What intuition is

The teaching

As the psychology of skilled intuition, after Gary Klein and Daniel Kahneman teaches it.

Intuition is recognition

Intuition, in this teaching, is knowing something quickly without being able to say how, and it is made of experience. Herbert Simon put it in a line: the situation offers a cue, the cue gives access to what memory holds, and memory gives the answer, so that intuition is recognition, nothing more and nothing less. The expert does not reason to the answer. They see it, because they have seen its like many times, and the seeing is faster than the words for it.

That is why intuition feels like a sense of its own. Its workings are out of sight, its answers arrive whole, and the person who has them often cannot explain them. Yet it runs on the ordinary senses: what the eyes, ears and hands have taken in, sorted by long practice.

The fire that was too quiet

Gary Klein's best-known case is a fire lieutenant who led his crew into a house to fight what looked like a kitchen fire. They sprayed water on it and it did not respond. The room was hotter than such a fire should make it, and quieter. Without knowing why, the lieutenant ordered everyone out, and moments later the floor they had been standing on collapsed. The fire had been in the basement beneath them.

The lieutenant put his decision down to a sixth sense. Klein's patient questioning showed something else. The fire had broken his expectations: a kitchen fire should yield to water, and this one did not, because it was not in the kitchen; it was quiet because the floor muffled it; the room was hot because the fire was below and heat rises. He had noticed all this without knowing that he noticed. His sixth sense was experience recognising that this was not the fire it seemed.

Recognition-primed decision

From such cases Klein built a model of how experienced people decide under pressure, which he called recognition-primed decision. The expert does not lay out options and compare them. They recognise the situation as a kind they know, and the recognition brings four things with it: which cues matter, what to expect next, which goals are realistic, and what action is typical. They take the first workable action that comes to mind and test it by imagining it played out. If it works in imagination they act; if it nearly works they adjust it; if it fails they take the next.

Two systems

Daniel Kahneman taught the same mind from the other side, by its errors. He describes two modes of thinking. The first, which he calls System 1, is fast, automatic, effortless and always on: it reads faces, completes phrases, senses danger and jumps to conclusions. The second, System 2, is slow, deliberate and effortful: it does sums, checks arguments and follows rules, and it is lazy, glad to accept what System 1 offers. Intuition is System 1 at work, and so are many of the mind's mistakes.

The mind's shortcuts

System 1 answers hard questions by quick rules of thumb, which Kahneman and Amos Tversky named heuristics. By availability it judges how likely a thing is by how easily examples come to mind, so that vivid and recent events seem commoner than they are. By representativeness it judges by resemblance to a type and forgets how common the type is. By anchoring, a number met first pulls later estimates toward it, even when it is arbitrary. And often it puts an easier question in place of the one asked, answering how do I feel about this when asked how likely it is.

Kahneman sums up much of this in a phrase of his own: what you see is all there is. The quick mind builds the best story it can from the evidence in front of it and does not count the evidence it lacks. The story feels complete, and so the judgement feels sure.

Confidence is not evidence

The most useful lesson of this teaching is that the feeling of being sure is not a measure of being right. Confidence reflects how coherent a story feels, not how good its evidence is. Kahneman calls the strong sense of seeing truly, where there is in fact little skill, the illusion of validity. A hunch can be vivid, insistent and wrong, and its vividness says nothing about which.

When a hunch deserves trust

Klein and Kahneman, who began from opposite sides, agreed on when intuition can be trusted. Two conditions must both hold. The field must be regular enough to have patterns that can be learned: fires, chess, the care of sick infants, a partner's moods after many years together. And the person must have had long practice in it with prompt, clear feedback on whether they were right. Where both hold, the hunch is experience speaking in shorthand and should be heard. Where either is missing, as in judging whether a stranger is lying, where a market will go, or what a new acquaintance is really like, the hunch is only a feeling, and it needs checking from outside before it is acted on.

Training the eye

Skilled intuition is built, not given. It grows from many cases met with honest feedback: the nurse who sees hundreds of infants and learns which of them fell ill, the player who goes back over lost games. Klein's ways of training follow from this. Work through hard cases, real or simulated, under some pressure of time; then compare your choices with an expert's and ask what they noticed that you missed. Experts' stories, told in detail, carry the cues they have learned to see.

The premortem

Klein also gives a way of turning intuition against its own blind spots, which he calls the premortem. Before a plan is adopted, those who will carry it out imagine that it is a year later and the plan has failed, and each writes down, briefly, why it failed. The exercise gives a voice to doubts that confidence would silence, and Kahneman counts it among the most useful checks on overconfident judgement.

Intuition and the sixth sense

The line between intuition and extrasensory perception is exactly the senses. Intuition is fast knowing through the ordinary senses and memory, and with patience it can be explained, as Klein explained the lieutenant's. A claim of knowing without any sense at all is a different claim, and the other branches of this art set out how it has been tested. The practical rule is the same for both: a feeling of knowing is a reason to look closer, not a reason to stop looking.