part0014

Science – bless it – provides an almost endless supply of esoteric terms that can make any theory, no matter how off-the-wall, sound respectable. The survival of consciousness after death? 'Quantum coherence in the microtubules.' ESP or telepathy? The Heisenberg Uncertainty Principle – or maybe quantum mechanics. Creationism and Intelligent Design? 'Evolution is just a theory.' The jargon factor, plus the fact that scientists themselves do not like to speak in certainties but hedge what they say with caveats and statistics, make it hard to explain why one statement is science and another anything but.

Skepticism is inquiry; science is a process. It is religions and belief systems that claim to provide answers. Science claims only to provide the best self-correcting method we have for establishing the best approximation to the truth at any given time. Anti-science sounds like science, but mangles it: quotes are taken out of context, concepts are wilfully or ignorantly misrepresented, and any new evidence that doesn't bolster the hypothesis under consideration is promptly discarded. Confirming evidence is, of course, accepted immediately; the television producer and science writer Karl Sabbagh has called this the 'ratchet effect'. This section compares and contrasts the workings of science and anti-science .

TV seems like it ought to be an unparalleled opportunity to present a skeptical point of view. The problem is that, more often, skeptical voices are used as counterweights to the more obviously sensationalist stuff that producers think is more entertaining. Here, Susan Blackmore, herself an experienced broadcaster, shows that even experienced interviewees can be hoodwinked. She also sets the record straight on why the BBC's The Day I Died (2003) was wrong about microtubules and near-death experiences. Appeared in XVII.1.

I never should have said yes. I'd promised myself I wouldn't do any more 'rent-a-skeptic' slots, and here I was appearing on one of the worst-ever TV shows on near-death experiences (NDEs). So how did it happen?

The producer, Kate Broome, told me that The Day I Died would take the science seriously, that there would be a searching exploration of the whole topic of consciousness, and that this programme would be entirely different from its predecessors. So I believed her. She and her BBC team came to my house and we did a very interesting and enjoyable interview. We covered not only the physiology of NDEs, but theories of consciousness, the reasons why quantum theories of consciousness fail, the nature of self, and why NDEs might be genuinely mystical experiences without being evidence for life after death.

Then I saw the advance advertising: 'NDEs used to be the domain of parapsychology, but now research by some scientists and medics is daring to suggest the impossible – that NDEs are evidence that the mind can live on after the brain has stopped functioning ' Different from its predecessors? Hardly. Popular? Of course. This is what every previous NDE programme has claimed, and this is what most people already believe.

In the end, as anyone who watched the programme will know, The Day I Died was just an updated version of all the myriad shows that have gone before. Some of the new cases were excellent, and the interviews with people who had experienced NDEs were fascinating, but the science was not. Peter Fenwick and Sam Parnia described their recent research and their belief that it proves the independence of mind. Rent-a-skeptic said her usual pieces about tunnels, lights, and how they are constructed in the dying brain (they could have cut them from interviews I did ten years ago instead of carefully extricating them from what I wanted to say this time).

Finally they got to consciousness. With clever computer graphics and 'Horizons sque' hype they explained that brave scientists, going against the reductionist grain, can now explain the power of the mind to transcend death. It all comes down to quantum coherence in the microtubules. And to make sure the viewer knows that this is 'real science', the ponderous voiceover declared, 'Their theory is based on a well-established field of science: the laws of general relativity, as discovered by Einstein.'

This was where my fury erupted. As I wrote to the producer afterwards,

It is dishonest to present a completely unworkable and mysterious theory as though it were real science, and to dress it up in the trappings of real science, as you did with Hameroff's theory. It may be true that you 'were very clear to point out it that is not proven', but pointing out that it is not proven is not the same as pointing out that it (a) does not make sense, (b) does not fit with lots of reliable evidence about the brain, and (c) is rejected utterly by most scientists and philosophers who know about it.

So, in case you are wondering, why can't quantum coherence in the microtubules explain consciousness and the NDE?

The theory first appeared in 1989 in The Emperor's New Mind by mathematician Sir Roger Penrose. Penrose argues that when mathematicians have conscious insights they are not doing ordinary computations such as might be carried out by a computer or a neural network. Instead, they must be capable of handling non-computable functions. He accepts that our brains are completely controlled by physics of some kind but, he claims, it needs to be an entirely new kind of physics.

