A growing body of research shows that our IQ can increase over time, and in fact, research on growth mindset by Stanford psychologist Carol Dweck shows that our beliefs about intelligence can actually affect our effort, and in turn, our performance.

It’s common to think of intelligence as something that you’re simply born with. Some people, after all, make being smart look effortless.

Intelligence isn’t a set trait, though. It’s a changeable, flexible ability to learn ...