Human Folly & the Paradox of Human Intelligence

Seeing Things: Collective Hallucinations

Perception is an active process. Our minds are not simply passive recipients of a series of sensory inputs. Our eyes are not video-cameras and our brains are not computers – it is all much more creative than that. We interpret what we perceive, and we do this in the terms of our cultural framework, and in the light of our own experiences and expectations. In fact we are constantly recreating an impression of the world and continually forming hypotheses about what we are seeing. In other words we see with our imagination as well as with our eyes. We are fairly good at this, but not perfect; perception has its limitations. As philosophers have long pointed out, our perceptions are constructs and should not be mistaken for reality itself - waking experience is just as much a construct of our minds as our dreams. But such is our reliance on a narrative format that a story has to be woven out of events as they present themselves – and even implausible explanations will be adopted when there is no alternative.


“The most striking indication of the greatly increased suggestibility of crowds are afforded by well-authenticated instances of collective hallucination, instances which, so long as we fail to take into account the abnormal suggestibility of the members of crowds, seem utterly mysterious, incredible, and super-normal.”

William McDougall

Phantom Armies, Strange Portents

From a modern perspective, what are we to make of the weird happenings in the skies of post-medieval Europe? There are literally hundreds of accounts from this period of what can only be described as apocalyptic apparitions, many of which are recounted in great detail by apparently reliable witnesses. These were not transitory mirages; most were prolonged and, typically, appeared above huge crowds of fascinated, and frequently terrified, onlookers. Some manifested as spectral battles, and there was often a martial theme to these aerial spectacles, but others, whilst equally dramatic, were less obvious in their meaning. Whatever form they took and whatever significance was placed upon them, these sightings were generally as ominous as they were mysterious. In 1554, the citizens of Nuremberg were awed by the spectacle of vast hordes of charging cavalry. In 1598, at Cockermouth in Cumbria, a furious battle took place between ghostly regiments of soldiers. There are reports of another ghostly army, visited on Berkshire in 1628, this time accompanied by the sound of heavy artillery and the steady beating of a drum - an event that, at the time, was taken to presage the Day of Judgement and ‘caused many to fall on their knees’. In fact, if we can believe contemporary accounts, there were similar occurrences in Britain, and all over the European continent, from around the middle of the 16th century to the early 17th.

Polish chronicles speak of an immense funereal procession of hooded black figures, treading a menacing path across the sky (1581). The inhabitants of Wittenberg were similarly awe-struck by the appearance of a huge bloody sword and cannon mounted on wheels (1547). Flaming swords also appeared over Devon, where they were interpreted as a sinister portent of impending calamity. The small town of Eisleben was the setting for an enormous crucifix, which was accompanied by a rod and two fiery pillars (1561). The heavens above Normandy and Picardy were, on several occasions, the spectacular stage for ‘angels brandishing dangerous weapons’. Tales of the appearance of monstrous animals (dragons, bears, lions or serpents) fighting in the sky were widespread, as were accounts of triple suns, inverted rainbows etc. There were many such narratives of strange and prodigious sightings around this time - and practically all induced a sense of foreboding.

What was really going on here? Phantom armies; incomprehensible but portentous signs; wild, aggressive animals; mystery, threat and fear. This is surely the stuff of nightmares? To the modern mind the accounts of these events raise a whole range of questions – not least, their reliability. Were these descriptions the product of a few inflamed imaginations? Were they grossly exaggerated for some underlying religious or political motive? Is it really conceivable, even in a far more credulous age, that hundreds of people, in widely separate localities, could have had such similar experiences, and agree in the details of their elaborate fantasies? And could they really have occurred with the frequency that the records indicate? Are, in fact, mass-hallucinations of this kind possible at all?

To begin with the last point, it would seem that, surprisingly, the answer has to be in the affirmative. So many of the contemporary accounts indicate that this was the case, and there are enough comparable examples from more recent times to believe that many, possibly the majority, of these events were experienced as real by those involved. That said, there remain many aspects these strange occurrences that warrant further investigation - and which have a strong bearing on the subject of collective delusion in general.

