🔗 Share this article Ancient Hominins and Modern Humans May Have Engaging in Intimate Contact, Researchers Propose From Galápagos albatrosses to Arctic mammals, chimpanzees to great apes, various animals appear to kiss. Currently, scientists suggest that Neanderthals also engaged in this behavior – and possibly locked lips with modern humans. Shared Oral Evidence It is not the first time scientists have proposed Neanderthals and Homo sapiens were intimately acquainted. In previous studies, researchers have discovered modern people and their thick-browed cousins shared the same mouth microbe for millions of years after the two species split, suggesting they exchanged oral fluids. "Likely they were kissing," she said, explaining that the idea chimed with research that has revealed humans of non-African ancestry have bits of Neanderthal DNA in their genetic makeup, revealing genetic mixing was at play. Romantic Interpretation "This offers a more romantic perspective on human-Neanderthal relations," the lead researcher said. Writing in the journal Evolution and Human Behavior, the researcher and colleagues report how, to explore the historical roots of intimate contact, they first had to come up with a description that was not limited to how people smooch. Defining Intimate Contact "Previously there were some efforts to define a intimate act, but it's very much been focused on humans, which means that basically other animals don't kiss. Currently we understand that they probably do, it might just not look from what our intimate contact looks like," said the evolutionary biologist. However, she said some behaviors that resembled intimate contact were something rather different – such as the processing and transfer of food, or "mouth contact", seen in fish known as certain marine animals. Consequently the team developed a definition of intimate contact centered around social behaviors involving intentional mouth-to-mouth contact with a individual of the identical group, with some movement of the oral area but absence of nutrition. Research Methods The lead researcher explained they concentrated on accounts of kissing in primates from the African continent and Asia, including primates, apes and great apes, and employed online videos to confirm the reports. The researchers then integrated this data with details on the evolutionary relationships between extant and ancient types of such animals. Historical Origins Researchers propose the results suggest intimate contact evolved approximately 21.5 million and 16.9 million years ago in the ancestors of the large apes. The position of Neanderthals on this evolutionary lineage suggests it is probable they, too, indulged in a intimate act, the researchers conclude. But the behavior may not have been confined to their own species. "Reality that humans engage intimately, the fact that we currently have demonstrated that Neanderthals probably kissed, suggests that the both groups are also likely to have engage," the researcher added. Biological Significance While the evolutionary explanation is debated, the expert said kissing could be employed in sexual contexts to potentially increase 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 activities of primates said that as intimate contact was observed in a wide range of primates it was logical its origins lie deep in our ancient history, and an analysis of different forms of intimate behavior among a wider variety of species might extend its beginnings back further still. "Things that we consider as characteristics of our species, like kissing, are not exclusive to us if we look closely at other animals," the expert noted. Social Aspects An archaeology expert said that kissing had a cultural element as it was not common to all societies. "Nonetheless, as people we succeed or struggle on the quality of our emotional bonds, and methods of encouraging trust and intimacy will have been significant for millions of years," the professor stated. "It might be an concept that seems a bit contradictory to our incorrect assumptions of a supposedly aggressive and aggressive past, but actually it ought to be expected that Neanderthals – and including Neanderthals and our own species collectively – engaged intimately."