What Men Will Do To Win

Christopher Wilson, a neurobiologist at Cornell, has recently offered an evolutionary explanation for why certain cultures developed the norm of male circumcision. In an article in Evolution and Human Behavior, Wilson describes circumcision as an “evolutionary challenge” because it “involves a dangerous and costly surgery.” Enter sperm competition theory, which predicts competition between males to fertilize a woman’s egg. Wilson points out that some cultures practice male genital cutting that is far more drastic than circumcision, and that undoubtedly decreases male fertility. As a review of Wilson’s article in The Economist describes:

Circumcision does not have quite such clear-cut effects. But there are several ways it may affect fertility: most obviously, the lack of a foreskin could make insertion, ejaculation or both take longer. Perhaps long enough that an illicit quickie will not always reach fruition.

Older men are in a position to form alliances with younger men—passing on knowledge, lending them political support and giving them access to weapons. By insisting that the young undergo genital mutilation of some form as a quid pro quo, an older married man can seek to ensure that even if he is cuckolded, he will still be the father of his wives’ children. Of course, the older man has probably undergone genital mutilation too, and seen his own fertility reduced. But that, if anything, increases his incentive to make certain that the young bucks are similarly handicapped. And if all the older men in a society conclude this is a good thing, it will rapidly become a socially enforced norm.

To test this theory, Dr Wilson made several predictions. Among them, he suggested that mutilation is more likely to be practised in polygynous societies (since a man with several wives is more vulnerable to cuckoldry), and is especially likely in those polygynous societies where a man’s co-wives live in separate households from their husband. It should also take place in a public ceremony watched by other men, to avoid cheating or free-riding. And there should be a strong stigma against men who refuse it.

To test his predictions, Dr Wilson looked at a database of 186 pre-industrial societies. Some 48% of the highly polygynous ones practised a form of male-genital mutilation, and the number rose to 63% when co-wives kept separate households. By contrast, only 14% of monogamous societies practised mutilation. Moreover, and also as predicted, the mutilations were almost always carried out in public, often as part of a coming-of-age ceremony at puberty, with strong stigma attached to unmutilated men.

What I find most interesting about Wilson’s work is that it relies on one of the most contested aspects of circumcision: its effect on male sexual pleasure and performance. The discussion over at Economist.com demonstrates this, with a fair percentage of comments weighing in on whether Wilson is right or wrong about the sexual effects of circumcision. You can find similar chatter at NewScientist.

This seems to me like a debate that is almost not worth having. Few men are likely to be convinced that they are worse off; few women are likely to be convinced that their partners are worse off; few parents are likely to be convinced that they have made their sons worse off. Note the deliberate ambiguity in the preceding sentence: “worse off” could apply to either the circumcised or the uncircumcised.

At least in the West, only a small percentage of men have been circumcised after becoming sexually active. (Adult circumcision is on the rise in Africa, as part of a practice that is intended to help decrease the transmission of HIV.) To my knowledge, only a couple of studies have been done on the sexual effects of circumcision; their sample populations were small and their results were inconclusive. One common complication was that sexual pleasure depends in part on body image; whether a man perceived his circumcision status to be “normal” often affected his responses. Another complication was the highly subjective nature of sexual pleasure. For those who are interested, some of these studies are referenced in an article I wrote about circumcision and social norms.

So we don’t really know how circumcision affects sex, nor are we likely to any time soon. Yet this is a terribly important question, because its answer sheds light on the morality of the routine infant circumcision that is practiced in the United States.

In the meantime, though, Wilson’s article provides a novel way of thinking about the origins of circumcision.

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