Waking Up to Sleep Paralysis

Chris Mooney

When it comes to “alien abduction” claims and any number of other sleep-related “paranormal” encounters—whether with ghosts, vampires, werewolves, or whatever else— skeptics have long suspected the existence of a simple, overarching explanation. And now a string of papers by scientists at Harvard University, the latest of which was published by Transcultural Psychiatry in March, bolster the notion that such stories can be traced back to the common experience known as sleep paralysis, and the hallucinations that sometimes accompany it.

The hypothesis that sleep paralysis could play this large explanatory role isn’t necessarily new. But the publication of high caliber scientific studies on alien abductees, strongly supportive of that hypothesis, marks a highly important departure. All in all, the newly accumulated evidence suggests that skeptics may even wish to consider launching a public education campaign to explain more broadly what sleep paralysis is and how it happens. Executed properly, such a campaign might counter the current tendency among many individuals to assume that their relatively harmless sleep-related hallucinations actually reflect paranormal encounters. The campaign would also promote critical thinking about which explanation for sleep-related claims of paranormal incursions—a mundane one or a supernatural one—better suits the evidence.

Sleep paralysis occurs in 30% of the general population. In it you wake up in bed, feel paralyzed, and tend to sense a terrifying presence in your room. Sometimes you see something; sometimes you hear noises or even feel electrical shocks throughout your body. I have personally seen a small humanoid during one occasion of sleep paralysis; during another, more recent one, I saw what looked like a dog in my room. Others see ghosts, vampires—whatever they have in their minds or are particularly afraid of. Deceased relatives and loved ones are particularly good candidates for showing up during bouts of sleep paralysis.

But what’s really happening here, according to Harvard psychologists Richard McNally and Susan Clancy, is nothing out of the ordinary. Rather, REM sleep—the phase of sleep in which most dreaming occurs—is simply malfunctioning. In a phone conversation McNally even likened the situation to getting a case of the hiccups.

Our bodies are paralyzed while we undergo REM sleep, and for good reason (lest we act out our dreams and injure ourselves). But in some small number of cases we can actually start to wake up before paralysis wears off, and yet still remain in a dreaming state. What results is hallucination, often of some extremely scary stuff. It appears that humans have always experienced sleep paralysis and sought to explain it, resulting in well known stories of incubi and succubi—demons thought to sexually attack people in their sleep—as well as related tales from other eras and cultures.

The emphasis on sleep paralysis emerged from a program of research that McNally and Clancy had originally undertaken to study women claiming to have recovered memories of childhood sexual abuse. The work got extended into alleged alien “abductees” to solve a scientific puzzle. Although the researchers had already found that women who recovered abuse memories were more likely to exhibit “memory distortion,” that in itself didn’t prove their alleged memories never happened. After all, real life traumatic abuse experiences might themselves trigger distorted memory. So for comparison, Clancy and McNally hit on the idea of studying memory distortion “in people who report recovered memories of traumatic events that seem unlikely to have occurred: abduction by space aliens.”

Since then they have reported that alien “abductees” are more prone to exhibit “false recall and recognition,” and scored higher than other individuals on scales designed to detect fantasy proneness and the tendency to believe in “unconventional phenomena.” Based upon such evidence—which strongly hints that alien abductees are more likely than other people to make up false experiences—in a phone interview McNally proposed a “recipe” for alien abduction claims, involving five separate “ingredients.”

First, McNally explained, abductees tend to hold a wide range of New Age beliefs, such as an interest in astral projection and crystals. “They’re not a bunch of straitlaced Republican wall street bankers,” McNally says. The second ingredient, he continues, is fantasy proneness, the features of which include “having a rich fantasy life, showing high hypnotic susceptibility, claiming psychic abilities and healing powers, reporting out-of-body experiences and vivid or ‘waking’ dreams, having apparitional experiences and religious visions, and exhibiting automatic writing.”

McNally’s third ingredient is awareness of the “cultural narrative of alien abduction”—which of course characterizes anyone who watches enough TV. Knowledge of this script inevitably plants it in the mind as something that can be drawn on later. The fourth ingredient, McNally continues, is the occurrence of sleep paralysis and its attendant hallucinations. And finally, the fifth ingredient in the making of an alien “abductee” is that most go to therapists who then hypnotize them and ask “inadvertently leading questions. And then they ‘remember,’” McNally says. This is often where the most salacious aspects of abduction accounts emerge, such as claims of sexual molestation and hybrid breeding programs conducted by the aliens.

All in all, according to McNally, these five factors working together can successfully explain why “individuals who are sincere and not psychotic could genuinely believe they were abducted by aliens.” That’s no small achievement. One successful mark of a scientific hypothesis or theory, after all, lies in its capacity to provide a plausible explanatory framework that can account for an observed phenomenon—the phenomenon in this case being the prevalence of alien abduction claims. And without a doubt, the explanation offered by McNally and Clancy enjoys much more plausibility and credibility than the notion that the alleged alien abductions actually happened.

That’s not to say that this powerful explanatory framework will convince abductees themselves to back away from their accounts. These individuals seem deeply wedded to their beliefs, according to McNally; it’s almost as though abduction claims fulfill a deep spiritual purpose in their lives. Perhaps those who cling to these views could never be convinced to relinquish them. Still, a very positive social benefit could be gained if more people generally understood what sleep paralysis is and how it contributes to widespread “paranormal” experiences. It’s even conceivable that a lot of grief and fear could be averted.

And there’s more at stake here than simply the esoteric group of alien “abductees.” In addition to abduction claims, sleep paralysis also seems likely to account for a wide range of alleged late-night ghost sightings. Moreover, as cultural notions shift over time, we can expect that the apparitions hallucinated during sleep paralysis will also shift their identities in relation to societal and media cues. When that happens—and reports begin to emerge on the next group of nighttime invaders—skeptics will have a powerful counter-explanation at the ready.

Literature relied upon:

  • Clancy, S.A., McNally, R.J., Schacter, D.L., Lenzenweger, M.F., & Pitman, R.K. (2002). Memory distortion in people reporting abduction by aliens. Journal of Abnormal Psychology, 111, 455—461.
  • McNally, R. J., Lasko, N. B., Clancy, S. A., Macklin, M. L., Pitman, R. K., & Orr, S. P. (2004). Psychophysiologic responding during script-driven imagery in people reporting abduction by space aliens. Psychological Science, 15, 493-497.
  • McNally, R. J., & Clancy, S. A (2005). Sleep paralysis, sexual abuse, and space alien abduction. Transcultural Psychiatry, Vol 42(1): 113—122.

Chris Mooney

Chris Mooney is a science and political journalist, blogger, podcaster, and experienced trainer of scientists in the art of communication. He is the author of four books, including the New York Times bestselling The Republican War on Science and The Republican Brain: The Science of Why They Deny Science and Reality. He blogs for Science Progress, a website of the Center for American Progress and Center for American Progress Action Fund.