The setting is always a prime consideration in these matters – including, of course, broader concerns of cultural conditioning and expectations. Europe, in this post-medieval period, was undergoing massive social change and political upheaval. The background to these numerous incidents of ‘Signs in the Sky’ was one of a historical phase-change. At the time much of Europe was affected by serious political and religious instability; these were tense, edgy days. Now, there is well-established psychological effect that a degree of dissociation may occur as a reaction to emotionally charged situations. Dissociation, particularly in conditions of anxiety and heightened emotional anticipation, tends to make the subjects involved more vulnerable to suggestion. Moreover, this response is enhanced in any collective milieu. In such circumstances the power of suggestion, particularly if it is from an authoritative source, can be very compelling. These are, in fact, precisely the conditions in which collective hallucinations may occur.

There is another factor. Hallucinations do not usually come out of thin air; they appear in response to suggestion or persuasive imagery, around which they are able, so to speak, to nucleate. In other words, suggestion and vivid imagery can give form and content to a prevailing mood or underlying anxieties. The principle source of the imagery that fired unsettled imaginations at this particular time came from the multitude of tracts, pamphlets and popular anthologies of prodigies that were then in circulation. There were older traditions of omens and portents in the sky, from biblical and even classical sources, so they had a cultural familiarity, but since the advent of printing (and the even more recent mass-production of paper), images of the sort of sky signs that might be expected became more widely available – moreover, they were presented in graphic and sensational forms. This popular literature became very influential, often fuelling and providing the graphic imagery for apocalyptic notions of an impending cosmic battle between good and evil. The old certainties of medieval life were disappearing; many felt that they were living in the Last Days,

As an aside - this was not to be the last time that an advance in media technology was to make a profound impression on a collective consciousness. One has only to think of the terrible misuse of radio by the 20th century dictators, and its devastating role in the Rwanda genocide. In post-medieval Europe, ideas that had hitherto been the province of the learned few, together with fantastic tales that had once been passed person-to-person, were now widely available, and were being presented in explicit detail, carrying all the authority, and persuasiveness, of printed words and images. The impact must have been enormous. One can then imagine that the appearance of unusual cloud patterns provided a sort of screen on which groups of agitated people could project their collective fears and fantasies.

In collective phenomena of this kind, however unusual, there is generally a high degree of agreement on the details of the experience. Always allowing for the possibility that there may be an element of telepathic rapport in mass-hallucinatory imagery, there is in any case always likely to be a consensus on what is seen, simply as a result of common preconceptions and expectations. This certainly appears to have been the case in post-medieval Europe. The visions were fantastic, and ominous - and were generally agreed upon. There is one other component to this equation, one that is a somewhat overlooked factor in investigations into outbreaks of irrational behaviour, and that is the ‘desire for excitement’. Humans have an almost physiological need for stimulation; boredom can be painful, excitement is stimulating. And what could be more exciting than witnessing extraordinary, miraculous events? They offer the ultimate distraction from the tedium of ordinary life.

Dissociation and The Group Mind

The circumstances in which a group, in a state of heightened emotional receptivity, is responding to some potent form of suggestion come very close to those of the classic prior conditions for hypnotic induction. Although there are important differences between the different forms of trance, probably the easiest way for us now to comprehend the strange phenomena of collective hallucinations of the kind described above is by analogy with the deluded behaviour of hypnotised subjects.

Stage hypnosis works by crudely exploiting the human capacity to enter a trance state. Its methods are ethically dubious, but they are relatively simple. The fact that they work at all, that apparently intelligent people can, in a very short space of time, go along with the most improbable suggestions, and act in the most outlandish ways, provides the best insight into the psycho-mechanisms that underlie collective delusions. The fact that the trance state is notoriously ‘contagious’ also seems to have a strong bearing on the broad subject of collective obliquity. The so-called observation technique, in which subjects are hypnotised as a result of watching others go into trance, is in fact a well-established method of hypnotic induction. The apparently contagious effects of hypnotically-induced trance also mean that in the course of a hypnotic demonstration of any kind an increasing proportion of the audience become dissociated and drawn into a receptive, i.e. hypnotizable, mood. In fact, this sort of collective vulnerability to suggestion can exert an extremely powerful influence on events, on stage or off. Clearly, there are analogies here with a whole range of irrational mass-movements in which contagion seems to play a role.

