Ghost-busting with Chris French

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Think you’ve seen a ghost? A third of people who believe in them claim their belief is based on personal experience.

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In the run-up to the year’s ‘spookiest’ night – Halloween - Professor of Psychology and Head of the Anomalistic Psychology Research Unit at Goldsmiths, Chris French, discusses some of the factors that might lead someone to believe they’ve encountered a visitor from ‘the other side’.

This article originally appeared in The Skeptic and is republished here with the permission of the Editor and author.

In May 2006, Reader’s Digest magazine published a report of a survey of over a thousand British adults regarding paranormal belief and experience. I was fortunate enough to be allowed access to the detailed results of that survey. One of the questions was, “Do you think that ghosts or the spirits of dead people can communicate with us or can come back in certain places or situations?” 

Over half of the respondents said “yes”, with just over a quarter saying “no” and the remaining fifth saying they didn’t know. Belief was higher in women (64%) than men (43%) and was markedly lower in the over-65s compared to other age groups. 

Another question was, “Have you ever seen a ghost?” More women (21%) than men (16%) answered positively and, once again, the lowest endorsement rate (11%) was found in the over-65s. 

Clearly, belief in ghosts is very widespread in British society, in line with similar results from other countries around the world. What is more, around a third of those who believe in ghosts claim that their belief is based upon direct personal experience.

It is my aim in this article to provide an overview of some of the factors that might lead someone to conclude that they had experienced a ghostly encounter. 

It is always possible, of course, that the traditional interpretation of hauntings and ghosts is correct: perhaps some essence of each individual human being really does survive bodily death and such experiences are simply direct encounters with spirits. Although the idea of life after death is central to most of the world’s religions, it most certainly does not fit with the worldview of most philosophers of mind or neuroscientists. 

If some aspect of our consciousness survives bodily death, this implies that dualism must be true, the idea that there are two basic kinds of stuff in the universe: the physical and the mental. Without going into details, no dualist theory of mind has ever adequately explained how a non-physical mind can interact with a physical body, much less how it can become detached from that body at death and continue to have an independent existence.

Although we are still a long way from fully understanding the nature of consciousness, neuroscientists have made great progress by basing their approach on the assumption that all mental states are ultimately reducible to physical states within the brain. If true, this implies that it is simply not possible for consciousness to become separated from the brain.

Of course, we would all like to believe that death is not the end for us and for those whom we love and we all find it much easier to believe in things that we want to be true anyway. This confirmation bias probably goes a long way to explaining why many people hold very strong beliefs in life-after-death on the basis of sometimes very flimsy evidence.

It is also worth noting that cultural influences appear to play a major role in determining the details of ghostly manifestations. As described by Finucane (1996), the physical aspects and behaviour attributed to ghosts has varied from age to age and from culture to culture.

If such encounters were truly reflections of an eternal afterlife, one would not expect such variation when comparing accounts from, say, ancient Greece, the early Christian era, the reformation, the Victorian age, and modern times. If, however, psychological influences such as belief and expectations play a major role in determining such accounts, this variation is easier to understand.



Many modern parapsychologists reject the spiritualistic interpretation of poltergeist activity but still maintain that the activity is genuinely paranormal in nature. Parapsychologists typically maintain that the disruptive activity in poltergeist cases is a psychokinetic externalisation of inner psychic conflict on the part of the focus, often a troubled adolescent. 

Such activity is often referred to as recurrent spontaneous psychokinesis. Sceptics agree that the source of the disruptive activity is indeed often a single troubled individual, but they maintain that the disruption is brought about by non-paranormal trickery as an attention-seeking device. There are certainly several well-documented cases that are widely accepted as being based upon deliberate hoaxes, including that of the so-called “Amityville Horror”, a notorious case that is now widely recognised to be nothing more than a hoax (Morris, 1977-78). Many other such cases could be cited (see, e.g., Baker & Nickell, 1992; Christopher, 1971). 

It seems likely, however, that only a small fraction of cases are best explained as deliberate hoaxes and so we will concentrate on the much larger proportion of claims that come from honest and sincere individuals. How are we to explain their experiences? A number of theories have been proposed (McCue, 2002). 

