Interpreting “cumulative extremism”: Six proposals for enhancing conceptual clarity

The concept of “cumulative extremism”—described in 2006 by Roger Eatwell as “the way in which one form of extremism can feed off and magnify other forms [of extremism],” has recently gained considerable traction in academic, policy, and practitioner discourses about extremism. Yet in spite of the growing usage of the term, particularly in analyses of the dynamic between extreme Islamist and extreme Right-Wing or anti-Muslim protest groups, there has to date been scant interrogation of the concept itself or of its application. In this article, we make a series of six proposals as to how we might enhance the conceptual clarity of these conversations about “cumulative extremism.” Our aim in doing so is to increase the likelihood that the concept might become a useful addition to the debates on extremism rather than becoming, to borrow a term from John Horgan—something of an “explanatory fiction”—an idea that appears to enable us to explain a great deal, but whose explanatory value is largely lost because there is insufficient scrutiny of the claims that it is used to make and whose liberal application becomes increasingly conducive to poor science.