John Horgan

John G. Horgan, Criminology & Justice Studies, Center for Terrorism & Security Studies, Security Studies

Professor, Director - Center for Terrorism & Security Studies
Health and Social Sciences Building #435


Terrorism & terrorist behavior, forensic psychology, international security studies

Research Interest

Though I am interested in virtually every aspect of terrorism, the main focus of my research is on the psychology of terrorist behavior. I am interested in how people become involved, remain involved, and disengage from terrorist movements. I study these issues across a wide variety of different non-state groups, and I examine these processes from the perspective of the individual militant as well as how the terrorist group and organization manages the processes of recruitment, selection, and disengagement. I am a psychologist by training, and I believe psychology has enormous potential for the study of terrorism. Much of my thinking about terrorist behavior (from the group and organizational perspectives) comes from organizational psychology and social psychology. But rather than solely relying on any one particular theory of terrorism or being bound by any one particular discipline, I’ve read widely literatures from other disciplines, including criminology and sociology.
My research interests travel two distinct but related pathways. I have always been interested in theoretical, conceptual, and methodological issues in the study of terrorism. But in recent years, I have come to realize the immense practical benefit that academic research can have in informing policy development and even operational counterterrorism. I believe it to be an important principle for the social and behavioral sciences to be more applied in this sense, but never at the expense of the rigor we hold dear in our research. I believe researchers can and should be policy-relevant, but non-partisan.
A strong theme that runs through my research is the need for us to rely on evidence from data. Much of what is said about terrorism continues to be opinion-driven, but social science I believe has enormous potential in this area of study. I have long encouraged the development of first hand-research, having realized the benefits of conducting rigorous, ethically sound and safe, first-hand research with those who have disengaged from terrorist movements.
Right now, I am conducting further research on how people disengage from terrorist groups. I am also working on a project that seeks to understand the development of so-called “lone wolf” terrorists. I am also looking deeper into some of the psychological mechanisms that help understand how those involved in terrorist groups transfer guilt and manage “double” lives.

Educational Background

Ph.D. and B.A. in Applied Psychology from University College, Cork


John Horgan is Professor of Security Studies at the School of Criminology and Justice Studies of the University of Massachusetts Lowell where he is also Director of the Center for Terrorism & Security Studies. An applied psychologist by training, his research focuses on terrorist behavior. He has over seventy publications on terrorism and political violence, and his books include The Psychology of Terrorism, Walking Away from Terrorism, Leaving Terrorism Behind, and Terrorism Studies: A Reader. His latest book Divided We Stand: The Strategy and Psychology of Ireland’s Dissident Terrorists was published by Oxford University Press in 2013. He is Special Editions Editor of Terrorism and Political Violence, Associate Editor of Dynamics of Asymmetric Conflict, and sits on the Editorial Boards of several further journals, including Studies in Conflict and Terrorism and Journal of Strategic Security. Professor Horgan is also a member of the Research Working Group of the FBI’s National Center for the Analysis of Violent Crime. Professor Horgan has previously held positions at Penn State University (as Director of the International Center for the Study of Terrorism from 2007-2013), the University of St. Andrews, UK, and University College, Cork, Ireland. His research has been featured in such venues as The New York Times, CNN, Rolling Stone Magazine, and the Chronicle of Higher Education

Selected Publications

  • Gill, P., Horgan, J., Cushenbery, L., and Hunter, S. (2013). ‘Malevolent Creativity in Terrorist Organizations’. Journal of Creative Behavior, 47 (2) 125-151.
  • Horgan, J. (in press). The Psychology of Terrorism 2nd Ed. London: Taylor and Francis.
  • Horgan, J. (2013). Divided We Stand: The Strategy and Psychology of Ireland’s Dissident Terrorists. New York: Oxford University Press.
  • Horgan, J. and Altier, M.B. (2012). ‘The Future of Terrorist De-Radicalization Programs’, Georgetown Journal of International Affairs, Summer/Fall, 83-90.
  • Horgan, J. (2012). ‘Interviewing the Terrorists: Reflections on Fieldwork and Implications for Psychological Research’. Behavioral Science of Political Aggression and Terrorism 4(3), 195-211.