moral or cultural terms, are biologically rooted. Since the male makes the lesser investment in reproduction, men are driven to favor quantity over quality. They are especially attracted to youth and beauty because these are signs of fertility. One man can reproduce with many women, so there is no evolutionary need to be selective. The most efficient way to pass on a genetic legacy is to father as many children by as many women as possible.

Reproductively speaking, that’s not an option for a woman, whose potential number of offspring is much smaller because she must endure the demands of carrying, bearing, and nurturing every child she produces. Thus it is in her evolutionary “interest” to value quality over quantity—that is, to be selective, choosing men who enhance her offspring’s chances of survival via some combination of their own genetic endowment and the resources they can contribute to the rearing of children.

It is crucial to understand that evolutionary “interests”—the interests of one’s genes—are not the same as individual interests. Evolutionary psychology posits not that men decide to be promiscuous and women hypergamous because they want to have as many or as robust children as possible, but that these sexual and emotional instincts developed because they were conducive to reproduction over many generations in the ancestral environment. Birth control and other modern developments can drastically change the outcomes of sexual behavior, but not the impulses that drive it.

YET SLATER CLAIMS “a new cohort of scientists have been challenging the very existence” of such sex differences: 

Take the question of promiscuity. Everyone has always assumed—and early research had shown—that women desired fewer sexual partners over a lifetime than men. But in 2003, two behavioral psychologists, Michele G. Alexander and Terri D. Fisher, published the results of a study that used a “bogus pipeline”—a fake lie detector. When asked about actual sexual partners, rather than just theoretical desires, the participants who were not attached to the fake lie detector displayed typical gender differences. Men reported having had more sexual partners than women. But when participants believed that lies about their sexual history would be revealed by the fake lie detector, gender differences in reported sexual partners vanished. In fact, women reported slightly more sexual partners (a mean of 4.4) than did men (a mean of 4.0).

Which proves absolutely nothing. The key to understanding why is the Hoffman-Manning Axiom: “It takes two to tango.” A man cannot add a sex partner unless a woman also adds one. Thus, assuming equal numbers of men and women, the actual average number of opposite-sex partners for men must be the same as for women. This is a meaningless statistic, a mathematical truism.

As it happens, there are more young men than young women. If we assume the sex ratio is 1.06 males per female—the standard observed ratio at birth—and the average male has 4.0 sex partners, then the average female has 4.24 partners. Lo and behold, that’s very close to Alexander and Fisher’s figure of 4.4 partners per woman.

What they do seem to have demonstrated is that if earlier studies found mathematically impossible variations in the reported number of sex partners, it is in large part because the survey subjects were dishonest: Either men wishfully over-reported their numbers, women regretfully under-reported them, or both. That would confirm the evolutionary psychology hypothesis that men have a greater desire than women for sexual variety.

Darwin 1, Slater 0.

Slater also purports to refute “the assumption that an enormous gap exists between men’s and women’s attitudes toward casual sex”:

Evolutionary psychologists typically cite a classic study published in 1989. Men and women on a college campus were approached in public and propositioned with offers of casual sex by “confederates” who worked for the study. The confederate would say: “I have been noticing you around campus and I find you to be very attractive.” The confederate would then ask one of three questions: (1) “Would you go out with me tonight?” (2) “Would you come over to my apartment tonight?” or (3) “Would you go to bed with me tonight?”

Roughly equal numbers of men and women agreed to the date. But women were much less likely to agree to go to the confederate’s apartment. As for going to bed with the confederate, zero women said yes, while about 70 percent of males agreed.

Those results seemed definitive—until a few years ago, when Terri D. Conley, a psychologist at the University of Michigan, set out to re-examine what she calls “one of the largest documented sexuality gender differences,” that men have a greater interest in casual sex than women.

Ms. Conley found the methodology of the 1989 paper to be less than ideal. “No one really comes up to you in the middle of the quad and asks, ‘Will you have sex with me?’“ she told me recently. “So there needs to be a context for it. If you ask people what they would do in a specific situation, that’s a far more accurate way of getting responses.” In her study, when men and women considered offers of casual sex from famous people, or offers from close friends whom they were told were good in bed, the gender differences in acceptance of casual-sex proposals evaporated nearly to zero.