The underpants bomber was an engineer. So were eight of the 25 terrorists involved in 9/11. In fact, half of all known "violent jihadists" reach higher education, and 44 percent of them are engineers. Uh, that looks like a pattern.
Even though engineers are obviously highly prized by terrorist recruiters for their skills, the reason, according to Diego Gambetta and Steffen Hertog writing in New Scientist is that they tend to have a more rigid, conservative mindset, and at least in Middle Eastern countries, there've been fewer jobs for them, so more of them have gone radical.
All of the engineers I know are just alcoholics. [Sphere]