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What brain-bending magic tricks can teach us about the mind

What brain-bending magic tricks can teach us about the mind


‘What happens inside your brain when you’re experiencing something that you know to be impossible?’

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Graphic by Michele Doying / The Verge

Pick a card, any card, and you might feel that you’re in control when you pull the queen of hearts from a magician’s deck. But magicians have strategies that force their audience’s choice — from packing the deck with identical cards, to fanning out the deck with just the right timing so that the choice becomes all but inevitable.

This illusion of free will is one of the many illusions and magic tricks that Gustav Kuhn, a magician turned psychology researcher at Goldsmiths, University London, describes in his new book Experiencing the Impossible: The Science of Magic. Published in March by The MIT Press, the book explores the ways in which magic tricks and illusions can teach us about our brains. Kuhn takes the reader into the psychological underpinnings of tricks — from optical illusions that reveal gaps in perception, to failures of memory that make people think they’ve seen a ball vanish, when in fact there was no ball to see in the first place.

“Seeing is very much believing.”

The book’s immersive dive into the worlds of magic and science is only possible because of Kuhn’s deep experience with both. Kuhn’s passion for magic was sparked at age 13 when a friend pulled an egg out of his ear. After a stop in London to work as a professional magician, Kuhn eventually decided to turn his attention away from the tricks themselves, and toward the minds that he was fooling during his shows. “It was always clear that if I wanted to create powerful magic tricks, I needed to understand the system that actually allows me to create them,” he says.

During his PhD research studying consciousness, he discovered that magic occupied a realm of psychology that few scientists were really investigating. “I realized that a lot of the questions that psychologists are interested in, magicians have been exploiting for centuries,” he says. “That’s really what started it for me, to try and bridge this gap between magic and science, and trying to use magic as a way of understanding human cognition.”

“If I wanted to create powerful magic tricks, I needed to understand the system that actually allows me to create them.”

Now, Kuhn is director of the MAGIC Lab at Goldsmiths, University of London, where he leads a team of researchers to probe the ways that magic and illusions can help us understand free will, perception, and even cybersecurity and game design. For Kuhn, magic is a window into the shortcuts our minds use to make sense of the world. “Perception is all about problem solving,” he says. “It’s all about you making a guess about what the world is actually like, rather than what the world is like in reality. So seeing is very much believing.”

The Verge spoke with Kuhn about magical thinking, fake news, and how humans and dogs see objects the same way.

This interview has been edited for clarity and brevity.

What is the science of magic? Isn’t that a contradiction?

Magic works not because magicians have got real supernatural powers, but instead they hijack our brain and manipulate and exploit a lot of our blindspots and limitations to create their illusions. For example, they will hijack your attentional system to manipulate what you see, and most importantly, what you miss. But the key to magic is that magic really only works if you’re not aware of these limitations. Think of a situation where a magician picks up a coin, blows on it, and suddenly it disappears. What happens inside your brain when you’re experiencing something that you know to be impossible? Over the last 15 years, magicians and scientists have come together to try and study the psychology that underpins magic — and by doing so, we’ve really learned a lot about the human mind.

You’re talking about how magic manipulates our free will, exploits our limitations, uses trickery and deception — why do people like this?

“There’s a deep-rooted cognitive mechanism that draws us to things we don’t understand.”

Magic is one of the most enduring forms of entertainment. And intuitively, you might think you wouldn’t really like someone to be lying to you. But of course, there’s a lot more to magic than just simple deception. Magic allows us to experience things that we believe to be impossible. And I think there’s a deep-rooted cognitive mechanism that draws us to things we don’t understand yet that encourages us to learn more about the world around us.

What is the most surprising thing you’ve learned about the psychology of magic?

There are a lot. The two main things are the extent that we’re not aware of internal processes. Now we’ve gotten used to the fact that you can fool your perceptual system, or you can fool your memory — but even the sense of free will [can be fooled]. In certain simple card tricks, we get someone to pick a card, and use fairly simple sleight of hand and deception, to get them all to pick the same card. They feel like they’ve had a genuinely free choice, and yet the decision has been influenced. The way that we can actually use magic tricks to undermine someone’s free will has been staggering.

“The way that we can actually use magic tricks to undermine someone’s free will has been staggering.”

