top of page

Eulogy of the Kiss: is kissing essential?

In addition to this post, you can listen to Cecilia Commo on RTL -

For many people, kissing is like breathing: it's natural. We kiss without really thinking about its meaning. We kiss our children as if this habit had always been there. We kiss our lover to let him/her know that we are intimate. We kiss our pets to show them we care. We kiss our sexual partners to build excitement. But for some others, it is a proximity to another one that disturbs and upsets. 

Kisses are studied and dissected from every angle (a science is dedicated to them: philematology), their benefits are discussed but from the point of view of the sexologist and couple therapist that I am, their presence or absence can weigh heavily on our relationships with others.

A little tour of our animal neighbors

For the chimpanzees, kisses are a form of reconciliation. It is more frequent with males than with females. It is not a romantic behavior. This notion of reconciliation is also true in humans, just look at children (and adults when they say, "Come on, make peace: give her a kiss.")

Bonobos kiss more often and put their tongues in. Whatever their sex or status within their social group, bonobos kiss to reduce tension after an argument, to reassure each other, to develop social bonds and sometimes for no obvious reason (for those who observe them of course because I assume that if bonobos kiss, at least they know why they do it). 

These two primates are exceptions. As far as we know, other animals do not kiss, although they do engage in kiss-like behaviors. Many mammals lick their faces, llamas rub their snouts together, horses bite their necks or shoulders, elephants entangle their trunks, birds touch their beaks, and snails stroke their antennae. In some cases, animals groom each other, in others they smell the scent glands on the face or in the mouth of their fellow animal.

Even those who have lips do not share their saliva by kissing with their mouths open; it seems that the behaviors listed above are enough to give them the expected answers (Do you forgive me? Do you want to reproduce with me? Do you want to do me good? etc.) and that in fact, we are the only ones with the great apes to kiss on the lips, and the only ones with the bonobos to mix our tongues.

How long ago was this going on?

In fact, no one knows. 

The earliest literary references to kissing are from about 1500 BC, and are found in India, in Vedic texts in Sanskrit. There is no word for "kiss", but there is a reference to lovers "putting mouth to mouth" and a man "drinking the moisture from the lips" of a female slave. 

Later, the Romans used and abused kisses: "The pleasure of the Romans is in the kiss on the skin. Even better than that, the kiss around the mouth. It is the exchange of breath that is sought. The Romans do not consider that the height of pleasure is ejaculation. The height of the delight, in Rome, and for a Roman, it is the kiss " (Thierry Eloi)

The Romans defined three different categories for kisses:

Osculum was a kiss on the cheek - Basium was a kiss on the lips (and will give the name "baiser" to the kiss in French) - Savolium was a deep kiss.

The Roman armies introduced kissing into many cultures where kissing was not practiced; later, European explorers perpetuated this spread. 

According to historian Yannick Carré, in the Middle Ages "the kiss on the mouth was a common practice between knights, an undeniable proof of friendship. It was also a great honor addressed by a lord to his vassal". In Europe, as in Persia, the kiss between men marked above all a social equality, a kiss between peers of the same rank. Social inferiority was marked by a kiss on the hand or even on the feet. The formal kiss takes up this notion of brotherhood (social or otherwise).

From the Renaissance onwards, the kiss takes up the ancient tradition of the sensual kiss as a mark of love between a man and a woman.

How many kisses do we have?

A lot! Depending on the part of the body, the message we want to send, the relationship we have with our own emotional system, our ability to share and connect, the circumstances, the closeness, we find (among others): 

The kiss on the forehead, the kiss on the hand, the lip to lip sandwich kiss (The Single-Lip Kiss), the smack, the greedy kiss on the cheek, the kiss with the tongue, the Air Kiss, the Wet Kiss without the tongue, the Biting Kiss, the love kiss, the ritual kiss, the protocol kiss, the affectionate kiss, etc...

How do we kiss on the planet?

The Eskimo kiss puts the noses of the two people in contact. It seems to result from the climatic context on the ice floes which only allows the nose to be put forward, the rest of the face being covered. 

Among the Papuans of the Trobriand Islands, lovers cut each other's eyelashes with their teeth. This is called "Mitataku".

The oceanic kiss consists of running one's open mouth over another's, sometimes even brushing against it. It is not a sexual expression but a way of discovering the other. 

In Russia, the kiss may have no sentimental connotation but signify a bond of brotherhood (such as the kisses exchanged by political leaders). It is attributed certain symbolic powers: during the wedding meal, the kiss of the newly consecrated couple has the power to sweeten! The custom is that if the assembly shouts "Bitter!" the bride and groom kiss as if to sweeten the alcohol.

