What it means for conspiracy theories to become mainstream In debates about conspiracy theories, it is often claimed that conspiracy thinking is on the rise or has even become mainstream. In this article, I want to explore this claim conceptually, and argue that there are at least three ways to interpret the claim that ‘conspiracy thinking has become mainstream’. First, there is the individual level, where it is a matter of counting heads. Mainstream then means that the majority believes in (...) conspiracy theories. But there are two other levels. There is the institutional level, which is about whether conspiracy theories circulate within social institutions in an acceptable way. Is it acceptable to express conspiracy theories as a politician, scientist or journalist? Mainstream here means that dominant institutions in society view conspiracy thinking as an acceptable form of communication. Finally, there is the cultural level. Here the question is whether conspiracy thinking is a culturally acceptable way of speaking and thinking about society. Is it socially accepted as normal behavior, or is it rather a form of deviant behavior, accompanied by (informal) sanctions or demands for additional justification or proof? Mainstream here means that conspiracy thinking is seen as a normal way of speaking, without being accompanied by strange looks, shunning or the need to justify oneself as a conspiracy thinker. By making this distinction, we can think more clearly about whether conspiracy thinking is actually on the rise, and how we should deal with it. (shrink)