The Case of the Female Orgasm (review)

Elisabeth A. Lloyd. The Case of the Female Orgasm: Bias in the Science of Evolution. Cambridge: Harvard Univ. Press, 2005. Pp. 311. $27.95.

A lot of people have problems with the human female orgasm, ranging from women who have difficulty in achieving sexual satisfaction to pharmaceutical companies trying to develop a female version of Viagra. Films like When Harry Met Sally take advantage of the cryptic nature of female orgasm to point to how easy it is to fake. Biologists, too, have problems with female orgasm, or at least its evolution, because it is an enigmatic trait compared with many others. Women can conceive without orgasm, making it less directly connected with reproductive success and hence fitness than male orgasm, which virtually always accompanies ejaculation. What is more, most women do not experience orgasm during so-called "unassisted" intercourse, in other words, without additional stimulation of the clitoris before, during, or afterwards. Freud thought that this type of orgasm was more mature than one resulting from clitoral stimulation, and although his ideas have largely been debunked, they have left a legacy of assigning ranks to female sexual response, so that women worry that their orgasms are somehow inferior or abnormal.

The orgasm has also taken its place in the battle about adaptationism, with scholars debating whether female orgasm evolved through natural selection in much the same way as morphological traits, because they enhanced the ability of their bearer to survive and reproduce. During the 1970s, while the debate over sociobiology was raging, biologists argued about how one could determine whether any characteristic, from the chin to a predilection for adultery, was an adaptation. Because of the perplexing aspects of orgasm in women, some early researchers, most notably anthropologist Donald Symons, author of The Evolution of Human Sexuality (1979), suggested that the trait was not an adaptation, but instead was a by-product of selection on male orgasm. The tissues of the clitoris and penis derive from the same embryonic source, so women ended up with something of a bonus because of selection on men. Such traits are sometimes called evolutionary artifacts, the result of selection on another character, itself subject to selection, to which it is genetically tied. According to Symons: "If . . . adaptive design can be recognized in such features as precision, economy, and efficiency, it seems clear to me that available evidence is, by a wide margin, insufficient to warrant the conclusion that female orgasm is an adaptation" (p. 89). The late Stephen Jay Gould (1987) also championed this viewpoint, using the idea of adaptive female orgasm as one of his examples of "just-so stories."

Members of the other camp suggest that just because female orgasm differs from male orgasm does not mean that it is less of an adaptation. Some scientists found a male bias in the notion that female orgasm is not adaptive; anthropologist Sarah Blaffer Hrdy responded to Symons by suggesting that "The notion that woman's orgasm is 'in an evolutionary sense a "pseudo-male" response' appears to be a vestige of Victorian thought on the subject." She proposed that females seeking numerous mating partners to satisfy their sexual needs within a relatively short time would also achieve an adaptive goal of confusing paternity, so that the various mates would be less inclined to harm and more inclined to protect offspring that had some chance of being their own (Hrdy 1981, 1996).

Other adaptation advocates proposed a variety of hypotheses about the utility of human female orgasm, many of which have rather creative names, like the Poleax hypothesis, which holds that women are more likely to remain supine, as if struck by the eponymous medieval weapon, and hence retain sperm in the reproductive tract, if they have had an orgasm (Baker and Bellis 1995). Female orgasm is thus viewed as an advantageous consequence of bipedal stance...