India and China are the least demonstrative countries about kissing. Indeed, the subject is still taboo there.

Among the Tonga of Mozambique, we do not kiss: kissing is a bestial and disgusting act.

Once the traces left by the kiss through time (the when), the different ways of showing affection or respect (the how and the where) have been noted, the question of "why ?" remains. 

Why do we kiss (or not depending on our culture)?

According to the evolutionary hypothesis, it is a behavior that is imposed on us but that initially comes from another behavior (that evolved into kissing). According to the acquired hypothesis, it is a cultural behavior that is transmitted from generation to generation (and keeps the form that the culture gives it).

For Rafael Wlodarski, a behavioral scientist, in some cultures, "the sniffing behavior that is still characteristic of some animals has evolved into physical contact with the lips. It is difficult to determine when this happened, but both would serve the same purpose." 

He found that women are more likely than men to prioritize kissing ability in a partner. This is especially true when they are first evaluating their partner for a relationship. Women also tend to view kissing as an important way to show affection in long-term relationships.

Another hypothesis suggests that mothers chewed the food and passed it from their mouth to their baby's mouth. After babies learned to eat solid foods, their mothers may have kissed them for comfort or to show affection. "If young lovers who explore each other's mouths with their tongues feel the archaic well-being that maternal oral feeding provided, it may help them increase their mutual trust and, therefore, their relationship as a couple," writes Desmond Morris in his book on human behavior, The Key to Gestures - 1977.

But the question that arises behind this is why in some cultures, even though mothers fed their babies in the same way, kissing only appeared with the contacts (or invasions) of the West?

Yet another suggests that women use the smell when they kiss to obtain certain information about their future partner's immune system (and possibly decide to procreate with him). Kissing as a private investigator to find out about the other person? To evaluate the quality of a potential partner via the biological substances that are exchanged? This is a hypothesis shared by many anthropologists since 100 million bacteria are transmitted in 1 ml of saliva and provide a lot of informations.

Helen Fischer confirms: kissing is a wealth of information about the other person because by kissing "we can get an idea of the person's oral health, what they have eaten, drunk, smoked, and these are all clues that we use to evaluate an individual before we consider having sex with them."

She distinguishes three primary brain systems used for mating and reproduction.

One is the sex drive, which is primarily related to testosterone. The second is romantic or passionate love, which motivates people to focus on a partner.

And the third is attachment, which helps couples stay together, at least long enough to raise a child.

She believes that kissing activates different chemical molecules (hormones, neurotransmitters) that stimulate these different areas of the brain.

If for some people kissing is a matter of biochemistry, neurotransmitters and evolution, for others it has everything to do with cultural transmission, "It is indeed a cultural gesture, because it is totally unknown in a very large part of traditional societies. Of course, now we kiss on the mouth in all societies of the world, since the generalization of television and Internet. But before, it was something incomprehensible and incongruous in many cultures", observes the geneticist André Langaney.

Beyond wanting to evaluate the quality of one's genes, to provide a social "glue" to the members of a species, one also kisses to mark: one's respect, one's affection, one's desire, one's submission, one's devotion, one's arousal, one's desire to possess the other, one's love, one's sensitivity, one's fragility, one's vulnerability, one's empathy, one's compassion, etc.

It is very likely, as the Serbian philosopher Zorica Tomić points out regarding the place that kissing occupies in public at the beginning of the twenty-first century, that "contemporary culture, subject to the principle of transparency, has shattered the magic of kissing, and stripped it of any spirit of adventure by reducing it to its physiological, biochemical, hygienic, medical, psychological, anthropological and cultural components". 

Nevertheless, I dare to believe that many people still feel the magical effects of a kiss that heals us when we are in pain, that consoles us when we are sad, that soothes us, that makes us desirable, that excites us, that makes us feel secure... So many powers in a single contact: isn't that the magic of a kiss?

The intimate and erotic kiss

Is kissing essential to sexual relations?

No. In fact, in the 1970s anthropologist Donald Marshall described the Pacific islanders of Mangaia as the most sexually active culture on record without a single kiss exchanged... before the arrival of Europeans.  

William R. Jankowiak, Shelly L. Volsche, and Justin R. Garcia published a study that caused a stir: while kissing on the mouth has become a common practice in most societies, less than half of the world's population would kiss romantically! 