Penrose explains that there are two levels of explanation in physics: the familiar classical level used to describe large-scale objects, and the quantum level used to describe very small things. The trouble starts when you move from one to the other. At the quantum level superposed states are possible; that is, two possibilities can exist at the same time. But at the classical level either one or the other must be the case. So when we make an observation at the classical level, the superposed states have to collapse into one or other possibility, a process known as the collapse of the wave function. Penrose argues that all conventional interpretations of the collapse of the wave function are only approximations, and instead proposes his own theory of 'Objective Reduction'. This new process is gravitational but non-local in nature. This means that it can potentially link things in widely separated areas, making large-scale 'quantum coherence' possible. Although this can only happen when the system is isolated from the rest of the environment, Penrose suggests that this might happen inside the brain – but where?

It was the American anaesthesiologist Stuart Hameroff who suggested that the answer might lie in structures called microtubules. He had come across evidence (subsequently found to be invalid) linking microtubules to the abolition of consciousness in anaesthesia. He reasoned that microtubules might therefore be necessary for consciousness. This was the idea that gave rise to the Penrose–Hameroff theory explained so enthusiastically in The Day I Died.

Microtubules are, as their name suggests, tiny, tube-like proteins. Hameroff and Penrose proposed that their shape and the spiral structure of their walls might mean that quantum effects within them could be kept reasonably isolated from the outside, making quantum coherence possible. But why is this relevant to consciousness? Hameroff argues that the real problems for understanding consciousness include the unitary sense of self, free will, and the effects of anaesthesia, as well as non-algorithmic, intuitive processing. All these, he claims, can be explained by quantum coherence in the microtubules. Non-locality can bring about the unity of consciousness, quantum indeterminacy accounts for free will (see Daniel Dennett's Freedom Evolves, for reasons why it cannot), and non-algorithmic processing, or quantum computing, is done by quantum superposition. As for NDEs, on The Day I Died, Hameroff explains that when the brain stops functioning, the information in the microtubules is not lost. Rather it leaks out into the universe at large and then continues to hang together by quantum coherence. This, he claims, can explain how the conscious self can be experienced as hovering above the body.

So how good is this explanation? We can begin with consciousness itself, which is conventionally equated with subjective experience. The 'Hard Problem' of consciousness (see David Chalmers' 1996 A Conscious Mind) is to explain how subjective experience can arise from (or perhaps be) the objective activity of brain cells. Penrose and Hameroff's theory has nothing whatever to say about this. If quantum computing does occur in the brain this would be very important, but it only adds another layer of complexity to the way the brain works. So we must still ask, 'How does subjective experience arise from objective reduction in the microtubules?' The strange effects entailed in quantum processes do not, of themselves, have anything to say about the experience of light or space or pain or colour or time.

One of the strengths of the theory is supposed to be that it accounts for the unitary sense of self, but nothing in the theory explains how to get from interacting quantum effects to the feeling that 'I' am a continuing self who makes decisions and lives my life. Also, as we have seen, the theory requires that the quantum process be isolated from the rest of the environment, but a hovering self during an NDE would not be.

Several commentators have pointed out these and many other problems. Many conclude that the theory just replaces one mystery (subjective experience) with another (quantum coherence in the microtubules?). Even people renowned for their unconventional thinking have rejected it outright, such as computer engineer and futurist Ray Kurzweil. But the most devastating critique is made by philosophers Rick Grush and Patricia Churchland. They take Penrose's arguments step by step, and demolish each one .

An obvious problem is that microtubules are not specialized structures confined to brains: they occur in almost all cells of the body, in both animals and plants, and are involved in supporting the cell's structure in cell division and in transporting organelles within the cell. It is true that some anaesthetics affect microtubules, but many others do not, even though they obliterate consciousness. Also, drugs are known that damage the structure of microtubules but appear to have no effect on consciousness, and there is no evidence that microtubules are implicated in other major changes in consciousness, such as sleep–wake cycles.

Concerning the physics, Grush and Churchland argue that microtubules cannot provide the conditions of purity and isolation required by Penrose's theory, nor could effects be transmitted from one microtubule to another, as is required for explaining the unity of consciousness in the way Penrose requires. In addition the theory provides no explanation of how the quantum effects could interact with effects at the level of neurons, neurotransmitters, and neuromodulators, when the microtubules are supposed to be isolated from their environment.

