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.
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.