How is performance on the selection task affected by pragmatic reasoning schemas?
Six experiments investigated Cheng and Holyoak's (1985) pragmatic reasoning schema theory and factors that increase subjects' rates of correct performance on variations of Wason's (1966) selection task. Cheng and Holyoak's content-based theory accounts for a wellknown effect associated with the selection task in which specific changes in its content increase subjects' rates of correct performance. Generally, they claim that reasoning is guided by pragmatic reasoning schemas, clusters of inferences that are abstracted from repeated exposures to particular situations. Their strongest piece of evidence comes from a selection task variation on which subjects' performance is attributed to content that purportedly elicits a pragmatic schema and leads to superior performance when compared to a control problem with descriptive content. However, their experiment contains several confounds. Cheng and Holyoak's problems differ from one another with respect to the kind and amount of information provided. For example, their experimental problem consistently employs negatives and requires subjects to role-play an authority figure, whereas their control problem does neither of these. Moreover, both of their problems employ a task requirement that is different than Wason's. The confounds were neutralized and six hundred subjects were run to investigate pragmatic schemas' role in facilitating rates of correct performance on selection task problems. Though Cheng and Holyoak's original finding was confirmed in Experiment 1, it appears that facilitation relies on the unique task requirement adopted by Cheng and Holyoak's paradigm. Experiment 2 demonstrated that when the problems remove the accessory information found in Cheng and Holyoak's pragmatic problem, and thus more closely follow the presentation of Wason's original problem, subjects' performance is poor. Experiments 3 through 5 honed in on a different factor that is responsible for the observed facilitation on a pragmatic problem--the manner in which negatives are employed. Experiment 6 indicated that descriptive problems are not affected by the same kinds of manipulations that facilitate correct performance on pragmatic problems. The results from these experiments raise doubts about Cheng and Holyoak's claim that reasoning is typically mediated by pragmatic reasoning schemas.