“Internal locus of control is a learned skill,” Carol Dweck, the Stanford psychologist who helped conduct that study, told me. “Most of us learn it early in life. But some people’s sense of self-determination gets suppressed by how they grow up, or experiences they’ve had, and they forget how much influence they can have on their own lives. “That’s when training is helpful, because if you put people in situations where they can practice feeling in control, where that internal locus of control is reawakened, then people can start building habits that make them feel like they’re in charge of their own lives—and the more they feel that way, the more they really are in control of themselves.”