🔗 Share this article Ancient Hominins and Modern Humans Were Likely Kissing, Researchers Propose From Galápagos albatrosses to polar bears, primates to orangutans, various animals appear to kiss. Currently, scientists suggest that Neanderthals also engaged in this behavior – and possibly locked lips with modern humans. Common Oral Clues This isn't the initial instance experts have suggested Neanderthals and Homo sapiens were closely connected. Among earlier research, scientists have found modern people and their Neanderthal relatives possessed the identical oral bacteria for millions of years after the two species split, implying they exchanged oral fluids. "Likely they were engaging in intimate contact," she said, explaining that the idea chimed with studies that has revealed people of non-African ancestry contain ancient genetic material in their genome, revealing genetic mixing was at play. Intimate Interpretation "It certainly puts a different spin on human-Neanderthal relations," Brindle said. Publishing in the publication a scientific periodical, the researcher and her team report how, to investigate the historical roots of kissing, they first had to come up with a description that was not limited to how humans smooch. Defining Kissing "There have been some previous attempts to define a intimate act, but it's largely focused on humans, which means that essentially other animals don't kiss. Currently we know that they likely engage, it may appear different from what human kissing looks like," said Brindle. Nonetheless, she noted some behaviors that looked like kissing were distinct activities – such as the processing and transfer of food, or "kiss-fighting", observed in fish known as certain marine animals. As a result the research group developed a description of intimate contact centered around social behaviors involving directed mouth-to-mouth contact with a individual of the identical group, with some motion of the oral area but no transfer of food. Study Approach Brindle explained they focused on reports of kissing in non-human species from the African continent and Asia, including bonobos, apes and great apes, and employed online videos to verify the observations. The researchers then combined this data with details on the genetic connections between living and ancient species of such primates. Historical Timeline Researchers propose the results indicate intimate contact developed approximately 21.5 million and 16.9m years ago in the predecessors of the large apes. The position of Neanderthals on this family tree means it is probable they, too, engaged in a intimate act, the scientists say. But the behavior may not have been confined to their own species. "Reality that modern people engage intimately, the fact that we currently have shown that ancient relatives very likely engaged, indicates that the two [species] are also likely to have engage," the researcher noted. Biological Importance While the scientific reasoning is discussed, Brindle explained intimate contact could be employed in reproductive situations to potentially increase mating outcomes or assist in selecting between partners, while it could assist reinforce bonding when practiced in a non-sexual manner. A separate researcher in the behavior of great apes commented that as intimate contact was seen in a wide range of apes it made sense its origins lie deep in our evolutionary past, and an examination of various types of intimate behavior among a wider variety of species might push its beginnings back further still. "Behaviors that we think of as signatures of human life, like kissing, are not unique to us if we examine carefully at different species," he said. Social Aspects Another professor said that kissing had a social component as it was not common to all human groups. "Nonetheless, as humans we thrive or fail on the quality of our emotional bonds, and methods of encouraging trust and intimacy will have been significant for millions of years," she said. "This could represent an concept that seems a bit contradictory to our incorrect assumptions of a supposedly aggressive and aggressive past, but really it ought to be expected that ancient hominins – and including them and our human ancestors together – kissed."