Primates’ same-sex sexual behaviour ‘may reinforce bonds amid environmental stress’. Behaviour among non-human species could help keep groups together in face of social challenges, says study. Same-sex sexual behaviour was found in 59 non-human primate species.

**Primates’ same-sex sexual behaviour ‘may reinforce bonds amid environmental stress’**

**Behaviour among non-human species could help keep groups together in face of social challenges, says study**

Same-sex sexual behaviour among non-human primates may arise as a way to reinforce bonds and keep societies together in the face of environmental or social challenges, researchers have suggested.

Prof Vincent Savolainen, a co-author of the paper from Imperial College London, added that while the work focused on our living evolutionary cousins, early human species probably experienced similar challenges, raising the likelihood they, too, showed such behaviour.

Writing in the journal Nature Ecology & Evolution, Savolainen and colleagues reported how they analysed accounts of same-sex sexual behaviour in non-human primates, finding it to be widespread in most major groups, with reports in **59 species** including chimpanzees, Barbary macaques and mountain gorillas. That, they added, either suggested an evolutionary origin far back in the primate family tree, or the independent evolution of the behaviour multiple times.

While some studies have previously highlighted the possibility such behaviour could help reduce tensions in groups or aid bonding, the new study looked across different species to explore its possible drivers. The results reveal it to be more likely in species living in drier environments, where resources are scarce, and where there is greater risk from predators.

For those interested, here’s the link to the peer reviewed journal article:

https://www.nature.com/articles/s41559-025-02945-8

The findings fit with the idea that affiliative behaviors may be selectively advantageous for maintaining group cohesion, especially in unstable or high-stress environments.

I wonder if there is a similar study on the environment of being in jail.

Wait, is homosexuality just a gene triggered by environmental stress to reduce the population while allowing for continued sexual hormonal cycles

Ah yes the old sailor effect.

So they goon together when they are stressed?

So can we correlate this behavior in primates to exhibition of homosexuality in prison?