Despite these differences, one of the most robust findings in the research on conspiracy theories is that there is a commonality to conspiracy theorists, even if the theories themselves are different. For instance, people who believe in the shape-shifting reptilian are much more likely also to doubt that Lee Harvey Oswald acted as a lone wolf. Indeed, those who believe that Osama bin Laden was dead before the Navy Seals shot him are also more likely to consider it plausible that bin Laden is still alive. This has led many researchers to conclude that the agreement with specific conspiracy theories is not so much dependent on the specific topic, but is rather the manifestation of a more general worldview.

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Most blame the conspiracy mentality on a sense of profound lack of control in their lives, whether due to randomness or the machinations of others. In one study, research participants who were asked to remember instances over which they had no control, such as the weather, were more likely to accept a conspiracy theory than those who were asked to remember instances in which they do have control (eg what they wear or eat). In a similar vein, survey respondents who faced working conditions with reduced levels of control (eg long-term unemployment, temporary employment) expressed greater levels of a conspiracy mentality than those who had more control (eg permanent employment). The rationale behind this is that lacking control increases the need to engage in the compensatory illusion of control—that is, in conspiracy theories. Detecting patterns where there are, in fact, none at least leaves open the possibility of gaining control, whereas the attribution of, say, a natural disaster to unchangeable and uncontrollable weather dynamics does not.

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Belief in conspiracies can serve to set oneself apart from the ignorant masses—a self-serving boast about one’s exclusive knowledge. Adherence to conspiracy theory might not always be the result of some perceived lack of control, but rather a deep-seated need for uniqueness.

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In other words, those with a conspiracy mentality were more likely to believe less popular theories, perhaps suggesting that the ‘exclusivity’ of the belief is the very commodity they seek.

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The ultimate litmus test for a causal effect in psychology is an experiment.

So we invented a conspiracy theory from scratch. We asked US participants to read about an entirely fictitious debate unfolding in Germany. ... Our hypothesis was that those with a higher conspiracy mentality (already correlated with a higher need for uniqueness) were more likely to endorse the conspiracy when finding out that fewer people believed in it than when they found out that many people believed it. And that’s exactly what our study showed. The new conspiracy seemed to be more attractive if it was a minority opinion. It set them apart from the masses.