The science of smooching

" What's in a kiss? Have you ever wondered just what it is? More perhaps than just a moment of bliss... Tell me what's in a kiss."

This question, asked by Gilbert O'Sullivan in l980, is one that scientists are still trying to answer. Apparently, it's not enough to say that it feels "good" or even "fantastic" - they must spoil the fun and dissect it. They have even coined a name for their research - philematology.

However, we do not need scientists to tell us that men and women look upon kisses differently. For whereas to women, the beginning of a kiss may be "enough for the time being", to a man, it is usually an invitation to "take it further". That is why a woman would describe this feeling as "fuzzy, like swimming in the warm sea", but a man would say it is "the prelude to a Queen concert".

The scientists mention neurotransmitters and moto-neurons, as well as adrenalin, dopamine, pheromones, norepinephrine, and phenylethylamine (PEA). They say that a kiss stimulates the same brain centres as distance running, bungee-jumping, high-board diving, paragliding..... and that's not just because of the risks involved.

And, just for the record, they mention pleasure receptors (of course) that help the body create feelings of elation, enthusiasm, exultation, ecstasy, euphoria, exhilaration, eagerness, excitement.... etc. Actually, components in amphetamines create similar feelings.... so you could say that a kiss acts like a drug.

Just as the aforementioned sports have a way of becoming "addictive" because people crave an "adrenaline rush"- so could kissing become something after which to hanker?

Just as some people are more vulnerable to the effects of substance abuse - so are some of us more defenceless against the power of a kiss.

Some celebrities think they are being hip when they claim to be "addicted to sex" - but the jury is still out about whether this is a bona fide psychological condition, or whether they are hamming it up to boost box-office or record sales. To say that wanting to kiss and be kissed is like a chemical dependency may sound over the top to some - and let's not forget that the rule with some prostitutes is "no kissing".

People in exclusive, monogamous relationships can theoretically kiss their partners as much as they like - but does this always happen? And - are they the best people to pass judgement on those who habitually seek to kiss others - even when the latter show their distaste for it?

Is kissing an instinctive behaviour, an acquired one, or a learned one? Is it true that kissing originated when mothers pre-chewed food for their babies... and later nourishment gave way to comfort... of more than one kind? Bonobos are famous for their slurpy, slobbery kisses.... but the islanders of Mangaia, the most southerly of the Cook Islands in the South Pacific knew nothing about kissing until Europeans arrived in the 1700s and introduced them to it.

This, in itself, is highly peculiar, because the culture of this people is one of those described by anthropologists as "sex positive", where sexual pleasure, especially for females, is par for the course in the nation's lifestyle, beginning from the early teens.

Cultures where food is passed on from one adult's mouth to another, still had not known about kissing until the Europeans arrived, either.

Does it make sense to exchange around 250 (some say as many as 300) colonies of bacteria, saliva and possibly morsels of food, with every kiss?

When we get a paper-cut on the lips through licking an envelope before sealing it, we realise full well that the lips are packed with nerve endings. So, for that matter, is the tongue - we don't stop to think for a moment that a smooch takes place at the place where the digestive tract begins. Ironically, this is why kisses are enjoyed even between people who do not love one another.

Perhaps this is because the heart pumps harder, making the blood pressure and pulse rates shoot up, creating a natural high. The pupils of the eyes grow larger (but it's not because we try to hide this that we close our eyes!).

Journalists say that content is king - kissers say that context is everything. When all is said and done, a kiss under the mistletoe may be not that far removed from one given after your eyes have locked with those of a stranger, across the room.

Both may lead to nothing - or everything.