The Cognitive Processes in Informal Reasoning

Abstract Two experiments investigated the factors that people consider when evaluating informal arguments in newspaper and magazine editorials. Experiment 1 showed that subjects were more likely to object to the truth of the premises and the conclusions of an argument than to the strength of the link between them. Experiment 1 also revealed two manipulations that helped subjects object to the link between premises and conclusions: rating how well the premises support the conclusions and rating the believability of the premises and conclusions. Experiment 2 further demonstrated that subjects who identified the premises and conclusions of an argument were better at formulating objections to the link between premises and conclusions. Moreover, subjects in Experiment 2 were better and faster at formulating objections to the truth of the premises and conclusions than to the link between premises and conclusions. The results are discussed in terms of the constraints they pose for developing a cognitive theory of informal reasoning.