Because most of humanity's time as a species has been spent in a hunting-and-gathering subsistence mode, living hunter-gatherers have always played a pivotal role in interpretations of pre-history and anthropological theory. It is widely believed that "human nature" can be seen more clearly at this "stage" than at any other. Challenging this preconception, Robert L. Kelly crafts a new theoretical position by emphasizing the diversity among hunter-gatherer societies - a diversity that belies attempts to establish a single model of a predominant or "original" foraging lifeway. Kelly reviews the anthropological literature for the differences among ethnographically known hunter-gatherers. By considering the actual, not imagined, reasons behind diverse behavior, The Foraging Spectrum argues for a revision of many archaeological models of prehistory. Written for archaeologists and ethnologists outside the field of hunter-gatherer research, it stresses explaining, rather than explaining away, variability.