Because of their vital role in the emergence of humanity, tools and their uses have been the focus of considerable worldwide study. This volume brings together international research on the use of tools among primates and both prehistoric and modern humans. The book represents leading work being done by specialists in anatomy, neurobiology, prehistory, ethnology, and primatology. Whether composed of stone, wood, or metal, tools are a prolongation of the arm that acquire precision through direction by the brain. The same movement, for example, may have been practiced by apes and humans, but the resulting action varies according to the extended use of the tool. It is therefore necessary, as the contributors here make clear, to understand the origin of tools, and also to describe the techniques involved in their manipulation, and the possible uses of unknown implements. Comparison of the techniques of chimpanzees with those of prehistoric and modern peoples has made it possible to appreciate the common aspects and to identify the differences. The transmission of ability has also been studied in the various relevant societies: chimpanzees in their natural habitat and in captivity, hunter-gatherers, and workmen in prehistoric and in modern times. In drawing together much valuable research, this work will be an important and timely resource for social and behavioral psychologists, anthropologists, paleontologists, and animal behaviorists.