If someone believes the lunar landing was a hoax, that person must have a mental illness, or so it was once thought. However, the prevalence of belief in conspiracy theories - ranging from 9/11 to John F. Kennedy's assassination - is so extensive that a new discipline has emerged to take a deeper look. It is called conspiracy theory psychology

So what psychological characteristics lead to a general belief in conspiracies? According to a 1999 study led by researchers at New Mexico State University, the strongest predictor is a "lack of trust." 

"People low in trust of others are likely to believe that others are colluding against them," the authors concluded. 

A later study led by a team at the University of Westminster drew similar conclusions, and also linked belief in conspiracies to "political cynicism."

The extreme form of distrust and cynicism can lead to paranoia. The milder form is the much more common cognitive bias known as the "fundamental attribution error." This bias leads us to attribute peoples' behavior to personality traits while excluding the importance of chance as well as situational factors. 

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