The Psychology of Families

Two illusions about the nature of human families are the Illusion of Gender Sameness and the Illusion of Family Socialization. The assumption of gender sameness is critically evaluated and found to be deficient. The lack of sex differences on many variables is not disputed, but on variables where sex-specific past selection pressures can be assumed, the differences are considerable. Neglecting to cut nature at its joints, to use Socrates’ butcher metaphor, and using effect size estimates averaged over “wrongly cut” areas gives a mistaken impression of the absence of sex differences. Moreover, socially important sex differences may appear as variance differences. How evolutionarily designed sex differences invade mating, parenting, grandparenting, and extended family relationships, and produce asymmetries in family life, is exemplified, particularly with respect to grandparenting. The Illusion of Family Socialization denotes the belief that the human adult personality is formed by parenting practices. Robust data from behaviorial genetics attest that the shared environment, and thus family-specific socialization practices, does not—with exceptions—account for the variances in personality. Considerations from evolutionary theory, particularly life history theory and parent–child conflict, deliver plausible reasons why parents are not able to mold permanently their offspring’s personality. A human evolutionary behavioral science is well equipped to expose and debunk these illusions.