Self-Discipline Predicts GPA Better Than IQ Among Adolescents

Getting good grades may be a primary concern of both parents and
teenagers.  Grades may reflect learning and the likelihood of getting into a good
college or university.  What predicts and determines GPA is an important
issue. Although intelligence would clearly play some role in achieving a high
GPA, there may other personal factors that could possibly play a larger role.
 Duckworth and Seligman (2005) investigated relations between IQ,
self-discipline, and academic performance among eighth-grade students.  In
their second study, the correlation between their composite self-discipline
measure and final GPA (r = .67) was significantly stronger than the correlation
between IQ and final GPA (r  = .32).  In their second study, they also found
that homework hours was significantly and positively correlated with
self-discipline.  On the other hand, the correlation between IQ and homework
hours was not statistically significant.   Thus, it is possible that self-discipline is
a better predictor of final GPA because it is associated to a greater degree with
the amount of time spent on homework.(1)   However, these correlational
findings do not allow us to make conclusions about cause and effect.  
Nonetheless, because of the possible importance of self-discipline, it may be
good for students to take a course on self-discipline.  For example, the course
on self-discipline could involve avoiding watching television until the
homework is completed.


1.  See their article for other findings.


Duckworth, A. L., & Seligman, M. E. P.  (2005).  Self-discipline outdoes
  IQ in predicting academic peformance of adolescents.  
, 16, 939-944.