Effects of Thinking Dispositions, General Ability, Numeracy, and Instructional Set on Judgments and Decision-Making.

To explore hypotheses based on Stanovich's proposal that analytic processing comprises a reflective-level, an algorithmic level, and specific mindware, 342 participants completed measures of thinking dispositions, general ability (GA), numeracy, and probabilistic and nonprobabilistic reasoning. In a control condition, numeracy predicted probabilistic reasoning at high levels of both thinking dispositions and GA, and GA predicted nonprobabilistic reasoning at high levels of thinking dispositions. In a logic instruction condition, numeracy predicted probabilistic reasoning when GA was high, and GA affected nonprobabilistic reasoning directly. Thinking dispositions moderated neither relationship. Instead, instructions facilitated reasoning for low thinking disposition/high-ability participants, suggesting that logic instructions cued low thinking disposition individuals to engage in higher order reflective processing. The evidence is consistent with the proposals that reflective processes are essential to the allocation of algorithmic resources, and algorithmic resources are necessary for effective mindware implementation.