Neanderthals and Modern Humans Were Likely Engaging in Intimate Contact, Scientists Propose
From seabirds to Arctic mammals, primates to orangutans, various animals appear to kiss. Currently, scientists propose that Neanderthals did it too – and possibly exchanged kisses with early Homo sapiens.
Shared Oral Evidence
This isn't the initial instance scientists have proposed Neanderthals and early modern humans were closely connected. In previous studies, scientists have discovered humans and their thick-browed cousins possessed the same mouth microbe for hundreds of thousands of years after the two species split, implying they swapped saliva.
"Probably they were engaging in intimate contact," she said, explaining that the concept chimed with studies that has found people of certain genetic backgrounds have bits of Neanderthal DNA in their genome, revealing interbreeding was occurring.
Romantic Interpretation
"This offers a more romantic spin on ancient interactions," the lead researcher said.
Publishing in the journal a scientific periodical, Brindle and her team report how, to investigate the historical roots of kissing, they first had to come up with a definition that was not restricted by how people smooch.
Describing Kissing
"Previously there were some efforts to define a kiss, but it's largely human-centric, which means that basically other animals don't kiss. Currently we know that they probably do, it might just not look from what our intimate contact resembles," said Brindle.
Nonetheless, she noted some behaviors that looked like intimate contact were distinct activities – such as the processing and transfer of food, or "mouth contact", observed in fish called certain marine animals.
As a result the team came up with a description of intimate contact centered around social behaviors involving intentional oral interaction with a member of the same species, with some motion of the oral area but no transfer of nutrition.
Research Methods
The lead researcher said they focused on reports of intimate behavior in non-human species from the African continent and Asian regions, including primates, chimpanzees and orangutans, and employed online videos to confirm the reports.
Scientists then combined this data with details on the evolutionary relationships between extant and ancient types of such animals.
Evolutionary Timeline
The team say the results indicate intimate contact evolved approximately 21.5m and 16.9 million years ago in the ancestors of the great primates.
Placement of ancient hominins on this family tree means it is likely they, too, engaged in a kiss, the scientists conclude. But the behavior may not have been limited to their own species.
"Reality that humans kiss, the fact that we now have demonstrated that ancient relatives very likely engaged, indicates that the two [species] are also likely to have engage," Brindle noted.
Evolutionary Significance
While the evolutionary explanation is debated, Brindle explained kissing could be employed in reproductive situations to potentially enhance mating outcomes or help choose between mates, while it might help reinforce bonding when practiced in a non-sexual manner.
A separate researcher in the activities of primates commented that as kissing behavior was seen in a wide range of primates it made sense its origins lie deep in our evolutionary past, and an analysis of various types of intimate behavior among a broader range of animals might extend its beginnings back even earlier still.
"Behaviors that we consider as signatures of our species, like kissing, are not exclusive to us if we examine carefully at other animals," the expert noted.
Social Aspects
Another professor said that intimate contact had a social component as it was not common to all human groups.
"Nonetheless, as people we succeed or struggle on the quality of our emotional bonds, and ways of promoting confidence and closeness will have been significant for millions of years," she said. "It might be an image that appears a bit contradictory to our misplaced ideas of a supposedly aggressive and aggressive past, but actually it should be no surprise that Neanderthals – and including Neanderthals and our human ancestors together – kissed."
