Two systems in one mind

Kahneman, a psychologist who won the Nobel Prize in economics, describes the mind as two characters. System 1 is fast, automatic and intuitive. It reads faces and jumps to conclusions without effort. System 2 is slow and deliberate. It does sums and checks arguments, but it tires easily and is often lazy.

System 1 answers quickly even when it is wrong, and System 2 usually accepts the answer. Asked what a ball costs if a bat and ball cost a dollar ten together and the bat costs a dollar more, most people say ten cents. The answer is five. System 1 also builds a tidy story from whatever it sees and ignores what is missing, which Kahneman calls what you see is all there is.