RESUMEN
Girls earn better grades than boys, but the mechanism explaining this gender difference is not well understood. We examined the relative importance of self-control and motivation in explaining the female advantage in grades. In Study 1, we surveyed middle school teachers and found they judged girls to be higher in both school motivation and self-control. In Studies 2 and 3-using self-reported motivation and teacher- and/or parent-reported self-control, and quarterly and final grades obtained from school records-we find that self-control, but not school motivation, helps to explain the gender gap in academic performance. In these studies, girls appeared to be more self-controlled than boys, but-contrary to teacher judgments in Study 1-did not appear to be more motivated to do well in school.