🔗 Share this article Neanderthals and Modern Humans May Have Kissing, Researchers Propose Among Galápagos albatrosses to polar bears, primates to orangutans, certain species appear to kiss. Now, scientists suggest that Neanderthals also engaged in this behavior – and possibly exchanged kisses with modern humans. Common Oral Clues It is not the first time scientists have suggested Neanderthals and Homo sapiens were closely connected. In earlier research, scientists have found humans and their Neanderthal relatives shared the same mouth microbe for hundreds of thousands of years after the two species split, implying they exchanged oral fluids. "Likely they were kissing," the researcher noted, explaining that the idea aligned with studies that has found people of certain genetic backgrounds contain ancient genetic material in their genetic makeup, demonstrating interbreeding was at play. Romantic Interpretation "This offers a more romantic spin on human-Neanderthal relations," Brindle said. Publishing in the publication a scientific periodical, Brindle and her team report how, to investigate the evolutionary origins of kissing, they first had to develop a description that was not restricted by how humans smooch. Defining Kissing "Previously there were some previous attempts to describe a kiss, but it's largely human-centric, which means that essentially non-human species do not engage in this. Now we understand that they probably do, it may appear different from what our intimate contact resembles," explained Brindle. Nonetheless, she said some actions that resembled intimate contact were something rather different – such as the chewing and food sharing, or "kiss-fighting", seen in fish known as French grunts. As a result the research group came up with a definition of kissing based on friendly interactions involving directed mouth-to-mouth contact with a member of the identical group, with some movement of the oral area but no transfer of food. Research Approach Brindle said they focused on reports of intimate behavior in primates from Africa and Asia, including primates, apes and orangutans, and used digital recordings to confirm the observations. The researchers then integrated this data with details on the evolutionary relationships between extant and ancient types of such animals. Historical Origins Researchers say the results suggest intimate contact evolved approximately 21.5 million and 16.9m years ago in the predecessors of the large apes. The position of ancient hominins on this evolutionary lineage means it is probable they, too, engaged in a kiss, the researchers say. But the behavior may not have been confined to their specific group. "The fact that modern people engage intimately, the reality that we currently have shown that Neanderthals very likely kissed, suggests that the both groups are also likely to have kissed," the researcher added. Biological Significance While the scientific reasoning is discussed, Brindle said kissing could be used in reproductive situations to potentially enhance reproductive success or assist in selecting between partners, while it might help strengthen connections when practiced in a non-sexual manner. Another expert in the behavior of great apes said that as kissing behavior was seen in a broad spectrum of primates it made sense its roots lie deep in our evolutionary past, and an analysis of various types of kissing among a broader range of animals might extend its beginnings back further still. "Things that we consider as characteristics of our species, like kissing, are not unique to us if we look closely at different species," he said. Social Aspects An archaeology expert said that intimate contact had a social component as it was not universal to all societies. "However, as people we succeed or struggle on the quality of our emotional bonds, and methods of promoting confidence and closeness will have been important for eons," the professor stated. "It might be an concept that appears a bit contradictory to our incorrect assumptions of a rather ruthless and ancient history, but actually it should be no surprise that ancient hominins – and including Neanderthals and our own species collectively – engaged intimately."