What makes a terrorist?

According to most things I've read, including this article, and contrary to most received wisdom, it isn't poverty or lack of education that causes people to become terrorists. As with revolutionaries more generally, they tend to be at least middle class and also fairly well educated types who feel that something significant has been taken away from them, whether that be wealth, status, prestige, or whatever.

http://www.american.com/archive/2007/november-december-magazine-contents/what-makes-a-terrorist