Conditional syllogistic reasoning and working memory capacity

A relationship between working memory capacity and propositional reasoning abilities is examined within the framework of Marcus & Rips (1979) verification model of conditional syllogisms and the mental operator model of cognitive development proposed by Pascual-Leone (1970). Using the four-stage verification model to explain required cognitive processes, it is argued that development in the ability to solve conditional syllogisms can be attributed, in part, to an epigenetically determined increase in working memory capacity. With a sample composed of 77 pre-adolescent and university students, micro-computers presented individual subjects with two 40-item conditional syllogistic reasoning (CSR) tasks and a backward digit span (BDS) task, in two sessions. The results are not as predicted. Indexing memory capacity by BDS, analyses of covariance and polynomial regression analysis, fail to identify a relationship with correct CSR responses. While grade is shown to explain a major percentage of variance in CSR scores, knowledge of the .conditional rule is also identified as an important factor. Arguments are grouped according to order of difficulty and validating response time, and the results of subjects identified as knowing the conditional rule fail to agree with the groupings predicted by the Marcus & Rips model while supporting development of a single operative scheme for conditional syllogistic reasoning.Education, Faculty ofEducational and Counselling Psychology, and Special Education (ECPS), Department ofGraduat