Further Evidence for the Theory: Predicting Intermediate and Multiple Conclusions in Propositional Logic Inference Problems

Chapter 7 used reasoning problems that had neutral content (so that preexisting knowledge or domain-specific skills could not provide a basis for inferences). It found that adults performed almost errorlessly on maximally simple problems embodying the model’s inferences (i.e., on prob-lems that can be solved in one step with one of the inference forms of the repertory,

without any other complexity). Furthermore, the difficulty of a problem was highly correlated with the number and kind of the inferential steps in the line of reasoning used by the model to solve the problem.