Well, the theory that people are innately "programmed" to be more cautious and apprehensive in a new, unknown place makes perfectly good biological sense.

But you're right, it doesn't explain persistent hauntings or hauntings in well-known places.

When I move into a new place, I always bless the hell out of it (you can take that literally if you like, though I don't believe in the usual dogmatic hell ), and ward all the entrances and exits. I even go around the perimeter of the property and bless the borders, and set up thoughtform wards periodically around the perimeter. It's just a precaution I like to take.