The same facts that make people into Neo Nazis or Jihadists.
Not much difference there -- Eric Hoffer's True Believer. The shared fanaticism reflects the hollowness of their beliefs. Extreme positions take far less to learn (those are almost theatrical stereotypes) than do moderate ones. I have heard of neo-Nazis becoming Jihadists.
Youth is often a frustrating time. Most young adults who have jobs are overworked and underpaid, but working in roles too small for their spirits. If they can't establish a family life as compensation, they can get very lonely very fast. Extremists of all kinds offer simple solutions that offer meaning in life that working poverty cannot. If one is disconnected from the kinship network one may even get a surrogate family that offers much that a family offers.
That is quite true indeed. I can relate. Of course, Neo nazis and Jihadists are socially reactionary by definition especially regarding Jews.
