Deciding before you think: Relevance and reasoning in the selection task

Two experiments are reported in which subjects are asked to solve various versions of the Wason selection task. The task involves deciding whether or not to pick any of four cards which may be turned over in order to test the truth of a conditional statement. Each experiment employed a novel methodology in which subjects recorded the amount of time they spend considering a card prior to either choosing or not choosing it. Problems were computer presented and subjects were required to point with a mouse at any card which was the card they were currently considering but only to click the mouse button if they were sure they wanted to select it. The total ‘inspection time’ was logged by the computer for each card (recording stopped if the card was selected). According to the Evans' (1984, 1989) theory of reasoning, card choices on the selection task are determined by preconsciously cued relevance. As predicted from this theory, cards with higher selection frequencies also had longer inspection times in all experiments. It was also shown that for any given card on a particular rule, the subjects who chose the card spent much longer inspecting it than the subjects who did not. The results are discussed with respect to the issue of whether decision making is in general consequential, i.e. based upon an analysis of the consequences of choices.