This unit examines the evolution of human sexuality in the contexts of primate reproductive strategies and the social learning environments that are unique to Homo sapiens. Various primate social and reproductive strategies will be studied, and aspects of human sexuality (such as mate choice and bonding, reproductive competition and divergent male and female strategies, loss of estrus, homosexuality, divergent male and female development trajectories) will be considered as phenomena exhibiting continuity or discontinuity with the primate behavioural range. Human behaviour will be examined from a Darwinian perspective, while social learning, the range of societies, and the concept of innateness will contribute to the overall analysis.