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Abstract The relationship between two forms of deductive reasoning - abstract and thematic - and working memory capacity were examined. Two forms (abstract and thematic) of the Wason selection task and the Ospan test for general working memory capacity were used. Seventy eight, third-year, distance psychology students were tested in a counterbalanced experimental design. Results indicated that both thematic and abstract deductive reasoning scores were significantly positively correlated with working memory capacity, with abstract reasoning having a stronger correlation than thematic reasoning. However, it was found that thematic deductive reasoning scores were significantly higher than abstract deductive reasoning scores. It appears that more complex cognitive processes are required for successful performance on abstract versions of the Wason selection task than on the thematic version. Results are discussed within the context of the mental model theory and dual systems theories, with specific reference to Evan’s (2006) heuristicanalytical theory. Areas for further research are discussed.
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Introduction Current theoretical approaches to deductive reasoning include the mental models theory (Johnson-Laird, 1999) and the various dual systems theories (Evans, 2006; Evans & Over, 1996; Stanovich & West, 2000). These have provided a framework to understand the empirical evidence that performance on deductive reasoning tasks is strongly linked to working memory capacity (De Neys & Verschueren, 2006; Kyllonen & Christal, 1990; Süβ, Oberauer, Wittman, Wilhelm & Schulze, 2002). According to the mental model theory, individuals use the information contained in the premise to form a mental model of the reasoning problem or task. Working memory capacity is the constraint on the ability to construct, assess and revise mental models