As our closest primate relatives, chimpanzees offer tantalizing clues about the behaviour and evolution of early human ancestors. Offering a detailed portrait of chimpanzee social behavior based on hundreds of thousands of hours of research, this book synthesises research findings from seven long-term field sites across the African rainforest belt. Why are the social lives of males and females so different? Why do groups of males sometimes kill their neighbors? Do chimpanzees cooperate when they hunt? Are their calls meaningful like words? Is their ability to use tools culturally transmitted? Addressing these questions and more, Arcadi examines well-researched behaviors to present a fascinating introduction to the chimpanzee social universe and its conservation. Also including an overview of the Primate order, an appendix describing field methods, and extensive endnotes with citations and supplementary data organized by field site, this is an essential resource for students and animal behavior researchers alike.