Category: Magic

People Agree It’s Harder To Conjure A Frog With Magic Than Change Its Colour – Suggesting We Use Our Intuitive Physics To Make Sense Of Imaginary Worlds

via McCoy and Ullman (2019)

By Christian Jarrett

In a world with magic, how much effort do you think it would take to cast a spell to make a frog appear out of nowhere? What about to turn a frog invisible? Or make it levitate? And would it be easier to levitate a frog than a cow?

The researchers John McCoy and Tomer Ullman recently put such questions to hundreds of participants across three studies and found they were in remarkable agreement. The findings, published in PLOS One, suggest that we invoke our intuitive understanding of the physical world – our “folk physics” – to make sense of imaginary worlds. And they help explain why fantasy TV shows and books can lose their magic as soon as it feels like anything goes. “Superman leaps tall buildings in a single bound, but a building takes more sweat than an ant-hill,” the researchers said. “And even for Superman, leaping to Alpha Centauri is simply silly.”

Continue reading “People Agree It’s Harder To Conjure A Frog With Magic Than Change Its Colour – Suggesting We Use Our Intuitive Physics To Make Sense Of Imaginary Worlds”

Massive Comparison Of Narrative Accounts Finds Ketamine Trips Are Remarkably Similar to Near Death Experiences (NDEs), Supporting The Neurochemical Model Of NDEs

Screenshot 2019-02-22 at 09.26.54.png
Similarity in the most frequently used words in accounts of near death experiences (NDE) and ketamine trips, via Martial et al, 2019

By Christian Jarrett

First-hand accounts of what it is like to come close to death often contain the same recurring themes, such as the sense of leaving the body, a review of one’s life, tunnelled vision and a magical sense of reality. Mystics, optimists and people of religious faith interpret this as evidence of an after life. Sceptically minded neuroscientists and psychologists think there may be a more terrestrial neurochemical explanation – that the profound and magical near death experience is caused by the natural release of brain chemicals at or near the end of life.

Supporting this, observers have noted the striking similarities between first-hand accounts of near-death experiences and the psychedelic experiences described by people who have taken mind-altering drugs.

“I had the feeling of floating, still tied to the remains of my heavy body, but floating nonetheless. I rocked and moved, at times as if on a liquid, undulating surface, at other times rising upwards, like a helium-filled flat container.” Excerpt from Amazing First-time Experience in the K-hole, published by Phaeton at the Erowid Experience vaults.

Perhaps, near death, the brain naturally releases the same psychoactive substances as used by drug takers, or substances that act on the same brain receptors as the drugs. It’s also notable that psychedelic drugs have been taken by the shamans of traditional far-flung cultures through history as a way to, as they see it, visit the after world or speak to the dead.

To date, however, much of the evidence comparing near death experiences and psychedelic trips has been anecdotal or it’s been based on questionnaire measures that arguably struggle to capture the complexity of these life-changing experiences. Pursuing this line of enquiry with a new approach, an international team of researchers led by Charlotte Martial at the University Hospital of Liège has conducted a deep lexical analysis, comparing 625 written narrative accounts of near death experiences with more than 15,000 written narrative accounts of experiences taking psychoactive drugs (sourced from the Erowid Experience vaults), including 165 different substances in 10 drug classes.

Continue reading “Massive Comparison Of Narrative Accounts Finds Ketamine Trips Are Remarkably Similar to Near Death Experiences (NDEs), Supporting The Neurochemical Model Of NDEs”

Is it a good idea to start a lecture with a magic trick?

MagicianBy Christian Jarrett

It’s late, the room’s warm, and the students look sleepy. To liven things up, how about starting the lecture with a magic trick? In favour of a little abracadabra, it’s known that exposing people to paradoxes gets them thinking creatively, and brain scan research has shown that watching magic fires up neural networks involved in problem solving. But on the other hand, maybe the magic could just end up a big distraction – the students might spend time wondering how the trick was done – or maybe the lecture will just seem dull by comparison.

Continue reading “Is it a good idea to start a lecture with a magic trick?”

