Why Do We Kiss?

Have you ever asked yourself what’s the reasoning behind one of the most sincere displays of affection and love? The kiss. Perhaps your answer would be simply “because we feel like it”.

The meaning of a kiss, that universal and characteristic action between human beings that serves as a display of love, has been the subject of many scientific studies. Research has shown that we kiss in order to determine if the other person is genetically compatible with us.

In this article, I’ll share some information with you about the act of kissing that will probably make you see kisses as not just a simple expression of love and caring, but as proof of our evolution as human beings.

“Kisses are like nuggets of gold or silver found in the dirt, not very valuable by themselves, but of great worth because they mean that there is a mine near by.”
-George Villiers-

The kiss

In her book “The Science of Kissing”, the scientist Sheril Krishenbaum affirms that “scientists are still not entirely sure why we kiss.” This is because there are still “many challenges when it comes to interpreting what a kiss means” due to the lack of studies on the subject, according to Krishenbaum.

Nevertheless, science has given us some clues and answers. Professor Joe Hanson affirms on the television show It’s OK to Be Smart, that kisses are a behavior that result from our evolution.

Hanson highlights that “as we learned to walk upright, we started to advertise our fertility face to face” through the act of kissing. This is due to the fact that, unlike other animals, humans have lips that face outward. Hence, the main meaning that scientists have given for kissing is that “with this act we are telling our partner that we are a good partner to procreate with”.

What information do kisses provide?

Now that we understand the origin behind kisses, we have reached the point where you are probably asking yourself “what information do kisses provide us?” When we kiss, we perform a specific movement with our mouths that is very similar to when we used to feed off of breast milk.

Why does this happen? The action of suckling our mother’s breast implies one of the activities that promotes the biggest enjoyment within our brain. Hence, when we kiss we are generating endorphins, or “pleasure hormones.”

A 2014 study conducted by scientists at a university in Norway confirmed one of the best pieces of data we have found to date. During a ten-second long kiss we receive 80 million bacteria. This transfer allows us to reinforce our immune systems, fighting off diseases and improving our inner health.

Also, we know that the act of kissing increases our levels of neurotransmitters such as dopamine and serotonin. This provokes an increase in oxytocin. This is known as “the love hormone” since its production and release fortifies the bond that exists between a couple.

Kissing invites us to truly appreciate the importance of the closeness between two people that this small action implies. The mere fact of getting that close to another person allows us to use another sense: smell.

The sense of smell allows us to obtain more information about the other person’s DNA. And this tied to all of the other information already mentioned lets us reach the conclusion that we kiss others in order to preserve our species.

In a certain way, this might sound very unromantic. But for those of us who continue to believe that a kiss is an emotional act, I will not leave you without sharing the fact that romanticism will always be a part of our lives. Even if it all comes down to preserving the species…

“The soul can speak through the eyes. It can also kiss with a single gaze.”
-Gustavo Adolfo Bécquer-