In the psychological literature, people are often deemed to be poor scientists. We argue that this is because many psychological measures are framed (at least tacitly) in a positivist tradition that emphasizes abstract formal rules rather than content. However, realist conceptions of science point out that formal or abstract rules can be used successfully only when content, or collateral information, is also taken into account. When psychological measures do take account of collateral information, then people perform appropriately. An especially important type of collateral information is information about mechanism, or theory. However, theories must also be evaluated to identify those that are plausible and to avoid being misled by those that are dubious. Realist philosophers note that theories or explanations can also be evaluated only by taking account of collateral information. We identify some of the types of collateral information that scientists rely on to evaluate explanations and examine the psychological function that such information plays in the reasoning of non-scientists. Furthermore, we note that the collateral information people search for is limited by the collateral information that is initially available to them and argue that it is limited as well by the social context of science.

Overview

If a large body of the psychological literature is to be believed, then people lack many of the dispositions that are prerequisites for sound thinking in general, and for scientific reasoning in particular. They have difficulty co-ordinating theory and evidence. They do not consider alternative accounts.