Chapter 10 – When do Individuals Radicalize?
The German Institute on Radicalization and De-Radicalization Studies gathers together a useful trove of research spanning primarily both European and North American contexts.https://www.sv.uio.no/c-rex/english/
As the name suggests, The Center for Research on Extremism (C-REX) is a powerhouse for research into radicalization, broadly understood. It has particular in-depth strength on the Extreme Right.https://www.start.umd.edu/data-tools/profiles-individual-radicalization-united-states-pirus
As described in Chapter 7 of this textbook (pages 123-4), The PIRUS (Profiles of Individual Radicalization in the United States) database offers a treasure trove of information on over 2,200 individuals in the USA dating back to 1948.