scienceneutral

The Ancient Art of Kissing: A Look into Its Evolutionary Roots

United KingdomWednesday, November 19, 2025
Advertisement

Kissing is a universal behavior seen in many species, from humans to animals like wolves and polar bears. Recent research suggests that this act of affection has been around for a very long time, dating back to around 21.5 million years ago. Scientists believe that the common ancestor of humans and great apes likely engaged in kissing, and even Neanderthals may have participated in this behavior.

The Study

The study aimed to understand the evolutionary origins of kissing, as it presents a puzzle. Unlike other behaviors, kissing doesn't seem to have obvious survival or reproductive benefits. Yet, it's prevalent across various species and human societies. To study this, researchers had to define kissing precisely:

  • Non-aggressive, mouth-to-mouth contact
  • Lip movement
  • No food transfer

By examining kissing behaviors in different species, scientists constructed an evolutionary family tree. They found that humans, chimps, and bonobos all kiss, indicating that their common ancestor likely did too. The study also revealed that Neanderthals, our closest ancient relatives, probably kissed as well. This is supported by evidence of shared oral microbes between humans and Neanderthals, suggesting saliva exchange.

Theories and Implications

However, the study didn't answer why kissing evolved. Some theories suggest it might have stemmed from:

  • Grooming behaviors in our ape ancestors
  • A way to assess a partner's health and compatibility

The lead researcher hopes this study will encourage further exploration of this behavior, emphasizing that it's not just a romantic human activity but something shared with other species.

Conclusion

Understanding the origins of kissing helps us see it as more than just a romantic gesture. It's a behavior that has evolved over millions of years, shared by various species. This perspective invites us to think critically about the role of kissing in both human and animal societies.

Actions