How can I kiss your navel

What we reveal about ourselves when we kiss

Kissing is much more than a bond. People exchange secret messages when they kiss - for example, whether the partner is more brutal or sensual, healthy or sickly, reserved or eager

For several decades, scientists have been arguing about the origin of a phenomenon that is as familiar to us as shaking hands: They wonder why people kiss each other. What drives us to caress someone else's lips an average of 100,000 times in a lifetime?

Sigmund Freud suspected at the beginning of the 20th century that sucking on the mother's breast gave babies such a great pleasure that the adult still yearned for that oral satisfaction. Throughout his life he tries to satisfy the desire with kisses.

Primeval women may have invented the kiss

Later, the British zoologist Desmond Morris put forward the thesis that the mothers themselves invented the original kiss: in the early days of mankind, women would have chewed food for their children and then poured it into it with pursed lips - similar to what female chimpanzees still do today. Over time, they went over to calming their children down with loving kisses and giving them a feeling of security. And from this the partnership kiss developed, as an expression of passion and eroticism.

Perhaps, however, according to Ingelore Ebberfeld, a cultural scientist from Bremen, it happened quite differently. Quite a few animals sniff at the rear of a conspecific as a greeting or while looking for a partner - but this ritual became difficult for our ancestors when they straightened their upper bodies and began to walk on two legs, the kiss researcher suspects. With the upright gait, the gesture probably shifted from the buttocks to the face.

After all, the scientists agree that a startling process starts as soon as two pairs of lips touch. In a fraction of a second, thousands and thousands of nerve cells send messages to the brain and body - information about how someone else's mouth tastes and smells, whether the lips are warm or cold, smooth or rough, firm or soft. Five of the twelve cranial nerves alone are activated.

When kissing, thousands of nerve cells send signals to the brain

The neural signal fire not only triggers a conscious, sensual experience in our head. Rather, the nerves send commands to the limbic system - an archaic area of ​​the brain that works subconsciously.

There, gland cells produce a cocktail of the body's own drugs and pour them into the bloodstream, which produces other messenger substances: endorphins and hormones, such as oxytocin, which reduce stress, increase the feeling of social bonding, and arouse us sexually.

Those kissing become more intimate, caressing each other. Touches on the hands, back or neck are registered via the spinal cord and passed on to the nervous system. The brainstem immediately instructs muscles in the arterial walls to relax: the blood flow increases, our face flushes.

Brain regions for depressive moods are deactivated. We breathe more shallowly, our heart beats faster. The body heats up - and is immediately cooled down again: sweat glands secrete tiny drops that release sexual fragrances. The adrenal glands produce adrenaline and stimulate the body with it. Sometimes our knees tremble or we get goose bumps. In total, a person moves more than 30 muscles when kissing.

If the excitement rises above a certain level, the testes and ovaries produce the pleasure hormone testosterone: the penis and clitoris erect, the vaginal walls and the outer labia swell. The particular skill with lips and tongue that Homo sapiens has acquired in the course of its developmental history can put it in a state of intoxication. It is no coincidence that the lips are the area of ​​the body with the thinnest skin and probably the highest density of sensory nerve cells that process sensory impressions.

When kissing, partners sniff out each other's pheromones

With the kiss, Plato once taught, “the soul shifts to the lips in order to get out of the body”. In a way, this finding is borne out by recent findings in philematology, the science of kissing.

Because those who kiss reveal more about themselves than they are aware of. Everyone has an individual odor profile. It is like an olfactory business card that contains, among other things, information about the nature of the immune system: for example, whether the person concerned has a strong resistance to pathogens.

Especially when kissing, the partners perceive each other's scents very intensely. This is probably why many of these pheromones are formed and secreted on the nostrils: When two people kiss, the noses of two people come as close as possible. Around 1900, the so-called sniff kiss, in which lovers rub their noses together, was more widespread than the kiss on the mouth.

Many animals - including cats, dogs, deer - have a pheromone detector: the vomeronasal organ, in order to perceive and evaluate even tiny amounts of a scent profile. It is hidden above the palate, between the mouth and nose. But anatomists are still arguing whether adult humans also have such a receiving station.

The kiss a kind of female aptitude test?

In any case, scientific research suggests that when we kiss we are able to perceive more than just the touch of lips or tongue. The psychologist Gordon G. Gallup from the State University of New York in Albany already carried out a study of 180 test subjects in 2007, which showed that more than half of the men surveyed and almost two thirds of the women had already decided from someone else People felt attracted, then kissed the potential partner - and experienced that afterwards all interest was extinguished, the previously perceived attractiveness evaporated.

In another survey, most women even claimed that they could tell from a kiss whether a suitor was suitable as a long-term partner. Apparently women in particular are able to subconsciously sense whether a man suits them. So is the kiss a kind of female aptitude test? A first taste?

From a biological point of view, that would make perfect sense: women bear the burden of pregnancy, the risk of childbirth. When choosing a partner, you should be sure that he will help you take care of the children - "and when a woman kisses a man, she not only finds out whether he is a nice guy," says the US anthropologist Helen Fisher, "but she also gets an idea of ​​whether he would be a good father".

People who kiss live longer

So it's no wonder that women evaluate kisses differently than men: They want to promote a relationship emotionally, to deepen the shared emotional world, to synchronize with their counterpart. Men, on the other hand, usually associate lip contact with a specific goal: orgasm. They prefer wet kisses, kisses with an open mouth. A French kiss is the prelude to a more sexually intense phase, a stopover to coitus.

Men probably also love wetter kisses because their saliva contains testosterone. If the hormone gets into a woman's mouth, it passes through her mucous membranes, is distributed in the blood and possibly puts the partner in a lustful mood.

Kissing is also healthy - the immune system is stimulated, and the breakdown of the hormone cortisol reduces stress. And researchers have found that people who kiss a lot live longer.