For a social group to develop, two opposing adaptive processes must be reconciled—mechanisms for developing cohesion and mechanisms for establishing a dominance hierarchy. The formation of stable groups provides significant evolutionary advantages: a source of protection, increased reproductive opportunities, and a larger store of survival strategies than any one individual could encompass. A recent theory of human evolution (Reynolds, 1981) stresses that social behaviour would seem to be the most likely single cause of the origin of human intelligence, if one origin must be isolated. Current interest in the biological basis of behaviour has been focused particularly on specific diagnostic categories and biochemical mechanisms. This paper reviews a different research tradition, based on ethological principles, and applies the findings to an understanding of human group behaviour.