Grush and Churchland concluded in 1995 that, 'the argument consists of merest possibility piled upon merest possibility teetering upon a tippy foundation of 'might-be-for-all-we-know's ... we judge it to be completely unconvincing and probably false' (p. 12). In 1998, Churchland put it even more strongly: 'Quantum coherence in the microtubules is about as explanatorily powerful as pixie dust in the synapses.'

They also ask why such a flimsy theory has proved so popular. Perhaps, they suggest, it is because some people find the idea of explaining consciousness by neuronal activity somehow degrading or scary, whereas 'explaining' it by quantum effects retains some of the mystery.

Whatever the reason, the TV show proved equally palatable, and if the producers' aim was popularity, then they certainly succeeded. Most viewers want to believe in life after death and they like to see 'evidence' that confirms their traditional dualism. I accused the producers of making a dishonest programme and misleading viewers, accusations they strongly denied. Kate Broome replied that, 'I think we tried to at least suggest that there are other ways of looking at this subject other than in a reductionist way.' Yes, they did. It's just that every previous programme on NDEs has done exactly the same, giving viewers the answers they want rather than trying to find out the truth. Although we may never get to see it on TV, the real science of NDEs is much more exciting than quantum coherence in the microtubules .

Nothing contributes as much to confusion about paranormal claims as innumeracy. At least some understanding of statistics ought to be – and isn't –a professional requirement for journalists. Chip Denman, a statistician at the University of Maryland College Park, explains the basics. Appeared in IX.4. This article originally appeared in Skeptical Eye, the newsletter of the National Capital Area Skeptics.

When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind. (William Thomson, Lord Kelvin, 1824-1907)

Measurement is not enough. Scientific understanding lies in comparing measurements and understanding their uncertainty. Statistics is the discipline which not only tolerates uncertainty, but embraces it. Virtually every field of scientific inquiry has contributed to the language, variations, and styles of presentation which make up the body of statistics.

Statistics : a word which has struck fear into many a student. Graduate students from Agronomy to Zoology have been left clueless by introductory statistics and research methods courses everywhere. Undergraduates have despaired over chi-square formulae and F-tests. Those who never had such a course may feel even less comfortable with the 'correlations', 'margins of error', and other terms slung around in the morning paper. Sometimes, I suspect, being more self-consciously ignorant may be better than being blissfully half-smart, statistics being merely the example that I know best.

The language of probability and statistics is everywhere. All of these are from the same edition of a newspaper:

The very term 'statistics' has many connotations. I once spent an hour on the phone with an attorney who called to find out if a certain product was safe. 'Give me the data', I suggested, 'and I can develop the risk estimates.'

'Data? You are a statistician; you are supposed to know these things!' A good librarian might have helped; I could not.

Let me be clear: My role as a statistician is that of a professional skeptic. My training is in mathematical tools for looking at data and evaluating hypotheses. My obligation is to ask tough questions about the data and its source.

The classic statistical paradigm (brushing aside the differences between the philosophies of Fisher, Neyman-Pearson, and Bayesian statistics) is a mirror of the mythic scientific method as promulgated in textbooks:

Of course, real-life data analysis rarely follows such a recipe exactly. But, hey, if you've seen me in the kitchen, you know that I rarely cook exactly by the book either. In the last twenty years graphical methods, especially those suited to exploratory data analysis, have expanded the statistical menu. Computer-intensive methods based in part on (pseudo) random numbers and repetitive enumeration were unthinkable even a few years ago.

All of these statistical methods have one fundamental theme: human intuition is very fallible at evaluating likelihoods and coincidence. Even the very meaning of 'random' is far from obvious. We can give a precise definition of probability in terms of abstract mathematical properties (for example, measure theory), but the mathematics per se do not define everyday experience. What is this probability thing anyway?

The so-called classical approach to probability provides a convenient way to calculate, at least for simple, finite situations. According to this approach, derived from gambling problems and formalized philosophically by Pierre Simon de Laplace (1749-1827), probability represents the ratio:

To call this the classical approach is misleading. Other ways of thinking about probability have been with us for just as long. The relative frequency interpretation is common among modern statisticians, but this same kind of thinking can be found in the mortality tables published in 1662 by John Graunt of London. In slightly more modern terms (proposed by John Venn in 1886 and developed mathematically in the 1920s by Richard von Mises), imagine an experiment in which we observe whether event E happens or not. If we repeat the experiment many, many, many times, the ratio:

This makes sense in a large number of practical problems. We can easily imagine people playing the lottery time and time again. We can imagine, at least in principle, running a horse in race after race. We can even imagine interviewing a large number of 'Cancers' and asking them about their love life. With a little more imagination we can make this work for, say, weather predictions. 'A 30 percent chance of showers' could mean that if we could somehow observe a really large number of days with conditions just like today, 30 percent of the time our picnics would be cancelled.

