The mental model theory of thinking and reasoning is the focus of this blog. Mental models are representations in the mind of real or imaginary situations. Scientists sometimes use the term “mental model” as a synonym for “mental representation”, but it has a narrower referent in the case of the theory of thinking and reasoning.
The idea that people rely on mental models can be traced back to Kenneth Craik’s suggestion in 1943 that the mind constructs “small-scale models” of reality that it uses to anticipate events. Mental models can be constructed from perception, imagination, or the comprehension of discourse. They underlie visual images, but they can also be abstract, representing situations that cannot be visualised. Each mental model represents a possibility. Mental models are akin to architects’ models or to physicists’ diagrams in that their structure is analogous to the structure of the situation that they represent, unlike, say, the structure of logical forms used in formal rule theories. In this respect they are a little like pictures in the “picture” theory of language described by Ludwig Wittgenstein in 1922.
Cognitive scientists have explored mental models and the mind generally. They have carried out an extensive programme of study on how models engender thoughts and inferences. They have studied how children develop such models, how a model of one domain may serve as an analogy for another domain, how mental models engender emotions, and how to design computer systems for which it is easy to acquire a model.
Many reasoning researchers world-wide have studied the model theory of deductive reasoning. They have published many papers on mental models in reasoning. Many of these articles present experimental evidence that corroborates the predictions of the model theory of deduction, and others suggest revisions and modifications to some of the theory’s tenets to accommodate new data. Critics of the model theory include proponents of alternative theories of deduction based on inference rules. The controversy about whether people reason by relying on models or on inference rules has been long but fruitful: it has led to better experiments, to explicit theories implemented in computer programs, and to developments of the mental model theory of thinking and reasoning in novel domains.
Phil Johnson-Laird and Ruth Byrne
May 2000 (updated July 2012)