Scattered and not widely disseminated evidence from primatology, anthropology, and history of childhood sexuality support the hypothesis that throughout much of human behavioral evolution that human children have learned about sex through observing parental sexuality and then imitating it in sexual rehearsal play with peers. Contemporary theories of psychosexual development have not considered the possibility that young children are predisposed to learn about sex through observational learning and sexual rehearsal play during early childhood, a primate-wide trait that is conserved in humans but suppressed in contemporary contexts.