In this book, field and laboratory researchers show that the Great Apes are capable of thinking at symbolic levels, traditionally considered uniquely human. They show these high-level abilities in both social and ecological domains, including tool use, imitation, pretense, self-awareness, deception, consolation, teaching and proto-culture itself. Here, contributors emphasize the mechanisms involved in building these abilities--especially the lengthy developmental and "enculturation" processes--suggesting changes to current views on how primate and human intelligence have evolved. Researchers...