In a previous article for the Skeptic, I speculated that if there really had been an increase in reports of ghostly encounters during the Covid pandemic, one possible cause might be the well-documented and widely reported decline in sleep quality that occurred over that period. Poor sleep quality is known to have negative effects on memory and attention and to increase the likelihood of hallucinatory experiences and paranoia – and, of course, to increase the incidence of our old friend, sleep paralysis. It is easy to see how such factors may lead people to have experiences which they interpret as being ghostly encounters even though other non-paranormal explanations may be more plausible. We have just published the results of a large-scale correlational study that appears to offer support for such speculation.
The data for this study were collected as part of a large-scale survey which was launched in October 2017 and was carried out in collaboration with BBC Focus magazine(subsequently renamed BBC Science Focus. The results reported, based upon data from 8,853 respondents, focus on the associations between a number of sleep variables and a range of paranormal beliefs. An index of self-reported sleep quality was computed based upon sleep efficiency (that is, the ratio between time spent in bed and time actually sleeping), insomnia symptoms, sleep latency and sleep duration. Poorer sleep quality was found to be associated with higher levels of belief in life after death, ghosts, demons, communication with the dead, near-death experiences as evidence for life after death, and alien visitation of the Earth.
Data were also collected regarding incidence of sleep paralysis and exploding head syndrome. Sleep paralysis is a relatively common sleep anomaly during which a temporary period of paralysis is experienced at sleep onset or upon awakening. It may be accompanied by additional symptoms including a strong sense of a malign presence, pressure on the chest and difficulty breathing, a range of sensory hallucinations, and intense fear. It typically lasts for only a few seconds but can sometimes last longer. Exploding head syndrome is another fairly common sleep anomaly, again occurring at the threshold between sleep and wakefulness. It often consists of the hallucinatory sensation of a loud noise such as an explosion, a scream, or a gunshot, but can also involve other senses such as a flash of light. The experience of both sleep anomalies was found to be correlated with belief that aliens visit the Earth. Additionally, the experience of sleep paralysis was also associated with the belief that near-death experiences provide evidence for life after death.
Although these findings are correlational, and therefore no definite conclusions regarding cause and effect can be drawn, it is reasonable to speculate that they may well be due to the effects of sleep deprivation upon memory, attention, the tendency to hallucinate, and so on, as referred to above. Hallucinatory experiences experienced during episodes of sleep paralysis or exploding head syndrome will sometimes be interpreted in paranormal terms.
The association between sleep paralysis and the belief that near-death experiences provide evidence in support of life after death is, we believe, a novel finding. It may be that two different psychological mechanisms underlie this correlation, both relating to the general belief that consciousness (or the soul, if you prefer) can become separated from the physical substrate of the brain. On the one hand, if the sufferer from sleep paralysis interprets their hallucination as involving an external ghost or a demon, this may well strengthen their belief in spiritual beings in general, including belief in a personal soul that may survive bodily death. On the other hand, sleep paralysis episodes often involve bizarre sensations of bodily distortion up to and including full-blown out-of-body experiences. If one is convinced that one’s consciousness has been separated from one’s body, it is likely that one would be more likely to endorse the idea that near-death experiences provide support for life after death.
The main strengths of this paper are its focus on an under-researched topic and the large sample size. However, a number of limitations are also noted by the authors in addition to the fact that the data are purely correlational as already noted. Participants were self-selected and it is very likely that those who had experienced sleep paralysis and/or exploding head syndrome were over-represented. Furthermore, over 90% of the sample classified themselves as white and our results may not generalise to other ethnic groups. Finally, all data were produced by self-report rather than by more objective means. Future research should be aimed at addressing these limitations.
The lead author of the paper, PhD student Betul Rauf, and her supervisor, Professor Alice Gregory, are both based at Goldsmiths. They were supported in their efforts by an international team of sleep researchers consisting of members from the US (Brian Sharpless), Spain (Juan Madrid-Valero), and the UK (Rotem Perach, Dan Denis, Guilia Lara Poerio, and yours truly).
