Female Choice, Male Dominance, and the Evolution of Low Voice Pitch in Men

David Andrew Putz

PhD Thesis 2004

Men voices are lower in pitch than women's, even controlling for body size. The developmental and anatomical reasons for this sex difference are known, but the evolutionary reasons are not. Some evidence suggests the evolutionary cause may have been intersexual selection via female mate choice, but other evidence implicates male dominance competition. This research tests the hypothesis that female choice for good genes and male dominance competition influenced the evolution of male voice pitch. Males were audio recorded while participating in an unscripted dating-game scenario. Recordings were subsequently rated by groups of males (for dominance) and females (for attractiveness).

Results from tests of the female mate choice hypothesis indicate that women's preferences for low male pitch increase with fertility over the ovulatory cycle, but that these preferences apply mainly to short-term mating contexts. Sociosexuality (interest in uncommitted sex) positively predicted women's sexual preferences for men with low voices. I examined the possibility that these relationships were due to an association between low voice pitch and low fluctuating asymmetry (FA), but FA did not correlate significantly with male voice pitch, and the voices of low-FA were not preferred by females.

Results from the male dominance hypothesis indicate that 1)low voice pitch increases men's appearance of physical and social dominance, augmenting the former more than the latter; 2) larger men have deeper voices; 3)men who believe they are physically dominant to their competitor lower their voice pitch when addressing him, whereas men who believe they are less dominant raise it; and 4) the appearance of social and physical dominance predict men's mating success and attractiveness to women. Because social dominance may be preferred by females due to associated non-genetic benefits, I also predict and find that, in absence of physical dominance, social dominance is preferred mainly by women in non-fertile menstrual cycle phases.