🔗 Share this article Neanderthals and Modern Humans Were Likely Kissing, Researchers Propose From Galápagos albatrosses to polar bears, primates to orangutans, certain species appear to kiss. Currently, researchers suggest that Neanderthals did it too – and might even have exchanged kisses with early Homo sapiens. Common Microbial Evidence It is not the first time scientists have suggested ancient relatives and Homo sapiens were intimately acquainted. In previous studies, scientists have found modern people and their Neanderthal relatives shared the same mouth microbe for hundreds of thousands of years after the evolutionary divergence, suggesting they swapped saliva. "Probably they were engaging in intimate contact," she said, explaining that the concept chimed with research that has found people of non-African ancestry contain ancient genetic material in their genome, demonstrating interbreeding was at play. Intimate Interpretation "This offers a different spin on human-Neanderthal relations," Brindle said. Publishing in the journal Evolution and Human Behavior, the researcher and her team report how, to explore the evolutionary origins of intimate contact, they first had to come up with a description that was not limited to how people kiss. Defining Kissing "There have been some previous attempts to define a intimate act, but it's largely human-centric, which implies that essentially other animals don't kiss. Now we understand that they likely engage, it may appear different from what human kissing looks like," explained Brindle. However, she said some actions that resembled kissing were distinct activities – such as the processing and transfer of food, or "mouth contact", observed in fish known as certain marine animals. Consequently the team developed a description of intimate contact based on friendly interactions involving intentional oral interaction with a member of the identical group, with some motion of the oral area but absence of food. Study Methods The lead researcher explained they concentrated on reports of intimate behavior in primates from the African continent and Asian regions, including bonobos, chimpanzees and great apes, and employed online videos to verify the observations. Scientists then combined this data with information on the evolutionary relationships between living and extinct species of such animals. Historical Timeline The team propose the results indicate kissing evolved somewhere between 21.5m and 16.9 million years ago in the predecessors of the large apes. The position of Neanderthals on this family tree means it is probable they, too, engaged in a kiss, the researchers conclude. But the behavior might not have been limited to their own species. "The fact that humans kiss, the reality that we now have demonstrated that ancient relatives very likely kissed, suggests that the both groups are also likely to have kissed," the researcher added. Biological Importance Although the evolutionary explanation is discussed, the expert said kissing could be employed in sexual contexts to possibly increase reproductive success or assist in selecting between mates, while it could assist strengthen connections when practiced in a non-sexual manner. Another expert in the activities of great apes said that as intimate contact was seen in a wide range of apes it made sense its roots lie deep in our evolutionary past, and an analysis of different forms of intimate behavior among a broader range of species might push its beginnings back even earlier still. "Things that we consider as signatures of our species, like intimate contact, are not unique to us if we look closely at other animals," the expert noted. Cultural Elements An archaeology expert explained that kissing had a cultural element as it was not common to all societies. "However, as humans we thrive or fail on the quality of our relationships, and methods of promoting confidence and intimacy will have been important for eons," the professor stated. "This could represent an image that seems a bit contradictory to our incorrect assumptions of a supposedly aggressive and ancient history, but actually it should be no surprise that ancient hominins – and even them and our own species together – kissed."