Sincere Misinterpretation of Natural Events

Often the initial idea that one’s house may be haunted arises because of some unusual unexplained event or series of events. Of course, “unexplained” does not necessarily mean the same as “unexplainable”. The late Vic Tandy and Tony Lawrence listed several obscure physical phenomena that might lead someone to suspect ghostly activity including “water hammer in pipes and radiators (noises), electrical faults (fires, phone calls, video problems), structural faults (draughts, cold spots, damp spots, noises), seismic activity (object movement/destruction, noises), […] and exotic organic phenomena (rats scratching, beetles ticking)”. 

Once the idea has taken root, even relatively mundane occurrences (eg. not being to find one’s keys) are taken as further evidence of a ghostly presence. The main point here is that many claimed hauntings are based upon sincere but erroneous interpretations of unusual phenomena. 

Context and Prior Belief

Context and prior belief in ghosts are both factors that influence the probability of subjective ghostly encounters. In one study (Lange & Houran, 1997), volunteers walked around a disused cinema having been told either that the building was undergoing renovation or that paranormal activity had been reported there. They were asked to note if they experienced any anomalous sensations during their tour and, as predicted, the latter group reported many more than the former.

Similarly, Richard Wiseman and colleagues (2002) had 678 participants walk around Hampton Court Palace, allegedly one of the most haunted locations in Britain. More anomalous experiences were reported by those who believed in ghosts than by those who did not and moreover the believers were more likely to interpret any such experiences as being due to ghostly activity. 

On Seeing Things That Are Not There

Another typical counter-explanation from sceptics to claims from people that they have “seen a ghost” is to simply say that the person in question must have been “seeing things” by which they mean, of course, “seeing things that are not there”. Such dismissals are typically angrily rejected by the claimant who will loudly insist that they are “not mad” and that they saw their ghost with their own eyes. 

In fact, visual, auditory, and tactile hallucinations are much more common amongst the general, non-clinical population than is generally realised and it certainly does not follow that you must be suffering from serious psychopathology in order to experience them. 

One of the common hallucinatory experiences that we are particularly interested in at the Anomalistic Psychology Research Unit at Goldsmiths is that of sleep paralysis (SP). Basic SP is surprisingly common. It refers to the frightening experience when, in a state somewhere between sleep and wakefulness, you realise that you cannot move. 

In fact, the muscles of the body are always paralysed during rapid eye-movement (REM) sleep, the stage of sleep associated with dreaming. Presumably this prevents the dreamer from actually carrying out the actions of the dream. It is only rarely that one becomes consciously aware of this state of paralysis, but around 40% of our Psychology first-year students report having experienced it at least once. 

It is transitory and harmless but can leave the sufferer shaken and perplexed. As if that is not frightening enough, it is often associated with a strong sense of presence and hallucinations of a visual, auditory and/or tactile nature. These hallucinations include the sight of people, strange creatures or moving lights, the sounds of voices, footsteps or mechanical sounds, and/or the sensation of being touched, held or dragged. Difficulty breathing and an intense sense of fear are also commonly reported.

Around 5% of the population report having experienced this more florid version of SP. Some sufferers of SP are likely to feel that their experience is either indicative of a serious psychological problem (it isn’t) or that they have had a genuine encounter with strange beings. Although our own research suggests that only a small minority of sufferers opt for a paranormal interpretation, given the large number of sufferers, this amounts to many hundreds of thousands of people worldwide.

It is interesting to note that the same core experience is interpreted in different ways in different cultures. In Newfoundland, tales are told of the Old Hag who comes and sits on the sleeper’s chest to suffocate them. In Japan, the phenomenon is referred to as kanashibari and is interpreted as a nocturnal attack by spirits. My favourite is the spine-chilling interpretation from St Lucia, where the phenomenon is referred to as kokma. 

Here, it is believed that the spirits of unbaptised children crawl onto the sleeper’s chest to throttle them. In centuries past in Europe, the same core phenomenon was interpreted as attacks on the sleeper by sex-crazed demons, either the male incubus or the female succubus. 

