What special qualities of mind set the great apes apart from other nonhuman primates, and indeed from ourselves? In this book, field and laboratory researchers show that the great apes have high level abilities in both social and ecological domains, including tool use, pretense, self-awareness, deception, consolation, teaching and culture itself. Great apes are also shown to be capable of thinking at symbolic levels, traditionally considered to be uniquely human. Here, the mechanisms involved in building these abilities - especially the lengthy developmental and 'enculturation' processes - are emphasized, showing how new discoveries are changing views on how primates and human intelligence evolved. This book is for anyone interested in current research and theoretical views of great ape cognition.