Why do we kiss?

It's Valentine's Day! So we thought a blog mixing some science with some romance would be just right for today, which brings us to the topic of kissing.

If you've ever wondered why humans kiss, you might be disappointed to find that the origins of kissing are not as romantic as you may hope. It is thought that kissing developed from the practice of our ancestors to give food to their offspring via mouth-to-mouth regurgitation. Not exactly glamourous, and quite unpleasant to think about.

In keeping with the theme of unpleasantness, a study from 2014 determined that for every 10 second kiss as much as 80 million bacteria can be transferred from mouth to mouth! In fact, according to a study published in Microbiome, couples who kiss regularly end up with very similar salivary microbiota populations.

However, before you decide that kissing is no longer for you, here are some of the benefits of having a smooch:

Kissing is good for your teeth

Who knew!? According to New York Dentist Sivan Finkel, kissing leads to increased saliva production which helps our teeth by getting rid of harmful bacteria.

Kissing can lower anxiety

The act of kissing can release the hormone oxytocin (known as the love hormone) and this hormone can induce a sense of relaxation and bonding in humans.

Kissing has an anti-aging effect

When you kiss you have higher blood flow to your lips and face and this increased blood flow can increase collagen production and contribute to anti-aging.

Kissing helps determine if someone is a good match for you

Anthropologists believe that we have preferences about potential partners' biological profiles. Kissing lets us swap saliva with a potential partner and 'figure out' if they are a good fit for us, biologically speaking.

Kissing burns calories

A passionate kiss can burn up to 6.5 calories a minute (and it's more fun than going to the gym!)

Kissing is enjoyable

Otherwise we probably wouldn't bother, would we?