Will not want: Self-control rather than motivation explains the female advantage in report card grades

• Teachers surveyed believe that girls exceed boys in both motivation and self-control.
• We test motivation and self-control simultaneously as predictors of course grades.
• Self-control mediated the relation between gender and grades.
• Motivation did not differ between boys and girls and did not predict grades.

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 that 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.