Why, exactly, do we like kissing so much?

Betcha didn’t think there was a science to the romantic holiday we just celebrated. While I’ve never really thought about it, I always knew there was some kind of chemical wiring between our brains, hearts, and lips that make this act of love and affection universal. Kissing, and the way we think about it, has certainly been influenced by movies and literature that are unique to our own social norms and customs, but (apparently) 90% of the world’s cultures kiss as  a sign of affection.

The first literary reference to kissing was supposedly the Vedas, the founding texts of Hinduism that date back to 1500 B.C. The word “kissing” is never used, but there are references to “drinking the moisture of the lips”. Raunchy. Much more explicit references were found later in the Kama Sutra, which includes descriptions on how to passionately kiss a lover, among other things…

Other ancient religious texts (such as the Old Testament) along with literary epics and historical reports mention kissing as a form of greeting and of love. The Romans, in particular, celebrated passionate kissing in poetry and art. But in addition to passion, kissing was also a sign of social status and obligation (ie: kissing the king’s hand or using a kiss to seal agreements by smooching a signed ‘x’ at the bottom of a contract…which is apparently why we use ‘x’ to symbolize a kiss. xoxo).

Global conquests, exploration, and trade carried the kiss across mountains and oceans so that by the late 1800s, kissing was so widely practiced that it was considered a natural human impulse. Even Charles Darwin found the desire to kiss and biological reaction to kissing to be a very intriguing part of human nature.

In 1936 a man named Hugh Morris published a pamphlet titled “The Art of Kissing” with illustrated instructions on how to properly kiss a young lady. Like so:


Like a bee that settles on the fragrant pistils of a flower, and sips in the nectar for honey, so should you sip in the nectar from between the lips of your love. And it is nectar. For there is in this mingling a symbol of the holy communion of the spirits of two soul-mates, joined together in the bonds of an indissoluble love.


A kiss can never be absolutely defined. Because each kiss is different form the one before and the one after. Just as no two people are alike, so are no two kisses like. For it is people who make kisses. Real, live people pulsating with life and love and extreme happiness.

Antiquated? A little. But extremely charming nonetheless.

In addition to the biological origins discussed in the video (which I believe, but also really hope that no one ever actually thinks about breastfeeding while they kiss), there actually is a relatively large connection between the brain (the somatosensory cortex specifically if, unlike me, you actually know anything about science) and the mouth that makes us significantly more sensitive to a touch to the lips than a touch to, say, the back.

My first kiss was a dare when I was 13 (romantic, I know), but it got me my first boyfriend (even though our kisses never advanced to anything more passionate than an awkward peck at my doorstep as his mom waited at the end of the driveway after picking us up from the movies). It wasn’t until two years later that I actually “locked lips” with someone and, admittedly, I thought it was really weird. But that same year I also experienced a kiss that made me swoon.

I started thinking about all of this when I read Brain Picking’s summary of the book The Science of Kissing by Sheril Kirshenbaum. Here’s a bit about what she has to say:

Scientists are not exactly sure why we kiss. This may be in part because they have not even definitively decided what a kiss is. Unlike most other areas of scientific investigation, there’s no accepted “taxonomy,” or classification system, for different kinds of kisses and closely related behaviors. What’s more, you don’t find the experts crunching the numbers and figures on kissing across world cultures, as researchers would surely do if they wanted to get a handle on the available data. Why so little analysis of osculation? Perhaps kissing seems so commonplace that few of us have paused to reflect on its deeper significance. Or it’s possible the subject has been intentionally avoided under the microscope given the challenges of interpreting what a kiss really means.


Because a kiss brings two individuals together in an exchange of sensory information by way of taste, smell, touch, and possibly even silent chemical messengers called pheromones (odorless airborne signals), it has the potential to provide all kinds of insight into another person. So even when our conscious minds may not recognize it, the act can reveal clues about a partner’s level of commitment and possibly his or her genetic suitability for producing children.

I don’t think many people are banking their partner’s genetic suitability on a kiss, but I do wish it was considered more important. Kissing has certainly come along way from 1896, when kissing in public was still considered quite scandalous and the first kiss in cinematic history shocked society. While not the case for a lot of my generation, I think the kiss has been diminished to the point of such insignificance and normalcy that it isn’t considered something as intimate as other physical actions that can simultaneously require both less clothing and intimacy. But I don’t think its totally lost…the earth-shattering build-up to sharing a quiet, blurry moment with someone who stirs you inside. Like these ones.

kissin1 kissin2

And the most iconic movie kiss of all…


I had to. To leave you with my favorite quote about kissing (by someone who happens to know a thing or two about science): “Any man who can drive safely while kissing a pretty girl is simply not giving the kiss the attention it deserves“. Well said, Einstein.

To celebrate the national day of kissing, I handed out Despicable Me valentines to my co-workers (you know, the kind you gave out when you were in kindergarten). They were silly and unnecessary, but the only thing I know with certainty is that there is no such thing as telling people you care too much. And it is always a good idea to give people free chocolate.


Some memorable moments of Valentine’s passed:

Senior year of college I tutored a 10 year old boy in writing. We met once a week and one of our sessions happened to be on Valentine’s day, so he gave me a box of those candy hearts that say things on them. On the front of the box there were three hearts that said, ‘Be Mine’, ‘You’re Great’, and ‘Let’s Kiss’. I didn’t realize until later that he had crossed through the ‘Let’s Kiss’ heart. Heaven forbid I get the wrong impression.

Growing up my dad would orchestrate a scavenger hunt throughout our house for the women in his life. We would start with one clue that would lead us to a different location in the house where there would either be another clue or a surprise. This went on until my sister, mom, and I each had a gift. He certainly spoiled us and I fully intend on carrying on this tradition.

But I think the most memorable Valentine’s Day I have ever had was when I was 15. I was never bullied growing up, but there was this one guy in physics class sophomore year of high school who liked to flirt with the shy girls in class. I guess he thought it was funny when we would blush and stumble over our words, despite the fact that we knew he was making fun of us. My teacher’s name was Mr. D (a Portuguese man who hated freshman and pretended to be grumpier than he actually was) and he tried to call this boy out on it every once in awhile. I knew he noticed and was bothered, but what can you do? This boy wasn’t being mean exactly, only playfully tormenting the awkward girls. But, just before Valentine’s day, I happened to meet a dreamy guy who didn’t think I was awkward. In fact, he made me feel desirable for the first time in my young life. The afternoon of February 14th, 2007, I walked into class and was immediately confronted by flirty boy. He asked me, with eyes full of false sincerity, if I would be his valentine. Barely able to contain my delight, I shook my head and sighed my reply: “God I wish I could, but I already have one.” Mr. D chimed in without missing a beat and said, “That, class, is what you call crashing and burning.” Then he winked at me, equally happy I suspect that the shy girl finally had her day.

After I watched the “Science of Kissing” video, I found this one on the math of finding love.

I heard about this equation on this episode of This American Life about improbable connections (both romantic ones and intimate friendships). As a hopeless romantic who fundamentally believes in soul-mates, reducing finding love to algorithms and equations and the joy of kissing to biological impulses makes me cringe a little, but it is certainly interesting to think about.

With all that said, I just spent the evening watching The Bachelor with Monica because we all know reality TV is where real love happens. I hope you were all able to celebrate all the love in your life this weekend. Or at the very least, ate a lot of chocolate.

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