The other one has to do with people’s beliefs in magic. We’ve had a large research program where we get a magician to pretend they’ve got psychic powers. We we get a whole class of undergraduate students to watch these performances, and then we ask them how they think it was done. What’s been really surprising is that a large proportion of our students genuinely believe this person’s got psychic powers. What’s even more surprising is that even if we tell the participants beforehand that they’re seeing a magician who’s using tricks and deception, they still genuinely believe that he’s got psychic powers. This has got really quite worrying implications for our interaction with fake news, because it demonstrates that if you’ve got these very emotive situations where people can see something that they know is fake, this can still have an impact on people’s beliefs. We are highly susceptible to misinformation, and we really struggle to distinguish between fiction and reality.

How do magicians misdirect their audience’s attention?

Magicians have developed so many different techniques that are all really fascinating in their own right. Typically, people think about attentional misdirection. I can hijack your attentional system and influence what you see and what you miss. One of the most powerful cues that magicians use is eye-gaze. Even newborn children follow another person’s gaze. So if I want you to look or attend to a certain direction, I will look in that direction. That’s a very powerful cue.

“I can hijack your attentional system and influence what you see and what you miss.”

We’ve been studying this for many years now by measuring people’s eye movements whilst we misdirect their attention. We find that these cues are so powerful that we get lots of situations where people actually look at something, and if their mental attention is being directed, or misdirected, they can fail to see things that are right in front of their eyes. Intuitively, we feel like we’re aware of most of our surroundings. Yet, in actual fact, once you start probing our conscious experience, we realize that we’re just simply unaware of most things.

How do we close these gaps in our cognition so we don’t get tricked?

“These gaps exist not because we’ve got rubbish brains — these gaps exist because our brains are truly amazing.”

That’s the wrong way to think of it! These gaps exist not because we’ve got rubbish brains — these gaps exist because our brains are truly amazing. Information processing requires resources that are expensive. Rather than just processing all of the information, we’ve evolved to use very clever tricks to solve a lot of these problems. Now with any shortcut or trick, it can be very effective, but it can lead to errors that magicians exploit. But without those errors, we just wouldn’t have the neural capacity to process all of that information. In some ways these illusions should be celebrated because they illustrate really how clever our brain is, rather than stupid.

In the book, you talk about how magicians used to attribute guessing a card correctly to mind reading and psychic powers. Now, some are turning more to equally improbable, pseudoscientific explanations like interpreting body language to guess the card. Why the shift, and what does it tell us about the practice and experience of magic?

Magicians have often used popular culture to inspire their magic tricks. During the Victorian era, magicians were very keen on exploiting this idea of spiritualism and would use that to frame their magic performances. In those effects, the magician may contact the dead to try and discover some secret information about an individual. Today, people are more skeptical about spiritualism, so a new trend has really evolved: rather than using spiritual explanations for what they’re doing, magicians are using pseudo-psychological principles.

“That’s quite worrying.”

That’s quite worrying. We’ve done some research on this — that actually these performances can misinform people about what they believe to be possible. In this study, we did one of these pseudo-psychological demonstrations, and half the participants were told they’re seeing a magician, and the other half of the participants were told that they’re watching a psychologist. That framing has zero impact on their interpretation of what they saw, in that they genuinely believe that the magician was using these psychological principles. That can fuel this belief that you can use psychology to discover things or do things that are simply not possible. And in the same way that fraudulent psychics and fraudulent spiritualists have used magic as a way of misinforming the public about spirituality, magicians today using those principles are really misinforming the public about what psychology really is.

What’s one of your favorite illusions?

One of my favorite illusions that I’ve studied is the vanishing ball illusion, where the magician throws a ball up in the air a couple of times and then pretends to throw the ball up in the air — and most people claim that they see it vanish in midair even though it never actually left the hand. Humans behave in exactly the same way as dogs do when you pretend to throw a stick. We may not run, but our perceptual experience is equally fooled. It’s not the most amazing magic trick, but I find the actual psychology very unsettling, and absolutely fascinating.

“I find the actual psychology very unsettling, and absolutely fascinating.”

Why do people see things that haven’t actually happened? The reason for this is that we actually see in the future. Because seeing doesn’t actually happen in the eye, seeing happens in the brain and it takes at least a tenth of a second for the information to travel from the eyes, to the visual cortex, which is part of the brain. The reason why we don’t see the world as lagging behind is because our brain is constantly predicting the future. So what you’re seeing as the now is not actually the now — it’s really your brain predicting what the now is going to be like based on past information. It’s quite a hard concept to get your head around. That’s a very clever system. It’s incredibly clever. But of course it can lead to errors, and the vanishing ball illusion is one of these errors. You’re seeing something that you expect to happen, but hasn’t actually.