Persistence and change in structural signatures of tie formation over time

Using data on the formation of Facebook friendships from over 100,000 students at the 1141 four-year colleges and universities in the Department of Education Scorecard dataset, we examine whether students' tendencies to form more open or closed relations (their closure "signature") persist as they leave high school and attend college, and whether this varies by the type of institution attended. Despite significant persistence of individual signature, for the case of Facebook friendships, individuals do tend to adopt the closure signature that characterizes their school. Contrary to expectation, students at more selective colleges are more, not less, likely to form friends with those with whom they share more friends. Yet, at the crucial time of transition to a new school, they form more open ties, due to the tendency of very popular students to reach out to those they generally would not form ties with.