Kissing has long been a symbol of love, affection, and even betrayal in human culture. But new research suggests that this intimate act may have evolved millions of years ago, long before humans walked the earth.
According to a study led by evolutionary biologist Matilda Brindle from the University of Oxford, kissing likely evolved between 16.9 million and 21.5 million years ago, after the ancestor of great apes split from lesser apes such as gibbons. This means that kissing may have been a common behavior among our ancient ancestors, including Neandertals.
The research team, which also included Catherine Talbot from the Florida Institute of Technology and Stuart West from Oxford, delved into past studies to uncover examples of kissing behavior in modern primates. They found that great apes, from humans to chimpanzees to orangutans, engage in kissing for various reasons, including conveying sexual desire and showing affection.
Interestingly, the researchers noted that species that kiss also engage in premastication, or chewing food before giving it to another individual. This behavior could be a precursor to kissing, suggesting a link between the two acts. However, the data on premastication in species that don’t kiss is limited, making the connection speculative.
Despite the findings, there is still much to learn about the evolution of kissing. Zanna Clay, a comparative psychologist at Durham University, pointed out that researchers have yet to determine if platonic and sexual kissing have the same origins. Further research is needed to expand our understanding of this intimate behavior.
Brindle emphasized the importance of collecting more data on primate kissing to unravel its evolutionary history fully. While the study provides a fascinating glimpse into the origins of kissing, there is still much more to uncover.
As we continue to explore the evolutionary roots of human behavior, it becomes clear that even the simplest acts, like a kiss, have deep-seated origins in our shared primate past. By studying our ancient ancestors, we gain valuable insights into the complexities of human behavior and the origins of our most cherished traditions.

