When it comes to first kisses, scientists agree with those who believe in love at first sight, happy endings and the power of that first glorious embrace. That’s because, Scientists say, a kiss is much more than just a way of saying you fancy someone. It’s an efficient means of working out if your potential partner is the one for you.

In her book: The Science of Kissing, Sheril Kirshenbaum explains: “When we are that close to another person, all our senses are engaged allowing our bodies to assess compatibility and the potential for a long-term relationship.”

This behaviour, she says, evolved to help humans fulfill three basic needs – sex drive, romantic love and attachment. “In other words,” she says, “kissing helps us find partners, commit to one person and keep couples together long enough to have a child.”So how does locking lips help us achieve all these? When you kiss, you can’t help smelling the other person. And biologists have found that women are more turned on by the smell of men who have very different immune systems from their own.

Kirshenbaum says; “This may be because potential children would have a higher level of genetic diversity, making them healthier and more likely to survive. In this manner, kissing serves as nature’s ultimate litmus test to help us determine when to pursue a relationship.”

And once we find our perfect genetic mate, our bodies respond instinctively to his kiss by flooding our systems with feel-good hormones. She explains that: “A good romantic kiss quicken our pulse and dilates our pupils, which is probably part of the reason so many of us close our eyes. Our brains receive more oxygen than normal and breathing can become irregular and deepen. Our cheeks flush too but that’s only the beginning. There’s an associated rise in the neurotransmitter dopamine, responsible for craving and desire.

“Meanwhile, serotonin spikes to stimulate obsessive thoughts about a partner. This is the same neurotransmitter involved in obsessive-compulsive disorder (OeD), Oxytocin, popularly called the love hormone, is involved in bonding, fostering a sense of attachment. This is the chemical likely responsible for maintaining a love relationship over years and decades.”

We should not underestimate the importance of these chemicals. After all, how many of us have left the cinema after a dull romantic comedy and pointed out the ‘lack of chemistry’ between the couple who are supposed to be mad about each other? Or dreamt about how it would feel to kiss someone we have fantasised about for months – then been disappointed by the reality? For while that first kiss can be powerful enough to spark a lifelong romance, it can also break the spell.

A study of more than 1,000 students by the evolutionary psychologist George Gallup found that two-thirds of women and over half of men had been attracted to a potential partner – until they shared a disastrous first kiss. His team also found that men and women used kissing for different reasons. While the men mostly saw kissing as just a necessary step on the way to eventually having sex, women thought it was much more important. More men than women said they preferred kissing their partners with open mouths and using their tongues.

And there’s even a good reason for that. Male saliva contains testosterone so it could affect how attractive the kissers find each other. Some scientists believe that men prefer sloppy kisses because they’re a way of working out how fertile a woman is – by ‘testing’ her saliva for tiny traces of oestrogen.

So when your kids scoff at your memories of that first magical kiss, tell them that without kissing, they might not have been here today. And make sure you don’t get out of the habit once your romance settles down.

Research shows that couples who kiss regularly are less likely to get depressed, and those who kiss each other hello and goodbye have happier relationships than those who no longer do this. (Sunday Vanguard)

Update news