DIANE VAUGHAN is professor of sociology and international and public affairs at Columbia University. She is the recipient of a Guggenheim Fellowship and the author of Controlling Unlawful Organizational Behavior: Social Structure and Corporate Misconduct, Uncoupling: Turning Points in Intimate Relationships, and The Challenger Launch Decision: Risky Technology, Culture, and Deviance at NASA, as well as numerous articles in a variety of academic publications.