We fret over not having enough sex, but what happens to our long-term relationships when we stop kissing? Stylist investigates the perks of puckering up

Words: Antonia Hoyle

It’s an outward symbol of potent chemistry; a tacit acknowledgement of affection between couples. From that first tantalising brush of lips to a slow, sensual snog at the end of a date, nothing captures the excitement and anticipation of a new romance quite like kissing. But let’s be honest – once we’re in an established relationship, how many of us still bother to actually do it? Surveys have revealed that not only do eight out of 10 couples not kiss each other before going to bed, but a fifth of married couples go for a full week without kissing at all – and even those who do, rarely touch lips for longer than five seconds.

Once we feel settled in a relationship, it seems the closest we get to a French kiss with lashings of tongue is tutting at teens snogging at the bus stop. But why is this? And does it really matter? After all, while it’s not uncommon for long-term couples to fret over whether they’re having enough sex, rare is the deep and meaningful conversation about kissing.

According to a 2013 study by researchers at Oxford University’s department of experimental psychology there are three reasons we kiss in a relationship: to assess how suitable a partner is, to help our relationship stay together and – not to put too fine a point on it – to arouse us. Sounds straightforward enough, except the science behind kissing is surprisingly complex, and involves a cocktail of bodily chemicals more powerful than anything in your medicine cabinet.

When we meet someone we’re attracted to, we are biologically driven to kiss because the closer our noses get to a potential partner’s body the better access we have to their pheromones – chemicals released from areas including the upper lip that emit a smell to attract the opposite sex.

“You can find someone tremendously attractive then get close to them and not feel a thing because their pheromones don’t do it for you,” explains Robert Page, creator of sex education film series The Lovers’ Guide. Our ‘signature smells’ are made up of proteins called the major histocompatibility complex (MHC) that regulates our immune system. Research suggests we subconsciously select partners with a different MHC to our own, so that any future children will develop immune systems that benefit from both.

Slip of the tongue

The idea that couples’ genes determine whether they’re destined for each other was actually spearheaded by Swiss biological researcher Claus Wedekind in 1995 with what is widely referred to as the “sweaty T-shirt” study. Men wore the same T-shirt for two days before women were asked to sniff the T-shirts and reveal which smell they were most attracted to. The results showed that, on the whole, women were most attracted to men with genes dissimilar to their own. And because genes can also affect how our brains interact, genetic compatibility is thought to be essential not only in ensuring we are attracted to our partner, but that our personalities gel as well.

As well as establishing each other’s scents, there are other very good reasons to pucker up. A passionate kiss on the lips triggers the release of a bonding hormone called oxytocin, along with the powerful neurotransmitter dopamine – a substance also stimulated by sex and class A drugs such as cocaine and heroin. “Dopamine helps us feel rewarded and experience pleasure,” explains Sheril Kirshenbaum, author of The Science Of Kissing: What Our Lips Are Telling Us. “It is responsible for the type of intense desire that makes a new romance feel addictive.” When that ‘spike’ of dopamine in the brain subsides, she says, it causes us to crave more and can even lead to a loss of appetite, insomnia or euphoria. So you can, quite literally, feel love sick.

But of course like all highs, the thrill we get from kissing a partner can’t be maintained, however many hours your teenage self – and a Robbie Williams poster – might have committed to it. As your partner’s pheromones and physical presence become more familiar, the dopamine release subsides. “Through dopamine, oxytocin and pheromones, nature is encouraging us to procreate,” says relationship therapist Marisa Peer, author of Ultimate Confidence. “But at around the 18-month to two-year mark it also programmes you to want less kissing and sex by stopping the dopamine rush and making the pheromones you and your partner emit less strong, so you can look after the baby you are supposed to have created.” Which is depressing enough if you’re a frazzled new mum in dire need of some comfort; even more so if motherhood isn’t on your agenda at all, or if you’re hankering after those passion-filled clinches of the honeymoon phase.

Necking it

Kissing also serves a functional purpose. As women, we are particularly reliant on it to weed out partners who might not be quite right.

One survey revealed that 66% of us have ended a relationship because the first kiss felt ‘wrong’ – not enough tongue, perhaps, or (more commonly) way too much – compared to only 59% of men who said the same. Another found that over half of men would be willing to have sex with someone without kissing them; only 14% of women would. “Women look to a kiss to assess relationship status,” says psychologist Susan Hughes. “Biologically speaking, females are limited reproductively [in terms of how long they can bear children before menopause], so they want to really bond with a mate, whereas males can have a lot of partners and so are generally more inclined to have promiscuous sex.”

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Somewhat bizarrely, a 2007 study in the journal Evolutionary Psychology also found that men prefer ‘wetter’ kisses than women. One theory to explain this is that by thrusting his tongue, a man hopes to boost a woman’s libido. “Male saliva has trace amounts of testosterone – and testosterone is an aphrodisiac,” says psychologist Gordon Gallup. “So passing saliva during open-mouth kissing over extended periods might help raise a woman’s testosterone levels and affect her sex drive.”

Of course, there is also the more graphic explanation that the tongue is a metaphor for the penis; the moistness of an open mouth a barometer of female arousal. “Men kiss as a means to an end, swapping saliva so they can swap something else later,” says Kirshenbaum.

