Analyzed cross-cultural child inculcation data from Barry, Josephson, Lauer, & Marshall (1976) by testing a hypothesis derived from natural selection theory: The ways in which boys are trained (vs. those for girls) should correlate with male and female reproductive strategies prevalent in each society. Boys are trained to be more aggressive, show more fortitude, and be more self-reliant than girls; girls are trained to be more industrious, responsible, obedient, and sexually restrained than boys. The more polygynous the society (the higher the potential reproductive rewards for males), the more sons in nonstratified societies were taught to strive. Stratified societies, which restrict men's reproductive striving, showed very different patterns. The more actual control women in any society had over resources, the less daughters were taught to be obedient.