It may never be possible to explain why some people construct conspiracy theories and others don’t, not necessarily because the reasons are so obscure but because they are so many. People prone to conspiracy modes don’t comprise a distinct grouping, as common experiences often reveal the perfectly normal person we are sharing a cocktail or plane ride with suddenly rolling out a grassy-knoll scenario for the latest catastrophe. Or just as plausibly, the person who chronically suspects the FBI of nefarious deceitfulness is vindicated in the cases of the falsely accused Richard Jewel in the Atlanta Olympics bombing or of Wen Ho Lee in the Alamosa atomic secrets fiasco.
Dan Dervin (2000) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: