Biologists from the University of Oxford have traced back the origins of kissing to large apes 21.5 million years ago, this according to a new study published in the journal Evolution and Human Behavior. The study concluded that our closest human relatives, Neanderthals, also kissed.
Kissing has been observed in many species, from wolves and prairie dogs to polar bears, but the study focused on primates. "Humans, chimps, and bonobos all kiss," Matilda Brindle, the lead researcher, explained. "It's likely that their most recent common ancestor kissed."
In humans, kissing is regarded as the ultimate display of affection. And kissing does have a wide range of effects on both our mental and physical health.
From triggering the production of a number of chemicals, to exposing us to germs, kissing has a surprising number of side effects. Curious to find out more about them? Then click on.