This common act is more intimate than sex

The first sign of trouble in a relationship is usually a drop-off in kissing, according to Dr Krueger. — dpa

Your heart beats faster, your blood pressure rises and your cheeks flush.

A cocktail of “cuddle” and “happy” hormones floods your body, including oxytocin, serotonin and dopamine; as many as 34 facial muscles spring into action; and millions of bacteria are transferred from mouth to mouth.

The chemistry and mechanics of kissing are well understood.

Nevertheless, the role in our lives of this millennia-old cultural practice is belittled, says Dr Wolfgang Krueger.

”Kissing is popularly seen as sexuality’s little sister, but it’s not.

“On the contrary, for couples, kissing is far more important,” maintains the psychologist, who calls it a relationship’s barometer.

While many couples worry about a flagging sex life, the first sign of trouble is a drop-off in kissing, he says.

“It may sound strange, but kissing is much more intimate than sex.

“Sexuality can sometimes be very impersonal, as if you’re reeling off a programme,” he says.

With kissing, on the other hand, you have to truly mesh gears with the other person, sense their tempo, and take in their smell and taste.

”When you kiss, you discern whether the other person is receptive and has social antennae.

“A good kiss is also ardent and able to increase in intensity,” he adds.

Be it a good-night peck on the cheek or soulful smooching on a date, Germans, for instance, kiss about two to three times a day on average, researchers calculate.

By age 70, they’ve spent 76 full days kissing – a number that’s rising, according to Dr Krueger.

Romantic kissing isn’t the norm worldwide though.

A 2015 study in the journal American Anthropologist found that 46% of 168 cultures surveyed engage in romantic/sexual kissing, defined as lip-to-lip contact that may or may not be prolonged.

It’s most prevalent in the Middle East, followed by Asia, Europe and North America.

No evidence of it was found in Central America, sub-Saharan African, New Guinea or the Amazon region.

The study is just one of many on kissing, to which an entire branch of science is devoted: philematology.

In the 1960s, a German study found that husbands who kissed their wives before going to work in the morning lived an average of five years longer than those who didn’t.

More recent studies have found, for example, that most people turn their head to the right when they give or receive a kiss, and that kissing can alleviate hay fever and dermatitis.

It hasn’t been conclusively determined why people started kissing in the first place.

The Austrian ethnologist Irenaeus Eibl-Eibesfeldt surmised it derived from early humans’ practice of pre-masticating food for their young and then spitting it into their mouths.

Other researchers think our ancestors, like many animals, sniffed each other’s genitalia to gather information on potential mates, but shifted their investigations upwards when they began walking upright.

Even some animals kiss. Chimpanzees and a number of fish species are known to press their mouths together.

This is hardly comparable to kissing by humans though, for whom kissing rituals at bedtime or leave-taking are just as important as romantic kissing, says Dr Krueger.

Has the Covid-19 pandemic encroached on our kissing behaviour?

He cites two opposite effects that he has noticed in his couple therapy sessions.

”Some couples are talking to each other a lot more again, and kissing more often too,” he says

However, others are having trouble handling the forced togetherness of stay-at-home guidelines – constantly quarrelling and avoiding physical contact.

”This is a problem. A relationship without kissing has all the charm of a youth hostel,” he remarks.

His advice to couples who want to get closer again: Keep kissing “until they’re wild with passion!” – By Corinna Schwanhold/dpa