Using a cocktail of magic and fMRI, psychologists implanted thoughts in people’s minds

By guest blogger Vaughan Bell

Can you think a thought which isn’t yours? A remarkable new study, led by psychologist Jay Olson from McGill University in Canada, suggests you can. The research, published in Consciousness and Cognition, used a form of stage magic known as “mentalism” to induce the experience of thoughts being inserted into the minds of volunteers. It is an ingenious study, not only for how it created the experience, but also for how it used the psychology lab as both a stage prop and a scientific tool.

Years before he was famous, stage illusionist Derren Brown wrote a book called Pure Effect, where he argued that presenting tricks as “psychology” could be an effective form of misdirection. In his innovative shows, Brown often claims he is debunking psychics by demonstrating how psychology can be used to manipulate people’s minds. In practice, his mind-reading and mind control feats can involve the same traditional techniques used by stage magicians, it’s just that he presents them as psychology rather than magic.

Olson and his colleagues from McGill took this approach a step further, telling their participants that they were taking part in a study to see if an fMRI brain scanner could read thoughts and influence their mind.

Hidden from the participants was the fact that the experiment was actually conducted in a mock scanner – something that exists in most neuroimaging facilities to test experiments before they are run on the genuine equipment. To add to the plausibility of the story, the participants went through a realistic briefing, safety screening, and calibration procedure for an fMRI brain scan.

Participants were then asked to complete what they thought were “mind reading” and “mind influencing” experiments.

In the “mind reading” stage, researchers asked each participant to lie in the “scanner”, silently think of any two-digit number and press a button when they were done. The fMRI machine then produced a number on screen and the researcher could be seen writing the result onto a clipboard.

Next, the participant was asked to name the number they had silently thought of. The researcher turned the clipboard, stunning the participant by showing exactly their number – seemingly “read” from their mind by the power of fMRI.

The researchers are coy about exactly how this was achieved, only referencing an old mentalism book. In fact, they likely used a variation on a technique called the “swami gimmick” where the mentalist – the researcher in this case – has a fake rubber tip on the end of their thumb, which includes a barely visible shard of pencil lead. Earlier, when the researcher appeared to be writing the fMRI “mind reading” results, he was just pretending. What really happened is that, in the split second after the participant announced their secretly selected number, the researcher discreetly wrote it down on the clipboard using their thumb.

In the second, “mind influencing” condition, the participant was told that the machine was programmed to put a number into their mind. This time the researcher “wrote down” the number the machine had chosen to “transmit”. As before, the participant was asked to silently think of any two-digit number and after the “scan” the researcher seemed to show that the participant had thought of exactly the number the machine had ‘transmitted’ to them – using, of course, exactly the same thumb-writing trick as in the mindreading phase.

So here’s where the real psychology came in. After the scans, the researchers asked the participants to rate how much control they felt they had over their choice of numbers. Of course, in reality all their choices were completely voluntary, but in the second stage of the experiment, they believed they had less control and that the machine had influenced their thinking. Consistent with this perception, they also took longer to choose a number in the mind influencing condition than in the “mind reading” condition.

The researchers checked whether anyone had worked out what was really happening. A few participants expressed doubts about whether the “fMRI machine” was really influencing them and were removed from the analysis, but none suspected stage magic.

Olson and his colleagues replicated their results using a second experiment, run in exactly the same way, but this time they also interviewed the participants to find out what they’d felt during the procedure. They reported a range of anomalous effects when they thought numbers were being “inserted” into their minds: A number “popped in” my head, reported one participant. Others described “a voice … dragging me from the number that already exists in my mind”, feeling “some kind of force”, feeling “drawn” to a number, or the sensation of their brain getting “stuck” on one number. All a striking testament to the power of suggestion.

A common finding in psychology is that people can be unaware of what influences their choices. In other words, people can feel control without having it. Here, by using the combined powers of stage magic and a sciency-sounding back story, Olson and his fellow researchers showed the opposite – that people can have control without feeling it.

