Now he had discovered a group—GED holders—whose good test scores didn’t seem to have any positive effect on their lives. What was missing from the equation, Heckman concluded, were the psychological traits that had allowed the high-school graduates to make it through school. Those traits—an inclination to persist at a boring and often unrewarding task; the ability to delay gratification; the tendency to follow through on a plan—also turned out to be valuable in college, in the workplace, and in life generally.
