The Secret History of Poltergeists And Haunted Houses by Claude Lecouteux

Stories of poltergeists and their mischievous and sometimes violent actions–knocking, stone or chair throwing, moving objects with invisible hands, and slamming or opening doors–are a constant through the ages. What changes is how we interpret this activity. For our pagan ancestors this phenomenon was caused by helper spirits whose manifestations revealed their unhappiness with a household. The medieval Christian church demonized these once helpful spirits and held exorcisms to expel them from the houses they haunted–which proved effective less than half the time. The Age of Enlightenment cast these incidents as clever hoaxes, and many still believe this today. But poltergeist manifestations continue to appear and often defy attempts to debunk them as pranks. What then is behind this phenomenon?