John Horgan is Director of the International Center for the Study of Terrorism at the Pennsylvania State University, where he is also Associate Professor of Psychology. Author of more than sixty publications, he is a leading expert on the psychology of terrorism. His books include The Psychology of Terrorism (2005), The Future of Terrorism (1999, with Max Taylor) and Walking Away from Terrorism: Accounts of Disengagement from Radical and Extremist Movements (2009).

Kurt Braddock is a Doctoral candidate in Communication Arts and Sciences at the Pennsylvania State University, where he is also a Graduate Research Assistant at the International Center for the Study of Terrorism.