But the research team’s motivations where not purely focused on everyday psychology. In some types of mental health problems, people start to experience their thoughts and actions being controlled by what seem like outside forces. Olson’s team hope that their work can provide a way of studying one aspect of this experience, safely and temporarily in the lab, potentially providing a window into how these more debilitating experiences affect the mind and brain.


Olson, J., Landry, M., Appourchaux, K., & Raz, A. (2016). Simulated thought insertion: Influencing the sense of agency using deception and magic Consciousness and Cognition, 43, 11-26 DOI: 10.1016/j.concog.2016.04.010

Post written by Dr Vaughan Bell (@vaughanbell). Vaughan is a senior clinical lecturer at University College London and a clinical psychologist in the NHS.

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What your favourite Harry Potter House says about your personality

Harry Potter fans strongly self-identify with the different Houses within Hogwarts, the story’s magical school. Now new research shows that a fan’s preferred House tells us something about their personality.

Laura Crysel and colleagues used an online Harry Potter community to get access to the more committed fans found there, and asked them to complete a personality test. Each fan reported their favoured House, and the results showed that significant average personality differences existed between the fans of the different Houses.

Griffendors were the most extraverted, Hufflepuffs more agreeable, Ravenclaws sought more need for cognition, meaning they are excited by intellectual challenge, and Slytherins reported more of the “Dark Triad” personality traits: narcissism, Machiavellianism and psychopathy. As even casual fans of the series will attest, these personality traits are reasonable characterisations of the fictional members of each House.

The feature of the Harry Potter story that I found curious was the sorting hat, used to allocate new magic pupils to one of these four Houses according to their qualities, abilities and beliefs. And following the sorting, the pupils went on to live up to the predictions: those joining Slytherin, for instance, became venomous bullies, cheats or thieves. At face value, it seemed as if the author JK Rowling was endorsing essentialism: people are what they are, or will turn out a certain way in a deterministic fashion, fated to the dark side. But I wondered also whether there was a rather sly critique going on about self-fulfilling prophecies (see our recent work on expectations about poverty to see real-world parallels).

You can turn the same kind of questions from the books to the readers in this study. Were our reader Slytherins always going to top the league for these Dark Triad traits, or did they start mainly thinking that snakes were cool, then, through a process of group identification, increasingly identify with more behaviours and attitudes endorsed by their fictional school-mates, through hundreds of pages? This is something the study can’t answer for us, but due to its influence, longevity, and presentation of characters over time, the Potter series would be a good candidate for examining how fictional in-groups shape our attitudes.


Crysel, L., Cook, C., Schember, T., & Webster, G. (2015). Harry Potter and the measures of personality: Extraverted Gryffindors, agreeable Hufflepuffs, clever Ravenclaws, and manipulative Slytherins Personality and Individual Differences, 83, 174-179 DOI: 10.1016/j.paid.2015.04.016

Post written by Alex Fradera (@alexfradera) for the BPS Research Digest.

Psychologists use magic to study the illusory feeling of free choice

Most of the time, when a magician asks you to “pick a card” she makes it feel as though you have a free choice, but you don’t really. The authors of a new paper say this is a microcosm for many real-life situations in which we feel free to choose, but in fact our choices are heavily influenced and constrained. Jay Olson, a magician and psychologist, and his colleagues, have put a classic card trick technique under the spotlight as a way to study the psychology behind this experience of illusory free choice.

For each of 118 participants approached on the street or on campuses, Olson “riffled” through a pack of cards before asking the participant to “pick a card”. The 30-second riffling procedure is part of a “forcing” technique in which the magician uses their thumb to pull up and gradually release one end of the deck, ostensibly to give the participant a glimpse of the available cards in rapid succession. It appears a casual gesture, but the technique is carefully performed so that one card – the target card – is displayed substantially longer than the others, and in fact is often the only card shown long enough to be identifiable.

