Pucker up: The history and mystery of kissing

Key Concepts

• Evolution of Kissing: The historical origins and evolutionary purpose of kissing.
• Animal Kissing: The prevalence of kissing-like behaviors across various animal species.
• Evolutionary Biology: Applying evolutionary principles to understand human and animal behaviors.
• Saliva Exchange & Hygiene: The biological risks associated with kissing and their implications for its evolutionary persistence.
• Neanderthal Kissing: Evidence suggesting kissing may have been practiced by Neanderthals.

The Ancient Origins of Kissing: An Evolutionary Perspective

The tradition of kissing, often associated with romance and affection, has a far deeper history than commonly believed. Recent scientific research indicates that kissing may date back over 21 million years, extending beyond human behavior into the animal kingdom. This was reported by CBS News correspondent Tina Krauss, referencing a new study originating from the UK.

Kissing Across the Animal Kingdom

Evolutionary biologist Dr. Matilda Brindle highlights the surprisingly widespread nature of kissing-like behaviors in animals. The practice isn’t limited to humans; it’s observed in primates such as gorillas, chimpanzees, bonobos, and orangutans. Furthermore, the behavior extends beyond primates to include species like polar bears, prairie dogs, and even albatrosses. This broad distribution suggests a potentially fundamental, rather than uniquely human, origin.

Evidence of Kissing in Ancient Hominids

The UK study proposes that Neanderthals, our ancient human relatives, likely engaged in kissing. This conclusion is drawn despite the lack of direct fossil evidence, relying instead on the evolutionary timeline and the prevalence of the behavior in modern species. The study doesn’t detail how this conclusion was reached, but implies it’s based on phylogenetic analysis and understanding of behavioral traits in related species.

The Evolutionary Puzzle of Kissing

A central question raised by Dr. Brindle is the evolutionary purpose of kissing. The behavior offers no obvious survival or reproductive advantage. In fact, it presents a biological risk. As Dr. Brindle points out, “It’s really not a very hygienic behavior, is it? You're literally sharing your saliva with another individual. We know that we can transmit diseases that way.” This inherent risk makes the persistence of kissing as an evolved trait particularly compelling and mysterious. The fact that it continues despite the potential for disease transmission suggests a strong underlying evolutionary driver.

Personal Accounts & Continued Practice

The CBS News report includes a personal anecdote from Tony and Christine Lewis, a couple who shared their first kiss in England 40 years ago and remain together. Their experience exemplifies the enduring cultural significance of kissing. Despite scientific inquiry into its origins and potential drawbacks, couples, as demonstrated by the Lewises, continue to engage in the practice.

Future Research & Synthesis

British researchers express hope that this new insight into the origins of kissing will stimulate further investigation into its underlying causes and functions. The report concludes with Tina Krauss reporting from London, emphasizing the ongoing mystery surrounding this intimate human and animal behavior. The core takeaway is that kissing is not merely a cultural construct, but a deeply rooted behavior with origins stretching back millions of years, prompting scientists to reconsider its evolutionary significance.