In special circumstances, and given appropriate cues, collective imagery appears to develop almost of own accord. In one well documented account the members of the crew of a French frigate that were searching for survivors of a wreck clearly saw a raft laden with men showing signs of distress (these events occurred in broad daylight on a fairly calm sea). When lifeboats were lowered from the frigate and were approaching the raft, the sailors and officers on the rescuing craft saw 'masses of men in motion, stretching out their hands’, they also heard the dull, confused noise of a great number of voices. When, however, the rescuers finally reached the 'raft' it was found to be nothing more than a few branches of a tree that had somehow been swept out to sea. The hopes of the crew, who had desperately wanted to find survivors, had somehow provided the rest of the mirage, which was experienced as real by a great many officers and men.

Obviously, in this example, the heightened emotionality of the situation was responsible for increasing the crew’s sensitivity to suggestion. The incident was apparently triggered by a sailor on watch calling out that he had seen a wrecked boat. The crew’s collective imagination then led them to construct the ensuing, elaborate fantasy. In another well-documented case, the crew of a ship were disturbed by the clear image of a cook who had recently died onboard. He was distinctly seen and recognised by all, walking with his distinctive limp on the surface of the water – until, on closer inspection, this ‘ghost’ also turned out to be a mirage – again based on a piece of wreckage bobbing about in the waves.

Incidents of these kinds of shared hallucination are often sparked off by rumour, particularly if these are of a sensational nature - and they are frequently associated with religious fervour. Rumour can provide the framework and the imagery, which, if the conditions are favourable, can rapidly be built up by a collective imagination; particularly by a pious collective imagination.

In the Realm of the Miraculous

In Cairo in 1968 rumours began to circulate among the (oppressed) Coptic Christian community of a miraculous appearance of the Virgin Mary on an ordinary, plain glass window in a local church. Within a very short time the church was besieged by believers, many of whom 'saw' the image and whose enthusiasm rapidly communicated itself to others. There soon developed a sort of communal religious panic, which, like a tornado, rapidly began to feed on itself. Thousands of people tried to force their way into the church, and in the chaos that followed there were several deaths and hundreds of injuries, many serious. When the incident was subsequently investigated it transpired that there had only ever been a slight, transitory discolouration of the glass, an effect that had lasted for just a couple of minutes. The visions, the wild enthusiasm, and the ensuing riot were all the result of a mass hysterical cascade.

The Cairene Coptic community was the focus of another series of strange sightings, which started around the same time (1968), but persisted for some years. The affair began when two mechanics (who happened to be Muslims) noticed a white figure standing high on the dome of the Coptic Church of St. Mary, Zeitoun. Fearing that the figure might be that of a nun, possibly intending to throw herself off, they acted quickly, phoning the fire station and fetching a priest. A crowd soon gathered as a result of their well-meaning actions, and together they observed the apparition for a few minutes until it disappeared from view. A week later it reappeared at the same spot - and it continued to recur at odd intervals. Occasionally the vision would persist for hours on end, and eventually the phenomena became so well-known and attracted such large crowds that a space was cleared to accommodate them by demolishing some old buildings.

For the majority of pious observers the figure was a visitation of the Blessed Virgin Mary. It seems that the figure’s arrival was usually preceded by flashes of light. Mary herself wore flowing robes of light and was sometimes accompanied by doves (who, strangely, flew around her without flapping their wings). Over time, the apparition continued to appear, though in a more sporadic way, becoming much less frequent by 1970, and finally ceasing in 1971, by which time she had been witnessed by hundreds of thousands of people. So what was going on? There seems little doubt that this Church was the setting of some unusual phenomena; the most likely explanation for which was that of phosphorescence associated with gas escapes that were linked to local seismic disturbances. Contemporary photographs of the apparition reveal vague, formless shapes of the kind associated with gas flares; but there is no doubt that crowds saw something far more miraculous. As always, the level of suggestibility was high among the expectant crowds - reflecting the general rule that the larger and more homogenous a group, the greater the pressure on individuals to respond to its collective moods and beliefs. Probably for these reasons the Church authorities have held somewhat ambivalent attitudes to sightings of the Blessed Virgin - sometimes the miraculous events are approved of; at other times they are condemned as the Devil’s mischievous work.

