The study analyzed survey data from 3,000 students at 78 schools across the United States and found that classes have a greater impact on friendship formation than sports or other after-school activities.
“Not everybody is in the play,” said Frank. “There are lots of kids who are not in an extracurricular activity. But every kid, every day, is in class for at least five hours—in most cases six or seven.”
The study also found that friendships tend to form in smaller, more unusual classes: in Latin class or band, for example, rather than gym or a geometry course that all students are required to take. Students enroll in these electives because of they’re interested in the subject, which gives them common ground with the other students in the class.
“At that point, we’ve got kind of a little group, a little niche in the school,” said Frank. “We’ve got a set of unusual common interests, so those are very potent potential friends.”
The power of classes to influence friendships has enormous potential for good. Friendships formed in class can offer a refuge from the relentless status-jockeying that characterizes teenage social life: The study found that these friendships tend to have less rigid hierarchies than friendships formed in other ways. These friendships also can help students do better in school. Friends in the same classes are more likely to study together and encourage one another when tackling challenging material. This effect can be particularly useful in encouraging girls to pursue advanced math classes. The same researchers previously found that girls were more likely to pursue challenging math classes if girls in their other shared classes were currently taking high levels of math.
But it has a dark side too, of course. By high school, students are more likely to be placed in classes by ability. Students with good grades and high test scores get assigned AP and honors classes, while struggling students are stuck in regular or remedial courses. Because of the way friendship formation works, there’s potential for teen social life to mirror and even exacerbate the achievement gap within a school. High-achievers hang out with other high-achievers and push each other to even higher achievement. Meanwhile, the struggling students cluster together, possibly compounding each others’ weaker performance.
Awareness, according to Frank, is the key to mitigating the negative effects of courses’ impact on friendship—and to encouraging the positive. Parents need to know that when their children are picking their classes, they’re also picking their friends.
“These friends are going to help you get through school, help you get jobs,” said Frank.
Schools themselves also need to be mindful of the power they have to shape students’ social lives.
“They’re not just assigning kids to academic experiences—they’re assigning them to social experiences,” Frank said. “They need to be very thoughtful about the social implications.”