Despite being roughly half their size, female gorillas can, and frequently do, overpower male gorillas when competing for status and resources, according to a recent study.
This discovery challenges the traditional belief that gorilla society is strongly patriarchal – characterised by male dominance over females – and has implications for the origins of human gender dynamics.
Scientists at the Max Planck Institute for Evolutionary Anthropology, Germany, and the University of Turku, Finland, analysed 25 years of data gathered by observing the behaviour of gorillas in four different groups.
Wild mountain gorillas have long been considered an example of strict male power structures among primates, due to the vast size difference between males and females – the starkest size difference among any great ape.
It’s true that gorilla society is hierarchical. Each group has one alpha male at the top, and the rest of the gorillas compete for status below him.
But this new study concluded that gorilla hierarchies are much more gender balanced than previously believed.
“Gorilla females often outrank males,” lead author Dr Nikos Smit, researcher at Max Planck and Turku, told BBC Science Focus. “This is important for our understanding and interpretation of power relationships; it is not all about size and strength.”
In fact, 88 per cent of female gorillas outranked at least one adult male in groups with multiple males – mostly if those males were particularly young or old.
Additionally, when female gorillas engaged in conflicts with non-alpha males, they were victorious more than a quarter of the time, despite being significantly smaller than their opponents.
Senior author Dr Martha Robbins – director of the Bwindi mountain gorilla research project – told BBC Science Focus that this success was likely due to the relationship between these high-ranking females and their alpha male.
“The gorillas are aware of their social position and the social dynamics in a group,” she said. “These non-alpha males are bigger and physically stronger than the adult females, but they know that they should restrain themselves to avoid aggression from the alpha male. If they want to remain in the group, it is better to acquiesce.”
The scientists found, too, that the prize for winning these conflicts seemed to be priority access to food – another finding that contradicts previous research.
Scientists used to think that female gorillas only fought other females for food, while male gorillas mainly competed with each other for female mates. But it turns out that males and females all fight over food.
The scientists concluded that these findings had implications for our understanding of gender dynamics in human societies.
They wrote that the dominance of men over women was not “an apparent and immediate consequence of evolution,” but instead the result of “the flexible social and mating systems of humans.”
And, they continued, this is further supported by the observation that among bonobos – one of our closest living relatives, alongside chimpanzees – males are much bigger than females, but females are dominant over the males.
From this, scientists have concluded that it's unlikely humans inherited patriarchy from our primate ancestors.
Read more:
- Male mammals aren’t bigger than females after all - new study
- Farting wonders: Here’s what hidden jungle cameras discovered about gorilla flatulence
- Gorillas: The bigger the groups, the weaker the friendships
About our experts
Dr Nikos Smit is a postdoctoral researcher at the University of Turku, Finland, and the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. His research focuses on the evolution of social and mating systems, and the boundaries between conflict and cooperation.
Dr Martha Robbins is the director of the Bwindi Mountain Gorilla Research Project and a group leader in the department of primate behaviour and evolution at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Her research focuses on the evolution of sociality.
