Neanderthals and Modern Humans Were Likely Engaging in Intimate Contact, Researchers Propose
From Galápagos albatrosses to polar bears, primates to orangutans, certain species engage in mouth-to-mouth contact. Now, scientists suggest that ancient hominins did it too – and possibly locked lips with early Homo sapiens.
Shared Microbial Clues
It is not the first time experts have suggested ancient relatives and early modern humans were intimately acquainted. In previous studies, scientists have discovered modern people and their thick-browed cousins shared the identical oral bacteria for millions of years after the evolutionary divergence, suggesting they swapped saliva.
"Probably they were engaging in intimate contact," the researcher noted, adding that the concept aligned with research that has revealed humans of non-African ancestry contain ancient genetic material in their genome, demonstrating genetic mixing was at play.
Romantic Spin
"It certainly puts a different perspective on ancient interactions," Brindle said.
Publishing in the journal Evolution and Human Behavior, Brindle and her team report how, to explore the evolutionary origins of intimate contact, they first had to develop a description that was not restricted by how humans smooch.
Defining Kissing
"There have been some previous attempts to define a kiss, but it's very much been focused on humans, which implies that essentially other animals do not engage in this. Now we know that they likely engage, it might just not look from what human kissing resembles," said Brindle.
Nonetheless, she noted some actions that looked like kissing were something rather different – such as the processing and food sharing, or "mouth contact", seen in fish known as French grunts.
As a result the research group came up with a definition of kissing centered around 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.
Research Approach
Brindle said they concentrated on accounts of intimate behavior in non-human species from Africa and Asian regions, including bonobos, chimpanzees and great apes, and used online videos to confirm the reports.
Scientists then integrated this information with information on the genetic connections between living and extinct species of such primates.
Historical Origins
The team propose the results suggest intimate contact developed somewhere between 21.5m and 16.9m years ago in the ancestors of the large apes.
The position of Neanderthals on this evolutionary lineage suggests it is likely they, too, engaged in a intimate act, the researchers say. But the activity may not have been limited to their specific group.
"Reality that humans engage intimately, the fact that we currently have shown that ancient relatives very likely engaged, suggests that the both groups are also likely to have engage," the researcher noted.
Evolutionary Importance
Although the scientific reasoning is debated, the expert explained kissing could be used in reproductive situations to potentially increase mating outcomes or assist in selecting between mates, while it might help reinforce bonding when used in a platonic way.
A separate researcher in the behavior of primates said that as intimate contact was seen in a wide range of apes it was logical its roots lie deep in our evolutionary past, and an examination of various types of kissing among a broader range of species might push its origins back further still.
"Things that we think of as signatures of human life, like intimate contact, are not unique to us if we examine carefully at different species," he said.
Social Elements
Another professor explained that intimate contact had a cultural element as it was not universal to all human groups.
"Nonetheless, as people we thrive or fail on the quality of our relationships, and methods of encouraging trust and intimacy will have been significant for millions of years," the professor stated. "It might be an concept that appears a bit contradictory to our incorrect assumptions of a supposedly aggressive and aggressive past, but actually it should be no surprise that Neanderthals – and including them and our own species together – kissed."
