Abstract
Wason's selection task: A study of individual differences. The present study examined the differential influence of rule content and instructions on subject's performance on Wason's four-card selection task. 384 undergraduate students each completed two psychometric ability tests (DAT-VR and PMA-E) and a standard or a tematic version of the same selection task. Performance was superior with direct experiential rules and with violation instructions. In terms of differential analyses it was found that the logic index was considerably better in the higher verbal group, but were not found differences in the matching indixes. These results are discussed in terms of actual theories of reasoning.