Discoveries

February 23, 2024

Battle of the Sexes

Listen to Today's Edition

Primatologists have held the belief that a vast majority of primate societies are dominated by the male species.

But a recent study is challenging those long-standing assumptions, Scientific American reported.

A research team analyzed dominance patterns in 79 living primate species, taking into account factors such as mating behavior, social structure and sexual dimorphism – differences between males and females in body size and other physical characteristics.

Their findings showed that female dominance or equality with males was present in 42 percent of the species examined, highlighting the diverse range of social dynamics among primates.

The team explained that key factors that influenced dominance included physical features, such as body size and canine tooth size.

For example, male chimpanzees are larger than females and would attack females in the hopes of mating with them. In contrast, male and female bonobos are similar in size and form tight bonds together – an arrangement that can lead to female-dominated societies.

Researchers added that power dynamics can also be impacted by a difference in male-to-female ratio and mating behavior: For instance, female dominance diminished sifaka lemurs – a species known to be matriarchal – when there were more females than males. The males became more assertive because they had a wider choice of mates.

Meanwhile, the study also examined fossils of extinct primates to understand dominance patterns in the last common ancestor of all primates. The analysis unveiled patterns that matched with a variety of intersexual power relationships – meaning that the dominance status of our last common ancestor could go either way.

Primatologist Erin Vogel from Rutgers University, who was not involved in the study, commended the innovative approach, noting its implications for understanding primate societies.

“The traditional old-school thinking in primatology has always been around male dominance, but this study allows us to rethink that,” she added.

This story originally appeared in the February 23, 2024 newsletter, Forced Predictability.