A recent evolutionary study has significantly extended the timeline for the origins of kissing, revealing that this behavior may date back over 21 million years, predating the existence of modern humans. Researchers suggest that the common ancestor of great apes practiced kissing, which raises intriguing questions about the purpose and implications of this seemingly universal behavior.
The research team began by addressing a fundamental question: if kissing serves no apparent survival advantage, why is it so ubiquitous across different species? They meticulously defined kissing as non-aggressive mouth-to-mouth contact involving movement but no exchange of food. This narrow framework allowed them to identify numerous examples of kissing-like behavior in various animals, including wolves, prairie dogs, polar bears, and albatrosses, though they focused primarily on primates.
Lead researcher Matilda Brindle from the University of Oxford posited that since both humans and our closest relatives—chimpanzees and bonobos—engage in kissing, it likely indicates a shared ancestral behavior. According to her, the behavior may have originated around 21.5 million years ago among large apes, marking kissing as a deep-rooted aspect of social interaction among hominids.
The study also explored links between modern humans and their ancient counterparts, including Neanderthals. Previous DNA research has indicated that Neanderthals and modern humans shared certain oral microbes from saliva, suggesting the practice of kissing or similar behaviors persisted even after evolutionary divergences. While the study establishes a timeline, it does not delve into the reasons behind the emergence of kissing. Concepts ranging from social bonding and grooming to health checks among partners remain unchanged by this new timeline.
The broader conclusion of the study emphasizes that kissing is not an exclusive human trait; rather, it is a behavior echoed through various species, including those with little genetic resemblance to humans. Brindle stresses the importance of recognizing this commonality, advocating for further serious study of kissing as a significant social interaction rather than merely a facet of romantic human relationships. The findings indicate that kissing may be less of a cultural invention and more of a fundamental social tool inherited from our early ancestors.
In summary, the study provides a fresh perspective on the age-old behavior of kissing, suggesting it has roots extending back millions of years, linking modern humans with ancestral traits shared across species. Understanding the historical context of kissing deepens our appreciation for the complexity of social bonding among living creatures.