In groups, endorphine release promotes a sense of fellowship – that’s why when someone starts laughing, others join in.

Another study found that there are differences in how we perceive laughter – again, you unconsciously know this: there’s joyous laughter, mocking laughter, rib-tickling laughter, each of which activates different parts of our brains, as our brains decipher what is being communicated.

There is also the role of laughter in relationships. It has been shown that women laugh more than men, but that men instigate laughter more – maybe the reason there are more male than female comedians. Apparently women rate a sense of humour in men as very important in a relationship, whereas men do rate women who laugh a lot, but especially at their jokes! Hardly surprising then that laugher is an important ingredient in a successful partnership.

On a purely medical note laughter can have a similar effect to anti-depressants: laughing activates the release of serotonin, a brain chemical active in SSRI type antidepressants (Serotonin Uptake Inhibitors).

And research has shown that laughter protects your heart: it is said to have an antiinflammatory effect on blood vessels and heart muscle thus giving some protection against cardiovascular disease. It’s not fully understood but the theory is that inflammation is linked to increased bodily stress, which laugher can mitigate.

So, folks – split your sides!