Science is the way we have of finding out how the components of the universe work. Science works very well, in general; our increase in understanding of everything from galaxies to quarks is really quite admirable. Nothing humans do is perfect, and the world’s scientific effort, for all its successes, has a history that also includes some missteps, prejudices, and erroneous conclusions. It is somehow not surprising that in investigating sexuality, which is still for some people a controversial endeavor, there have been consequential mistakes. This is probably because the subject is both vitally important to us all and also private and covert. Compound this with particular investigation of female sexuality, and all sorts of prejudices might be expected to occur. In The Case of the Female Orgasm: Bias in the Science of Evolution (Harvard University Press), Elisabeth A. Lloyd has examined how scientists have tried to understand how female orgasms evolved. “Female orgasm is a source of fascination for groups ranging from sex researchers to the lay public, and evolutionists are no exception,” she writes. Unfortunately, Lloyd shows that the evolutionists’ fascination has borne erroneous explanations. This is a tiny area of evolutionary science, but it has been explored and written about by many, often in opposing camps, and Lloyd has given a detailed and serious refutation of all explanations but one, the one she championed in a paper twenty years ago. Others might find this a tempest in a teapot, but Lloyd’s serious tone and exhaustive analysis of the flaws in other researchers’ ideas, and the causes of those flaws, make this a fascinating book of scientific advocacy.
Males have orgasms, and no one wonders why; in the short term, male orgasms feel good, but in the long term male orgasms ensure that genes are carried over into the next generation. The two are obviously linked. Female orgasms aren’t so simple; females don’t have to have orgasms to bring forth children, so why do they have orgasms? Lloyd has tried to find every explanation that evolutionists have proposed, and has come up with twenty-one of them. Almost all have found the female orgasm to be an adaptation, meaning that it is a trait that has evolved to promote fitness in some way, but over and over again, she shows how the proposals of the “adaptationists” are flawed. Quite simply, they have been eager to show that the female orgasm helps females reproduce, but Lloyd is adamant: “There is no plausible evidence that links orgasm to reproductive success.” In other words, no one has scientifically shown that having orgasms make a woman more likely to get her genes into the next generation.
The problems with the adaptationists’ position, Lloyd finds, are many. Among the most significant are that a substantial portion of women, maybe 14%, never have orgasms, that even more women rarely have them, and that coitus (which features only indirect stimulation of the clitoris) is not the easiest way for a woman to have an orgasm. The number of women who always orgasm with coitus is a minority, about 20%; one would think that if orgasms were an important adaptation that led to successful reproduction, they would be far more common and far easier to get by coitus, rather than, say, masturbation. (Significantly, few women masturbate by simulating the piston-and-cylinder motions of sexual intercourse; almost all who do so rely on direct clitoral stimulation.) Readers of the popular writer Desmond Morris will understand that orgasm was proposed as cementing the pair bond, which might be good for reproductive success, but this proposal cannot stand if coital orgasms are relatively rare. Adaptationists have brought up arguments that have to do with ancestral responses, hormonal influence, characteristics of our primate relatives, and so on. Lloyd methodically shoots each adaptationist idea down.
A particularly attractive explanation, one which has even been spotted on the Discovery Channel, is charmingly called “The Upsuck Hypothesis”. It says that during orgasm, the uterus has a drop in pressure, becoming a sort of vacuum cleaner to suck up any sperm deposited by the male. There is much lore to recommend this idea. Upsucking would speed sperm on their way to fertilizing the egg. Women evolved to have orgasms with men with whom they want orgasms, and would deny the upsuck advantage to, say, rapists or incompetent lovers. Better male lovemaking would thus be selected for through the generations. The degree of enthusiasm and clever analyses by adaptationists of the effect of the upsuck remind me of Lytton Strachey’s words about the esthetic judgements of Samuel Johnson on the poets, which were “. almost invariably subtle, or solid, or bold; they have always some good quality to recommend them — except one: they are never right.” There is scant evidence that there is any vacuum in the uterus or any physiological upsuck caused by orgasm. Masters and Johnson, for instance, found no such thing, nor did their predecessor Grafenberg. Lloyd cites a study that showed a drop in uterine pressure with orgasm in two episodes of coitus in a single female subject, and that seems to be the just about the extent of evidence for upsuck. Not only has no one shown clear evidence for the mechanism of upsuck, but there is positive evidence that it does not exist. Adaptationists seem guilty of holding an attractive hypothesis in the face of facts which contradict it.
Lloyd finds plausible one explanation of female orgasm, the one that does not insist that it is an adaptation. Donald Symons in 1979 proposed the “byproduct account”. Female orgasm is a potential based on anatomy, a potential activated only in some females of some few species. The anatomical foundation is similar to the nipple in the male. Operating female nipples are strongly selected for, since they supply nutrition, and are present in the embryo, even before the embryo differentiates sexually. Thus, inoperative male nipples are a byproduct of selection operating on the female. In the same fashion, orgasm and ejaculation are strongly selected for in the male because of sperm delivery. The hardware involved in such actions is there in the embryo that might turn male or might turn female, and females get the erectile, highly-enervated clitoris because the analogous penis in the male is so important. (This also offers an explanation for the puzzling fact that the key point of sexual stimulation for females is not in the vagina which receives the sexual organ of the male, but on the connected tissue of the clitoris.) There are feminist objections to this idea, because a female orgasm is derivative from the male one, but this is putting ideology before science: “Its historical genesis does not dictate our cultural attitudes toward female orgasm.” Lloyd has looked widely at this explanation and all the others, and has taken pains to list evidence and arguments pro and con. She has also given a broader critique to show how androcentrism or illusory concepts of human uniqueness have caused the mistakes in reasoning of the adaptationists. This is a far from titillating volume; surely there are not even fetishists who could get off on so many pages of deconstruction of one arcane theory after another. As an account of competing scientific ideas and how preconceptions form them, however, it is a uniquely valuable account.
The Case of the Female Orgasm: Bias in the Science of Evolution
(Harvard University Press (April 22, 2005) ISBN 0674017064)
Available at: Amazon.com / Amazon UK / Amazon CA
© 2006 Rob Hardy. All rights reserved. Content may not be copied or used in whole or part without written permission from the author.
