Steffen Hertog presents his new book, Engineers of Jihad co-authored with Diego Gambetta. In the book, the authors uncover two unexpected facts about violent extremists: they find that a disproportionate share of Islamist radicals come from an engineering background, and that Islamist and right-wing extremism have more in common than either does with left-wing extremism, in which engineers are absent while social scientists and humanities students are prominent.