[thedoc (OP)]

mpho kgosi asked the Naked Scientists:















   















My curiosity is about tickles. Why do we laugh (to an extent!) when tickled, and why can it be only done in certain areas of the body? Is there an evolutionary explanation for it? I understand cars purr when patted, is it by the same physiologic mechanism that this happens in humans?































Thank you. I would like to say I love your show and find it absolutely fascinating.































What do you think?