1990 年 38 巻 2 号 p. 106-116
Cheng et al.(1985) proposed that peop le typically reason about realistic situations by using pragmatic reasoning schemas, which are generalized sets of rules defined according to classes of goals. We examined the credibility of such hypothesis through two experiments. Experiment I demonstrated that even subjects, regarded as not having pragmatic reasoning schemas, could solve a reasoning task exemplified by athematic four-card problem and also that, many of the subjects who correctly solved a normal thematic four-card problem failed to solve similar four-card problems. Experiment II demonstrated that the thematic four-card problem in which the task goal was introduced, could be solved just as easily even though no rule defining the task goal was introduced. Based on these results, we concluded that there were no pragmatic reasoning schemas as proposed by Cheng et al. that might solve reasoning tasks ; and we interpreted these results from the viewpoint of the “deformation theory” anteriorly proposed. Finally, the argument that the hypothesis of pragmatic reasoning schemas supporting the idea of ecological rationalism was criticized.