🔗 Share this article Ancient Hominins and Early Humans Were Likely Kissing, Scientists Suggest Among seabirds to polar bears, primates to great apes, various animals appear to kiss. Currently, scientists propose that ancient hominins also engaged in this behavior – and might even have exchanged kisses with early Homo sapiens. Shared Microbial Evidence This isn't the initial instance experts have proposed Neanderthals and early modern humans were intimately acquainted. Among previous studies, researchers have discovered humans and their thick-browed cousins possessed the same mouth microbe for hundreds of thousands of years after the two species split, suggesting they swapped saliva. "Likely they were kissing," she said, explaining that the concept aligned with studies that has revealed people of non-African ancestry contain Neanderthal DNA in their genome, revealing genetic mixing was occurring. Intimate Spin "It certainly puts a different spin on human-Neanderthal relations," the lead researcher commented. Publishing in the journal a scientific periodical, the researcher and colleagues report how, to investigate the historical roots of intimate contact, they first had to develop a definition that was not restricted by how humans kiss. Defining Kissing "There have been some efforts to describe a kiss, but it's very much been human-centric, which means that basically non-human species don't kiss. Now we know that they probably do, it may appear different from what our intimate contact looks like," explained Brindle. Nonetheless, she noted some behaviors that looked like intimate contact were something rather different – such as the processing and food sharing, or "mouth contact", seen in fish known as certain marine animals. As a result the team came up with a description of intimate contact centered around friendly interactions involving directed mouth-to-mouth contact with a individual of the identical group, with some motion of the oral area but absence of nutrition. Study Methods The lead researcher explained they concentrated on accounts of kissing in non-human species from Africa and Asia, including bonobos, chimpanzees and orangutans, and employed online videos to confirm the reports. The researchers then combined this information with details on the evolutionary relationships between extant and extinct types of such animals. Evolutionary Timeline Researchers say the findings suggest intimate contact evolved approximately 21.5 million and 16.9 million years ago in the predecessors of the large apes. The position of ancient hominins on this family tree means it is likely they, too, indulged in a intimate act, the scientists conclude. But the activity may not have been limited to their specific group. "The fact that humans kiss, the reality that we now have demonstrated that ancient relatives probably kissed, indicates that the both groups are also likely to have kissed," Brindle noted. Biological Importance While the evolutionary explanation is discussed, the expert explained intimate contact could be used in sexual contexts to possibly enhance reproductive success or assist in selecting between partners, while it could assist reinforce bonding when used in a platonic way. Another expert in the activities of primates said that as kissing behavior was observed in a wide range of apes it made sense its origins lie deep in our ancient history, and an examination of different forms of intimate behavior among a broader range of animals might push its beginnings back further still. "Behaviors that we consider as characteristics of our species, like kissing, are not unique to us if we look closely at other animals," the expert noted. Cultural Elements Another professor explained that intimate contact had a social component as it was not universal to all societies. "However, as humans 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. "This could represent an image that seems a bit incongruous to our incorrect assumptions of a rather ruthless and ancient history, but really it should be expected that ancient hominins – and including Neanderthals and our own species collectively – kissed."