Upper-body strength predicts hunting reputation and reproductive success in Hadza hunter–gatherers

Hunting is a characteristic feature of early human subsistence, and many theories of evolution have emphasized the role of hunting in hominization. Still today hunting ability continues to be selected for in extant foragers with better hunters experiencing greater reproductive success. Yet little is known about the traits that comprise a successful hunter traits that are presupposed to also be under selection. Two complementary empirical analyses were conducted to examine this question using data collected from Hadza hunter–gatherers in Tanzania. First, data on upper-body strength, running speed, target precision and visual and auditory acuity were collected to examine the traits that predict hunting reputation in men. Second, interview data were collected from Hadza informants regarding the traits they deem important for hunting. Results from the first study implicate upper-body strength as the strongest and most consistent predictor of men's hunting reputation. Hadza conventional wisdom also accord with these findings. Although informants stressed the importance of non-physical traits, such as “intelligence” and “heart”, strong arms were cited as the most important physical trait for hunting. Finally, men with stronger upper-bodies experienced greater reproductive success, a result that is largely mediated by hunting reputation. These findings suggest that selection for hunting ability may have acted on men's upper-bodies. Nevertheless, the importance of effort on strength and hunting success cannot be dismissed. This is also discussed.