No, that's not what they meant. What they mean roughly is that if you were a college student who were interested in signing up for classes in psych, you probabl

No, that's not what they meant. What they mean roughly is that if you were a college student who were interested in signing up for classes in psych, you probably already have some interest in it (and related things), and that interest is what helps you become better (at understanding human dynamics etC). It's not a causal link, just highly correlated.