“System 1 is powerful because it draws on our accumulated years of experience and our deep emotions. System 1 gives us the survival reflex in moments of danger, and the astonishing deftness earned through thousands of hours of deliberate practice in a chosen field of expertise. In the interplay between Systems 1 and 2—the topic of Malcolm Gladwell’s book Blink—your instantaneous ability to size up a situation plays against your capacity for skepticism and thoughtful analysis. Of course, when System 1’s conclusions arise out of misperception or illusion, they can steer you into trouble. Learning when to trust your intuition and when to question it is a big part of how you improve your competence in the world at large and in any field where you want to be expert. It’s not just the dullards who fall victim. We all do, to varying degrees. Pilots, for example, are susceptible to a host of perceptual illusions. They are trained to beware of them and to use their instruments to know that they’re getting things right.”