Nearly 100 per cent of participants ended up picking this target card, which the magician duly anticipated and showed to the participants, thus seeming to read their minds. The researchers then quizzed the participants about the experience. Nearly all those who chose the target card felt that they’d had a free choice over which card they’d selected from the pack. Asked why they’d picked the card they had, most said “no reason”, others said it had “stood out”, while the remainder confabulated, such as claiming they’d been thinking of that card earlier, or that the target card had been a bright colour (even when it was black).

Next, the research moved to more controlled laboratory conditions. The basic riffling procedure was repeated but using a computer simulation, in which cards were shown briefly in succession with one “target card” presented for significantly longer than 25 other possible choices (150ms vs. 20 to 70ms).  Participants were again asked to “pick a card”. The simulation was less effective than the real magic trick, with the target card now selected by participants around 30 per cent of the time (of course this still shows a heavy influence on participants’ choices).

The researchers next asked participants whether they’d noticed that one card was displayed for substantially longer than the others: 60 per cent said they had. Particularly interesting differences emerged between those aware of this fact, and those unaware. Among the unaware, personality factors were associated with whether they chose the target card – for example, people with a more external locus of control (they feel their lives are controlled by outside factors) were more likely to have picked the target card. Among those aware that one card had been shown for longer than others, personality factors were irrelevant to whether they picked the target card. Instead, features of the target card became significant, with more visually salient and memorable target cards picked more often by this group.

Olson and his colleagues said their findings have practical significance – they show the potential for using magic to study how people’s decisions can be influenced without them knowing, perhaps ultimately to help them make wiser, healthier decisions. Of course such findings could also be used for malicious ends, although this wasn’t mentioned by the researchers! They did add that their findings also have clinical significance: they say the current study demonstrates feelings of control in the absence of objective control, which is the converse of the experience of some patients with schizophrenia and other conditions, in which they feel their choices are being influenced by outside agents, when in fact they are not.

Olson’s team have made their new data freely available for others to access. “By doing so,” they explained, “we hope to help researchers participate in this growing field [of “forcing” and the factors that influence choice]. In particular, we hope that similar methodologies which combine the realism of the performing environment with the control of the laboratory will foster collaboration between the art of magic and the science of psychology.”


Olson, J., Amlani, A., Raz, A., & Rensink, R. (2015). Influencing choice without awareness Consciousness and Cognition DOI: 10.1016/j.concog.2015.01.004

further reading
The new psychology of everyday playing cards

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

The new psychology of everyday playing cards

Aces are easier to see and remember than other cards

Playing cards, used for games and magic, are so familiar, yet we know remarkably little about the way we perceive and think about them. Are some cards more memorable than others? Are some easier to identify? With so much at stake in games like poker, and card magic a staple of family entertainment, it’s surprising that no-one has thought to study this before.

Jay Olson, Alym Amlani and Ronald Rensink first tested if some Western playing cards are easier to spot than others. Ninety-six students were shown visual streams of 26 playing cards on a computer, each displayed for a tenth of a second, and they had to say if a certain target card was present in the stream or not. The students were pretty good, achieving an accuracy rate of 80 per cent, but they performed better for some cards than others. For example, they detected the Ace of Spades more easily than any other card, and they detected Aces in general more easily than other cards – probably because of their simple, distinct pattern. Surprisingly, face cards (e.g. Jack, Queen etc) were no easier to spot than number cards, despite being more distinctive. Another curious finding was the students’ particular tendency to say the two red sixes (Six of Hearts and Six of Diamonds) were present when they weren’t. It’s not clear why.

To test the memorability of cards, Olson’s team employed a similar methodology. The students saw a stream of seven cards, each displayed for a quarter of a second, and then they were asked to say whether a particular card had been in the stream or not. Again, the Ace of Spades especially, and all Aces to a lesser extent, were more memorable than other cards.

What about likeability? Students were shown pairs of cards and in each case had to say which they preferred. Regards numerical value, the participants liked the highest (10) and lowest (2) cards the most. And they had a tendency to prefer Spades and Hearts over Clubs and Diamonds – maybe because of their rank in games, or their curved shape. Two cards were especially popular – the Ace of Hearts and the King of Hearts. There was also a gender difference in taste. Men tended to prefer higher value cards and women to prefer lower value.