A third (and by no means, final) way to interpret probabilities is as a degree of belief, also known as the subjective interpretation. Only a mental contortionist could devise a frequency interpretation of the statement 'Lee Harvey Oswald probably acted alone'. In this way of thinking, probability represents a measure of your strength of belief. Variations on this idea are useful in trying to represent the degree to which evidence may confirm or disconfirm, say, 'the single bullet theory'. It is also a natural way of talking about the 'prior distributions' in Bayesian analysis. The mathematical niceties of this idea are recent (F. P. Ramsey in 1926 and L. J. Savage in 1954). However, the concepts can be traced to sixteenth- and seventeenth-century jurisprudence in which 'probability' was apportioned to evidence according to its certainty.

In practice, it rarely matters which interpretation is chosen. The numbers remain the same.

Even simple problems can knock intuition sideways. I just tossed a penny in the air. What's the probability that heads is showing? One-half, of course. One equally likely chance out of two. But now I have tossed a penny and a nickel together, and I tell you that one of them, and maybe both, heads. What's the probability that both are heads? Surely one coin has no effect upon the other, so is it one-half again? The correct answer is one-third. Huh?

Looking at the four possible outcomes of tossing the two coins shows why ( Figure 4 ).

There are four equally likely scenarios when we toss both coins. Although the nickel and the penny are certainly independent, we know that they are not both tails up, leaving three possibilities. Double heads is one out of three. The key here is that I did not tell you which of the two coins I was talking about when I said that one of them was heads. If I had let on that it was the nickel, then we'd be left with only two scenarios, which does yield the answer of one-half. Something as seemingly trivial as naming or not naming a coin makes all the difference.

If this still seems a bit weird, try the experiment. Toss two coins on the carpet. If both are tails, forget it. Pick them up and toss again. But if at least one head is showing, record the result. Repeat the process until you have a good number of recorded data. What percentage of the record shows double heads? (This same problem is sometimes given in terms of a person with two children, at least one of whom is a boy. For some reason this seems to confuse intuition even more effectively than coins. Try it on someone.)

Another simple problem makes a great classroom demonstration. It is rather unlikely that you and I share the same birthday (day and month, ignore the year). Obviously the more people that we pull into the party, the more likely it is that at least two people will match. How many people do we need in order that a match is more likely than not?

Wishing away the pesky matter of leap years, it's pretty clear that if we invite 366 people, at least two of them must share a birthday. So how many before the chances are fifty-fifty? (When I've posed this problem in large gatherings, I sometimes get answers like 'One thousand'. Go figure.)

If you've never heard the answer before, it just doesn't feel right: twenty-three. Figure 5 shows the calculation.

The key again is that we did not specify which birthday had to match. We did not specify 25 June, nor did we require that James and Shirley had to match. We are merely looking for some coincidence, somewhere, anywhere.

Simple puzzles like these do more than point out the weakness of intuition. They also can give us a start toward quantifying more real-life coincidences. Persi Diaconis and Frederick Mosteller have presented extensions to the birthday puzzle that show how easy it is to get near-misses like birthdays one or two days apart. But what about the 'psychic' puzzlers like we've all encountered, at least second-hand? Is Aunt Martha's dream that came true beyond the reach of probability and statistics?

Here's a way of thinking about such events that I first saw sketched out in Innumeracy by John Allen Paulos. If there are absolutely no psychic powers whatsoever, it's pretty unlikely that a dream of yours will predict the future. How unlikely? I don't know ... let's start with the guess of one chance out of ten thousand. What constitutes a hit? It doesn't really matter; be your own judge. Since this is just an approximation, let's also pretend that you remember one dream a night and that each dream is independent of the rest. Just like in the birthday calculation, start by looking at the probability that a dream does not match with the future. Probability of one non-matching dream:

But this means that we should also expect those other 3.6 percent to have at least one dream each which seems to predict the future. And remember, we are talking about what would happen without psychic powers, just relying on pure blind luck. The population of the United States is about 250 million, so we should expect about 9 million people in the US alone to have 'precognitive' dreams just by chance!

