Forms of Marriage

While the family serves the same basic functions everywhere, its particular structure changes in response to different situations. Because families everywhere regulate sexual relationships, and because there are roughly as many men as women in most societies, it is hardly surprising that the most common form of marriage is monogamy, or marriage between one man and one woman. Societies with a shortage of eligible mates frequently also permit polygamy, or marriage to more than one partner.

Polygyny, the most common form of polygamy, is the marriage of one man to two or more women. The anthropologist George Murdock found that polygyny was permitted in 75 percent of the 565 mostly tribal societies he studied. Wives are generally a sign of wealth, which brings a man prestige in the community; more wives also produce more children, who provide extra labor. The hard economic fact that additional wives and children cost more to support, however, usually limits polygyny to a wealthy elite, like the sultans of the Ottoman Empire.

Polyandry, the marriage of one woman to more than one man, occurs only under unusually severe economic conditions. The most frequent type of polyandry is the sharing of a wife by brothers who are too poor to support separate households.