Researchers have long found that a large number of violent terrorists come from engineering backgrounds. Recently, social scientists Diego Gambetta and Steffen Hertog looked at a data set of almost 500 violent Islamist extremists dating back to the 1970s, and were able to confirm the correlation between engineering education and terrorism. Violent neo-Nazis and neo-Stalinists in Russia as well as neo-Nazi and white-supremecist groups in the US also had high numbers of engineers.