What has the colour of your hair got to do with your capacity to withstand pain? We investigate the claim, which regularly circulates on social media, that natural redheads are 25% tougher than their brunette peers. Pain expert Jeff Mogil explains how it all comes down to something called MC1R. Presenter: Charlotte McDonald Producer: Lizzy McNeill Series Producer: Tom Colls Editor: Richard Vadon Production Co-ordinator: Katie Morrison