During the 1990s there was an upsurge of interest in the application of evolutionary thinking to the study of human behaviour. Darwin's basic ideas concerning natural and sexual selection have been revised, refined and extended in scope. This book is a response to the need for a student textbook dealing explicitly with Darwinism and human affairs. It provides an overview of the key theoretical principles of human sociobiology and evolutionary psychology and shows how they illuminate the way humans think and behave. It should be of value to psychology and biology undergraduates but specifically those studying evolutionary psychology, animal behaviour and evolutionary theory, sociobiology, biological anthropology and behavioural ecology.