Neanderthals and Early Humans Were Likely Engaging in Intimate Contact, Researchers Propose
From Galápagos albatrosses to Arctic mammals, primates to orangutans, certain species appear to kiss. Currently, researchers suggest that Neanderthals also engaged in this behavior – and might even have locked lips with early Homo sapiens.
Shared Microbial Evidence
It is not the first time experts have suggested ancient relatives and early modern humans were intimately acquainted. Among previous studies, scientists have found modern people and their thick-browed cousins shared the identical oral bacteria for millions of years after the two species split, implying they swapped saliva.
"Probably they were kissing," she said, explaining that the idea aligned with studies that has revealed people of certain genetic backgrounds contain ancient genetic material in their genetic makeup, revealing interbreeding was occurring.
Romantic Interpretation
"This offers a different spin on ancient interactions," the lead researcher said.
Writing in the journal Evolution and Human Behavior, Brindle and her team detail how, to explore the historical roots of intimate contact, they first had to come up with a definition that was not limited to how humans smooch.
Describing Intimate Contact
"There have been some previous attempts to describe a kiss, but it's largely human-centric, which implies that basically non-human species do not engage in this. Now we know that they probably do, it may appear different from what our intimate contact looks like," said the evolutionary biologist.
However, she noted some behaviors that looked like intimate contact were distinct activities – such as the processing and transfer of food, or "mouth contact", seen in fish called French grunts.
As a result the team came up with a description of intimate contact centered around friendly interactions involving intentional mouth-to-mouth contact with a individual of the identical group, with some motion of the mouth but absence of food.
Research Methods
The lead researcher explained they concentrated on accounts of intimate behavior in non-human species from Africa and Asia, including bonobos, chimpanzees and orangutans, and used digital recordings to verify the reports.
Scientists then combined this information with details on the evolutionary relationships between living and ancient species of such animals.
Evolutionary Timeline
The team say the findings indicate intimate contact developed approximately 21.5m and 16.9 million years ago in the ancestors of the great primates.
Placement of ancient hominins 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 humans engage intimately, the fact that we currently have demonstrated that Neanderthals very likely engaged, suggests that the both groups are also likely to have kissed," the researcher added.
Evolutionary Importance
While the evolutionary explanation is discussed, Brindle said kissing could be employed in sexual contexts to possibly increase reproductive success or assist in selecting between mates, while it might help reinforce bonding when practiced in a platonic way.
A separate researcher in the activities of primates commented that as intimate contact was seen in a wide range of apes it made sense its roots extend far into our ancient history, and an analysis of different forms of kissing among a broader range of animals might push its beginnings back further still.
"Behaviors that we think of as characteristics of our species, like kissing, are not unique to us if we examine carefully at different species," the expert noted.
Cultural Elements
An archaeology expert explained that kissing had a cultural element as it was not universal to all societies.
"Nonetheless, as people we succeed or struggle on the strength of our relationships, and ways of promoting confidence and intimacy will have been significant for millions of years," the professor stated. "This could represent an image that seems a bit contradictory to our incorrect assumptions of a rather ruthless and aggressive past, but actually it should be no surprise that Neanderthals – and even them and our own species together – kissed."