I would challenge anyone who doubts that some of this could happen (note I say some) to talk with Anthropologists who have spent time in Africa. Whether its blind faith (aka a mind trick) or "something else", there is significant evidence that witches and witch doctors actually do things to people - heal, curse, etc.

We ultra-rationalists in the West want to believe that there is nothing outside our understanding, but that is only faulty logic. We don't have a clue for how little we understand about the world. Who could have predicted the near collapse of our financial system a mere 18 months ago, but that is what we are living through today. Its not rational, nor do our markets behave rationally.