1) Your mind-set makes you smarter: Carol Dweck, the Stanford psychologist, has identified two mind-sets that shape, well, our minds. There’s the fixed mind-set, in which you think your thinking abilities can’t change. Then there’s the growth mind-set, in which your thinking abilities can be developed.
"These beliefs matter," Paul observes, "because they influence how we think about our own abilities, how we perceive the world around us, and how we act when faced with a challenge or with adversity."
The question, then, is how to own our development—which is a matter of deliberate practice.
2) Your concentration makes you smarter: If we consider intelligence to be our ability to solve complex tasks, then we need to appreciate how to deal with complexity—namely, with sustained focus, since that’s the only way we can load difficult problems into our heads.