Why do almost all of us struggle with a simple reasoning test, yet get it right the moment it’s about a pint in a pub? This week, Professor Hannah Fry and Michael Stevens take on the Wason Selection Task, one of the most intensely studied problems in the history of psychology. They unpack why a rule involving letters and numbers can feel strangely difficult, while the exact same logic becomes immediate and instinctive when it’s about people, rules, and catching someone out. From counterexamples and conditional statements to confirmation bias and the limits of human reasoning, they reveal why we rarely look for what proves us wrong. Along the way, they tackle a bigger question: did reasoning evolve to uncover truth, or simply to help us get along? ------------------- 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 Producer: 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 ------------------- 00:00 Intro 02:23 Cancer Research UK 03:36 The reasoning test psychologists still can't explain 05:12 Can Hannah pass the Wason selection task? 08:15 Does changing the context make it easier? 12:34 Who are the people who get the original test right? 16:20 Modus Ponens 22:12 Why did humans’ reasoning ability evolve? 24:52 The most common responses to the test 31:45 How quickly can Hannah guess the rule? 34:50 The enigma of reason 37:17 Confirmation bias 38:28 The deficit model 44:10 Michael’s idea for electing a fair government 45:02 Civilian panels and town halls 48:00 What is phatic communion? 52:00 Where ‘goodbye’ came from 57:40 Outro