Mental Models

Understanding phenomena’s in daily life.

History and Orientation

Boltzmann (1899) made a statement which refers in a way to the use of mental models today: “All our ideas and concepts are only internal pictures”. Craik (1943) first thought and wrote about small scale models, to anticipate events.

Core Assumptions and Statements

Mental models are representations of reality that people use to understand specific phenomena. Mental models are consistent with theories that postulate internal representations in thinking processes Johnson-Laird (1983) proposes mental models as the basic structure of cognition: “It is now plausible to suppose that mental models play a central and unifying role in representing objects, states of affairs”. We can summarize the theory in terms of its three principal predictions, which have all been corroborated experimentally: 1) Reasoners normally build models of what is true, not what is false -- a propensity that led to the discovery that people commit systematic fallacies in reasoning. 2) Reasoning is easier from one model than from multiple models. 3) Reasoners tend to focus on one of the possible models of multi-model problems, and are thereby led to erroneous conclusions and irrational decisions.

To build models of what is true is a sensible way to deal with limited processing capacity, but it does lead to illusions. Yet, it does not imply that people are irredeemably irrational. The fallacies can be alleviated with preventative methods. Without them, however, reasoners remain open to the illusion that they grasp what is in fact beyond them. We suspect that similar short-comings may underlie judgment and choice in game-theoretic settings.

Conceptual Model

Not applicable.

Favorite Methods

Experimental research.

Scope and Application

The theory accounts for the informality of arguments in science and daily life, whereas logic is notoriously of little help in analyzing them. If people base such arguments on mental models, then there is no reason to suppose that they will lay them out like the steps of a formal proof.


To be added.


Key publications

Johnson-Laird, P.N. (1983). Mental models: towards a cognitive science of

language, inference and consciousness. Cambridge, UK: Cambridge University


Craik, K. (1943) The Nature of Explanation. Cambridge: Cambridge University Press.

Friedman, L.A., & Neumann, B.R. (1980). The effects of opportunity costs on project investment decisions: A replication and extension. Journal of Accounting Research, 18, 407-419.

Girotto, V., & Gonzalez, M. (1998) Strategies and models in statistical reasoning. In Schaeken, W., and Schroyens, W. (Eds.) Strategies in Deductive Reasoning. In press.

Johnson-Laird, P.N., & Byrne, R.M.J. (1991) Deduction. Hillsdale, NJ: Lawrence Erlbaum Associates.

Johnson-Laird, P.N., & Goldvarg, Y. (1997) How to make the impossible seem possible. Proceedings of the Nineteenth Annual Conference of the Cognitive Science Society, 354- 357.

Johnson-Laird, P.N., Legrenzi, P., Girotto, V., Legrenzi, M.,& Caverni, J-P. (1998) Naive probability: a mental model theory of extensional reasoning. Unpublished MS, Princeton University.

Johnson-Laird, P.N. & Savary, F. (1996). Illusory inferences about probabilities. Acta Psychologica, 93, 69-90.

Legrenzi, P., & Girotto, V. (1996) Mental models in reasoning and decision making processes. In Oakhill, J., & Garnham, A. (Eds.) Mental Models in Cognitive Science. Hove, Sussex: (Erlbaum UK) Taylor and Francis, Psychology Press, pp. 95-118.

Legrenzi, P., Girotto, V., & Johnson-Laird, P.N. (1993) Focussing in reasoning and decision making. Cognition, 49, 37-66.

Medvedev, Z. A. (1990) The Legacy of Chernobyl. New York: W.W. Norton.

Metzler, J., & Shepard, R.N. (1982) Transformational studies of the internal representations of three-dimensional objects. In Shepard, R.N., & Cooper, L.A. Mental Images and Their Transformations. Cambridge, MA: MIT Press. pp. 25-71.

Rips, L.J. (1994) The Psychology of Proof. Cambridge, MA: MIT Press.

Shafir, E., & Tversky, A. (1992). Thinking through uncertainty: nonconsequential reasoning and choice, Cognitive Psychology, 24, 449-474.

Simon, H.A. (1959) Theories of decision making in economics and behavioral science. American Economic Review, 49, 253-283.

Wittgenstein, L. (1922) Tractatus Logico-Philosophicus. London: Routledge & Kegan Paul

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