Finally, the researchers looked at the verbal and visual accessibility of cards. To do this they asked a new batch of hundreds of students (some of them online and some in the lab) to “Name a playing card” or to “Visualise a playing card” and then say which it was. Simply asked to name a card, there was a strong bias for choosing the Ace of Spades, followed by the Queen of Hearts and then other high-ranking cards. When participants chose a number card, there was a bias for naming 3s and 7s the most and 6s the least (a phenomenon well known by magicians). Overall, cards from the Spades and Hearts were chosen more than the other two suits. There was a gender difference again: men tended to name the Queen of Hearts more than women, and women more often named the King of Hearts than men. These same results were pretty much repeated when participants were asked to visualise a card before naming it.

The different card features investigated here tended to interact in ways you might expect. For example, the same cards that participants tended to say mistakenly were in a visual stream, also tended to be the most accessible verbally and visually. More accessible cards were also liked more.

Olson’s team acknowledged that their study was limited by the fact that they only studied a sample of Canadian students. But still, they said their work could “serve as a foundation for more rigorous studies of card magic”, and more generally could “provide new perspectives on how people perceive and evaluate everyday objects.”


Jay Alson and Alym Amlani (2012). Perceptual and cognitive characteristics of common playing cards. Perception DOI: 10.1068/p7175

Read more Digest posts on the psychology of magic.

Post written by Christian Jarrett for the BPS Research Digest.

A real study of magicians’ fake movements

Magicians trick us with their sleights of hand, reaching for objects that aren’t there and pretending to drop others that they’ve really kept hold of. This ability is all the more remarkable because research has shown how poor the rest of us are at faking reaching gestures and other movements. Now Cristiana Cavina-Pratesi and her colleagues have used motion-tracking technology to investigate how the magicians do it.

First off, ten magicians and ten controls reached for and picked up a wooden block, or mimed reaching and picking up an imaginary block situated next to the real one. Just as the participants began reaching, their sight was completely obscured by shutter glasses – this was to simulate the way that magicians often look away from where they’re reaching. The participants’ grasps were performed either with forefinger and thumb or little-finger and thumb, and markers were worn on these digits so they could be monitored with a motion-tracking system.

Just as has been found in earlier research, the controls’ pantomime grasping movements were quite distinct from the real thing – the ‘maximum grip aperture’ (the maximum gap between thumb and finger) was smaller, as was a metric called the ‘grip overshoot’, calculated from the position of the thumb and fingers during the actual grasp. In contrast, the magicians’ maximum grip aperture and grip overshoot were the same whether they actually grasped a real wooden block, or mimed grasping an imaginary one next to it.

Having confirmed that magicians’ fake movements really are like the real thing, a second experiment, involving batteries rather than wooden blocks, made things harder. This time, the miming condition was performed without a real, to-be-grasped object anywhere in sight. The seven magicians and seven controls performed their real grasps as before, but when the miming grasps were performed, the batteries were hidden away. Curiously, under these conditions, the magicians were no better at faking than the controls.

The researchers said this suggests that ‘the talent of magicians lies in their ability to use visual input from real objects to calibrate a grasping action toward a separate spatial location (that of the imagined object).’

How do they develop this ability? Cavina-Pratesi’s team think it reflects a flexibility in the magicians’ occipito-parietal system (located towards the back of the brain). ‘This flexibility,’ they said, ‘might exploit mechanisms similar to those underlying people’s ability to adapt to spatially displacing prisms through repeated target-directed movements.’ They’re referring here to the human ability to adapt to prism glasses that distort the visual world. At first the glasses are disorientating, but most people are able to adapt quickly. The researchers said future brain imaging studies will help reveal exactly what’s going on in the magicians’ brains as they perform their trickery.

ResearchBlogging.orgCavina-Pratesi, C., Kuhn, G., Ietswaart, M., and Milner, A. (2011). The Magic Grasp: Motor Expertise in Deception. PLoS ONE, 6 (2) DOI: 10.1371/journal.pone.0016568

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

Magic trick reveals gaze direction and attention are not always linked

When magicians trick people using sleight of hand, you’d think it was all about misdirecting where the audience – specifically their eyes – are looking, hence the aphorism: “the hand is quicker than the eye.”

