A new study published in Evolution and Human Behavior suggests that kissing-a behaviour frequently enough linked to romance-has roots stretching back over 21 million years. Researchers found evidence of mouth-to-mouth contact amongst various animal species, indicating the practise predates modern humans and likely originated with our primate ancestors. The study, which carefully defines kissing as a gentle, non-aggressive mouth touch not related to food exchange, offers a surprising new perspective on a common human behavior and its potential evolutionary drivers.
Kissing, a behavior often associated with romance and intimacy, has a surprisingly ancient history. A new study reveals that the practice of kissing dates back more than 21 million years, predating the existence of modern humans and originating with our early ancestors. The research, published in the journal Evolution and Human Behaviour, examined behaviors in animals that align with the scientific definition of kissing.
For the purposes of the study, kissing was defined as a gentle, non-aggressive touching of mouths, involving slight lip or mouth movement, and crucially, not intended for food giving or receiving.
Kissing Observed in Great Apes
Researchers focused primarily on primates, particularly great apes like chimpanzees and bonobos, both of which have been observed engaging in behaviors resembling kissing as a way to strengthen social bonds. Given the similarities in behavior between humans, chimpanzees, and bonobos, the researchers concluded that their common ancestor likely also engaged in this practice. This finding supports the estimate that kissing originated around 21 million years ago, with the ancestors of great apes. Understanding the evolutionary roots of human behaviors can offer insights into our social development and the importance of connection.
The study also suggests that Neanderthals, an extinct human species that disappeared around 40,000 years ago, likely kissed. Further evidence supporting this idea comes from a DNA study showing that modern humans and Neanderthals share the same oral bacteria, which would only occur with prolonged saliva exchange.
Other Animals Exhibit Similar Behaviors
Scientists identified behaviors similar to kissing in a variety of other animal species, including:
- Wolves, touching mouths as a display of affection.
- Prairie dogs, touching mouths to recognize one another.
- Polar bears, engaging in the behavior with significant tongue movement.
- Albatrosses, touching beaks as part of mating rituals.
The Evolution of Kissing in Humans
While the research establishes *when* kissing began, scientists haven’t yet determined *why* the behavior evolved. Some theories propose that kissing may have developed from grooming behaviors observed in early primates.
Another possibility is that kissing served as a primitive way to assess a potential partner’s health through taste and scent, analyzing bacteria present in the mouth.
Dr. Matilda Brindle, the lead researcher from the University of Oxford, emphasized that kissing is not exclusively a human behavior.
“We need to understand that this behavior is also exhibited by many other animals, so it should be studied scientifically and not just considered romantic,” she said.
Sumber: BBC