This might be the place to note the semantic distinction between hallucinations and illusions. A hallucination occurs without any actual event providing the sense-impression; in other words, the events perceived are not real, but they are experienced as if they were (hallucinations may be complex and affect several senses, which, of course increases the sense of reality). Illusions, by contrast, are simply a misinterpretation of some aspect or other of a real event. In practice though, as in so many aspects of this subject, there are no hard and fast distinctions. Eidetic imagery, the vivid mental images which some children can produce at will, seems to approach the clarity of visual hallucinations. But there is no way of measuring the intensity of these images, anymore than there is the normal recollections of memory, or of ordinary imaginative recall.

Interestingly, science has yet to come up with a convincing hypothesis that applies to ‘states of altered consciousness’ in general, hypnotically-induced or otherwise. There is still controversy as to whether the hypnotic state itself is a genuinely separate condition (i.e. distinct from both sleep and waking), and there has been no real resolution of old arguments over the extent to which subjects are compliant in the hypnotic state (social compliance theory). The reality seems to be that the trance/hallucinatory phenomena is multiform; that there are many behavioural variants in this area, and that these states are highly responsive to conditions. It would appear that every event involving trance, hypnotic induction, suggestion, auto-suggestion etc., has its own characteristics and its own dynamic. In short, the subject does not lend itself to neat classification

What is clear, however, is that suggestion can indeed be a powerful motivating force - and it can have a long reach. In May 1953 thousands of pilgrims began to pour into the remote area of Sabana Grande on Puerto Rico in response to a rumour of the imminent appearance of a Virgin Saint. They came from all over the island and from Haiti, the Dominican Republic, Cuba, and even from as far away as Miami and New York. The rumours had started about a month earlier when seven children reported that the Virgin had appeared to them by a small well, promising to return at a specified time. The story had been taken up, first by the local press, then by the national newspaper El Mundo. In no time at all, the local Mayor had an altar built by the well, and reporters from the national Radio station were making daily broadcasts from the site. Although the children’s story had clearly gotten out of hand, their parents encouraged them in their fantasy. The Church, in this case, took a dim view of the proceedings, but was unable to quell the enthusiasm.

By the day of the promised appearance an excited crowd of between 100,000 – 150,000 pilgrims were crammed into the small valley where the well was situated. Since no provision of any kind was made for them, conditions soon became difficult, and as the promised hour approached the tension mounted. Many miraculous events were reported and rapidly circulated – rain fell off the children’s clothes in various colours; the Virgin appeared silhouetted in the clouds; people who had felt sick for years suddenly felt well. Just after the expected moment a cry went up that the Virgin, dressed in black, was making her way to the well down the west hillside, at which point many rushed in that direction, whilst others were entirely overwhelmed with emotion. It turned out though, that this figure was just an old peasant woman dressed in black. It took quite a while for the crowds to accept this and calm down. Then rumours spread that the Virgin was on the east side of the hill, wearing white. There was another wave of excitement, but this vision soon proved to be based on nothing more than an old man in a white shirt. The crowds waited and watched for several hours, but the Virgin did not in fact appear at all. By evening there was a general drift away from the site.

The aftermath of this non-event is a case-study in itself, presenting all the elements of wishful thinking, self-deception and retrospective falsification. Those who had not seen the Virgin themselves believed that the children had; most of the pilgrims apparently felt that something supernatural had happened that day, even though most were unsure of what it was; there were many reports of unusual celestial phenomena; and many others of cures from those who had come to get relief from illness. Whatever else did or didn’t happen, Sabana Grande became firmly established as a place of pilgrimage. The following years saw a regular flow of visitors to the site (an average of 200 on weekdays, 3000 on Sundays). Pilgrims collected water from the well to pour on afflicted parts, or to take home for others, and money was regularly donated to erect ever more altars around the location of the original miracle.

