Unbiased transmission cannot maintain cultural boundaries under any mixing

Evidence

When transmission is unbiased, any amount of cultural mixing will rapidly obliterate cultural differences between groups. To see why, consider the following example: suppose people living in two neighboring cultures have different ideas about the appropriate level of bride price. Further, suppose that in each culture, 95% of the groups’ members acquire their beliefs about the appropriate levels of bride price by accurately internalizing the values of their local community, whereas 5% acquire their beliefs from individuals in the other culture. Such mixing could be due to intermarriage, other forms of migration, or simply contact with members of the other group. With these assumptions, the average difference between the two groups will decrease at 5% per generation. Given that intermarriage and other forms of cultural influence are common along cultural boundaries and that cultural boundaries often persist for many generations, unbiased transmission by itself cannot explain the maintenance of cultural boundaries. — Joe Henrich and Robert Boyd, The Evolution of Conformist…, 26

Categorization

• DEFINE: Establishes the baseline ‘unbiased transmission’ model that conformist transmission is later contrasted against - foundational context for the conformist-frequency-dependent model.
• XREF: connects to: Cultural mixing exceeds racial mixing precisely because it goes unobserved — David Theo Goldberg, The Threat of Race: Reflections on…, 1330; Full cultural assimilation cannot erase ineradicable traces of another place; Larger interconnected populations counteract the inherent lossiness of cultural copying — Joseph Henrich, The Secret of Our Success: How Culture…, 715 (+1 more)

Broader Connections

• Full cultural assimilation cannot erase ineradicable traces of another place #corroborates (0.78)
• Cosmopolitan cultural mixing does not erase allegiance to an encompassing group #qualifies (0.76)
• Larger interconnected populations counteract the inherent lossiness of cultural copying #corroborates (0.75) — Joseph Henrich, The Secret of Our Success, 715
• Cultural mixing exceeds racial mixing precisely because it goes unobserved #complicates (0.72) — David Theo Goldberg, The Threat of Race, 1330