Of the 168 cultures studied during 2014, 77 of them (or 46%) would practice romantic kissing (defined as lip-to-lip contact that may or may not be prolonged). 91 do not practice it at all. The researchers therefore defined that kissing on the mouth was not part of the universal language. 

If 54% of human beings do not kiss each other when they are in a relationship, in love or during their sexual relations, it is clear that kissing is not essential to sexuality (because we can reasonably postulate that the 91 cultures that do not practice romantic kissing still have a sexual life). 

But in our Western societies, things may be a bit different... 

A 2007 University at Albany study of more than 1,000 students found that not only do women place more importance on kissing, but most women do not want to have sex without kissing first. They are more likely than men to insist on kissing before sex and more likely to stress the importance of kissing during and after sex. In comparison, men responded that they would be happy to have sex even without kissing. Yet, when kissing, men are more likely than women to prefer kissing with their mouths open and with their tongues (knowing that saliva contains testosterone, anthropologist Helen Fischer surmises that this male preference for kissing with the tongue corresponds to an unconscious desire to transfer testosterone to trigger the sexual drive in women)

So, is the romantic kiss essential to the quality of the sexual relationship?

Although touching is a major part of sexual arousal, kissing (which is also touching with the mouth) is also a major part of keeping the libido alive and active within the couple. 

Just like the 54% of cultures where couples do not kiss, couples who tell me they never kiss anymore continue to have sex. The only difference is that they are unanimous in saying that at the very beginning of their relationship, they were kissing! This is consistent with the aforementioned University at Albany study: sex involves (at least at first) being able to kiss. A 2014 study by Rafael Wlodaski found that kissing well can make some people more attractive for short-term relationships. Attraction and libido are, as we know, highly correlated.

Gordon Gallup, an American psychologist from the University of Albany, argues that in long-term relationships, the frequency of kissing is a good barometer of the health and well-being of the love connection.

I would not be as categorical as he is, but when kisses desert the erotic-sexual relationship, the couples who come to see me report a weakening of desire, excitement and satisfaction. So we can reasonably think that kissing impacts the quality of sexual relations of a couple for the least. 

This is also confirmed by the data I collected from my patients via a data modeling system specifically created to "objectify" their narrative: responses to the question "Regarding the way we kiss when we have sex" are systematically correlated with those of the question "Regarding the quality of our sexual relations" in one direction or the other. The higher the satisfaction with the way we kiss during sex, the more important the quality of sex is perceived to be, and vice versa.

The kissing language in a relationship

In our western culture, kissing is a language in its own way. It says things that verbal language cannot say or is not enough to say. It completes a body language. It allows us to enter a unique mode of communication.

The relevant question would be to ask ourselves if kisses bring something to sexual relationships, and more broadly to love relationships?

And the answer, from my point of view, is clearly affirmative given the society and culture in which I live.

In their famous study, William R. Jankowiak, Shelly L. Volsche and Justin R. Garcia note that the more socially complex the culture, the higher the frequency of kissing on the mouth. Are our so-called complex societies societies where the bonds between individuals are more distanced? Is the kiss then used to get closer, to express one's vulnerability in the face of loneliness?  Perhaps indeed the more complex a society becomes, the more its language requires alternatives in terms of communication, other means to feel supported and surrounded...

The couple is a cell that over the centuries has become isolated from the rest of the family. Before, parents, grandparents, and children lived under the same roof or in the same village. The couple was rarely alone - except in the bedroom (and even then!) - and never isolated. With the industrial age and job opportunities located sometimes far from their town or village, the couples that formed were often alone far from their respective families. This is even more true today and from there to think that the kiss tends to solidify this small isolated cell, there is only one step that I easily cross.

Almost all the couples I meet confirm that at the beginning of their relationship, kisses were present. With or without tongue, they kissed. If the kiss on the mouth resists somehow - and sometimes quite well - the one that fades away is the erotic kiss, lips open and wet. The kiss with the tongue does not last long. Once the first emotions are over, it disappears purely and simply! The question, when I ask it, sometimes seems incongruous: "Snogging? We haven't done that for a long time". It seems that such a kiss is not adapted to a couple that is solidifying, that is anchored in permanence and in security. I wonder what a study comparing the kisses of official couples to those of unofficial couples would show... I think that in the latter, the frequency of erotic kisses (with the tongue) would be much higher. 

This kiss does not contain any ambiguity unlike others that can deliver a double message depending on the pressure of the lips, the place where they are placed, their humidity, the opening of the mouth, etc... It is an erotic and sexual kiss. It signifies the state of arousal that the partner provokes and clearly invites him to share this arousal. With this kiss, we touch, we taste and we feel each other. This intimate discovery of the Other is a determining factor for the rest, i.e. the desire to share more than saliva.