But now psychologists in Durham and Dundee have shown that it’s not so much where the audience’s gaze is directed that is important, but rather where they are focusing their attention. That’s right, the two things are not necessarily the same.

Most of the time we pay attention to where we’re looking, but we don’t have to. For example, we can, if we want, stare straight ahead while focusing our attention to the side.

Gustav Kuhn and colleagues played university students a clip of a short magic trick in which the magician appears to make a cigarette and lighter disappear. The cigarette “disappears” when the magician drops it into his lap while directing the audience’s attention to his other hand.

Surprisingly, recordings of the students’ eye movements showed that whether or not they spotted the cigarette drop (and hence realised how the trick was done) had nothing to do with their eye position at the moment of the drop. Blinks or eye movements during the drop were also irrelevant.

By contrast, the students’ eye position after the cigarette drop was associated with whether they saw it. Specifically, those students who, after the drop, moved their eyes more quickly to the (now empty) cigarette hand, were more likely to report having seen the cigarette fall.

The likely explanation is that those students who, post drop, made the faster glance to the cigarette hand had already shifted their attentional spotlight (but not yet their eyes) to the cigarette, in time to see it drop. This would be consistent with previous research showing that our eye movements to a given location are preceded by an attentional shift to that same spot. This means that for the trick to work, the magician needs to misdirect the audience’s covert attentional spotlight, not necessarily their overt eye position.

There’s a final complication. Several of the students who spotted the dropped cigarette actually moved their eyes to the magician’s face before his cigarette hand. They still glanced, post drop, to the cigarette hand faster than the students who didn’t see the drop, but they looked at the face first. However, this is still consistent with our explanation. It merely suggests, in line with previous research, that the attentional spotlight can be two or more locations ahead of where the eyes have yet to move.

Link to magic trick.
Link to earlier related Digest item.

Kuhn, G., Tatler, B., Findlay, J., Cole, G. (2008). Misdirection in magic: Implications for the relationship between eye gaze and attention. Visual Cognition, 16(2), 391-405. DOI: 10.1080/13506280701479750

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

Magic trick fools us but not our eyes

The magician throws the ball twice into the air and catches it, then he throws it a third time and it vanishes! Of course, he’s really secreted the ball in the palm of his hand, so why do so many observers believe they’ve seen the ball vanish mid-flight?

Gustav Kuhn and Michael Land recorded the eye movements of 38 participants while they watched a video clip of this vanishing ball illusion.

On the final throw, the magician looks skyward as if the ball really has been thrown and this social cueing is crucial to the illusion. Half the participants were shown a version of the trick in which the magician looked at his hand on the final throw instead of looking skyward, and in this case only 32 per cent of the participants experienced the illusion, compared with 68 per cent of the participants who witnessed the trick performed properly.

Moreover, whereas the participants said they had kept their eyes on the ball, the eye movement analysis revealed that before each throw, the participants glanced at the magician’s face.

But there’s a way in which the participants’ eyes were not fooled by the illusion. Those participants who experienced the illusion said they had seen the ball leave the top of the screen, and they guessed the illusion was created by someone catching the ball off screen. However, their eyes were not tricked – the analysis showed they only looked at the top of the screen when the ball was really thrown.

“These results illustrate a remarkable dissociation between what participants claimed to have seen and the way in which their eyes behaved”, the researchers said.

Their perceptual experience was based on their expectation of what would happen to the ball (informed by the magician’s misleading skyward gaze), whereas their eye movements were controlled by actual visual input. The finding is consistent with the huge body of research showing that perception and action are based on separate visual systems in the brain.

Gustav, K. & Land M.K. (2006). There’s more to magic than meets the eye. Current Biology, 16, R950-R951.

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

Link to videos of illusion and further info on methods.
Link to cool online illusion, via author’s homepage.