The Science and Incidental Romance of Kissing

Love is strange. We learn that early on, as pimply youths, nervously fumbling with zippers and buttons and our genitalia in the backseat of a car. If you were lucky, that first kiss was something special, and you know why people celebrate the experience with poems and songs.

As we grow older, we learn a little more, but things only get even stranger and more complicated.

We live – and hopefully, love – until, one day, mortality comes within the frame of our attention, and we are suddenly face-to-face with a terminal date.

Chances are, we’ll still be talking love and eternity. If we are lucky, we’ll be surrounded by people who love us.

If that same strand of luck runs long and the fog of old age hasn’t thickened into black smoke, we’ll probably still remember that first kiss.

But why do we kiss at all? Is the romance of kissing simply a construct of culture and society or is there some biological basis for our longing to kiss people we love?

Poets and musicians have celebrated the act of kissing for thousands of years.
Poets and musicians have celebrated the act of kissing for thousands of years.

Why We Kiss

Charles Darwin described kissing in his 1872 book The Expression of the Emotions in Man and Animals. He made an important distinction between kissing with the lips and various “kissing-like behaviours.”

Darwin’s list of “kissing-like behaviours” included a series of interactions between individuals that involved the use of the lips, face, and sometimes other body parts.

The biologist and eccentric beekeeper clustered kisses with similar activities that included “the rubbing or patting of the arms, breasts, or stomachs.”

Darwin notes that these and other related practices often oblige a similar purpose and might be forerunners to the modern, romantic, mouth-to-mouth kiss.

Subsequently collecting a multitude of accounts of equivalent exchanges all over the world, Darwin assumed that the drive to kiss is innate. People kiss to receive “pleasure from close contact with a beloved person.”

Darwin’s list of “kissing-like behaviours” included a series of interactions between individuals that involved the use of the lips, face, and sometimes other body parts.
Darwin’s list of “kissing-like behaviours” included a series of interactions between individuals that involved the use of the lips, face, and sometimes other body parts.

Kissing an African Princess

Some anthropologists disagree with Darwin’s assumption, maintaining that the kiss is simply a cultural phenomenon. 

Their argument is that we learn to kiss from what we see in our own communities or in the media. The kiss as we know it is certainly not a required intimate activity from a reproductive standpoint.

That, they argue, explains why not all peoples express love and desire with interlocked lips.

In fact, new research published in the American Anthropologist reports that only 46 percent of cultures kiss mouth-to-mouth.

History is replete with examples. In his 1864 book Savage Africa, the Scottish explorer William Winwood Reade describes how he fell in love with the beautiful daughter of an African king.

The 25-year- old explorer wooed the young woman for months, and – at one point – endeavored to steal a kiss. To Reade’s utter horror, the girl screamed and ran away in tears.

Only later did Reade learn that this princess had interpreted his kiss as an intention to eat her – and not in the way that many women enjoy.

New research says that only 46 percent of cultures kiss mouth-to-mouth.
New research says that only 46 percent of cultures kiss mouth-to-mouth.

Not One Kiss

In the Pacific Island of Mangaia, in the Cook Islands, 13-year- old boys are taken away from society by an older man for two weeks. During these two weeks, each boy is “educated on sexual intercourse, positions and techniques,” says one historical account.  

The training focuses heavily ensuring that the boys’ female partners achieve orgasm multiple times.

Men of the island then spend their late teens and 20s having an average of 21 orgasms a week. That works out to more than a thousand ejaculations in a year.

That – and other customs – led the anthropologist Donald Marshall to famously describe the Mangaians as the most sexually active culture on record.

They are also apparently among the most sexually liberated. Young Mangaian girls are encouraged to explore their sexuality and sexually engage multiple partners before marrying.

What astonished Marshall even more was the fact that the Mangaian people had been observing these practices for countless generations without a single mouth-to-mouth kiss.

The men of Mangaia spend their late teens and 20s having an average of 21 orgasms a week.
The men of Mangaia spend their late teens and 20s having an average of 21 orgasms a week.

Kissing as Foreplay

But then some research shows that – for women, at least – kissing does play an important biological function. In many ways, women kiss to assess a potential mate. The act of locking lips also plays an important role in their decision to hit the sheets.

That said, female participants in one 2007 study claimed they were less likely to have sex with someone without kissing first. They also reported that how well someone kisses can make or break their partner’s chances of getting to third base.

And, as the anthropologist Helen Fisher points out, people engage in “kissing-like behaviours” even in societies in which people don’t kiss.

Prior to the arrival of European explorers, people in these societies “patted, licked, rubbed, sucked, nipped, or blew on each other’s faces prior to copulation.” (Perhaps Reade could have done better with his African princess had he licked her face, instead.)

Female participants in one 2007 study claimed they were less likely to have sex with someone without kissing first.
Female participants in one 2007 study claimed they were less likely to have sex with someone without kissing first.

The Chemistry of Kissing

“When you stop and really think about the act of kissing, it’s kind of strange, isn’t it?” say writer Adrienne Santos-Longhurst and sex therapist Janet Brito in an article for Healthline. “Pressing your lips against someone else and, in some cases, swapping saliva? It turns out there’s some science behind this strange but enjoyable behavior.”

In their article, Santos-Longhurst and Brito explain how kissing releases the feel-good hormones – serotonin, oxytocin, and dopamine. These allow the body some of the same chemical reactions that make exercise a beneficial activity.

They likewise point to research that says men kiss to introduce sex hormones and proteins that make their female partner more sexually receptive. In short, the more spit you swap, the more turned on the ladies get.

Kissing releases the feel-good hormones - serotonin, oxytocin, and dopamine.
Kissing releases the feel-good hormones serotonin, oxytocin, and dopamine.

The First Kiss

We’ll probably never know how and why people began to kiss, but the first literary evidence for kissing dates back 3,500 years, in India.

In Vedic Sanskrit texts, there is no word for “kiss.” However, there are a multitude of references to lovers “setting mouth to mouth.” There is even one account that describes how a man liked to drink “the moisture of the lips” of a slave woman.

From there, we trace historical accounts of social kisses in ancient Greece in Homer and Herodotus down to passionate kissing in the Roman empire.

Over the millennia, the act of kissing flourished in some parts of the world and nearly disappeared elsewhere because of religious doctrine and, at times, rampant contagion.

True, romantic kissing as we know it may not have been as widespread in the past, and its romance might simply be incidental to our biological urges.

But just as Darwin observed nearly 150 years ago, “kissing-like behaviours” appear to be part of our evolutionary heritage.

How we kiss at any given time and place might be influenced by our diverse cultures. But the sentiment conveyed – however strange it might seem – is most certainly universal.