Winner Take All (review of Barash’s Out of Eden)

(originally published in The Weekly Standard on March 14 2016:

Winner Take All
Polygamy is more common, and more consequential, than you think.

Mar 14, 2016 | By Ann Marlowe

If you’ve ever wanted to know why Albuquerque topless pole dancers get significantly higher tips on days when they are more fertile—and who doesn’t?—this book is for you. Like many other aspects of human behavior, it has to do with the fact that men and women both try to maximize the success of their genes, but they necessarily follow different strategies. In a state of nature, men try to impregnate as many women as possible, while women try to secure the best providers possible for their children. It’s not necessary that a woman have all her children with one man, but it’s generally best for their survival if children grow up with the man who fathered them. Thus, men try to become harem masters, while women try for serial monogamy.

Of course, it’s been a long time since we lived in a state of nature, and it’s another matter whether we want to validate all of our biological impulses. But David Barash has one big theme, repeated again and again: Polygamy is the “default setting for human intimacy.” Barash, an evolutionary biologist and professor of psychology at the University of Washington, outlines humanity’s past and our similarities with other mammals to show that human culture incorporates both polygyny and (almost always covertly) polyandry. Along the way, he argues that serial monogamy is better than polygamy for most people. The reasons differ for each gender.

Polygamy is close to winner-take-all for males of all species: “Under polygyny, the ‘variance’ in male reproductive success is high, whereas the variance in female reproductive success is low.” Some unsuccessful males don’t get to reproduce at all, though a few will get to father many, many children. On the other hand, nearly all fertile females will be impregnated by some male.

The question, in terms of reproductive success, is whether a woman was better off being the fifth wife of a high-status man or the sole wife of an average-status man. It has to do with how many of her children survive. And infant mortality can be very alarming in polygynous households: For example, almost half of Dogon children in Mali die before the age of 5, and kids from polygamous Dogon households die at a rate 7 to 11 times that found in monogamous households. Closer to home, anecdotal evidence from the police blotter is confirmed by studies showing that the biggest risk factor for children is living with a nonbiological parent. And in a harem, all children live with nonbiological parents.

There are a lot of illuminating facts here. “When any species shows a consistent pattern of males larger and stronger than females,” Barash writes, “it’s a good bet that polygyny is involved.” This is because bigger males tend to win out in male-male competition for mates. Males and females are around the same size in species lacking this competition. Barash has previously written on the biological basis for violence, and it’s fascinating to learn that a 2014 United Nations report found that between 2000 and 2014, homicide and “acts of personal violence” killed more people around the world than wars did—about six million. This is testimony to the place of competition among males in human evolution, for almost all these murders were committed by men—and most were committed on men, too.

There are also some duds. Barash includes too many extended quotes from H. L. Mencken, and his literary scholarship can be unreliable (John Calvin did not live in 18th-century Geneva!). At least one argument is alarmingly careless: In most animal species, females keep breeding until death. What’s the evolutionary payoff to stopping? Barash discusses the “grandmother hypothesis,” which argues that senior women help perpetuate their genes by caring for grandchildren. This may be true—but it isn’t true that, in the conditions under which we evolved, “women undergo menopause at the age when their own children are beginning to reproduce.” It’s more likely that women began reproducing in their mid-teens in prehistoric times, becoming grandmothers in their early-to-mid-30s. The age of menopause, at 50 or so, was near death.

Barash is predictably deferential to the bien pensant: “The more we know about the crucial role of cooperative breeding, the more we see that ‘biparental’ care can be provided by a range of parent-like figures, definitely including same-sex adult partners with commitment to each other.” This insistence on not giving offense might be what leads Barash to avoid one obvious topic: the effect of 1,400 years of Islam, with its official sanction of polygyny, on the cultures where it has held sway. Barash points out that only a few percent of Muslim men seem to have more than one wife. But up until fairly recent times, these would have been the richest and most influential among them.

If Barash is right to argue that children in polygynous households have a higher mortality rate, because of the stepmother effect, one could say that the richest, most successful Muslim households have not been producing children at the rate of the richest, most successful Christian households. And the wives in polygynous households, who would be expected to be the highest-status women from the richest families—who are likely to be the daughters of men who are more clever and resourceful—are not reproductively as successful as they would be if they were monogamously married. So, over the course of centuries, it’s possible that the most talented portion of the population in the Muslim world has been under-reproducing.

But although Barash doesn’t ask, or answer, all the questions one might want him to address, he does provide a lucid, well-organized review of the current state of knowledge about polygamy. Anyone who thinks or writes about related issues will find this a valuable guide.

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