By Becca Lewis
| Published
If you’re into a good rom-com, you might not like to hear the reason that scientists believe people evolved the behavior of kissing. Often attributed to the idea of sharing a breath that came about around 4,500 years ago, kissing in humans has been a part of romantic expression for millennia, but the real roots of the kiss are a lot more disgusting than you might think. Early hominids likely groomed parasites off of each other, an act we can currently observe in our closest living ancestors, the apes.
Kissing Was A Way To Remove Parasites
A recent paper on the practice of kissing in humans published by Adriano R. Lameira, an Associate Professor and UK Research & Innovation Future Leaders Fellow at the Department of Psychology, University of Warwick in the UK, suggests that the behavior originated from a grooming activity primates participate in.
As people evolved to have less hair, the soothing behavior of grooming became less of a practical activity and more of a soothing behavior. The study for the paper was based on the current, observable behavior of primates, using a living source to evaluate the current behavior of people and their descendants.
Grommer’s Final Kiss
The grooming behavior has been termed “groomer’s final kiss” because lip sucking is usually the final part of a grooming ritual that apes take part in for the purpose of bonding as well as practical parasite removal. Once the hair on a fellow primate’s body has been thoroughly cleaned by its grooming partner, the last step is to make a final pass on the grooming subject’s lips. The study suggests that this groomer’s “final kiss” is at the root of human kissing.
Because there’s no visual or written record from early hominids to determine their behavior or reasons for kissing, there’s a big gap in the observable evidence for scientific theories on the subject. While we can see that there are similar behaviors in apes that appear similar to kissing in humans as well as motivated by social bonding, we can’t say for sure how that is related to modern human ideas about kissing.
While anthropologists can evaluate current behaviors and compare them to the behavior of living primate ancestors, there’s no way to evaluate physical evidence on the subject beyond what humans have recorded.
Other Theories
Previous theories about the origins of human kissing posit that people begin suckling while nursing and translate that sucking behavior to sucking a mother’s lips, and perhaps sucking the lips of others they are bonding with.
Less well-developed hypotheses include the idea that women’s mouths have been seen as a sexual proxy and that kissing comes from this sexualization of mouths, but this idea doesn’t show how this behavior developed over time or when it was introduced. It’s more likely that the behavior began as a grooming behavior and bonding ritual that transcended the practical cause for the impulse.
Regardless of how disgusting it is, the idea that we inherited the act of kissing from our primate ancestors does more fully explain why the behavior exists across continents and cultures, and why it is so inherent to our idea of romantic love.
Kissing as a continuation of a bonding ritual explains why the practice occurs between close family members in some cultures or between acquaintances in others. As the practice developed, the bonding rituals of humans evolved to fulfill the needs of the societies we built, making the practice similar but different for different social and cultural circumstances.
Source: Evolutionary Anthropology