Conspiracy theories

No.11827610 ViewReplyOriginalReport
What's the fundamental explanation for belief in unsubstantiated conspiracy theories? Why are they almost always tightly clustered? (Obviously many real conspiracies occur and become documented. I just mean unsubstantiated/untrue allegations of conspiracies, which are the majority that are propagated.)

I know why they're so common on 4chan (such beliefs typically result in ostracization from normal society so they can only freely share them anonymously), but how do they come to be in the first place?