Overview
- The peer-reviewed study, led by the University of Oxford with Florida Institute of Technology collaborators, is published in Evolution and Human Behavior.
- The team mapped observations of non-aggressive, mouth-to-mouth contact without food transfer across primates onto the evolutionary tree.
- Bayesian models run 10 million times estimate the behavior originated between 21.5 and 16.9 million years ago in the ancestor of great apes.
- Kissing is documented in humans, chimpanzees, bonobos, orangutans, and gorillas, supporting inheritance from a shared ancestor.
- Evidence of interbreeding and shared oral microbes supports the inference that Neanderthals likely kissed, as authors highlight sparse data and note the behavior is recorded in only 46% of human cultures.