What Do "Intelligence Tests" Really Measure?

(...) Seeing yourself as such can be poisonous: Think of the public intellectuals who embarrass themselves by straying far from their area of expertise. Think of the smart people who twist logic in impressive ways to convince themselves of crankish ideas. Think of, say, a man who has had great success in business, who decides that means he must be equally good at cutting government bureaucracy. One of the cruelest things about the genius myth is that its sufferers cannot understand their failures: I’m so clever. I can’t possibly have screwed this up. I prefer to talk about moments of genius: beautiful paintings, heartbreaking novels, inspired military or political decisions, scientific breakthroughs, technological marvels. (...)