The Fallibility of Memory

We have also become increasingly interested in the reliability – or rather, the unreliability – of human memory. After all, in evaluating paranormal claims of all kinds, including those of encounters with ghosts, one is typically dealing with the claimant’s report of the event, not the event itself. No matter how honest and sincere the claimant is, this is no guarantee of accuracy. 

Some investigators have examined the reliability of eyewitness accounts of events such as séances. Richard Wiseman and colleagues have confirmed and extended observations made as long ago as 1887, that reports of the spooky (although thoroughly faked) goings-on in the dim illumination of the séance room should be taken with at least a bucket of salt (eg. Wiseman, Greening, & Smith, 2003). 

Furthermore, believers were more susceptible to the power of suggestion but only when the suggestion was consistent with their belief in the paranormal. Wiseman and Morris (1995) had previously presented results relating to the accuracy of eyewitness reports of videotaped “pseudopsychic demonstrations” – more commonly known as conjuring tricks, such as “psychokinetic” metal bending. 

Believers in the paranormal tended to rate such demonstrations as being more likely to involve genuine paranormal forces and to be less accurate in remembering important details of the demonstration. 

Electromagnetic Fields and Infrasound

An interesting, if controversial, hypothesis has been advanced by Michael Persinger to account for a variety of ostensibly paranormal experiences. In such cases, he believes, the weird experiences may be due to abnormal activity in the temporal lobes. Such activity is thought to be associated with a variety of mystical and unusual perceptual experiences. 

At the extreme end of the continuum of temporal lobe activity are temporal lobe epileptics, who sometimes report that a seizure is preceded by odd sensations, déjà vu, hallucinations, out-of-body experiences and mystical feelings. Persinger has developed a technique whereby he claims he can induce bursts of firing in the temporal lobes of volunteer subjects. Reports of weird bodily sensations have resulted (eg. Blackmore, 1994). 

Persinger and colleagues have even reported that they were able to induce the subjective appearance of an apparition in a susceptible volunteer using this technique. If such an effect were to be replicated by independent investigators, it could be of tremendous significance in accounting for a whole range of ostensibly paranormal phenomena. 

Unfortunately, a direct replication attempt by Pehr Granqvist and colleagues (2005) failed to replicate Persinger’s results and Granqvist suggested that the most parsimonious explanation of the findings was in terms of participant suggestibility and poor double-blinding in Persinger’s studies. 

An attempt by a team at the APRU to induce anomalous experiences using complex EMFs was also unsuccessful, although it should be noted that the technique used in our study differed in important ways from that used by Persinger. 

Jason Braithewaite (2010) comprehensively reviewed the evidence for and against Persinger’s intriguing hypothesis in The Skeptic. He concluded: “Although the suggestion of an effect between low-intensity magnetic fields and strange experience has some evidenced support, it is unlikely to be a common cause of haunt reports and is, almost certainly, not as common as other psychological factors such as expectation, prior-belief, suggestion and cognitive biases.” 

A similar hypothesis was proposed by the late Vic Tandy with respect to infrasound. Infrasound is sound energy below the audible frequency range for humans. Tandy reported that in two reputedly haunted locations, he had found standing waves at around 19 Hz.  Although space limitations preclude a detailed assessment of this hypothesis here, Braithwaite and Townsend (2006) argued strongly that the evidence in favour of the idea that infrasound plays a specific role in haunt-type experiences is, in fact, very weak. 

To conclude

It would be extremely naïve to expect that a single ‘one-size-fits-all’ explanation can be given for all cases of alleged ghostly encounters. The factors outlined above, along with others, will combine and interact in interesting ways to produce accounts and experiences that may appear, at first glance, to defy any conventional explanation. 

But careful critical reflection on the known facts of a case will usually, if not always, suggest plausible non-paranormal explanations for the events involved.

Most believers, however, are likely to reject any such explanations outright due to the simple fact that, like Fox Mulder, they just want to believe! 

Find out more about the APRU at Goldsmiths

(Images - Creative Commons: 'Beware of the Ghost' - Klearchos Kapoutsis / 'Ghost' - Pascal)