Social scientist and author Damon Centola is an associate professor at the Annenberg School for Communication and the School of Engineering and Applied Sciences at the University of Pennsylvania. Centola's work focuses on how information is transmitted and how behaviors are changed or adopted and reinforced through contacts with multiple members of our social network. KSFR's Ellen Lockyer spoke with Centola on today's Wake Up Call, about his research and about his new book, "How Behavior Spreads, the Science of Complex Contagions."