Moving Pictures: Expectations, Suggestion and Format

“Beliefs are contagious”

Bertrand Russell

There is in fact a long history of ‘Marion apparitions’ in the Catholic world. The Reformation actually saw a decline in this tradition, but it saw a revival in the 19th century with, among others, the famous sightings at La Salette, Lourdes and Fatima. In the course of these latter-day appearances, a general pattern seems to have emerged. Each began with young children claiming to have seen the Virgin Mary, an encounter that typically met with initial disapproval, followed by belief, and then encouragement. The apparitions is revealed to have made promises of further appearances, leading at first to a localised religious panic, which, as the word spreads, develops into a mass pilgrimage. Healing springs are usually woven into the picture, and visiting pilgrims frequently witness miraculous signs in the sky (the Sabana Grande episode closely followed these prototypes). The less religiously inclined have observed that these apparitions tend to occur at times of social stress

Naturally, the more sensational aspects of these events generally received early and wide publicity, with the effect that true believers were given some notion what to expect, and how to react.. In other words, rituality becomes established. This is a response that resonates with the post-medieval hallucinations; in addition to the elements of dissociation and openness to suggestion, expectations are usually modelled by some more general notion of format. Pre-publicity can be an important factor, and of course cultural influences play their part; Christian believers witness Christian marvels, Hindu believers see Hindu-flavoured ones. But brand new forms are always there to be discovered. The modern version of ‘mysterious objects in the sky’, the UFO craze, is a case in point (q.v.).

One of the more peculiar genres of collective hallucination, which seems to have a particular vogue in the late 19th century, is that of pictures and statues ‘coming to life’. This phenomenon was obviously closely related to the ancient belief in wonder-working icons, holy relics and the like. One of the most dramatic outbreaks took place in a church at Santander in Spain in 1919. This strange affair began when members of the congregation noticed that the eyes of some of the paintings of saints appeared to move, and others seemed to drip blood. Very soon, it would appear, the saints were even stepping out of their panels! Naturally, as soon as word got out about these miraculous events, people came from miles around. The church was soon packed, day and night, with curious and excited believers. In this highly charged atmosphere there were a number of further miraculous sightings. Later, when the event had blown over, many of those who had been present made sworn statements testifying to the incredible scenes that they had witnessed. Several professional people of the highest integrity were among those who were convinced of the authenticity of these remarkable events.

The Santander episode was exceptionally florid, but it had precedents in an earlier series of outbreaks in Italy. There were instances in a church in Rimini where, on five separate occasions between 1850 and 1905, the eyes of paintings had been seen to move and shed tears. Similar miracles had occurred at Campocavallo in 1893. And in Soriano, Calabria there was a statue that had become famous for moving an arm and hand. In these events, as in all such occurrences, belief and hallucination were mutually confirming; that is to say, the certainties of belief were strengthened by witnessing miracles, but the nature of the incidents was largely programmed by faith.

It is probably no coincidence that this genre of ’moving pictures’ came to an end at around the time that the cinema and ‘movies’ began to appear. This is not to say that the advent of modern technology banished collective sensory hallucinations; rather that its imagery, as ever, adapted to reflect new realities and new anxieties. It is worth reiterating that every kind of trance behaviour is culturally conditioned, and obviously will have a particular relevance to its social setting The classic 20th century version of ‘signs in the sky’ is of course the UFO phenomena, which emerged in the U.S. in the mid-century, quite literally out of the blue. These presented entirely new forms of imagery, which in time lead to strange new mythologies. But the rapidity with which this craze caught on and became a focus for collective imaginations (the numbers of sightings and their world-wide spread were soon enormous) make for an interesting comparison with the aerial apparitions of the post-medieval world.

Flying Saucer Mysteries

“Because of the unusual character of the story there is much eagerness to pass it on”

Ibn Khaldun

At the time of writing, an internet search for ‘UFO’s’ generates close on eight million sites; if this is qualified by the term ‘hard evidence’ the number of sites is reduced to some two and a half million; if ‘scepticism’ is added the list is diminished to a mere 813 (the majority of which provide neither hard evidence nor scepticism). But this casual survey presumably provides some indication of the extent of interest in the subject at present; the emerging picture is of an abiding fascination, bordering on obsession among a hard-core of believers, and a widespread half-belief. It is now some sixty years since ‘flying saucers’ were first sighted, and despite a paucity of any real evidence for alien spacecraft (the hard-nosed would say that there is none at all), despite this, there is a huge body of interest and belief in the existence of UFO’s, and a virtual industry of speculation, based on their existence.

