Endogamy

Endogamy was the rule, but even slight exogamy in an average generation over a couple of thousand years (estimates are of a European contribution of around 0.5% per generation) can have a pronounced effect.

The Volokh Conspiracy » More Interesting DNA Information 2010

Endogamy was the rule, but even slight exogamy in an average generation over a couple of thousand years estimates are of a European contribution of around 0.5% per generation can have a pronounced effect.

The Volokh Conspiracy » More Interesting DNA Information 2010

Note 86: Martin, "Sign Endogamy," 82 – 90; quotation at 86; Barbara Mathieu, "The Shiloh Farms Community: A Case of Complementarity in Sex-Role Dualism," 160 – 71; in Sex Roles in Contemporary American Communes, ed.

Manhood in the Age of Aquarius: Masculinity in Two Countercultural Communities, 1965–83 2007

Endogamy is required marriage within a specified social group as opposed to required marriage outside of a specified social group.

Irving Kristol and Evolution - The Panda's Thumb 2009

For communities evidencing somewhat less rigid sexual divisions of labor than the above group (yet still more rigid than that of The Farm), see Ilse Martin, "Inequality, Chastity, and Sign Endogamy in the New Age Brotherhood," in Sex Roles in Contemporary American Communes, ed.

Manhood in the Age of Aquarius: Masculinity in Two Countercultural Communities, 1965–83 2007

Endogamy is all the rage (traces of journalism's Jewish origins perhaps?) with pundits only talking to pundits who are interviewing pundits.

Shaun Jacob Halper: Beyond Jeremiah: A New Kind of Media for Obama's New Kind of Politics 2008

Endogamy within such a small group resulted in some complex webs of relationships (see Figure 3.7).

Gutenber-e Help Page 2005

Melissa Yuan-Innes delivers a Bradburyian shocker in "Mrs. Marigold's House" and Mark Shainblum does military SF intelligently and gracefully in "Endogamy Blues."

Asimov's Science Fiction 2004

Endogamy and exogamy are forms of the mores in which one of these policies has been adopted to the exclusion of the other.

Folkways A Study of the Sociological Importance of Usages, Manners, Customs, Mores, and Morals William Graham Sumner 1875

"Inequality, Chastity, and Sign Endogamy in the New Age Brotherhood."

Manhood in the Age of Aquarius: Masculinity in Two Countercultural Communities, 1965–83 2007