🔗 Share this article Neanderthals and Modern Humans Were Likely Kissing, Researchers Suggest From Galápagos albatrosses to polar bears, chimpanzees to orangutans, various animals engage in mouth-to-mouth contact. Currently, researchers suggest that Neanderthals did it too – and might even have locked lips with early Homo sapiens. Common Microbial Clues This isn't the initial instance scientists have suggested ancient relatives and Homo sapiens were closely connected. In previous studies, scientists have discovered humans and their Neanderthal relatives possessed the same mouth microbe for hundreds of thousands of years after the two species split, implying they exchanged oral fluids. "Likely they were kissing," she said, adding that the idea aligned with research that has revealed humans of non-African ancestry have bits of ancient genetic material in their genome, demonstrating genetic mixing was occurring. Intimate Interpretation "It certainly puts a different perspective on ancient interactions," the lead researcher said. Writing in the publication Evolution and Human Behavior, the researcher and her team report how, to investigate the evolutionary origins of intimate contact, they first had to come up with a description that was not restricted by how humans smooch. Describing Intimate Contact "Previously there were some efforts to define a intimate act, but it's very much been human-centric, which means that essentially other animals do not engage in this. Now we know that they probably do, it might just not look from what our intimate contact resembles," explained the evolutionary biologist. However, she said some behaviors that resembled kissing were something rather different – such as the processing and food sharing, or "mouth contact", observed in aquatic species known as certain marine animals. As a result the team came up with a description of intimate contact based on social behaviors involving intentional oral interaction with a member of the identical group, with some movement of the mouth but absence of food. Research Approach Brindle explained they focused on accounts of intimate behavior in non-human species from Africa and Asia, including bonobos, apes and orangutans, and used online videos to confirm the observations. Scientists then combined this data with information on the genetic connections between extant and extinct species of such animals. Evolutionary Origins The team propose the findings indicate intimate contact developed somewhere between 21.5 million and 16.9 million years ago in the ancestors of the large apes. The position of Neanderthals on this evolutionary lineage means it is probable they, too, engaged in a kiss, the scientists say. But the activity may not have been confined to their own species. "The fact that modern people kiss, the fact that we currently have shown that ancient relatives probably kissed, suggests that the two [species] are also likely to have engage," the researcher noted. Evolutionary Significance While the scientific reasoning is debated, Brindle explained intimate contact could be employed in sexual contexts to possibly increase reproductive success or help choose between mates, while it might help reinforce bonding when used in a platonic way. A separate researcher in the activities of primates commented that as kissing behavior was seen in a wide range of primates it was logical 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 beginnings back even earlier still. "Behaviors that we consider as characteristics of our species, like kissing, are not exclusive to us if we examine carefully at different species," he said. Cultural Elements An archaeology expert said that intimate contact had a social component as it was not universal to all human groups. "Nonetheless, as people we thrive or fail on the strength of our relationships, and ways of encouraging confidence and intimacy will have been important for millions of years," she said. "This could represent an concept that seems a bit contradictory to our misplaced ideas of a supposedly aggressive and ancient history, but actually it ought to be no surprise that ancient hominins – and even Neanderthals and our human ancestors collectively – kissed."