Rational choices in wason's selection task

Sixty-eight subjects were asked to solve a series of six Wason selection problems by physically turning relevant cards over until they could say whether the rule was correct or false. In the first experiment most of the subjects misunderstood the rule they were asked to verify, different subjects misunderstanding in different ways, but commonly reading (a) top/underneath for one side/other side and (b) a dual conditional for if..., then.... However, a majority of subjects thereafter responded in complete logical consistency with the rule as they understood it to be. When the misunderstandings revealed in the first experiment were themselves presented as rules to be verified in a second experiment, performance was much more logical than is usually reported. It is concluded that the illogicality commonly associated with Wason's selection task is only apparent.