A reasoning puzzle
The Wason Selection Task
The same logic, two ways. Try the abstract puzzle first, then the everyday one — and notice which feels easier.
Why is the second one so much easier?
Both versions have exactly the same logical structure. Yet people are far better at the bar than at the abstract cards.
Roughly how often people choose correctly
Every rule here has the shape if P → then Q. The only cards that can ever break such a rule are the P card and the not-Q card — the vowel and the odd number; the beer and the underage drinker. In both tasks the right answer is the same two logical roles.
In the abstract version most people instead pick the cards that simply match the words in the rule — the vowel and the even number. This pull toward matching is called matching bias, and it quietly leads to the wrong answer.
The bar version is easier because it isn't really abstract logic anymore — it's checking whether someone is cheating on a permission rule, something we reason about fluently in everyday social life. Two influential explanations are pragmatic reasoning schemas (we carry ready-made “permission” rules; Cheng & Holyoak, 1985) and social contract theory (we evolved to spot cheaters; Cosmides, 1989).
Sources. Wason (1968) introduced the selection task. Griggs & Cox (1982) reported the drinking-age “facilitation” effect. Cheng & Holyoak (1985) proposed pragmatic reasoning schemas; Cosmides (1989) proposed the social-contract account. Success-rate figures are approximate and vary across studies.
Turn the card over — that was always the point.