🔗 Share this article Neanderthals and Early Humans May Have Engaging in Intimate Contact, Scientists Propose From Galápagos albatrosses to polar bears, primates to great apes, certain species engage in mouth-to-mouth contact. Currently, scientists propose that Neanderthals did it too – and possibly locked lips with early Homo sapiens. Common Oral Evidence It is not the first time experts have proposed Neanderthals and early modern humans were intimately acquainted. In earlier research, scientists have discovered humans and their Neanderthal relatives shared the same mouth microbe for hundreds of thousands of years after the evolutionary divergence, implying they exchanged oral fluids. "Likely they were engaging in intimate contact," the researcher noted, adding that the concept aligned with research that has found people of non-African ancestry have bits of ancient genetic material in their genome, revealing genetic mixing was occurring. Romantic Spin "It certainly puts a different spin on human-Neanderthal relations," the lead researcher commented. Writing in the journal Evolution and Human Behavior, the researcher and colleagues detail how, to investigate the evolutionary origins of kissing, they first had to develop a definition that was not limited to how people kiss. Defining Kissing "Previously there were some efforts to describe a intimate act, but it's largely human-centric, which implies that essentially non-human species do not engage in this. Now we understand that they likely engage, it may appear different from what our intimate contact looks like," said Brindle. Nonetheless, she noted some behaviors that resembled intimate contact were something rather different – such as the chewing and food sharing, or "mouth contact", observed in aquatic species known as French grunts. As a result the team came up with a description of intimate contact centered around friendly interactions involving directed oral interaction with a member of the identical group, with some motion of the mouth but no transfer of nutrition. Research Methods Brindle said they focused on accounts of kissing in non-human species from Africa and Asia, including primates, apes and great apes, and used digital recordings to verify the reports. Scientists then integrated this information with details on the genetic connections between extant and extinct types of such primates. Evolutionary Timeline Researchers propose the results suggest intimate contact evolved approximately 21.5m and 16.9 million years ago in the ancestors of the large apes. The position of ancient hominins on this evolutionary lineage means it is likely they, too, indulged in a intimate act, the scientists say. But the behavior might not have been confined to their own species. "Reality that modern people engage intimately, the reality that we now have demonstrated that ancient relatives very likely kissed, indicates that the two [species] are also likely to have kissed," Brindle noted. Evolutionary Significance While the evolutionary explanation is discussed, Brindle said intimate contact could be used in sexual contexts to possibly enhance reproductive success or assist in selecting between mates, while it might help strengthen connections when practiced in a non-sexual manner. Another expert in the behavior of great apes commented that as intimate contact was seen in a wide range of primates it was logical its origins extend far into our evolutionary past, and an examination of different forms of intimate behavior among a wider variety of animals might extend its origins back further still. "Things that we consider as characteristics of human life, like kissing, are not unique to us if we look closely at other animals," he said. Cultural Aspects An archaeology expert said that kissing had a cultural element as it was not universal to all societies. "Nonetheless, as people we succeed or struggle on the quality of our emotional bonds, and methods of encouraging trust and closeness will have been significant for millions of years," the professor stated. "It might be an image that appears a bit contradictory to our misplaced ideas of a supposedly aggressive and aggressive past, but actually it ought to be no surprise that Neanderthals – and including Neanderthals and our human ancestors collectively – kissed."