In 2001, during my 23-year stint as an FBI special agent, my colleagues and I looked into what Kaczynski, McVeigh and Rudolph had in common. The results were startling. All three were highly intelligent and well educated, with no previous history of criminal violence. But they all shared a profound inability to forge meaningful relationships.

― Beware the lone wolf radicals - health - 04 September 2011 - New Scientist