🔗 Share this article Neanderthals and Early Humans May Have Kissing, Researchers Propose From seabirds to Arctic mammals, chimpanzees to great apes, certain species appear to kiss. Now, researchers suggest that Neanderthals did it too – and possibly locked lips with modern humans. Shared Oral Clues It is not the first time scientists have suggested Neanderthals and Homo sapiens were intimately acquainted. In earlier research, scientists have discovered humans and their thick-browed cousins shared the identical oral bacteria for millions of years after the evolutionary divergence, suggesting they swapped saliva. "Likely they were engaging in intimate contact," the researcher noted, explaining that the concept aligned with studies that has found humans of non-African ancestry have bits of Neanderthal DNA in their genetic makeup, revealing genetic mixing was at play. Intimate Interpretation "This offers a more romantic spin on human-Neanderthal relations," the lead researcher said. Writing in the publication a scientific periodical, the researcher and colleagues report how, to investigate the evolutionary origins of kissing, they first had to come up with a description that was not restricted by how people kiss. Describing Kissing "There have been some efforts to define a kiss, but it's very much been human-centric, which implies that basically other animals do not engage in this. Currently we know that they likely engage, it may appear different from what our intimate contact looks like," explained the evolutionary biologist. Nonetheless, she said some behaviors that resembled kissing were distinct activities – such as the chewing and food sharing, or "mouth contact", observed in aquatic species known as French grunts. Consequently the research group came up with a definition of intimate contact centered around friendly interactions involving intentional mouth-to-mouth contact with a member of the identical group, with some movement of the mouth but absence of food. Research Methods The lead researcher said they focused on reports of kissing in non-human species from the African continent and Asia, including primates, apes and great apes, and used digital recordings to confirm the reports. The researchers then integrated this information with details on the genetic connections between extant and extinct species of such animals. Historical Origins The team propose the findings suggest kissing developed approximately 21.5m and 16.9 million years ago in the ancestors of the large apes. The position of ancient hominins on this family tree suggests it is likely they, too, indulged in a kiss, the researchers say. But the activity may not have been confined to their own species. "Reality that modern people engage intimately, the reality that we now have demonstrated that Neanderthals very likely engaged, indicates that the two [species] are also likely to have kissed," Brindle noted. Evolutionary Significance While the scientific reasoning is discussed, Brindle explained kissing could be employed in reproductive situations to potentially increase reproductive success or assist in selecting between mates, while it might help reinforce bonding when used in a non-sexual manner. A separate researcher in the behavior of primates said that as intimate contact was seen in a wide range of apes it made sense its roots extend far into our ancient history, and an examination of various types of intimate behavior among a broader range of species might push its origins back even earlier still. "Behaviors that we consider as characteristics of our species, like intimate contact, are not exclusive to us if we examine carefully at other animals," the expert noted. Social Aspects An archaeology expert explained that intimate contact had a cultural element as it was not universal to all societies. "Nonetheless, as people we thrive or fail on the strength of our relationships, and methods of encouraging confidence and intimacy will have been significant for millions of years," the professor stated. "This could represent an concept that appears a bit incongruous to our incorrect assumptions of a supposedly aggressive and ancient history, but actually it should be expected that Neanderthals – and even Neanderthals and our human ancestors collectively – engaged intimately."