From the article:
“What’s powerful about these pairs is that they increase capacity for doing damage but not the vulnerability to detection, because of the tightness of the tie,” said Clark McCauley, a research professor at Bryn Mawr College who has studied radical groups. “It’s a creative solution; you get more hands to help than a lone wolf, but the same kind of security.”
McCauley has also been called on for comment recently by Mashable and The Psychology of Everything.
McCauley's research interests include stereotypes, group dynamics, intergroup conflict, and the psychological foundations of genocide and terrorism. He is a consultant and reviewer for the Harry Frank Guggenheim Foundation for research on dominance, aggression, and violence, and a principal investigator of the National Consortium for Study of Terrorism and Responses to Terrorism (NC-START). With Dan Chirot, he is author of Why Not Kill Them All? The Logic of Mass Political Murder and Finding Ways of Avoiding it. With Sophia Moskalenko, he is author of Friction: How Radicalization Happens to Them and Us. He is founding editor of the journal Dynamics of Asymmetric Conflict. McCauley received his Ph.D. in social psychology from the University of Pennsylvania in 1970.