Neanderthals and Early Humans May Have Kissing, Scientists Suggest

From Galápagos albatrosses to Arctic mammals, primates to orangutans, certain species appear to kiss. Now, scientists suggest that Neanderthals did it too – and might even have locked lips with early Homo sapiens.

Shared Oral Evidence

It is not the first time experts have proposed Neanderthals and early modern humans were closely connected. In earlier research, researchers have discovered modern people and their Neanderthal relatives possessed the same mouth microbe for hundreds of thousands of years after the two species split, suggesting they swapped saliva.

"Likely they were kissing," the researcher noted, adding that the idea chimed with research that has found people of certain genetic backgrounds contain ancient genetic material in their genome, demonstrating interbreeding was occurring.

Romantic Spin

"It certainly puts a more romantic perspective on human-Neanderthal relations," Brindle commented.

Publishing in the publication Evolution and Human Behavior, Brindle and colleagues detail how, to explore the evolutionary origins of kissing, they first had to come up with a definition that was not limited to how people kiss.

Describing Kissing

"Previously there were some previous attempts to define a intimate act, but it's very much been focused on humans, which means that essentially other animals do not engage in this. Now we know that they likely engage, it may appear different from what our intimate contact looks like," explained Brindle.

Nonetheless, she said some behaviors that resembled intimate contact were something rather different – such as the chewing and food sharing, or "kiss-fighting", observed in aquatic species known as French grunts.

As a result the team came up with a definition of intimate contact based on friendly interactions involving intentional mouth-to-mouth contact with a member of the same species, with some movement of the oral area but absence of food.

Study Approach

The lead researcher said they focused on reports of kissing in non-human species from Africa and Asian regions, including primates, apes and great apes, and employed digital recordings to verify the reports.

Scientists then combined this data with information on the genetic connections between extant and ancient species of such primates.

Evolutionary Origins

The team propose the results suggest intimate contact developed approximately 21.5m and 16.9m years ago in the predecessors of the great primates.

The position of Neanderthals on this evolutionary lineage suggests it is likely they, too, engaged in a kiss, the scientists conclude. But the activity might not have been confined to their specific group.

"Reality that humans kiss, the fact that we currently have demonstrated that Neanderthals very likely kissed, indicates that the both groups are probably did engage," the researcher added.

Evolutionary Importance

Although the scientific reasoning is debated, the expert explained kissing could be used in reproductive situations to potentially enhance reproductive success or help choose between mates, while it might help strengthen connections when practiced in a non-sexual manner.

A separate researcher in the activities of great apes said that as intimate contact was observed in a broad spectrum of apes it made sense its roots lie deep in our evolutionary past, and an examination of different forms of kissing among a wider variety of species might push its beginnings back further still.

"Things that we consider as characteristics of human life, like intimate contact, are not exclusive to us if we look closely at different species," the expert noted.

Cultural Elements

An archaeology expert said that intimate contact had a social component as it was not universal to all human groups.

"Nonetheless, as people we succeed or struggle on the strength of our relationships, and methods of encouraging confidence and intimacy will have been important for eons," the professor stated. "It might be an image that appears a bit incongruous to our misplaced ideas of a rather ruthless and ancient history, but actually it should be no surprise that ancient hominins – and including Neanderthals and our human ancestors together – kissed."