Endogamy

Endogamy (ancient Greek ἔνδον éndon, German 'innen' and gámos 'wedding': "inner marriage") in ethnosociology refers to a marriage order that favours or prescribes marriages within one's own social group, community or social category; the partner should, for example, belong to the same ancestral or ethnic group, religious community or social class. The opposite is exogamy, in which marriages are or should be outside one's own community, for example in societies with a bipartite moiety system. Both rules are based on respective moral, religious or legal ideas of one's own and the other's group membership and which groups marriageable persons belong to.

Like all marriage rules, endogamy can act as a target expectation (preferential) or as a prescribed norm (prescriptive). In the case of a strict endogamy prohibition, marriages outside one's own local, economic, political, religious or ethnic community are not tolerated and may be punished by exclusion from the group. However, such prohibitions on marriage need not apply to sexual contacts between unmarried members and members of other groups. A separate form of endogamy is isogamy as the preferred marriage union of partners with the same social status, i.e. within the same stratum, class or caste.

Endogamous marriage rules are found worldwide among many immigrant groups who marry only among themselves, as well as among many ethnic groups and indigenous peoples in the form of cross-cousin or parallel-cousin marriages (see the Bintʿamm marriage). Along with endogamous provisions, there are usually concurrent (subordinate) exogamous marriage rules, which often refer to common ancestry: While the spouse should come from the same social grouping, he or she may not in principle belong to the same subgroup; for example, he or she should belong to one's own religion but not to one's own clan.

Reasons for endogamy

The reasons for triggering endogamy vary: it can be geographically determined, for example, when a population lives largely isolated on an island for a long time. Well-known examples are the Icelanders, the inhabitants of some islands in Croatia, inhabitants of the American island of Martha's Vineyard, the French island of Réunion, Tristan da Cunha, Norfolk Island and Cape Verde.

Geographically isolated populations may also occur in remote areas outside islands and accordingly have a higher frequency of hereditary diseases. Examples exist in northern Sweden and Finland, Saudi Arabia, Lebanon, Israel, Poland, Switzerland, Italy, Pakistan, India, Iran, Tunisia, Brazil and the Netherlands, among others.

In the past, religious affiliation often defined the possible marriage space ("relative endogamy"). There were exceptions, especially at the edge of endogamous spaces. Today, there are still religious reasons for endogamy among members of religions with a limited number of adherents, a negligible number of converts and a taboo against marrying people who do not belong to the same religion (ethno-religious groups). The hereditary diseases that are statistically more frequent here too as a consequence of endogamy have so far been best researched among the Amish, traditionally living Mennonites (such as the Old Mennonites) and Hutterites, as well as among Ashkenazi and Sephardic Jews.

Finally, endogamy can also be culturally determined, for example, within a language group with relatively few speakers and little mixing with surrounding language groups. Examples of such cultural groups with endogamy-related inherited disorders are the Basques in France and Spain, a population of Turkish origin in the Netherlands, and the French-speaking Canadians in Québec.

In contrast, Christianity, which depended on growth through mission, radicalized the exogamy commandment - probably also due to the rapid urbanization and population mixing of late antiquity - beginning with Ambrose of Milan and Augustine of Hippo, and gradually expanded the endogamy prohibition until in the 11th century it was extended to the 7th degree according to the Roman counting method and thus became practically no longer feasible.

Social meaning

Endogamy strengthens group cohesion (the "we-feeling") and external demarcation (see also social homophily). Last but not least, endogamy ensures joint kinship power over social and material resources (e.g. land ownership), which is why the upper classes tend to use it. It is found as social endogamy, mostly as a transitional phenomenon, especially among immigrant groups. Endogamy protects minorities from being absorbed into majority societies or environments with different social practices and beliefs. While in societies with caste systems or comparable traditions endogamous marriage facilitates the integration of a group into the overall social structure, endogamy protects minority groups in other societies from hostility by preventing group competition through a division of the marriage market.