As students head to college at the beginning of the year, the formation of friendships becomes important. A story on NPR discusses the proximity effect in the creation of friendship ties.

“Several sociology studies, some going back decades, point to this proximity or “distance” effect. In Sacerdote’s own research, he studied e-mail exchanges among students on his campus. The e-mails were stripped of personal identification and content, as he was only looking to analyze the volume of e-mails.”

To see the full story, click here.