The story attracted considerable press coverage in British newspapers such as the Daily Mail and Daily Mirror, and has been the subject of books, featured in television documentaries, and dramatised in horror films.
In August 1977 single parent Peggy Hodgson called police to her rented home in Enfield, claiming she had witnessed furniture moving and that two of her four children said that knocking sounds were heard on walls. The children included Margaret, age 13, and Janet, 11. A police constable said that she saw a chair "wobble and slide". Later claims included disembodied voices, loud noises, thrown toys, overturned chairs, and children levitating. Over a period of 18 months, more than 30 people, including neighbours, psychic researchers and journalists, said they variously saw heavy furniture moving of its own accord, objects being thrown across a room and the daughters seeming to levitate several feet off the ground. Many also heard and recorded knocking noises and a gruff voice.
Society for Psychical Research members Maurice Grosse and Guy Lyon Playfair reported "curious whistling and barking noises coming from Janet's general direction." Although Playfair maintained the haunting was genuine and wrote in his later book This House Is Haunted: The True Story of a Poltergeist (1980) that an "entity" was to blame for the disturbances, he often doubted the children's veracity and wondered if they were playing tricks and exaggerating. Still, Grosse and Playfair believed that even though some of the alleged poltergeist activity was faked by the girls, other incidents were genuine. Janet was detected in trickery; a video camera in the room next door caught her bending spoons and attempting to bend an iron bar. Grosse had observed Janet banging a broom handle on the ceiling and hiding his tape-recorder.
According to Playfair, one of Janet's voices she called "Bill" displayed a "habit of suddenly changing the topic—it was a habit Janet also had".
When Janet and Margaret admitted "pranking" to reporters, Grosse and Playfair compelled the girls to retract their confession. They were mocked by other researchers for being easily duped.
The psychical researcher Renée Haynes had noted that doubts were raised about the alleged poltergeist voice at the Second International SPR Conference at Cambridge in 1978, where video cassettes from the case were examined. The SPR investigator Anita Gregory stated the Enfield poltergeist case had been "overrated", characterising several episodes of the girls' behaviour as "suspicious" and speculated that the girls had "staged" some incidents for the benefit of reporters seeking a sensational story. John Beloff, a former president of the SPR, investigated and suggested Janet was practicing ventriloquism. Both Beloff and Gregory came to the conclusion that Janet and Margaret were playing tricks on the investigators.
American magician Milbourne Christopher briefly investigated, failed to observe anything that could be called paranormal and was dismayed by what he felt was suspicious activity on the part of Janet. Christopher would later conclude that "the poltergeist was nothing more than the antics of a little girl who wanted to cause trouble and who was very, very, clever." Ventriloquist Ray Alan visited the house and concluded that Janet's male voices were simply vocal tricks.
Skeptic Joe Nickell
examined the findings of paranormal investigators and criticised them
for being overly credulous; when a supposedly disembodied demonic voice
was heard, Playfair noted that, "as always Janet's lips hardly seemed to
Nickell states that a remote-controlled still camera—the
photographer was not present in the room with the girls—timed to take a
picture every fifteen seconds was shown by investigator Melvin Harris
to reveal "pranking" by the girls. He argues that a photo allegedly
depicting Janet levitating actually shows her bouncing off the bed as if
it were a trampoline. Harris called the photos examples of common
"gymnastics", and said "It's worth remembering that Janet was a school
Nickell asserted that a tape recorder malfunction that Grosse attributed to supernatural activity and Society for Psychical Research president David Fontana described as an occurrence "which appeared to defy the laws of mechanics" was a peculiar threading jam capable of occurring with older model reel to reel tape recorders.
In 2015, Deborah Hyde commented that there was no solid evidence for the Enfield poltergeist: "... the first thing to note is that the occurrences didn't happen under controlled circumstances. People frequently see what they expect to see, their senses being organised and shaped by their prior experiences and beliefs."
Skeptics have argued that the alleged poltergeist voice that originated from Janet was produced by false vocal cords above the larynx and had the phraseology and vocabulary of a child. In a television interview for BBC Scotland, Janet was observed to gain attention by waving her hand, and then putting her hand in front of her mouth while a claimed "disembodied" voice was heard. During the interview both girls were asked the question "How does it feel to be haunted by a poltergeist?" Janet replied "It's not haunted" and Margaret, in a hushed tone, interrupted "Shut up". These factors have been regarded by skeptics as evidence against the case.
As "a magician experienced in the dynamics of trickery", Nickell examined Playfair's account as well as contemporary press clippings. He noted that the supposed poltergeist "tended to act only when it was not being watched" and concluded that the incidents were best explained as children's pranks. In an interview with the Daily Mail, the adult Janet admitted that she and her sister had faked "2 percent" of the phenomena. This prompted Nickell to comment in another publication, "the evidence suggests that this figure is closer to 100 percent".
Although Maurice Grosse made tape recordings of Janet and believed no trickery was involved, the magician Bob Couttie said, "he made some of the recordings available to me and, having listened to them very carefully, I came to the conclusion that there was nothing in what I had heard that was beyond the capabilities of an imaginative teenager." An article by psychology professor Chris French in 2016 described five reasons why he believed the case to have been a hoax.