School friends may play a major role in a teenager's academic success.

To study the relation between having school friends and academic achievement, researchers studied 629 American students from the 12th grade, who filled out a questionnaire and then kept a record of activities such as time spent studying and time spent with school friends and out-of-school friends.

It was found that students with higher grade-point averages (GPAs) had more school friends than out-of-school friends. The more school friends a student had, higher was the GPA.

The finding could be attributed to the fact that school friends are more likely to be achievement-oriented and share and support school-related activities, including studying, because they all share the same environment.