This video answers the question: Why are conspiracy theories illogical from a personality perspective? There are a wide variety of conspiracy theories including: vaccinations, global warming, chemtrails, flat earth, no moon landing, area 51, cure for cancer being suppressed, and elite lizards (shape-shifting aliens) who seek world domination. Some conspiracy theories turned out to be supported by evidence like the CIA testing LSD on Americans and the government monitoring communications around the world. Many people believe in one or two conspiracy theories, but many conspiracy theorists believe in dozens. All conspiracy theories share one thing in common: large numbers of organized, evil people conspiring to cause harm. People may believe in conspiracy theories for many reasons, some of which have no relationship to personality and mental health. Others may tend to find meaning from randomness and believe it affects them personally (ideas of reference). We also see a tendency to hold odd beliefs and to have magical thinking. At a subclinical level, these traits align with schizotypy. Many conspiracy theorists feel uncertain, insecure, anxious, powerless, and isolated.
Why would conspiracies fail? People aren’t good at conspiring, especially in the long run when the stakes are high. Some traits associated with deliberately or inadvertently revealing the truth are high altruism, low conscientiousness (not being careful), high neuroticism (impulsivity), high extraversion (talkative), narcissism (fantasy, jealously, lack of empathy, admiration), high adventurousness, and substance use.
Grimes, (2016), On the Viability of Conspiratorial Beliefs. PLOS ONE 11(3): e0151003. https://doi.org/10.1371/journal.pone.0151003
Douglas, K. M., Sutton, R. M., & Cichocka, A. (2017). The Psychology of Conspiracy Theories. Current directions in psychological science, 26(6), 538-542.