Inept reasoners or pragmatic virtuosos? Relevance and the deontic selection task

Most individuals fail the selection task, selecting P and Q cases, when the y have to test descriptive rules of the form "If P, then Q". But they solve it, selecting P and not-Q cases, when they have to test deontic rules of t he form "If P, then must Q". According to relevance theory, linguistic comp rehension processes determine intuitions of relevance that, in turn, determ ine case selections in both descriptive and deontic problems. We tested the relevance theory predictions in a within-participants experiment. The resu lts showed that the same rule, regardless of whether it is tested descripti vely or deontically, can be made to yield more P and Q selections or more P and not-Q selections. We conclude that the selection task does not provide a tool to test general claims about human reasoning. (C) 2001 Elsevier Sci ence B.V. All rights reserved.