But while this kind of kissing – which requires 34 facial muscles and the exchange of a quarter of a cup of saliva – is the norm in mainstream western society, it is far from a global phenomenon. Last year, academics at the University of Nevada and Indiana University found there is no evidence that the romantic-sexual kiss is a universal practice. In fact, anthropologists have discovered that out of 168 cultures around the world, only 46% kiss to express sexual desire. Surprisingly, only 70% of European cultures consider kissing a romantic pastime, while Sub-Saharan African, New Guinea and Amazonian populations weren’t found to perform romantic kissing at all.

Nevertheless, some anthropologists still believe we are biologically predisposed to kissing. Many think that the practice actually stems from pre-mastication, or ‘kiss-feeding’ – a ritual in which our ancestors weaned their children by pushing chewed-up food into their babies’ mouths with their tongues, in doing so reinforcing an intimate connection.

“I think the oldest record we have of romantic kissing is the Karma Sutra,” says psychiatrist and philosopher Dr Neel Burton, author of Heaven And Hell: The Psychology Of The Emotions. The ancient Hindu text champions the exchange of saliva to boost erotica and dedicates a whole chapter to kissing, which Hindus described as inhaling each other’s souls.

Experts believe kissing with the mouth open has probably been around as long as we have, because bonobos – a type of chimpanzee that has inhabited the earth for around two million years – also display affection this way (they are not the only mammal to ‘kiss’ – foxes, for example, lick each other’s faces and elephants put their trunks into one another’s mouths).

However, it wasn’t until Roman times that ‘making out’ with our partners became socially acknowledged. “The social status of a Roman citizen determined the part of the body on which he or she could kiss the emperor, from cheek to foot,” says Burton. “Couples got married by kissing in front of a gathered assembly, and because people were mostly illiterate they would sign contracts with a kiss – which is where the saying ‘sealed with a kiss’ comes from and the reason we still mark the spot on a contract we need to sign with an X.”

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In the 16th century, the kiss between Shakespeare’s Romeo and Juliet (the Hollywood blockbuster of its time) embedded kissing firmly in British culture. Yet fast-forward a couple of centuries and an increasingly reserved society meant an unmarried woman kissing a man in public was cause for shame and punishment, says Julie Peakman, author of The Pleasure’s All Mine: A History Of Perverse Sex. “Kissing with tongues in public was seen as wanton and inadvisable to modest women [during the Victorian era].” And the term ‘French kiss’ only entered the English vocabulary in the early 20th century – thought to be the result of US travellers to France noting the locals’ predilection for open-mouthed kissing.

Part-time lovers

So from the right kind of hormone rush, to closer bonds and stronger immune systems, there’s no doubt about it: kissing is crucial. In fact, according to an Oxford University study, frequent kissing can be linked to the quality of a relationship in a way that frequent sex simply isn’t, and experts remain united in their belief that couples in long-term relationships should continue to kiss as much as they can. “When a relationship is breaking down, kissing usually stops before sex,” says Page. “Sex is a basic urge driven by hormones in a way that kissing isn’t. I think it would be very difficult for a relationship to survive without kissing with tongues. Even if you’re still giving each other pecks on the lips or cheeks the relationship is in trouble.”

Peer suggests that couples should try to kiss on the lips, even if it’s only a peck, every single day. “The ideal time is in the evening, when you’re relaxed. Try to recreate your kissing habits from the early stages of your relationship – share a kiss on the sofa and before you go to bed. When kissing is likely to be a prelude to sex, use tongues.”

It might seem like a bit of a slog at first (for some of us), but the good news is that the more you kiss your partner, the more you’re likely to want to do it. “You might not get the same buzz as you did in those early days,” says Peer, “but you are building the foundations for better intimacy, which is cause for celebration in itself.” Indeed. XOXO.

Three couples reveal the role kissing plays in their relationships

Clare Longhurst, 27, is a legal PR from London. She has been with her fiancé George, 24, a barber, for nearly two years. “George was gentle and hardly used any tongue for our first kiss. To me, it was a sign of a caring personality. On our second date we kissed for 90 minutes in my car until the battery ran out and I had to call the AA. From then on our kisses were long, passionate and usually a prelude to sex. Now, it’s normally me that initiates a kiss. I want to kiss George all the time, even if we’re just passing in the hallway. It’s essential to our relationship.”

Emma Parry, 27, is an events coordinator from Bournemouth. She has been with Ed, 35, a hotel booking agent, for two years and they are expecting a baby. “Ed and I used to kiss constantly but when we moved in together this February our kissing became less passionate and more loving. During the day we might peck on the lips – French kissing is usually reserved for the bedroom. And if we’ve had an argument we always kiss to make up. Kissing is just as important to us as it always has been, but it’s driven by love more often than desire these days.”

Caroline Blair, 29, from Edinburgh is a blogger at Finding Mum. She has been with her husband, David, for five years. “David and I used to kiss all the time. Our first kiss was on our second date, in the middle of the road during our walk home. It was incredible. Five years later, we can go for weeks without really kissing. It’s more platonic – a peck on the lips or cheek to say hello after work or as we go to bed. The other night I kissed David properly on the sofa and he was taken aback, but told me it meant a lot to him. It made us feel closer. Our kisses might be fewer now, but aren’t they worth a bit more? I think so.”