With what populations have the studies been conducted?
First, if all the participants have been American, this is likely not applicable across the earth. I have lived in both Asia and the US, I'd say that on average Americans express significantly more self-confidence than those in Asia (whose customs tend to value humility and self-deprecation. And they tend to do so, at least to other people.).
Second, if the populations have mostly been students at universities like Chicago and Virginia. They are far from average people. Youths could be more optimistic. Those in good universities might have been exposed to the good sides of things much more than most people. Their academic success could stem from their optimistic outlook and vice versa. And so on...
Psychology needs to diversify from studying Americans, esp. students in good American colleges.
First, if all the participants have been American, this is likely not applicable across the earth. I have lived in both Asia and the US, I'd say that on average Americans express significantly more self-confidence than those in Asia (whose customs tend to value humility and self-deprecation. And they tend to do so, at least to other people.).
Second, if the populations have mostly been students at universities like Chicago and Virginia. They are far from average people. Youths could be more optimistic. Those in good universities might have been exposed to the good sides of things much more than most people. Their academic success could stem from their optimistic outlook and vice versa. And so on...
Psychology needs to diversify from studying Americans, esp. students in good American colleges.