Kissing on the Lips Dates Back 21 Million Years, Study Finds
LONDON - A new analysis suggests that kissing on the lips, a behavior often considered uniquely human, has surprisingly deep evolutionary roots, originating approximately 21 million years ago. The research, published this week, identifies a strong evolutionary signal linked to the act, tracing its origins to ancient primate interactions.
While not universal across human cultures – documented in only 46% of them, according to a 2015 study – the findings indicate kissing isn’t a learned behavior or recent social construct, but rather an inherited trait. Researchers emphasize that understanding why this trait evolved remains a key question for future investigation. “What we’ve done, wich is a realy important first step, is show that it’s an evolved trait,” said researcher Orlando Brindle. “It’s really old. But why? And that’s the incredible next step if people want to pick up the slack.”
The study relied on data gathered from observing animals in captivity and sanctuaries, highlighting the need for further research into kissing behaviors across a wider range of species. Researchers also caution that while the evolutionary link is strong, the practice isn’t without risk, noting the potential for disease transmission.”Primates are extremely flexible, very clever species, so kissing might be useful in some contexts, but not in others. And if it’s not useful, it’s quite risky,” Brindle explained.
Evolutionary psychologist Adriano Reis e Lameira, who was not involved in the study, pointed out that the research doesn’t explain the nuances of how humans kiss. “The vast majority of kisses that humans give are not mouth-to-mouth,” he said. Further research is needed to understand the complexities of human kissing behavior beyond simple mouth-to-mouth contact.
