Hunter-gatherer bands are mostly not made up of close genetic kin.

Evidence

The problem with this explanation is that the best available evidence indicates that hunter-gatherers do not live in groups mostly composed of close kin. Based on work by Kim Hill and colleagues, figure 9.1 shows the average composition of both Ju/’hoansi and Aché bands. “Primary kin” includes siblings, half-siblings, and parents, while “distant kin” includes anyone with a blood link going back up to five generations (extending to second cousins). Together, these two categories plus oneself make up only about a quarter of the band. That means that about three-quarters of band relationships are based on something besides genetic relatedness. Among the Aché, for which the data are most detailed, band members are on average only very distant relatives, a bit more related than second cousins and about one-tenth that of a full brother or sister (genealogical r = 0.054). — Joseph Henrich, The Secret of Our Success, 509

Categorization

• XREF: connects to: Cultural evolution sustains costly norms that help neither the group nor the individual. — Joseph Henrich, The Secret of Our Success: How Culture…, 475