Re: Why folks believe in conspiracy theories.
Good to see a higher end discussion taking place here.
For another insight into why we think like we do, read "THE DRUNKARD'S WALK: How Randomness Rules Our Lives" by Leonard Mlodinow (no, don't ask me how to pronounce it).
It does not deal with conspiracy theories per se, but is a fascinating look into how we make what we believe to be informed decisions, which in many cases are "informed" only by our lack of understanding of logic and probability.
Not an overly dry or heavy read. Guy does a great job of making and illustrating points. Highly recommended.