Cue redundancy and extra logical inferences in a deductive reasoning task

This study investigated the influence of extraexperimental knowledge on deductive reasoning. Two groups of subjects solved modified abstract or concrete versions of Wason’s (1966) four-card selection problem in which the “if-then” implication rule provided the sole cue to underlying logical structure. Six other groups solved abstract or concrete comparison problems in which additional information was supplied by varying the relationship between antecedents and consequents in a manner consistent with logical structure. Selection responses and subjects’ explanations were analyzed using log-linear models of data arrayed in multiway contingency tables. Results showed improved performance for concrete over abstract problems and for both abstract and concrete problems that included relational information. Subjects capitalized upon the redundancy between the implication rule and the relational cues to reason effectively with either abstract or concrete stimuli.