Smart? Discipline more important

It's no big revelation to say that discipline, delayed gratification, pays off. But compared to intelligence, how well does it correlate with academic success? More closely than you might think. In a study of middle school students:

Both IQ and self-discipline are correlated with GPA, butself-discipline is a much more important contributor: those with low self-discipline have substantially lower grades than those with low IQs, and high-discipline students have much better grades than high-IQ students. Even after adjusting for the student's grades during the first marking period of the year, students with higher self-discipline still had higher grades at the end of the year. The same could not be said for IQ. Further, the study found no correlation between IQ and self-discipline—these two traits varied independently.