The world’s cultures
The study: a survey of the world’s cultures by the American anthropologist Erika Bourguignon, paid for by the US National Institute of Mental Health in the 1960s. She went through the records of 488 societies across the world to see how many believe a spirit can take a person over, and how many see it happen in their rituals.
Bourguignon1963–68
Seen with their own eyes
The surveys: the Pew Research Center, an American polling organisation, has asked people in several of its surveys of religion whether they have ever seen the devil or evil spirits driven out of a person.
- 74%
of Christians in Ethiopia said yes.
Pew, 2009 - 59%
of Latino Pentecostals in America said yes.
Pew, 2014 - 34%
of American Pentecostals said yes.
Pew, 2007 - 11%
of all American adults said yes.
Pew, 2007
The attack in the night
The study: The Terror That Comes in the Night, by the American folklorist David Hufford, 1982. In Newfoundland, people tell of the “Old Hag”, something that comes in the night and holds a sleeper down. Hufford set out to find whether people only have the attack because they grew up hearing the story. He asked 93 Newfoundlanders: “Have you ever awakened during the night to find yourself paralyzed, unable to move or cry out?” Those who said yes all described the same attack: awake, held down, afraid, in their own room, and often something in the room with them. He then found people in America who had never heard the story. They described the same attack.
HuffordThe Terror That Comes in the Night, 1982
Killed in their sleep
In the 1980s, Hmong refugees in America began dying in their sleep. They were healthy young men. Doctors never found a cause. The Hmong said an evil spirit was killing them. They call it dab tsog. It comes in the night, sits on the sleeper’s chest and smothers him. One Hmong man explained: “once you are seen by one of those evil spirits, often they will come back to you, until you have the worst nightmare and probably die.” The study: the anthropologist Shelley Adler spent fourteen months asking 118 Hmong people in California about dab tsog. She published what they told her in her book Sleep Paralysis, 2011.
- 117
refugees from Southeast Asia died in their sleep, with no cause found. All but one were men.
- 92
in every 100,000 young Hmong men died this way each year at the peak, in 1981 and 1982. That is as many as the five biggest natural killers of American men their age, put together.
- 58%
of the Hmong Adler asked had been attacked by dab tsog in their sleep at least once.
- 72%
of the Christian Hmong she asked had been attacked by dab tsog.
- 54%
of the Hmong who kept the old religion had been attacked by dab tsog.
- 74%
of the Christian Hmong who gave a reason for the deaths blamed spirits, or the loss of the old rituals that kept the spirits away.
AdlerSleep Paralysis, Rutgers University Press, 2011
Someone on top of them
People who wake in the night unable to move often feel that someone is in the room with them. Many feel it climb onto them, press down on their chest, and touch them. The old name for the spirit that lay on sleepers and raped them is the incubus. The study: the psychologist Allan Cheyne, at the University of Waterloo in Canada, surveyed 2,397 people who had woken unable to move.
- 80%
felt someone in the room with them.
- 41%
felt themselves touched.
- 2 in 3
felt a weight pressing down on them.
- 82%
of those who could tell whether it was a man or a woman said it was a man.
- 96%
were afraid.
Cheyne2002, as given by McNamara, Dreams and Visions, 2016
After abuse
People who were sexually abused as children are attacked in their sleep far more often than others. The study: the Harvard psychologists Richard McNally and Susan Clancy asked adults whether they had ever woken unable to move. Some had been sexually abused as children; some had not. A later study found that abuse survivors also met more intruders in the night, and felt more of the weight on the chest.
McNally & ClancyJournal of Anxiety Disorders, 2005; Abrams et al., 2008
Raped in the night
Psychiatric patients tell their doctors that something comes to them at night and has sex with them. In one Dutch clinic, two patients “reported nightly visits by an intruder who climbed upon them to have sexual intercourse with them.” Several described “the sensation of being penetrated and sexually abused.” The psychiatrists call these “probably the most neglected types of hallucination, even in psychiatric settings”: patients are ashamed to say it, and doctors do not ask. The study: in 2024 the same Dutch group, led by Jan Dirk Blom, gathered every study they could find: 79 studies, covering 390 patients. Most of these experiences, they found, “cause significant distress”. In ordinary people, the likeliest source is the incubus: the thing that sits on sleepers.
Blom et al.Frontiers in Psychiatry, 2018; Harvard Review of Psychiatry, 2024
Beings met on DMT
The study: “Survey of entity encounter experiences occasioned by inhaled DMT”, by researchers at Johns Hopkins University, 2020. People who smoke the drug DMT often say they meet beings. The researchers set out to record what those beings are like. 2,561 people who had met one answered their survey.
Davis et al.Journal of Psychopharmacology, 2020
Something cruel
The study: “Survey of subjective ‘God encounter experiences’”, by Roland Griffiths and colleagues at Johns Hopkins University, 2019. They surveyed 4,285 people who had each met something they took to be God, a higher power, an angel or the ultimate reality. Most had met it on a psychedelic drug; 809 had met it with no drug at all. The survey asked what the thing they met was like. One of the answers they could give was “malicious: unkind, cruel, vengeful”.
- 9%
of those who met it on psilocybin mushrooms said it was malicious.
- 10%
of those who met it on LSD said it was malicious.
- 8%
of those who met it on DMT said it was malicious.
- 7%
of those who met it on ayahuasca said it was malicious.
- 1%
of those who met it with no drug said it was malicious.
Griffiths et al.PLOS ONE, 2019
After ayahuasca
The study: the Global Ayahuasca Survey, the largest survey ever made of people who drink ayahuasca. In 2022 its researchers published what harm had followed drinking it, from the answers of 7,839 people. In 2025 they looked again, and found that those who had felt attacked were in worse mental health afterwards. They wrote that these “spiritual attacks can be highly threatening, and people may end up traumatized.”
- 1 in 7
said that after drinking they felt “energetically attacked”, or felt a harmful connection with a spirit world.
- 191
of them said the attack was severe.
- 1 in 12
of those who had drunk ayahuasca only once felt attacked.
Bouso et al.PLOS Global Public Health, 2022; Andión et al., PLOS Mental Health, 2025
Trouble that stayed
The study: “Extended difficulties following the use of psychedelic drugs”, by researchers at the University of Greenwich and others, 2023. They gathered 608 people whose problems went on for weeks, months or years after taking a psychedelic, most often magic mushrooms, then LSD, and asked them to describe what happened.
- 24
people had been in a hell, or met demonic beings, and were left terrified of meeting them again.
- 14
people felt they had been possessed, or cursed.
Evans et al.PLOS ONE, 2023