Neanderthals and Early Humans May Have Kissing, Researchers Suggest
Among seabirds to polar bears, primates to orangutans, certain species engage in mouth-to-mouth contact. Currently, scientists suggest that Neanderthals did it too – and possibly exchanged kisses with modern humans.
Shared Oral Clues
It is not the first time experts have suggested Neanderthals and Homo sapiens were intimately acquainted. Among previous studies, researchers have discovered humans and their thick-browed cousins possessed the identical oral bacteria for millions of years after the two species split, suggesting they swapped saliva.
"Likely they were kissing," the researcher noted, explaining that the concept chimed with research that has revealed humans of non-African ancestry have bits of Neanderthal DNA in their genome, demonstrating interbreeding was occurring.
Romantic Interpretation
"This offers a different perspective on human-Neanderthal relations," the lead researcher said.
Writing in the journal a scientific periodical, the researcher and her team detail how, to investigate the evolutionary origins of intimate contact, they first had to develop a description that was not limited to how humans smooch.
Defining Intimate Contact
"Previously there were some efforts to describe a kiss, but it's very much been focused on humans, which implies that basically other animals don't kiss. Now we know that they likely engage, it might just not look from what human kissing looks like," said the evolutionary biologist.
However, she said some actions that resembled kissing were something rather different – such as the chewing and food sharing, or "mouth contact", seen in aquatic species called certain marine animals.
As a result the research group developed a definition of intimate contact based on friendly interactions involving directed oral interaction with a member of the same species, with some movement of the mouth but no transfer of nutrition.
Research Approach
Brindle said they concentrated on accounts of intimate behavior in non-human species from the African continent and Asian regions, including bonobos, apes and orangutans, and used digital recordings to confirm the reports.
The researchers then combined this data with details on the evolutionary relationships between living and ancient species of such primates.
Evolutionary Origins
The team propose the findings suggest intimate contact evolved somewhere between 21.5m and 16.9m years ago in the predecessors of the great primates.
The position of Neanderthals on this evolutionary lineage means it is likely they, too, engaged in a intimate act, the scientists conclude. But the behavior may not have been limited to their specific group.
"Reality that modern people kiss, the fact that we now have shown that ancient relatives probably engaged, suggests that the two [species] are probably did kissed," Brindle added.
Biological Significance
Although the scientific reasoning is discussed, Brindle explained kissing could be used in reproductive situations to possibly enhance mating outcomes or help choose between partners, while it might help strengthen connections when practiced in a platonic way.
Another expert in the activities of primates commented that as intimate contact was observed in a broad spectrum of primates it made sense its roots lie deep in our ancient history, and an examination of various types of kissing among a wider variety of animals might extend its origins back further still.
"Behaviors that we consider as characteristics of human life, like intimate contact, are not exclusive to us if we examine carefully at different species," the expert noted.
Cultural Aspects
Another professor explained that intimate contact had a social component as it was not common to all societies.
"However, as humans we thrive or fail on the strength of our relationships, and methods of promoting confidence and closeness will have been important for millions of years," she said. "It might be an concept that seems a bit incongruous to our incorrect assumptions of a rather ruthless and aggressive past, but actually it ought to be no surprise that Neanderthals – and including them and our human ancestors together – kissed."
