exogamy

Exogamy is a social pattern in which marriage occurs outside a defined social group. The term contrasts with endogamy, which requires marriage within a particular group. Exogamy can operate across descent groups such as clans or lineages, as well as between villages, ethnicities, or religious communities, depending on the culture.

Purposes and effects: By linking different groups, exogamy facilitates alliances, exchange, and cooperation, and can enhance genetic diversity by reducing the likelihood of close-kin mating. It commonly functions as a demographic and political strategy in traditional societies, integrating disparate segments of a population.

Variants and scope: Some societies mandate exogamy at the level of a descent group (clan exogamy), requiring individuals to marry outside their own clan while permitting matches elsewhere. Others restrict or tolerate exogamous marriages at broader scales, such as between neighboring communities or across ethnic or religious lines. In modern states, legal frameworks and individual choice further shape exogamy patterns.

In anthropology, exogamy is a central concept in kinship and alliance theory and is closely related to the incest taboo, which culturally forbids mating with close relatives and thereby encourages alliance-building through marriage with other groups.

See also: Endogamy, Kinship, Incest taboo, Marriage.