Fundamental dispositions and traits of humans. Theories about the nature of humankind form a part of every culture. In the West, debate has traditionally centred on whether humans are selfish and competitive (seeThomas Hobbes; John Locke) or social and altruistic (Karl Marx, Émile Durkheim). Recent research in genetics, evolutionary biology, and cultural anthropology suggests that humans may be both, and that there is a complex interaction between genetically inherited factors (nature) and developmental and social factors (nurture). Basic drives shared with other primates include food, sex, security, play, and social status. Gender differences include greater investment in reproduction and child-rearing among females, hence less risk-taking; and concomitantly less investment and greater risk-taking among males. See alsobehaviour genetics; Homo sapiens; personality; philosophical anthropology; sociobiology.