### The Ancient Roots of Kissing: A Surprising Discovery Recent research has unveiled that the act of kissing may date back as far as **21 million years**, suggesting that our ape ancestors and Neanderthals likely engaged in this intimate behavior. This groundbreaking study, led by scientists from the University of Oxford, provides new insights into the evolutionary origins of kissing, challenging previous assumptions about its timeline and significance in human and primate behavior [https://www.manilatimes.net/2025/11/21/world/americas-emea/monkey-business-neanderthals-ancient-apes-likely-kissed-too/2228732]. ### Understanding the Hypothesis and Structure of the Research 1. **Evolutionary Origins**: The study posits that kissing likely evolved in the common ancestor of humans and great apes, with evidence suggesting it began between **21 to 17 million years ago** [https://www.scmp.com/news/world/article/3333341/when-was-first-kiss-probably-around-20-million-years-ago-scientists-say]. 2. **Behavioral Analysis**: Researchers defined kissing as a **non-aggressive, mouth-to-mouth contact** that does not involve food transfer, allowing for a clearer understanding of its evolutionary significance [https://www.firstpost.com/explainers/first-kiss-humans-neanderthals-science-13952038.html]. 3. **Neanderthal Connection**: The findings suggest that Neanderthals likely engaged in kissing, possibly as a means of social bonding or warmth during the ice age [https://www.perthnow.com.au/news/world/neanderthals-used-to-kiss-early-humans-scientists-discover-c-20731373]. 4. **Modern Primate Evidence**: The study also examined modern primates, such as chimpanzees and bonobos, which exhibit kissing behaviors, providing a comparative framework for understanding the origins of this practice [https://www.theguardian.com/science/2025/nov/19/neanderthals-early-humans-kissed-research-evolution]. ### Supporting Evidence and Data - **Kissing in Modern Primates**: Observations of kissing behaviors in species like chimpanzees, bonobos, and orangutans support the idea that this behavior is deeply rooted in primate evolution [https://www.sci.news/othersciences/anthropology/kissing-evolution-14365.html]. - **Evolutionary Mapping**: Researchers mapped kissing as a trait across the primate family tree, estimating the likelihood of its occurrence in ancient ancestors [https://www.thebrighterside.news/post/scientists-trace-the-origins-of-kissing-back-more-than-21-million-years]. - **Microbial Evidence**: Previous studies indicated that humans and Neanderthals shared oral microbes through saliva, suggesting that kissing may have been a common practice between the two species [https://24newshd.tv/19-Nov-2025/monkey-business-neanderthals-ancient-apes-likely-kissed]. ### Conclusion: The Significance of Kissing in Evolution The research highlights that **kissing is not merely a modern cultural phenomenon but an ancient behavior** that has persisted through millions of years of evolution. The findings can be summarized as follows: 1. **Kissing likely originated in our common ancestors with great apes** around 21 million years ago, indicating its deep evolutionary roots [https://www.greenmemag.com/science-technology/the-first-kiss-dates-back-21-million-years-a-surprising-evolutionary-discovery]. 2. **Neanderthals probably engaged in kissing**, which may have served various social and survival functions [https://english.elpais.com/science-tech/2025-11-19/neanderthals-also-kissed-a-gesture-of-love-that-is-21-million-years-old.html]. 3. **Modern primate behaviors provide a framework** for understanding the evolutionary significance of kissing, reinforcing its role in social bonding [https://edition.cnn.com/2025/11/19/science/kissing-evolution-study]. This research not only sheds light on the origins of kissing but also emphasizes the complexity of social behaviors in our evolutionary history.