The Reasoning Test Psychologists Still Can't Explain

The Reasoning Test Psychologists Still Can't Explain

From The Rest Is Science by Goalhanger

April 20, 2026 · 1h 2m · Season 1 · Episode 44

About this episode

The episode explores the complexities of human reasoning through the lens of the Wason Selection Task and its implications in psychology.

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…

People in this episode

Guests: Professor Hannah Fry, Michael Stevens

Topics covered

  • reasoning
  • psychology
  • Wason Selection Task
  • confirmation bias
  • human reasoning

Keywords

  • reasoning test
  • Wason Selection Task
  • psychology
  • confirmation bias
  • human reasoning

Mentioned in this episode

Organizations: Cancer Research UK

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