The human being is a funny old creature and the power of the mind is something that is greatly overlooked. How much effect can sub conscious thoughts have on you during a paranormal investigation?
Do you consider yourself open to suggestions? Person A suggests to Person B that a house is haunted. Will person A be that type of person that will instantly start to think that they see or hear things? Even if you believe you are not a suggestible kind of person you would be surprised the amount of information you store, without even realising. In years to come a piece of information you picked up from somewhere might pop back in there and lead you to take a certain course of action.
You are going into a haunted house! Leading on from suggestibility we come to expectation. As above the expectations may be planted via a suggestion, or you may just be a naturally expectant person! The expectation of something happening can lead very easily to something happening. For example, you have heard that people hear disembodied voices in the building. Wind suddenly whistles past the window and you swear you hear a voice. If you weren’t expecting this, would you have heard differently?
I have noticed a very very high level of expectation from people who attend public ghost hunts. They have seen Most Haunted, Ghost Hunters etc etc and they expect that in every place something paranormal will happen. It’s only a matter of time till a random squeaky floorboard or wind whistle has them jumping out of their skins.
Well, you can’t beat a bit of imagination! But when it comes to the paranormal it can all go wrong. You see a photo with an ‘orb’ on it, the orb has a face! OMG it’s a spirit. You see a shadow move across the corner of the room! OMG it’s a demonic entity. Or, it could quite easily be (and more likely be) you seeing faces in shapes that aren’t there and your eyes not working very well in the dark. Because our eyes don’t work in the dark, hopefully you’ve noticed that. Stand in a darkened room for long enough and you start seeing all manner of goodies. None of them proof of the paranormal.
Unfortunately this is what makes paranormal investigations woolly. The human being. As in the ways mentioned we can be flawed when it comes to open mindedness and freedom from influence.