We know that the taste of the Other as well as his smell are clues that will ignite or extinguish our excitement. Is this what "established" couples want to avoid? In one way or the other? To leave as little room as possible for sexual arousal, variable and inconstant by nature, so that it does not interfere with the stability of the couple? This is a strong hypothesis when we know that sexual excitement (and not sexuality) follows more or less the same downward curve as the erotic kiss in the couples who come to see me. 

This kiss, which is naughty, no longer finds its place in the erotic territory of the couple. As if it symbolized the uncertainty and fragility of the emerging couple. Once the latter is solidified, the erotic kiss has no more reason to exist and its message "I want to conquer you" evaporates. There is no need to "drink the moisture from the lips" of the other (as in the Vedic texts), no need to taste it either. On conquered ground, no need to seduce the other.

It often gives way to a more chaste, dry kiss: the kiss on the mouth... closed. This one is supposed to mean "We are intimate" "We are a couple". But the strength of this meaning is temporary, because very quickly, we realize that such kisses are not exclusively reserved for the couple. The "smack" as it is called in our country, contains a very low degree of eroticism in an established couple. It is a sign of affection, closeness, bonding but not eroticism. When we know that "smack" in English means "to hit, to knock" we understand better the meaning: to slap each other on the mouth.

In couples with a lack of sexual desire, it is often present but no one is mistaken, it has no sexual connotation.

Note that it can easily change its meaning when the lips open up and get wet, when they no longer touch each other but caress each other...

There are still couples where it also disappears. When we talk about it and I ask them if they kiss, they are often surprised to find out that no, they don't even kiss anymore. It's as if they didn't even realize it, for at least one of them. This observation is often sad, rarely indifferent. They miss the kisses when they think about it. They didn't see them disappear. They just notice that they don't kiss anymore. Has erotic desire survived this loss? No.  

When kisses disappear, it is a form of language that disappears. A language that often says I love you. Sometimes this absence is compensated by a very strong reassuring presence (like those adults who remember parents who were not very tactile but whose strength of love was never in doubt) but this is not always the case. Very often the absence of kisses is coupled with an absence of touch and the people who experience it feel that they are deprived of a very particular form of relationship with the Other. A handicap that can be very problematic depending on the expectations of those around them. These people will be seen as distant or insensitive, even though it is perhaps an excess of sensitivity that cuts them off from a proximity through the mouth that is considered too threatening. Don't we say "devouring ourselves" with kisses?

If kissing isn't your thing, you should pay attention to the study that American researcher Wendy Hill, professor of neuroscience at Lafayette College in Pennsylvania, conducted in 2009: the goal was to find out if kissing was a stress reducer and a bonding enhancer for people who kissed. 

She set up two groups of 15 heterosexual couples between the ages of 18 and 24: a group that kissed for 15 minutes and a group that just sat, held hands and talked. She took blood and saliva samples from each member of the two groups before and after the experiment to measure cortisol levels (a hormone involved in stress) and oxytocin levels (a hormone involved in attachment and associated with a form of well-being) before and after the 15-minute experiment.

Conclusions: cortisol levels dropped in couples who were kissing, but they also dropped in couples who were holding hands and talking. So in terms of benefits on stress, there is no difference between intimate physical contact and kissing. 

What about in terms of attachment?

She found that oxytocin levels increased in men after they kissed or simply held their partner's hand (while talking). In contrast, oxytocin levels in women decreased. The hypothesis put forward to explain this decrease is that women are more sensitive to the ambient atmosphere (in this case a medical center) than men. 

In any case, if you don't kiss your partner, it seems appropriate to spend time with him or her, to sit next to him or her and hold his or her hand while talking...

Even though I strongly encourage you to discover this wonderful language of kissing and to "play with fire" as the French singer Charles Aznavour sings: its benefits are infinite...


- William R. Jankowiak, Shelly L. Volsche et Justin R. Garcia-

- Thierry Eloi

- Wendy Hill : “Affairs of the Lips: Why We Kiss”-

- Yannick Carré, Thèse de doctorat en Histoire « Le baiser sur la bouche au Moyen age : histoire, pratiques et symbolique du baiser, du XIe au XVe siècle, à travers les documents écrits et l'iconographie »

- Susan M. Hughes, Marissa A. Harrison, et Gordon G. Gallup, Jr.  -

- Charles Aznavour « Quand tu m’embrasses » 

bottom of page