Cultural evolution sustains costly norms that help neither the group nor the individual.

Evidence

Two other interesting results arise from studies using cultural evolutionary game theory. First, it turns out that any behaviors, underpinned by certain beliefs, strategies, or motivations, that call for individuals to pay personal costs, such as not eating a tasty type of food (e.g., bacon) or not having sex with an attractive distant cousin, can be sustained by cultural evolution, for example, through reputational damage. Norms even make nonsocial behavior (e.g., masturbation) into social behaviors, because uninvolved third parties come to care about such behavior. Second, social norms will tend to remain stable even when they help neither the group nor the individual. In fact, cultural evolution can produce sticky social norms that are bad for everyone. Ethnographic examples are numerous and range from cutting off the clitorises of young girls (female genital cutting) to consuming the brains of dead relatives at funerals (which can transmit a deadly prion disease). — Joseph Henrich, The Secret of Our Success, 475

Categorization

• XREF: connects to: Hunter-gatherer bands are mostly not made up of close genetic kin. — Joseph Henrich, The Secret of Our Success: How Culture…, 509; Food taboos induce meat sharing without anyone understanding they do so. — Joseph Henrich, The Secret of Our Success: How Culture…, 515; Synchronous singing and movement measurably increase cooperative contributions, even in four-year-olds. — Joseph Henrich, The Secret of Our Success: How Culture…, 526 (+2 more)

Broader Connections

• Cultural evolution can lock groups into maladaptive equilibria, not just prosocial ones #corroborates (0.95)
• Cultural evolution can create selection pressures stronger than natural ones #complicates (0.80) — Joseph Henrich, The Secret of Our Success, 282