Why can't you leave a sealed envelope unopened? Professor Hannah Fry begins by refusing to allow Michael Stevens to open a mystery envelope addressed to him. A small act of torture that turns out to be the perfect way in to today's subject: curiosity. What is it, why does it feel almost physical, and how far will people actually go just to resolve a nagging uncertainty? From there Hannah and Michael trace curiosity's surprising reputation through history; how for well over a thousand years it was branded a vice, even a sin, before a couple of inventions flipped it into a virtue almost overnight. Along the way they delve into the psychology and neuroscience of this itch. Why your brain can't stop worrying at a missing answer, why getting something wrong could be the key to remembering it, and which animals share the drive (and one surprising creature that doesn't). Plus curiosity's darker side, the way the modern world has learned to hijack the very same circuitry, and a rather lovely story about how a Mars rover got its name. ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Video Editor: Oli Oakley Animator: Sam Benson Video & Social: Bex Tyrrell Assistant Producer: Lucy Lipscombe Producer: Simona Rata Senior Producer: Lauren Armstrong-Carter Head Of Digital: Samuel Oakley Exec Producer: Neil Fearn