An individual who dreams for 19 years will have almost exactly an even chance of having at least one such spooky dream (1 - .9999)365 x 19 = .5002. It's no surprise to me that many of my students at the university tell me it's happened to them.

Even if you think that our original guess of 1/10,000 was too high, this kind of analysis is still revealing. What if we try one chance out of 100,000? We still should expect 900,000 people to have the illusion of a psychic flash. Even if we try a ridiculously low chance of only one out of a billion, we should expect enough 'precognitive' dreams for Unsolved Mysteries to reenact one a week and have plenty left over as fodder for The X-Files.

These kinds of tentative analyses are not proof. The numbers are guesses –your mileage may vary. But they are educated guesses. They show how even elementary arithmetic can go a long way towards slowing the jump to hasty conclusions.

Astute readers will have noticed that I said that I would talk about statistics, but in fact I have talked mostly about probability. I lied .

About ten years ago, I was on two TV shows in the same week. One was about ghosts; the author of a new book described waking up at night, cold , with a heavy weight pressing on his chest, knowing there was a presence nearby. One was on alien visitations: the author of a new book described waking up at night, cold, with a heavy weight pressing on his chest, knowing there was a presence nearby. The first said he'd been visited by a ghost, the second by art alien. My rather obvious conclusion: both were describing a common phenomenon that they interpreted individually according to their pre-existing beliefs. There was indeed such a phenomenon: sleep paralysis. Here, Nick Rose, now a science teacher but then a research assistant in Susan Blackmore's lab at the University of the West of England, explains the connection in the case of alien abductions. Appeared in X.4.

In October I was asked to take part in a radio interview commenting on a report in the tabloid press that a man from Dagenham had paid £100 to insure himself against being abducted by aliens.

Whether or not the original story was true, which is highly doubtful given its source, it does represent something of a continuing trend in UFO mania. If the story were true then it would raise some interesting questions. How would an insurance company define an alien abduction? How would the company evaluate the risk of Dagenham 'Dave' being abducted? What proof could satisfy a skeptical claims assessor that an abduction had taken place?

In 1992, Budd Hopkins, David Michael Jacobs, and Ron Westrum commissioned a Roper Poll survey of unusual experiences which they believed were associated with UFO abductions. Over the period of three months, and at considerable cost, this carefully sampled survey was carried out on nearly 6,000 adult Americans. Might they have the answers to any of these questions? From Hopkins' and his co-authors' interpretation of the poll it appears that we can define an abductee as anyone who has had, at any time in their lives, four out of five 'symptoms' of an alien abduction. At the risk of being accused of attacking a 'straw man', I'd like to examine these 'symptoms' a little closer. Just what do they tell us, if anything, about the apparent phenomenon of alien abduction?

It is interesting to note that the item which yielded the highest number of 'yes' responses is the experience of waking up paralysed with a sense of a strange person or presence or something else in the room. Something like 18 percent of their poll had experienced this at least once, which they equated with about 33.3 million Americans. This item in the poll is actually a combination of two separate experiences: an experience of waking up paralysed, and sensing a strange presence .

Sleep paralysis is the phenomenon of feeling that your body is paralysed, and usually manifests when you are in a half-awake/half-asleep state. From our own research this appears to be a common experience. About 34 percent of children and 46 percent of adults reported an experience of sleep paralysis. This compares well with a Japanese survey which found an incidence of around 40 percent.

The paralysis itself may be due to the body being locked up from having been in, or entering, dreaming (it is known that the body is paralysed so that you don't act out your dreams). Sometimes sleep paralysis occurs with hypnagogic or hypnopompic hallucinations, often accompanied with the feeling of a presence in the room. Hypnagogic hallucinations are the period of hallucination that everyone gets once in a while when falling asleep; hypnopompic hallucinations occur just as you start to wake up. Hallucinations of this sort can include hearing strange humming noises or voices, feeling apparent changes in size, shape, or position of one's body, seeing faces (sometimes malformed or horrific), seeing lights and patterns, and an array of quite bizarre, but perfectly normal, effects. A combination of hallucination and sleep paralysis can be understandably terrifying.

