Kissing Evolved 21 Million Years Ago

A new study led by the University of Oxford, with contributions from Matilda Brindle, Stuart West, and Catherine Talbot, suggests that kissing evolved between 21 million and 16 million years ago in a common ancestor of humans and other great apes. The research, published in Evolution and Human Behaviour, is the first to reconstruct the evolutionary history of kissing across primates. It also provides evidence that Neanderthals and Human likely kissed each other, based on shared oral bacteria and DNA. The study defines kissing as non-aggressive, mouth-to-mouth contact without food transfer and observed it in various great apes. While the study explains how kissing evolved, it does not fully clarify why, though hypotheses include mate quality assessment and social bonding. Zanna Clay and Troels Pank Arbøll provided additional commentary on the findings.