We linked this intelligent article this week: The Lethal Cocktail of Terrorism: The Four Necessary Ingredients that Go into Making a Terrorist.
One minor problem with it: she omits the power of religious conversion and religious fervor.
Another "minor" problem with it: She mostly neglects the destructive aspects of people, as if "normal" people had no destructive, wicked, or evil impulses. They do. Unleashed, the dark side can be a terrible thing. That is not news, and Jihadism offers many rationales for behavior that Western Civ. finds abhorrent today. These people did not buy into the historical arc of Western Civ. and perhaps never will.
One major problem with it: Many behaviors and choices of youth can be explained in similar terms so I see nothing specific to joining Jihad here. Similar motives could turn a suburban kid into a stoner Grateful Dead groupie.
The problem is that you can psychologize anything - after the fact. That is not a weakness of Psychology, but, instead, a statement about the complexity of human nature and human cultures.