Although strange to modern eyes, the practice of endogamy was not uncommon among Jewish rabbinical families.This history is an exhaustively researched work that is not likely to be surpassed in its descriptions of the political, diplomatic and social contacts of what Heine called "the exceptional family".
But the urban trend in India is against endogamy.
Mandatory marriage within one's own group is known as endogamy.
Although much has been written about the so-called caste systems among the tribes of the lower Mississippi, the Chitimachas appear to have been the only society to have possessed true castes in the sense of ranked groups that practiced strict endogamy, or marriage within the group.
Kayan society has a class system, with class endogamy being marked among the aristocrats; as a whole, however, class distinctions have become less pronounced since the late 20th century.
Far from being evidence that these places were somehow originally separate states, the prohibition was more like a ban on endogamy: in other words, the two communities were regarded like members of a family as being too close to be allowed to intermarry.
Expectations of caste endogamy persist in parts of India and the Indian diaspora, although many claim that this is a form of caste discrimination, a practice made illegal in the mid-20th century.
Some combination of endogamy and exogamy is found in most societies.
There is no evidence, however, of either exogamy or unilineal descent; in fact, marriage records from the post-conquest period show a strong tendency toward endogamy.
McLennan introduced the terms exogamy (marriage outside the group, as in bride capture between warring tribes) and endogamy (marriage within a specific group, leading to monogamy and determination of kinship through males, rather than females).
Endogamy keeps societies small, prevents the growth of rapacious nation-states.
