The question addressed by this volume is how human beings have evolved as creatures who can make and use more complex tools, communicate in more complex ways, and engage in more complex forms of social life, than any other species in the animal kingdom. The topics explored include the parallels among speech, manual gesture and other models of communication; a comparison of the tool-using skills and imitative abilities of humans and nonhuman primates; the neurological links among the cognitive processes involved in language, gesture and tool use; how linguistic and technical capacities merge together in processes of cognitive development; and a discussion of what the archaeological record and the ethnography of modern human cultures can tell us about the relationship among tools, language and social life.