It's true, I shouldn't lump all cases into my personal critical paradigm of sexual abuse, religious trauma or mental health mislabeled as 'paranormal.' But in the prominent cases I've read about in North America those themes seem to be repeating. I have not read the German figures in the field, but I'd be curious to know the role of those other issues in my questions above in prominent cases from the investigators you cite.
"Poltergeist" may be a german term, but there are actually relatively few prominent cases here in Germany (the actual number is probably much higher, but I'll get to that). Like UFO sightings and other paranormal claims, poltergeist cases are as a rule ridiculed in the media and considered hoaxes or possible mental problems by people who are just imagining things. I guess you might like that about my country.
The most prominent german case was the "Rosenheim Poltergeist" which took place in an attorney's office in 1967. I guess it's interesting enough to warrant a thread of its own, so I'll just say that it has never been "solved" although debunkers claimed to have found proof for a hoax. The case was declared genuine by Germany's only official, university-based parapsychologist, Hans Bender.
Hans Bender - Wikipedia, the free encyclopedia
Bender was a psychologist who investigated several alleged haunting and poltergeist cases. He would always start by getting psychological profiles first, to exclude schizoid and paranoid delusions. In the Rosenheim case, he identified the focus person, a 19 year old girl. Bender 's psychological profile described her as having an unstable character and low frustration tolerance (she tended to get a temper really fast), but there was no sign of mental illness, religious fanaticism or involvement with the "occult".
The case itself was unuasual in that it consisted mainly of electrical phenomena (phones ringing, numbers being dialled, unexplained high voltage, lightbulbs exploding), no rapping or "direct voices", but a few moving objects. One was even filmed, but I guess I'll expand on that in a thread of its own. What I guess is important here: there never was any religious figure or "alternative worldview" involved, there was no occult interest or strict religious background with the focus person. And the main events only occured in the office. There seem to have been minor events following the girl to her next workplace and even to her spare time activities (a bowling machine is said to have been affected), but it seems those were never as pronounced as the 1967 events.
Another "infamous" case Bender was involved with had happened two years earlier. Unfortunately, I couldn't find much on it, but it seems to have happened around a 14 year old boy who had a job in a porcellain shop (of all places). Like the Rosenheim case, this was later said to have been debunked as a hoax, but it turned out that a news reporter had given the boy a substantial amount of money for his "confession". In any case, there doesn't seem to have been any occult or religious connection there, either. The media would have seized that immediately.
In the 1980s, Germany's only parapsychological department at a University was closed down permanently (Lloyd Auerbach in his recent interview said that the same happened in U.S. universities at about the same time, I guess that's no coincidence). Bender's successor, Walter von Lucadou, continues his work to this day, by heading the now privately funded Institute for fringe areas of psychology and psychohygienics (the latter word meaning "mental health theory"), which is concerned with people who seek help with problems with the occult and mental problems. It's the go-to institute if your kids have problems following a traumatic ouja-board experience etc.
Von Lucadou, who holds doctorates in psychology and physics, is even more concerned with looking at the possible mental and occult involvements first. He says that they do have many cases like that, where people are having schizophrenic episodes etc., and can't differentiate any more between reality and (religious/occult) delusion. For these, cases, they have associated psychologists and psychiatrists.
But, according to Von Lucadou, there is also the occasional genuine haunting or poltergeist, where no mental health or occultism / religious problem can be found. Nowadays, there is no more nationwide media coverage, though. People tend to try and keep these things secret, probably because of the overly agressive ridicule and debunking that took place in cases like Rosenheim.
Von Lucadou is a very level-headed and much more conscientious scientist than Bender ever was, the latter having become somewhat of a credulous believer type in his later years.
Still, he tells of one case he investigated that revolved around a grown-up landlady, who would get agitated when her husband, who had taken up a job elsewhere but should really have been with her at the pub in the opinion of his wife, had to work late and wasn't there to help her. Whenever she got worked up into that state of mind, glasses and plates would tend to slide from tables or trays, chairs and tables would move on their own, etc., often witnessed by patrons or the landlady herself. He does not mention any history of mental illness, strange worldviews, etc.
In another case, where stones appeared to be thrown at or sometimes seemed to materialize inside a house out of nowhere, he witnessed such an event himself, where a stone landed in a pot of soup. The only one with him was the cook who was just as baffled as he was and proceeded to pour the soup down the kitchen sink, because the event had scared him so much. There was no open window, and the door was closed. If someone had managed to slip into the room and out of it again without being noticed, he or she would have to have been a veritable ninja. I don't know about any occult or religious involvement in this case, or if there was a "focus person", but there is no mention of anything like that.
So much for the german researchers.
Other than that, regarding Poltergeist cases, I have only read William G. Roll's book "The Poltergeist". As a psychologist, Roll basically was of the same persuasion as the above, that in every case it is important to evaluate the psychological situation first. I think both he and Hans Bender might have had the idea from J. B. Rhine of the Duke University.
William G. Roll - Wikipedia, the free encyclopedia
The Poltergeist - William G. Roll - Google Books
There's many interesting cases in "The Poltergeist", so maybe I'll make that another post. This one, I guess is already long enough to have lost any attractivity for interested readers
.