Dr. Andrew J. Hill, a Californian economics professor who studied 20,000 students, found that having no friends of the opposite sex at high school can make you smarter. The study, titled “The Girl Next Door: The Effect of Opposite Gender Friends on High School Achievement”, putlished in the American Economics Association Journal, states:

This paper finds that a student’s share of opposite gender school friends negatively affects high school GPA. It uses the gender composition of schoolmates in an individual’s neighborhood as an instrument for the gender composition of an individual’s self-reported friendship network. The effect occurs across all subjects for students older than 16, but only in mathematics and science for younger students. Additional results indicate effects may operate inside the classroom through difficulties getting along with the teacher and paying attention, and outside the classroom through romantic relationships.

The study compared answers about the friendship groups of children from more than 80 schools in a large-scale study from the mid-1990s. The results showed a strong correlation between being friendly with the opposite sex and doing worse in class.

Thd data, dubbed the National Longitudinal Study of Adolescent to Adult Health, founds that students who had “trouble paying attention in class” and “trouble getting along with the teacher” were likely to have more friends from the opposite sex. These students were also more likely to have troubles outside the classroom.

CLICK HERE for the full study.