What if the first kisses did not come from humans, but from our primate ancestors?
Kissing is present throughout the animal kingdom. It seems romantic and deeply human to us. However, it would be much older than our species. To trace the origins of this gesture, researchers at the University of Oxford began by observing the behaviors of several current primates – chimpanzees, bonobos, orangutans – all capable of exchanging mouth-to-mouth contact, with a few movements of the lips and without exchange of food. They then used this definition of kissing to trace its history down the evolutionary tree.
Using millions of computer simulations, they were able to estimate when this behavior emerged in human history. The verdict is surprising: this gesture has existed for more than 20 million years, well before the appearance of the first humans, according to their conclusions published in Evolution and Human Behavior. The kiss dates back to a common ancestor of humans and great apes, between 21.5 and 16.9 million years ago. It would have been preserved throughout evolution and transmitted to different species.
Homo sapiens were already kissing each other
The study also suggests that Neanderthals probably kissed. Previous work shows that Homo sapiens and Neanderthals not only shared genes, but also some oral microbes – a transmission that involves close contact, of which kissing could be a part. Why kiss, when this gesture exposes you to germs? Researchers believe that it could strengthen social bonds, soothe others, create complicity or help evaluate a partner through smell and taste. Social behavior before being in love.
Another interesting point: kissing is not universal. It is only found in 46% of human cultures. Proof that ancient behavior can also be largely shaped by traditions. For scientists, this study opens a new path: understanding how our most intimate gestures have also evolved. And perhaps remember that some of our ways of loving have much deeper roots than we think.
