Intuition is an effortless, immediate, automatic feeling or thought. It arises without deliberate reasoning and often without the person being able to explain its source.

Experts develop reliable intuitions within their domains of expertise. A chess master senses the right move; a clinician senses that something is wrong with a patient. These intuitions are the product of extensive pattern learning, not mystical insight. In unfamiliar domains, however, intuition is prone to the same biases that affect deliberate judgment—availability, representativeness, overconfidence. The feeling of certainty that accompanies an intuition is not a reliable guide to its accuracy.

Dual-process theories contrast intuitive (System 1) thinking with deliberate (System 2) thinking. Intuition is fast, parallel, and associative; deliberation is slow, serial, and rule-governed. Effective decision making often involves using intuition to generate candidates and deliberation to evaluate them. Training can improve the calibration of intuitive judgments by providing rapid, accurate feedback.

Intuition is the mind’s rapid, automatic verdict. Sometimes it is wisdom; sometimes it is merely fluency.