Overview
- Published January 12 in Nature Ecology & Evolution, the meta-analysis reports same-sex sexual acts in 59 nonhuman primate species, with repeated occurrences in 23.
- The team surveyed roughly 1,700 publications spanning 491 species and counted only clearly sexual behaviors such as mounting, genital contact and fellatio, excluding nonsexual interactions.
- Statistical patterns associate the behavior with dry, resource-scarce environments, higher predation risk, longer lifespans, pronounced sexual dimorphism and complex social hierarchies.
- Authors suggest these acts can function as social "currency" that reduces tension, strengthens bonds and builds alliances, while noting adaptive value remains unproven without links to increased offspring.
- Researchers highlight likely underreporting and warn against extrapolating to modern human sexual orientation, and they plan targeted tests in macaques after prior work found a modest heritable component.