College Friendships and Social Networks

The Internet has made it easier than ever for people to keep in touch with other people. Now, e-mail messages are becoming a tool for studying social networks—who knows whom—and how the relationships that people form throughout their lives change over time.

In the Jan. 6 Science, Gueorgi Kossinets and sociologist Duncan Watts of Columbia University describe a study in which the researchers analyzed 14,584,423 messages exchanged by 43,553 students, faculty, and staff at a large university over the course of a year.