This week on Public Discourse, Chris Kaczor discusses recent empirical research that suggests that polygamy is socially detrimental:

"...Pushed by advocates of same-sex marriage and multiculturalism, some scholars, such as the signers of "Beyond Gay Marriage," argue that it is irrational and bigoted for contemporary society to limit marriage to just two people. However, there is no bigotry in treating different things differently, and there are many important differences between polygamy and monogamy in practice as well as in principle.

There are three main forms of polygamous relationships: polygyny, polyandry, and polygynandry. In polygyny, by far the most common form of polygamy, one man may marry a number of wives. In polyandry, one wife has two or more husbands. This form of polygamy is extremely unusual, and often takes the form of two brothers marrying the same woman. In polygynandry, two or more wives marry to two or more husbands. Polygynandry is even more rare than polyandry, but will be similar in some respects to polygyny, insofar as a man has more than one wife. Since both polygynandry and polyandry are virtually non-existent, I'll focus on the more common case of one man with multiple wives, and use the more common term polygamy to describe this arrangement."