This is not true in my experience. It's just as likely that someone's "intelligence" in one area gives them a false sense of their ability to understand other

This is not true in my experience. It's just as likely that someone's "intelligence" in one area gives them a false sense of their ability to understand other areas. They'll jump into some unrelated or semi-related area, learn a little, and quickly act as if they understand it as well as the understand their main area of expertise. This is especially true if the new area is something they're peripherally familiar through everyday experience. I'm a teacher, so teaching comes to mind, here. Everyone has opinions about teaching and learning because everyone spent 15-20 years of their life doing it. Intelligent people often act as if Understanding of Area A + Familiarity with Area B = Understanding of Area B But as Hegel said, "The familiar is not understood precisely because it's familiar." See also: every thread ever on HN about law, politics, race, or gender. In my experience, one's ability to develop expertise in many fields has much more to do with one's temperament. Most people I've met who who are able to do this live in a kind of visceral, mortal fear that they might believe something that isn't true. They're more likely to see certainty (in others as well as themselves) as a symptom of utter, hopeless confusion than as a symptom of understanding. Blah blah anecdotes, yadda yadda caveats.