Groundbreaking research shows that female-biased and egalitarian power structures are common in primates, contradicting the common assumption of male dominance and highlighting the importance of women’s roles in primate societies.

Male dominance has long been thought to be nearly universal in primates; female domination was seen 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 in every major primate group and have likely existed throughout evolutionary history.

A study published in the journal animalsIt challenges the assumption of male dominance in primates and may have implications for other animal species.

The team reviewed previous literature on 79 primate species, categorized them as male-dominant, female-dominant or co-dominant, and then analyzed which variables were associated with these social patterns.

They found that male potency likely evolved in species where males had larger body size and longer canines than females. Female dominance may occur when the number of available mating partners is lower than the demand for males, giving females of these species greater social influence, especially if size differences between the sexes are minimal.

“In the past, primatologists have generally focused on the role of men and male power in primate societies,” said Rebecca Lewis, professor of anthropology and co-author of the paper.

“What is sometimes overlooked is the important role of female power in primate societies. Our study suggests that more economic forms of power may indeed come to the fore in primate species where males and females are the same size and females are less challenged by males.”

Among primates, female power structures are common in lemurs. Previous researchers have often tried to explain this phenomenon as an abnormality caused by unique environmental factors. But new research points to the existence of female-biased and egalitarian power structures in many other primate species, such as gibbons in Southeast Asia and marmosets in the Americas. In addition, the study was also able to estimate the likelihood of biased male strength in primate ancestral groups.

The study found that no single pattern of intersexual strength can be confidently attributed to the ancestors of many large primate groups, and therefore the assumption of male-biased ancestral strength is not warranted.

“Primates are thought to be overwhelmingly male-dominated, suggesting that male dominance in primates was present early in their evolutionary history,” said UT anthropology professor and co-author Chris Kirk.

“If this assumption is correct, it should explain the existence of female-dominated societies and societies with greater gender equality. However, we show that this biased assumption of ancestral power in primates is not necessarily supported by the data.”

“In fact, other types of intersex power relations are quite common in primate societies, so it is not clear what the ancestral state might be. Therefore it is necessary to explain All not just the existence of female-biased power, but cross-gender types of power.”