ABSTRACT
This chapter provides an account of the biological and cultural background to social interaction. The territory provides for the basic biological needs of hunger and thirst. Territorial aggression is aroused when an intruder invades the home territory. Hunger and thirst are needs in the sense that they are aroused by deprivation, and satiated by eating and drinking. Male sexual behaviour in the form of penile erection and thrusting is found shortly after birth; homosexual behaviour occurs in childhood; heterosexual intercourse occurs during adolescence, and the correct position is gradually acquired. Sex, dependency and affiliation are all approach tendencies directed towards social objects, though with somewhat different goal responses; sex and affiliation are indeed sometimes difficult to distinguish. Innate tendencies towards affiliation do more than create positive social bonds; they prescribe the form of group life for each species. Dominance is one of the dimensions of human social behaviour, and is in some ways the opposite of dependence, or of submission.
