🔗 Share this article Ancient Hominins and Early Humans Were Likely Kissing, Researchers Propose Among seabirds to polar bears, chimpanzees to great apes, certain species engage in mouth-to-mouth contact. Now, researchers suggest that Neanderthals did it too – and might even have locked lips with early Homo sapiens. Common Microbial Evidence This isn't the initial instance scientists have suggested Neanderthals and early modern humans were closely connected. Among previous studies, researchers have discovered humans and their Neanderthal relatives shared the same mouth microbe for millions of years after the evolutionary divergence, suggesting they exchanged oral fluids. "Probably they were kissing," the researcher noted, explaining that the concept chimed with studies that has revealed humans of non-African ancestry have bits of ancient genetic material in their genetic makeup, demonstrating interbreeding was at play. Intimate Interpretation "This offers a different spin on ancient interactions," Brindle said. Writing in the journal Evolution and Human Behavior, Brindle and colleagues report how, to investigate the historical roots of intimate contact, they first had to develop a definition that was not limited to how people smooch. Defining Kissing "There have been some efforts to describe a intimate act, but it's very much been focused on humans, which means that essentially other animals do not engage in this. Currently we know that they likely engage, it may appear different from what human kissing resembles," said Brindle. Nonetheless, she said some actions that looked like kissing were something rather different – such as the chewing and food sharing, or "kiss-fighting", seen in aquatic species known as French grunts. Consequently the research group came up with a description of kissing based on social behaviors involving intentional mouth-to-mouth contact with a individual of the same species, with some movement of the mouth but absence of food. Study Approach Brindle explained they concentrated on accounts of intimate behavior in non-human species from the African continent and Asian regions, including bonobos, chimpanzees and great apes, and employed online videos to confirm the reports. The researchers then combined this information with information on the genetic connections between extant and ancient types of such primates. Evolutionary Timeline Researchers propose the findings indicate intimate contact evolved approximately 21.5 million and 16.9m years ago in the predecessors of the great primates. The position of ancient hominins on this evolutionary lineage means it is probable they, too, indulged in a kiss, the researchers conclude. But the activity might not have been confined to their specific group. "The fact that modern people kiss, the fact that we currently have demonstrated that Neanderthals probably kissed, indicates that the both groups are also likely to have engage," the researcher added. Biological Importance While the scientific reasoning is discussed, the expert said kissing could be used in sexual contexts to possibly increase mating outcomes or assist in selecting between mates, while it might help reinforce bonding when used in a platonic way. Another expert in the activities of primates commented that as kissing behavior was observed in a wide range of apes it was logical its roots extend far into our ancient history, and an analysis of various types of kissing among a wider variety of animals might push its beginnings back even earlier still. "Behaviors that we think of as signatures of human life, like intimate contact, are not unique to us if we examine carefully at other animals," he said. Social Aspects Another professor said that kissing had a cultural element as it was not common to all societies. "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," the professor stated. "This could represent 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 Neanderthals – and including them and our own species together – kissed."