Except for the bacteria and bits of Hunky Dory, what’s in a kiss? And WHY do we snog so enthusiastically, asks Farouq Manji.

Considering 90 per cent of human cultures today display kissing behaviour, we know surprisingly little about it. We are unsure where kissing originated, whether it is learned behaviour or wired into our very nature.

A plethora of animals use kissing, or similar behaviour in their normal social interactions. Bonobos monkeys for instance, kiss for just about any reason at all. Similar behaviour can be seen in birds, foxes and groups of rowdy Trinity Nurses.

This lends credence to the theory that kissing is a natural part of us. Documented acts of kissing date back to earliest recorded history. Alternatively, some anthropologists postulate that kissing was first used for affection in India, and became widely spread upon its invasion by Alexander the Great in 328 BC.

Since then, amour affecianadoes the world over, including your sister, have spent many years perfecting their technique, but to what end? Recent studies suggest that kissing can have a dramatic impact on mating and relationships.

The close-contact nature of kissing brings us closer to our partner, allowing the exchange of physical pleasure, chemicals such as pheromones, and the kissing disease. The exciting nature of kissing at the beginning of the relationship releases dopamine – a chemical associated with romance.

Maybe because of this, the first kiss can make or break a relationship. And for those of you in long-term relationships, one experiment demonstrated that couples who kissed for 15 minutes saw a reduction in their levels of cortisol – a stress hormone.

Clearly, kissing is awesome.

So go right ahead. You have my permission.