Introduction

For centuries, people have pondered the question, “What is it about human life that sets us apart from all other species in the animal kingdom?” In response to this question, social scientists, among countless other scholars, have supplied sundry answers (for recent discussions, see Betzig 1996; Cartmill 1990). Some investigators suggest that humans alone communicate symbolically and thus language is the definitive trait (e.g., Deacon 1997; Lieberman 1991; Noble and Davidson 1996: 8, 15); others argue that the ability to make tools is unique to our species; still others see only in people a capacity for self-awareness or consciousness (e.g., McGuire 1995; Noble and Davidson 1996: 215); and some say that culture is confined to humans.1