As is the case with many collective phenomena, the flying saucer genre was precipitated by a trigger-event. The saga began back in June, 1947 when a businessman flying his private plane over the Cascade Mountains in Washington noticed a group of mysterious objects, apparently flying in formation at high speed. When he landed he reported what he had seen to a local newspaper - ‘They flew as if they were linked together, swerving in and out of the mountains with flipping, erratic movements’; ‘Like a saucer would if you skipped it across the water.’ The story was so intriguing that it was immediately wired to other newspapers across the U.S. - and it rapidly took on a life of its own.

Despite the fact that the original report did not refer to the UFO’s as saucer-shaped this profile became their defining image. The craze soon spread from America to the rest of the world, and people began to see flying saucers all over the place; newspapers were absolutely inundated with reported sightings. This initial phase of the flying saucer craze, when it really gripped the popular imagination, took place in the late 1940ies - early 1950ies. During this period it was also taken up by Sci-Fi magazines who published many accounts that carelessly blurred the distinctions between fact, fantasy, rumour and low-grade journalism. It was in these publications that the connection was established between flying saucers and beings from outer space. These imaginative, usually over-heated, stories went on to provide much of the stock repertoire of saucer mythology - their extra-terrestrial origin, their super-intelligent alien crews, their highly advanced technology etc. There was less certainty about the visitor’s intentions towards the human race; these were sometimes portrayed as benign, though rather more often they were depicted in a menacing light.

There are obvious comparisons to be made between the broad, almost subliminal influence of these writings and that of the fantasies promulgated by the post-medieval tract-writers referred to earlier. Each provided a framework that could explain and give meaning to all manner of unusual phenomena – and, as with religious miracles, faith and imagination have tended to be mutually confirming.

UFO mythology is extraordinarily persistent. Even the briefest catalogue of UFO incidents over the past half-century would be far too long to include here, but the following account from 1966 is typical ...On this occasion the UFO, which was accompanied by four sister ships, landed in a swamp near Ann Arbor, Michigan. The landing was witnessed by more than fifty people, including twelve policemen and all later agreed on what they had seen. The craft was shaped like a football (American, of course); it was about the length of a car, had a greyish-yellow colour and seemed to have a coral-like pitted surface. It had a blue light at one end and a white light on the other. The spectators on this occasion were curious rather than afraid – one man sat in his car blinking a coded message with at it with his headlights, another dashed off and brought his fiddle to the scene Others ran to within 500 yards of the craft, when, ‘with a sound like a ricocheting bullet’ it suddenly took off. The UFO then apparently joined its sister craft in the sky, and together they sped off. Six police cars chased the formation as far as they could, but the group soon vanished. Detailed statements about the incident tallied closely. The U.S. Air Force was reliably tight-lipped about the affair; the Flying Saucer Society chalked the incident up as yet another piece of confirmation.

There are hundreds of accounts like this, especially in the U.S. during the early, heady days of UFO spotting. They leave those of a moderately-sceptical disposition nonplussed – can the testimonies of randomly-selected groups of solid citizens be dismissed as utter fantasy? Are the incidents related and/or ascribable to some perfectly explicable phenomenon, or are we really being monitored by an alien intelligence? The problem is that anecdotal evidence of this kind, however sincere, is notoriously unreliable; the fact that a larger group rather than individuals are involved does not, in reality, support the veracity of their claims. There are various well-established psychological responses that have contributed to collective illusions of the flying-saucer kind. To begin with, the UFO credenda has been sustained over the years by a great deal of communal reinforcement – this is the process by which suppositions and theories harden into strong beliefs simply by repeated assertion. Then there is confirmation bias – the tendency to take note of data that confirm one’s ideas and beliefs, and ignore evidence to the contrary. If we add wishful thinking and the willing suspension of disbelief to the list, the stage will be set for a UFO event.

Unfortunately, this field, which has always been characterised by a propensity for untrammelled speculation, has also been the subject of hoaxes, frauds and forgeries. There have been so many of the latter that it must always difficult to exclude the possibility of deception in any particular incident – so duping delight, the never-to-be-underestimated impulse to ‘put one over’, must also be taken into account in UFO incidents. Naturally, conspiracy theories (see Book 4) also enter into the picture; most dedicated Ufologists subscribe to some version or other - if only to the belief that the absence of any official acknowledgement of UFO’s simply indicates that they, the authorities, do not want us to know what is really going on.

