Neanderthals and Modern Humans Were Likely Kissing, Scientists Propose
Among seabirds to polar bears, chimpanzees to orangutans, certain species appear to kiss. Now, researchers suggest that Neanderthals did it too – and possibly exchanged kisses with modern humans.
Shared Oral Clues
This isn't the initial instance scientists have proposed ancient relatives and Homo sapiens were intimately acquainted. In previous studies, researchers have found humans and their Neanderthal relatives possessed the same mouth microbe for hundreds of thousands of years after the two species split, implying they swapped saliva.
"Probably they were kissing," the researcher noted, adding that the concept chimed with research that has found people of certain genetic backgrounds have bits of Neanderthal DNA in their genome, demonstrating interbreeding was occurring.
Intimate Spin
"It certainly puts a more romantic perspective on ancient interactions," Brindle said.
Publishing in the journal a scientific periodical, the researcher and colleagues report how, to investigate the evolutionary origins of intimate contact, they first had to develop a definition that was not restricted by how humans kiss.
Defining Intimate Contact
"Previously there were some previous attempts to define a kiss, but it's very much been human-centric, which implies that basically other animals do not engage in this. Now 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 actions that looked like kissing were distinct activities – such as the chewing and transfer of food, or "mouth contact", seen in aquatic species called French grunts.
As a result the team developed a definition of kissing centered around friendly interactions involving intentional oral interaction with a member of the identical group, with some movement of the oral area but absence of food.
Study Methods
The lead researcher said they concentrated on reports of kissing in primates from Africa and Asia, including bonobos, chimpanzees and orangutans, and employed digital recordings to confirm the observations.
Scientists then integrated this data with details on the genetic connections between living and ancient types of such animals.
Historical Origins
Researchers say the results suggest intimate contact developed approximately 21.5 million and 16.9 million years ago in the ancestors of the large apes.
The position of Neanderthals on this family tree suggests it is likely they, too, engaged in a kiss, the researchers conclude. But the activity may not have been limited to their own species.
"Reality that modern people kiss, the fact that we currently have shown that ancient relatives very likely kissed, indicates that the two [species] are probably did kissed," the researcher added.
Evolutionary Importance
Although the evolutionary explanation is discussed, Brindle explained intimate contact could be used in sexual contexts to potentially increase reproductive success or help choose between partners, while it could assist reinforce bonding when used in a platonic way.
Another expert in the behavior of primates commented that as intimate contact was observed in a wide range of apes it was logical its origins lie deep in our ancient history, and an analysis of different forms of kissing among a wider variety of animals might extend its beginnings back further still.
"Things that we consider as characteristics of human life, like kissing, are not unique to us if we look closely at different species," he said.
Social Elements
An archaeology expert explained that intimate contact 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 relationships, and ways of encouraging trust and intimacy will have been important for eons," the professor stated. "This could represent an concept that appears a bit contradictory to our misplaced ideas of a rather ruthless and ancient history, but actually it should be no surprise that Neanderthals – and including them and our human ancestors together – engaged intimately."
