Genetic variation in North Amerindian populations: association with sociocultural complexity.

A survey of nine polymorphic loci for 82 North Amerindian populations was undertaken to test the hypothesis that increasing levels of sociocultural complexity are ineluctably accompanied by increased heterozygosity. The data reveal a significant relationship in the predicted direction. Moreover, the significant correlation between average heterozygosity and sociocultural complexity is substantially increased by the removal of 19 highly admixed samples. However, this relationship, at least among North Amerindian populations, may be more apparent than real since both mean heterozygosity and the level of sociocultural organization are significantly negatively correlated with latitude. When this latter variable is controlled for, all correlations between heterozygosity and sociocultural complexity are rendered nonsignificant.