In 'The Evolution of Social Systems' J.P. Scott for the first time combines genetic theories of evolution, system theory and theories of behavioural evolution to explain the evolution of social behaviour and organisation. He proposes that caregiving has evolved from self care, to care of fertilised eggs, to developing embryos, to hatchlings. Care may then be extended to adult offspring, collateral relatives and to unrelated others. Humans, Scott shows, ae unique in the degree to which caregiving behaviour is extendable to nonrelated humans, other animals as pets, and even to plants. He concludes that social organisation is based on caregiving as well as processes such as unconscious physiological cooperation, site attachment, sexual behaviour, defensive behaviour, competition and conflict. Competition is thus not the sole mode of evolution. This view challenges some of the conventional sociobiological theories of the evolution of altruism. The book's broad interdisciplinary scope and social relevance has significant import for the general reader as well as for researchers and students in evolution, animal behaviour, ecology, psychobiology, and the human sciences of anthropology, political science and sociology.