Sexual selection for low male voice pitch among Amazonian forager-horticulturists

Publication date: Available online 25 July 2019Source: Evolution and Human BehaviorAuthor(s): Kevin A. Rosenfield, Agnieszka Sorokowska, Piotr Sorokowski, David A. PutsAbstractPitch is the most perceptually salient feature of the voice, yet it is approximately five standard deviations lower in men than in women, a degree of sexual dimorphism exceeding that of all extant nonhuman apes. Evidence from Western samples suggests that low-frequency vocalizations may have augmented male mating success ancestrally by intimidating competitors and/or attracting mates. However, data are lacking from traditional societies living under conditions more similar to those in which our traits evolved. We therefore investigated sexual selection on male pitch (measured by fundamental frequency, fo) in a population of Bolivian forager-horticulturists, the Tsimané. We found that experimentally lowering fo in audio clips of men speaking increased perceptions of fighting ability but did not affect perceptions of prestige and decreased their attractiveness to women. Further, men with lower speaking fo reported higher numbers of offspring, and this was mediated by the reproductive rates of men's wives, suggesting that men with lower fo achieved higher reproductive success by having access to more fertile mates. These results thus provide new evidence that men's fo has been shaped by intrasexual competition.
Source: Evolution and Human Behavior - Category: Psychiatry & Psychology Source Type: research