Male Violence Among Ache´ and Hiwi Hunter-Gatherers

In order to understand how warfare and violence have shaped the natural history of our species, and perhaps favored adaptations that respond to this important life threat, we need to document what types of violence were common in our ancestors and what were the levels of violent death in the past. Archeology has allowed us to detect some fraction of violent deaths in ancient people, and assign a rough percentage of all deaths due to violence. Observation on modern hunter-gatherers, who live under conditions similar to our ancestors, provides another important source of information. However, because we can directly observe and interview living hunter-gatherers, we are able to obtain much more precise estimates of violent death rates than can be obtained via archeological interpretation. Currently there are five hunter-gatherer tribes from around the world whose death rates have been systematically studied. We worked with two of these tribes, the Ache of Paraguay and the Hiwi of Venezuela. We found that crude death rates from violence approached 1% per year, and that a third to a half of all deaths in these societies were due to human violence. Because many killings involve coalitions of individuals in conflict with other coalitions, the threat of violent death may be a major force in favoring mechanisms of cooperation within human groups.