“generalized trust is highly correlated with intelligence” – They may be holding the wrong end of the stick; I suspect that it would be more correct to say that generalized distrust is inversely correlated with intelligence.
The attraction of conspiracy theories is that they promise “simple, obvious, and wrong” answers to complex questions, which is going to tend to appeal to those who can’t handle complexity. I think the same mechanism will cause folks on that end of the scale to distrust folks who tell them that they’re wrong but present an argument they can’t follow.
