Coady, David. 2007. “Are Conspiracy Theorists Irrational?” Episteme: A Journal of Social Epistemology 4 (2(Special Issue: Conspiracy Theories)): 193–204.
Kurtis Hagen (2018) “Conspiracy Theories and the Paranoid Style: Do Conspiracy Theories Posit Implausibly Vast and Evil Conspiracies?”, Social Epistemology, 32:1, pp. 24-40. Hagen argues that the answer to the question is “no” and that each conspiracy theory must be judged on its own merits.
Saslow, Eli (2018). Rising out of Hatred: The Awakening of a Former White Nationalist. New York City: Doubleday. (This is the story of Derek Black.)