Strategies in Reasoning

Princeton University, Princeton NJ

Investigators

Abstract

This project will investigate the reasoning of adults untrained in logic. When such individuals tackle a series of logical problems, they spontaneously develop different strategies for going about the task; that is, they come to rely on different sequences of mental steps to make inferences. Some individuals, for instance, try to keep track of all the possibilities compatible with the premises, while others try to concatenate the premises into a complex conclusion, and still others follow up the consequences of a single possibility. There are also other sorts of strategy, and they all have a profound impact on logical performance. The first step in the research will therefore be to trace the development of strategies, to examine their effects on logical accuracy and speed of response, and to attempt to gain experimental control over which strategies participants are likely to develop. The research will test predictions from Johnson-Laird's theoretical account of how reasoners discover strategies, which is based on his earlier theory of mental models. One of its predictions is that the process of strategy discovery is biased by the possibilities compatible with the premises. Experiments will test this prediction, along with others made by the theory. The second step in the research will be to apply the strategic theory to teaching people to improve their reasoning. The pedagogical aim for this step is to devise a strategy that can be taught in a few minutes, that enhances performance, and that can be carried out without the use of pencil and paper. The intellectual aim is to throw further light on strategic thinking. The third step in the research will be to apply the new theory to the study of complex inferential problems from everyday life. Although such problems are outside the scope of current psychological theories of reasoning, the ability to cope with them correlates with intelligence and is crucial for success in academia, science, and business. The project should yield a deeper understanding of the development of strategies in reasoning, an effective pedagogical aid, and an account of the mental processes underlying reasoning in daily life.