ProphetofOccam
Paranormal Adept
Interesting discussion. Can you cite these "several studies" you are using as a reference please? I'd like to have a closer look at them.
The wikipedia article on conspiracy theory does a pretty decent job of categorizing and explaining all of the accepted psychological roots for conspiracism with footnoted links to some studies and articles that can direct you to studies.
"Clinical psychology" and "Socio-political origins" possibly being the most relevant, but it's all connected to the same idea.
The most interesting summarization comes from the Socio-political origins section:
Conspiratorial accounts can be emotionally satisfying when they place events in a readily understandable, moral context. The subscriber to the theory is able to assign moral responsibility for an emotionally troubling event or situation to a clearly conceived group of individuals. Crucially, that group does not include the believer. The believer may then feel excused of any moral or political responsibility for remedying whatever institutional or societal flaw might be the actual source of the dissonance.[38] Likewise, Roger Cohen, in an op-Ed for the New York Times propounded that, "captive minds... resort to conspiracy theory because it is the ultimate refuge of the powerless. If you cannot change your own life, it must be that some greater force controls the world."[39]
EDIT: I found one that was interesting last night, but, for some reason, I couldn't access the forums.
The Determinants of Belief in Conspiracy Theories by Scott Radnitz :: SSRN
You'll have to download it, and it's pretty long, but if you read the entire thing, it's interesting.