Research by Stanford psychologist Carol Dweck reveals that people subscribe to one of two theories about the nature of ability. Entity theorists believe that their abilities are fixed and, more often than not, innate. They expect their performance to be relatively stable. In other words, you have just so much intelligence (or creativity, or charm), and there isn’t anything you can do about it. (They are, incidentally, wrong. Ability doesn’t work that way.) Incremental theorists, on the other hand, believe that ability is malleable —that it can and does change with effort and experience. And according to the evidence, they are perfectly right. You can get more ability if you want more. All you need is grit.