[playful page] A toy, not a test. It runs in your browser; nothing you do here is sent anywhere, and the only thing kept is a "played" tick in your own browser so the toy shelf can show it.

TOY #6 OF 6 works with a mouse, a finger or a keyboard

ach card has something on both sides; you can see one side. You are given a rule. Tap the cards you would need to turn over to find out whether the rule is broken, and no others. Two rules, same logic.

This toy needs JavaScript. The notes below still say what it would have shown.

What it shows. Peter Wason's selection task. With abstract letters and numbers, most people in his studies chose the vowel, often with the even number, and few chose the odd number, the card that could actually break the rule (Wason, 1968) [paraphrase, not a quotation]. Versions about familiar permissions tend to be much easier; Griggs and Cox found this with a drinking-age rule (Griggs & Cox, 1982) [paraphrase, not a quotation]. Why is still argued. Cosmides proposed that people are especially good at spotting cheaters on social rules (Cosmides, 1989) [paraphrase, not a quotation]; others put it down to familiarity and to what "if" is taken to mean. What it cannot show. Two items, one person, and you may have seen the puzzle before (it is famous). The beer rule here is ours, written in the spirit of the published versions, not copied from them. Getting the first one wrong says nothing about how well you reason in general; it is one of the most studied traps in psychology precisely because so many careful people fall into it.

Sources

1. Wason (1968). Reasoning about a Rule. Quarterly Journal of Experimental Psychology. doi:10.1080/14640746808400161
2. Griggs & Cox (1982). The elusive thematic‐materials effect in Wason's selection task. British Journal of Psychology. doi:10.1111/j.2044-8295.1982.tb01823.x
3. Cosmides (1989). The logic of social exchange: Has natural selection shaped how humans reason? Studies with the Wason selection task. Cognition. doi:10.1016/0010-0277(89)90023-1

see also

	bounded rationality — good-enough reasoning
	Herbert Simon — who thought about limits on reasoning
	selection task — in the glossary