The source of intuitive errors in Wason's THOG problem

Two explanations for the intuitive errors that occur in Wason's THOG problem are considered in this paper. The first claims that subjects make an incorrect assumption about the critical properties involved in the rule, but then proceed to reason logically. The second claims that subjects respond on the basis of non-logical perceptual matching to the properties in the designated positive instance. The results from three experiments gave unequivocal support to neither explanation. It was concluded that perceptual matching is the better explanation of intuitive errors on this task, but that it may be used only when subjects are confused by the logic of the problem and have recourse to no other basis for responding.