Endogamy

Endogamy is the practice of marrying within a specific ethnic group, class, or social group, rejecting others on such a basis as being unsuitable for marriage or for other close personal relationships.

Endogamy is common in many cultures and ethnic groups. Several ethnic religious groups are traditionally more endogamous, although sometimes with the added dimension of requiring marital religious conversion. This permits an exogamous marriage, as the convert, by accepting the partner's religion, becomes accepted within the endogamous rules. Certain groups, such as Orthodox Jews adhering to endogamy in Judaism, have practised endogamy as an inherent part of their religious beliefs and traditions.

Adherence

Further information: Population genetics and inbreeding

Endogamy can serve as a form of self-segregation; it helps a community to resist integrating and completely merging with surrounding populations. It helps minorities to survive over a long time as distinct communities within societies with other practices and beliefs.

The isolationist practices of endogamy may lead to a group's extinction rather than its survival, as genetic diseases may develop that can affect a larger percentage of the population. However, this disease effect would tend to be small unless there is a high degree of close inbreeding, or if the endogamous population becomes very small in size.