Perception, Interpretation and Imagination

It may seem easy to dismiss most of the more extreme examples cited above as little more than the product of over-excited imaginations. But the reality is that most of us at some time or other will have experienced hallucinations. To momentarily mistake a complete stranger on a busy street for a close acquaintance is a common experience, just as it is to see things that are not really there whilst fatigued and driving alone at night. Minor illusions, such as ‘seeing’ a bunch of flowers on the pavement that turn out, on closer inspection, to be a pile of litter, are commonplace. Misconstructions of this kind are usually quickly resolved as part of the normal process of ‘reality checking’. They occur in the first place because imagination has an essential role in perception. Perception is not a passive process, but involves the active participation of a great many subtle and complex mind/brain mechanisms, including the creative faculty involved in imagination.

These cognitive processes provide us with a perfectly adequate approximation of the ‘real’ world for most ordinary purposes, but they are not designed to provide a complete picture of our surroundings or a total recall of past events – this would require far too much data-storage. So, like microprocessors, we compress data - but unlike microprocessors we are also habitual formers of hypotheses; we make predictions. The brain seems to work by continually guessing about what we are seeing, how it will be in the near future, and continually comparing these notions with received images (reality testing). So we ‘see’ with our imagination as well as with our eyes. These thought processes are not, of course, usually apparent; in normal functioning they are unconscious and instantaneous. But perception tends to be a somewhat broad-brushed affair and habitually take all kinds of ambiguities and contradictions in its stride. To complicate matters we humans are also inveterate seekers after meaning, consistency and coherence, and habitually ascribe these qualities to objects and events, even when they are not really there.

The perceptual incongruities that occur during hypnosis (i.e. when subjects are convinced of the reality of a situation that has been suggested to them) seem to derive from a ‘decoupling’ of the imaginative and monitoring faculties. In the state of hypnotic trance, with the monitor temporarily off-duty, the imagination, bolstered by suggested imagery, is given full reign – while the faculty that confirms meaning and coherence functions as usual, and sanctions the images. Something like this happens to us all in the dream state. Dreams can be weird, but we completely accept their ‘reality’ at the time.

Despite its obvious relevance to any model of consciousness, and to patterns of social behaviour, neuroscience has long been wary of the trance/hypnotism phenomena. In fact there is a long history of controversy associated with the subject, and it is easy to see why it has been treated somewhat perfunctorily. So many of the contributory factors seem to be on a sliding scale - the cultural background; the degrees of anxiety and expectation operating at the time; the suggestibility, or otherwise, of the subjects; the power of the suggested images; the influence of the group; the manipulative skills of an inductor. All of these things, as we have seen, can profoundly influence proceedings. The problem is, with so many variables and ambiguities it is very difficult to come to any reliable conclusions on this matter - which is the whole point of scientific investigation.

Neuroscientific reservations on the subject of ‘altered states of consciousness’ is mirrored to some extent by the cautious approach that has, over the years, been adopted to the study of collective behaviour. Understanding the collective mind is obviously as impossibly complex a task as delving into the individual mind – both are subject to many conditioning influences. The notion, espoused by some bold neuroscientists, that everyone is permanently in a trance-state to some degree, and that we move from one trance state to another only by means of hypnotic suggestion, is particularly distasteful to those who take a more reasoned, rational (and conventionally scientific) approach to the subject. It is a strange theory, but it goes a long way to explaining many of the more peculiar occurrences depicted in this book. Excessive collective behaviour often seems alien and peculiar because it appears to be such a gross departure from civilised norms. But there is less of a step from the one to the other than most of us would like to suppose. In fact, there is no aspect of deviant collective behaviour that does not have its roots in the emotions of ordinary life; fear, hostility, enthusiasm, greed, hypochondria etc. – and, as we have seen, visual misperception. The reality is that, at bottom, the norms of rational, polite social behaviour are no less a social construct than the more extreme manifestations of contagious, collective delusions and mass-hallucinations.