What's So Wrong with Polygamy?

By Anna Dorminey, Staff

Libby Copeland writes for Slate on the effects of polygamy and monogamous marriage on crime in “Is Polygamy Really So Awful?” While we disagree with Ms. Copeland's conclusion (that the best form of union for a society is best not because it is moral, but because it “works”), the research she references in her piece is extremely interesting. Read along:

History suggests that [plural marriage] is [harmful]. A new study out of the University of British Columbia documents how societies have systematically evolved away from polygamy because of the social problems it causes. The Canadian researchers are really talking about polygyny, which is the term for one man with multiple wives, and which is by far the most common expression of polygamy. Women are usually thought of as the primary victims of polygynous marriages, but as cultural anthropologist Joe Henrich documents, the institution also causes problems for the young, low-status males denied wives by older, wealthy men who have hoarded all the women. And those young men create problems for everybody.

“Monogamous marriage reduces crime,” Henrich and colleagues write, pulling together studies showing that polygynous societies create large numbers of unmarried men, whose presence is correlated with increased rates of rape, theft, murder, and substance abuse. According to Henrich, the problem with unmarried men appears to come primarily from their lack of investment in family life and in children. Young men without futures tend to engage in riskier behaviors because they have less to lose. And, too, they may engage in certain crimes to get wives—stealing to amass enough wealth to attract women, or kidnapping other men’s wives.

Ms. Copeland also addresses the effects polygamy produces for individual men, women, and children. These effects are consistently negative:

That polygyny is bad for women is not necessarily intuitive. As economist Robert H. Frank has pointed out women in polygynist marriages should have more power because they’re in greater demand, and men should wind up changing more diapers. But historically, polygamy has proved to be yet another setup that [harms] the XX set. Because there are never enough of them to go around, they wind up being married off younger. Brothers and fathers, realizing how valuable their female relations are, tend to control them more. And, as one would expect, polygynous households foster jealousy and conflict among co-wives. Ethnographic surveys of 69 polygamous cultures “reveals no case where co-wife relations could be described as harmonious,” Henrich writes, with what must be a good dose of understatement.

Children, too, appear to suffer in polygamous cultures. Henrich examines a study comparing 19^th-century Mormon households, 45 of them headed by wealthy men, generally with multiple wives, and 45 headed by poorer men, generally with one wife each. What’s surprising is that the children of the poorer men actually fared better, proving more likely to survive to age 15. Granted, this is a small study, but it’s consistent with other studies, including one from Africa showing that the children of monogamous households tend to do better than those from polygynous households in the same communities. Why? Some scholars suspect that polygyny may discourage paternal investment. Men with lots of children and wives are spread too thin, and to make things worse, they’re compiling resources to attract their next wives instead of using it on their existing families.

For more on the benefits of intact, monogamous marriage for society and individuals, visit www.marri.us.