Scientific studies of monkeys, apes, and other nonhuman primates began just over 50 years ago. Since then tens of thousands of hours of observation have been made on these animals in the wild and in captivity. The chief rationale for scientific primatology has always been the belief that important insights into human behaviour and society could be gained through studies of our evolutionary kin. This book reviews what we have learned. Distinguished researchers outline primatological insights in six areas: sex, parenting, behavioural development, aggression/dominance, culture and kinship. The chapters show how primates have been used as simplified models of human behaviour and how they have contributed to scenarios of human evolution. Lay readers, students, and specialists alike will find this a readable and useful compendium of the findings of scientific primatology. Covering topics from orgasm to ontogeny, parental investment to penis size, and kinship to culture, this book summarizes what studying monkeys and apes has taught us about ourselves.