The Role of Implicit and Explicit Negation in Conditional Reasoning Bias

Abstract

Matching bias in conditional reasoning consists of a tendency to select as relevant cases whose lexical content matches that referred to in the conditional statement, regardless of the presence of negatives. Evans (1983) demonstrated that use of explicit rather than implicit negative cases markedly reduced the matching bias effect on the conditional truth table task. In apparent contrast, recent studies of explicit negation on the Wason selection task have failed to find evidence of logical facilitation. Experiment 1 of the present study strongly replicated the Evans (1983) findings and extended them to three forms of conditional statement. Experiments 2 and 3 showed further that the use of explicit negatives removed completely the matching bias effect on the Wason selection task. However, consistent with other recent studies, this elimination of bias didnotlead to facilitation of correct responding. The findings are interpreted as providing evidence that matching bias reflects a linguistically cued relevance effect.