Theories of Medical Decision Making: Explaining, Predicting, and Improving Health and Healthcare

In principle, scientific theories explain why patients, providers, and policy makers make specific decisions and, because they are about causal mechanisms, they provide guidance for the design of effective interventions for improving those decisions. In practice, however, problems rather than theories often motivate research and, when theory is invoked, its application can be piecemeal and ad hoc. Thus, human behavior—on which so much depends—remains essentially a black box, exhibiting biases and fallacies that seem inevitable and cumulative progress is stunted.

This symposium summarizes and critically reviews major theories of health and medical decision making with the goal of building on the best evidence, weeding out weak theories, and improving strong ones. Whenever possible, we integrate approaches that have demonstrated success but emphasize empirical tests of alternative approaches. Among the evidence-based theories we discuss are dual-process theories (e.g., default interventionism); theories of numeracy and numerical cognition; fuzzy-trace theory; theory of reasoned action; self-determination theory; and the difficulty X motivational matrix.