A study involving 629 12th-grade students from three Los Angeles-area high schools has revealed that, across both genders and all ethnicities, adolescents with more in-school friends, compared with out-of-school friends, had higher grade point averages. It’s assumed that this is due to the fact that in-school friends are more likely to support school-related activities, including studying.
(2010). In-School Versus Out-of-School Friendships and Academic Achievement Among an Ethnically Diverse Sample of Adolescents.
Journal of Research on Adolescence. 9999(9999),