Why does tickling make us laugh?

Laughter is most often associated with pleasure, but, for many people, tickling brings with it a certain amount of pain. So laughing when being tickled is a rather odd response, especially when you consider that tickling has historically been used as a form of torture. Prof Sophie Scott, a neuroscientist and laughter expert at University College London, believes that the laughing response evolved in mammals as a form of social bonding. It’s a way for parents to bond with their children, and for children to play and compete without being hurt. As well as great apes, we also find social laughter in rats – they make high-pitched squeaking noises when being tickled, particularly the younger rats.

Rory Galloway is the producer of What’s The Point Of Laughter? – an episode of CrowdScience that can be streamed at bbcworldservice.com/crowdscience