From the New York Times:

Who Will Become a Terrorist? Research Yields Few Clues By MATT APUZZO MARCH 27, 2016 WASHINGTON — The brothers who carried out suicide bombings in Brussels last week had long, violent criminal records and had been regarded internationally as potential terrorists. But in San Bernardino, Calif., last year, one of the attackers was a county health inspector who lived a life of apparent suburban normality. And then there are the dozens of other young American men and women who have been arrested over the past year for trying to help the Islamic State. Their backgrounds are so diverse that they defy a single profile.

What turns people toward violence — and whether they can be steered away from it — are questions that have bedeviled governments around the world for generations. Those questions have taken on fresh urgency with the rise of the Islamic State and the string of attacks in Europe and the United States. Despite millions of dollars of government-sponsored research, and a much-publicized White House pledge to find answers, there is still nothing close to a consensus on why someone becomes a terrorist.

“After all this funding and this flurry of publications, with each new terrorist incident we realize that we are no closer to answering our original question about what leads people to turn to political violence,” Marc Sageman, a psychologist and a longtime government consultant, wrote in the journal Terrorism and Political Violence in 2014. “The same worn-out questions are raised over and over again, and we still have no compelling answers.”

When researchers do come up with possible answers, the government often disregards them. Not long after the attacks of Sept. 11, 2001, for instance, Alan B. Krueger, the Princeton economist, tested the widespread assumption that poverty was a key factor in the making of a terrorist. Mr. Krueger’s analysis of economic figures, polls, and data on suicide bombers and hate groups found no link between economic distress and terrorism.

More than a decade later, law enforcement officials and government-funded community groups still regard money problems as an indicator of radicalization. When President Obama announced plans in 2011 to prevent homegrown terrorism, the details were sketchy, but the promise was clear. The White House would provide warning signs to help parents and community leaders. “It’s going to be communities that recognize abnormal behavior,” Denis McDonough, the deputy national security adviser at the time, said. As an example, he cited truancy, which he said was an indicator of possible gang activity. “Truancy is also going to be an early warning sign for violent extremism,” he said. But the years that followed have done little to narrow the list of likely precursors. Rather, the murky science seems to imply that nearly anyone is a potential terrorist. Some studies suggest that terrorists are likely to be educated or extroverted; others say uneducated recluses are at risk. Many studies seem to warn of the adolescent condition, singling out young, impatient men with a sense of adventure who are “struggling to achieve a sense of selfhood.”

Europe, too, is grappling with these questions, but there is no clear answer.

Hey, over here! I’ve got a clue.I know it sounds crazy, but I’ve thought of a factor that ties together all the terrorist incidents mentioned in this article. I’ll admit, nobody paid me millions of dollars for my clue, but still …Granted, I don’t have a big consulting contract like the Beltway Bandits, but I do have a clue.I can think of a demographic factor that correlates with 9/11, Brussels, San Bernardino, etc. etc.What, oh, what could be the common factor?If only somebody had a clue about what might unite Brussels, Charlie Hebdo, and last fall’s Paris slaughter …