"One of the most fascinating examples of heuristics and biases is what we call intuition — a complex cluster of cognitive processes, sometimes helpful but often misleading. Kahneman notes that thoughts come to mind in one of two ways: Either by orderly computation, which involves a series of stages of remembering rules and then applying them, or by perception, an evolutionary function that allows us to predict outcomes based on what we’re perceiving. (For instance, seeing a woman’s angry face helps us predict the general sentiment and disposition of what she’s about to say.)
It is the latter mode that precipitates intuition. Kahneman explains the interplay: 'There is no sharp line between intuition and perception. … Perception is predictive. . . . If you want to understand intuition, it is very useful to understand perception, because so many of the rules that apply to perception apply as well to intuitive thinking. Intuitive thinking is quite different from perception. Intuitive thinking has language. Intuitive thinking has a lot of word knowledge organized in different ways more than mere perception. But some very basic characteristics [of] perception are extended almost directly to intuitive thinking.'"