This is a spirit, usually mischievous and occasionally malevolent, which manifests its presence by making noises, moving objects, and assaulting people and animals. The term "poltergeist" comes from the German poltern, "to knock," and geist, "spirit." Some cases of poltergeists that remain unexplained and may involve actual spirits. In other cases the phenomena may be produced by subconscious psychokinesis (PK) on the part of an individual.
Included in the most common types of poltergeist activities are the rains of stones, dirt, and other small objects; moving or throwing of objects, including large pieces of furniture; loud noises and shrieks; and vile smells. It seems that poltergeists have adapted to the development of technology. They are known to have caused interference in telephones and electronic equipment, and turning lights and appliances on and off. Some poltergeists are said to pinch, bite, hit, and sexually attack the living.
Generally poltergeist activity starts and stops abruptly. The duration of it may extend over several hours to several months; however, some cases have been reported to last over several years. The activity almost always occurs at night when someone is presence. Typically this is the "agent," an individual who seems to serve as a focus or magnet for the activity. In most cases the agent is a factor, both those that seem paranormal or that may be caused by human PK. The agent is usually female and under the age of twenty.
Poltergeist disturbances have occurred globally since ancient times. In the late 1970s parapsychologists Alan Gauld and A. D. Cornell did a computer analysis of those cases collected since 1800 to that time. They identified sixty-three general characteristics, which include the following: 64 percent involved the movement of small objects; 58 percent were most active at night; 48 percent featured raps; 36 percent involved movement of large objects; 24 percent lasted longer than one year; 16 percent featured communication between the poltergeist and agent; 12 percent involved the opening and shutting of doors and windows.
Before the 19th century, poltergeist activity was blamed on the Devil, demons, witches, and ghosts of the dead. The Gauld-Cornell analysis found only 9 percent of the cases attributed to demons, 7 percent to witches, and 2 percent to spirits of the dead. Most of the demon and witches attributions occurred in non-Western countries. Poltergeist activity at sťances was attributed to spirits of the dead.
The development and increase of psychical research during the late 19th and early 20th centuries helped confirm the conviction that poltergeist activity was genuine. Among the early investigators were two founders of the Society for Psychical Research, Sir William Barrett and Fredric W. H. Meyers. Meyers believed in the genuineness of poltergeist activity and that it was distinguishable from ghost hauntings.
In the 1930s the psychologist and parapsychologist Nandor Fodor advanced the theory that some poltergeist disturbances were caused not by spirits but by human agents suffering from intense repressed anger, hostility, and sexual tension. Fodor successfully demonstrated his theory in several cases, including the most famous "Thormton Heath Poltergeist" in England, which he investigated in 1938. The case involved a woman whose repressions caused a poltergeist outbreak and apparently a vampire attack. The Spiritualists severely criticized Fodor, but he won a libel suit against a Spiritualist newspaper.
William Roll, project director of the Psychical Research Foundation in Durham, North Carolina, further explored this psychological dysfunction theory. Starting in the 1960s, Roll studied 116 written reports of poltergeist cases spanning over four centuries in more one hundred countries. Roll identified patterns that he labeled "recurrent spontaneous psychokinesis" (RSPK), which are inexplicable, spontaneous physical effects. Generally, he discovered, the most common agent was a child or teenager whose unwitting PK was a way of expressing hostility without the fear of punishment. The individual was not aware of being the cause of such disturbances, but was, at the same time, secretly or openly please that they occurred.
Other investigators have also investigated agents finding that those in poor mental and physical health are vulnerable to stress. Patient having unresolved emotional tensions have been associated with houses where poltergeist activity occurred. When studying the personalities of agents psychologists found anxiety reactions, conversion hysteria, phobias, mania, obsessions, dissociative reactions, and schizophrenia. In some cases therapy eliminated the poltergeist activity.
However, the psychological dysfunction theory has been disputed by other researchers, including Gauld and Cornell who said the psychological tests employed were invalid. Psychiatrist Ian Stevenson proposed that spirits of the dead may account for more poltergeist activity than realized. In his study of a number of cases attributed to agents and to spirits of the dead, Stevenson noted significance differences. The phenomena in living agent cases was without purpose and often violent, while cases involving spirits of the dead featured intelligent communication, purposeful movement of objects, and little violence.
Poltergeist activities have been reported in many countries, and chronicled by occult writers such as A. R. G. Owen and Colin Wilson. The Epworth Poltergeist case is one of the best-documented cases of poltergeist activity.