Overview
- The peer‑reviewed paper, published November 19 in Evolution and Human Behavior, was led by researchers at Oxford with collaborators from UCL and Florida Institute of Technology.
- Ancestral reconstructions place the origin of kissing in the common ancestor of large apes around 21.5–16.9 million years ago, with the behavior retained in most great apes.
- Models assign about an 84% probability that Neanderthals kissed, aligning with evidence that humans and Neanderthals exchanged oral microbes and interbred.
- The team defined kissing as non‑aggressive, intra‑specific mouth‑to‑mouth contact without food transfer and mapped observations across primates using 10 million Bayesian simulations.
- The authors emphasize sparse and uneven observations, note romantic kissing is documented in only about 46% of sampled human cultures, and call for standardized field reporting to test these inferences.