Adherence
Endogamy can serve as a form of self-segregation; a community can use it to resist integrating and completely merging with surrounding populations. Minorities can use it to stay ethnically homogeneous 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, 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.
