Marriage residence norms measurably shape Y-chromosome and mitochondrial variation

Evidence

There is also evidence that culturally prescribed forms of social organization can shape our genome. This is important since some have argued that the forms of social organization created by cultural evolution are too weak or unstable to affect our genes. One important aspect of human social organization is what anthropologists call postmarital residence . In many human societies, especially until recently, local norms specified that a newly married couple went to live either with the husband’s family or with the wife’s family. The first is called patrilocal residence , and the second, matrilocal residence . Working in three patrilocal and three matrilocal farming populations in Northern Thailand, Hiroki Oota and his colleagues examined the variation in people’s mitochondrial DNA and Y chromosomes. Both sons and daughters get their mitochondrial DNA from mom, and only mom. Sons get their Y chromosomes from dad, whereas daughters don’t get Y chromosomes at all. If social organization is stable enough to influence the genome, than patrilocal communities should have relatively low variation in their Y chromosomes compared to mitochondrial DNA because sons always stick with their fathers. Similarly, because daughters stick with their mothers, matrilocal communities should show the opposite pattern, low variation in mitochondrial DNA and higher variation in Y chromosomes. This is precisely what Oota’s team found, showing that culturally evolved social norms can shape the genome. — Joseph Henrich, The Secret of Our Success, 312

Categorization

• XREF: Connects to the reader’s broader question of whether culture-level institutions (not just individual biases) have measurable causal force on human outcomes, paralleling the conformist-bias transmission question. — connects to: Residence norms measurably shape patterns of human genetic variation — Joseph Henrich, The Secret of Our Success: How Culture…, 311; Cultural economic packages drive genetic differences even between nearby populations — Joseph Henrich, The Secret of Our Success: How Culture…, 311
• SEED: An essay angle: marriage customs as a genetic force — how invisible social norms literally write themselves into our DNA over generations.

Broader Connections

• Residence norms measurably shape patterns of human genetic variation #expands (0.92) — Joseph Henrich, The Secret of Our Success, 311
• Cultural economic packages drive genetic differences even between nearby populations #corroborates (0.78) — Joseph Henrich, The Secret of Our Success, 311