Sleep paralysis is not a recent discovery, and nor are sleep paralysis myths. In his 1982 book, The Terror That Comes in the Night, DJ Hufford examined the folklore surrounding the legends and traditions of the 'old hag' among the people of Newfoundland in Canada. The Vietnamese have long had stories of a 'grey ghost' that enters their rooms at night. In medieval times demonic incubi and succubi came to their victims at night to seduce them. Is alien abduction our modern equivalent of a sleep paralysis myth? It seems that many people interpret sleep paralysis as some external force or agent, restraining their movements or crushing the breath from their chest. If the paralysis feels like an external force then many people, in their search for an explanation for the experience, will assume that it is. What form that external force takes will depend much upon that person's cultural information. In this country, for the moment at least, the interpretation of the force as an extraterrestrial one is still relatively rare. Ghosts and spirits still enjoy a relatively strong position in popular belief compared with extraterrestrials.

Of the Roper Poll's other symptoms, two were experiences that could be associated with sleep states: a 'feeling that you were actually flying through the air although you didn't know why or how' and having 'seen unusual lights or balls of light in a room without knowing what was causing them, or where they came from'. The first of these 'symptoms' is basically a description of an out-of-body experience (OBE).

Many people who regularly have OBEs describe a period of paralysis shortly before the experience begins, traditionally known as 'astral catalepsy'. A number of OBE-ers might believe that this experience stems from something actually leaving the body and flying around, although a more convincing explanation has been offered by Susan Blackmore in her books Beyond the Body and Dying to Live. Within our research, however, none of the OBE-ers have interpreted their experiences as extraterrestrial in origin, usually preferring a psychic or spiritual interpretation. As for the 'balls of light' we, too, found a number of respondents who claimed to have had such an experience. The Roper Poll found that 8 percent of Americans reported lights. In our surveys the figure was higher: 17 percent of adults and 28 percent of children. Strange lights and patterns of lights are common forms of hypnagogic or hypnopompic hallucination, so it is unsurprising that the incidences are so high. What is surprising is the suggestion that such natural, common experiences are indicative of alien abduction.

I have little to say about the final two 'symptoms'. They were: losing track of time for an hour or so (more ominously called 'time-loss'), and the finding of 'puzzling scars' the origin of which the respondent could not recall. Suffice it to say that human memory is not a video tape recorder and absences and inaccuracies in our memories are neither uncommon or evidence of extraterrestrial activity.

None of these individual 'symptoms' is exclusively 'caused' by alien abduction, and to be fair Hopkins et al. do not suggest that they are. To come under their definition of an abductee, you have to have experienced at least four of the five symptoms. This roughly comes out as 3.7 million Americans (about 2 percent). On that basis, I'm surprised that the insurance premium was not higher, as the chances of getting snatched (if we can assume that abduction rates are the same across the Atlantic) seem pretty high!

Even Hopkins, Jacobs, and Westrum accept that individually any of the symptoms can arise naturally, independently and without the intervention of ETs, so why should we accept that any combination of the experiences be evidence of abduction? If a person suffered four out of the five symptoms within a single episode that might be more impressive (but hardly inexplicable), but the poll gives no indication of whether these symptoms

occurred together or separately over a space of many years. From having delivered similar types of questionnaires myself, I suspect that the latter is more likely and that the respondents to the Roper Poll were remembering: that time in 1988 when they had an attack of sleep paralysis, an occasion when they were little when they thought they saw a light in their room, an occasion last week when they discovered a small cut on their hand but didn't remember how they did it, and so on.

For the past year Dr Susan Blackmore and I have been collecting reports and conducting surveys of sleep paralysis and other unusual experiences for a research project funded by the Perrot-Warwick fellowship. From our research it appears that, rather than 'symptoms' like sleep paralysis and hypnagogic hallucinations being caused by alien abduction, it is rather the other way around .

Alien abduction, in many cases, is an interpretation of sleep paralysis and hypnagogic hallucination. Experiences of abduction that follow this form will be entirely subjective experiences, so there will be no physical proof that the person has been 'snatched'.

Any skeptical claims assessor would require more than reports of nonspecific 'symptoms akin to post-traumatic stress' or accounts elicited while a person is under hypnosis before handing over the cheque. I doubt very much that the story of Dagenham Dave has any basis in fact, but if it were true the insurance clerk who sold the policy would be laughing up his or her sleeve.