I used to dowse for answers to a lot of things, like food allergies, gender of baby for a pregnant friend, lottery numbers, you name it, lol! I think a lot of it has to do with our own subconscious, and if you believe that thought creates energy, then that would probably explain a lot of the dowsing mechanism. What I was trying to say really, without everything else clouding the issue, is that the dowsing item is the medium through which energy travels, and even if you are not actually or consciously thinking about something, your subconscious mind would. Another explanation would be, that since everything is surrounded by electro magnetic fields, an item like a needle would rotate in either directions depending on the charge, although it may not explain the crystals, unless you believe that crystals also respond to electromagnetic fields.