Category Archives: Wright: Moral Animal


Whence Monogamy?

by Neil Godfrey

This post offers some explanation for the monogamous societies as a “footnote” to my previous post on the statistical benefits of monogamy for men. Robert Wright (The Moral Animal) points out that most societies have not been strictly monogamous, so it’s not as though we’ve evolved to be monogamous by nature:

A huge majority — 980 of the 1,154 past or present societies for which anthropologists have data — have permitted a man to have more than one wife. And that number includes most of the world’s hunter-gatherer societies, societies that are the closest thing we have to a living example of the context of human evolution. (p. 90)

It’s been a mixed bag:

Actually, there is a sense in which polygynous marriage has not been the historical norm. For 43 percent of the 980 polygynous cultures, polygyny is classified as “occasional.” And even where it is “common,” multiple wives are generally reserved for a relatively few men who can afford them or qualify for them via formal rank. For eons and eons, most marriages have been monogamous, even though most societies haven’t been.

Still, the anthropological record suggests that polygyny is natural in the sense that men given the opportunity to have more than one wife are strongly inclined to seize it. (p. 91)

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Monogamy is not so bad (at least for men) after all

by Neil Godfrey

robertwrightAnother work I’m finally catching up with is Robert Wright’s Moral Animal: The New Science of Evolutionary Psychology (1994). We all know the usual narrative about men being shaped by their genes to want to reproduce with everything in sight while women are always on the shrewd lookout for the best candidate to protect and provide for her children.

To cut to the chase and speaking in broad evolutionary/social psychological terms, Wright raises an interesting question (at least for me who is shamefully twenty years late in reading his book!):

[W]hereas a polygynous society is often depicted as something men would love and women would hate, there is really no natural consensus on the matter within either sex. Obviously, women who are married to a poor man and would rather have half of a rich one aren’t well served by the institution of monogamy. And, obviously, the poor husband they would gladly desert wouldn’t be well served by polygyny. (p. 96, my formatting and bolding in all quotations)

Wright adds that the males who are advantaged by monogamy are not only those at the bottom of the income scale.

Consider a crude and offensive but analytically useful model of the marital marketplace. One thousand men and one thousand women are ranked in terms of their desirability as mates. Okay, okay: there isn’t, in real life, full agreement on such things. But there are clear patterns. Few women would prefer an unemployed and rudderless man to an ambitious and successful one, all other things being even roughly equal; and few men would choose an obese, unattractive, and dull woman over a shapely, beautiful, sharp one. For the sake of intellectual progress, let’s simplemindedly collapse these and other aspects of attraction into a single dimension.

Suppose these 2,000 people live in a monogamous society and each woman is engaged to marry the man who shares her ranking. She’d like to marry a higher-ranking man, but they’re all taken by competitors who outrank her. The men too would like to marry up, but for the same reason can’t.

Now, before any of these engaged couples gets married, let’s legalize polygyny and magically banish its stigma. read more »