science

Male dominance has long been assumed to be nearly universal in primates, with female power viewed as a rare exception to the rule. However, according to researchers at The University of Texas at Austin, female-biased power structures or social equality between the sexes can be found within every major primate group and probably existed throughout evolutionary history.

The study, published in the journal Animals, challenges presumptions of male dominance in primates and may also have implications for other animal species.

The team reviewed previous literature on 79 primate species, dividing them into male-dominant, female-dominant, or co-dominant categories, and then analyzed which variables correlated with these social patterns.

They found that male-biased power was likely to develop in species in which males had larger body sizes and longer canine teeth than their female counterparts. Female power may emerge when the supply of available female mating partners is lower than male demand, thus giving the females in those species greater social leverage, particularly if size differences between the sexes are minimal.