McGill researchers show how magicians sway decision-making

Jay Olson, a psychology major at McGill University in Quebec, Canada uses magic tricks to study perception, memory, and influence.

One card trick, in particular, captured his imagination as he set about his research. It involved flicking through a deck in front of an audience member, who is asked to pick a card randomly. Unknown to the volunteer, he already worked out which card they would choose, allowing him to reach into his pocket and pluck the exact card they had named – much to the astonishment of the crowd.

The secret, apparently, is to linger on your chosen card as you riffle through the deck. (In our conversation, Olson wouldn’t divulge how he engineers that to happen, but others claim that folding the card very slightly seems to cause it to stick in sight.) Those few extra milliseconds mean that it sticks in the mind, causing the volunteer to pick it when they are pushed for a choice.

As a scientist, Olson’s first task was to formally test his success rate. He already knew he was pretty effective, but the results were truly staggering – Olson managed to direct 103 out of 105 of the participants.

Unsurprisingly, that alone has attracted a fair amount of media attention – but it was the next part of the study that was most surprising to Olson, since it shows us just how easily our mind is manipulated.

For instance, when he questioned the volunteers afterwards, he was shocked to find that 92% of the volunteers had absolutely no idea that they’d been manipulated and felt that they had been in complete control of their decisions. Even more surprisingly, a large proportion went as far as to make up imaginary reasons for their choice. “One person said ‘I chose the 10 of hearts because 10 is high number and I was thinking of hearts before the experiment started’,” says Olson – despite the fact that it was really Olson who’d made the decision. What’s more, Olson found that things like personality type didn’t seem to have much influence on how likely someone was to be influenced – we all seem equally vulnerable. Nor did the specific properties of the cards – the colour or number – seem to make success any less likely.

The hidden tricks of powerful persuasion

Notable Replies

  1. Am I a dick for making an effort to choose my card in advance of seeing the magician's deck at all? I mean - I know what cards are going to be in it.

  2. The psychology behind magic is so fascinating to me.

  3. If you read into the articles the 'study' done where the researchers say a card is bent to force it to present slightly longer, near the bottom of the page is a video, showing the routine in action with four 'forces'. The fourth isn't actually a force at all, the spectator chooses a number, and then after he tells the prestidigitator the number, it is then written on a piece of paper. If you watch that section very closely, you can see it happen, and the clue is that his right hand, which holds whatever passes for a pencil, is put away when the paper is presented with the left hand.

    As to @Barnabus' argument, first of all, welcome to BoingBoing. Hope you aren't here just for this one post. Anyway, I also think you have missed the point. The point is that the spectator is forced to choose a card based on the way the cards are presented, BUT THEY FEEL AS IF THEY CHOSE FROM AMONG MANY CARDS THEY SAW. You said we can't read their minds, and perhaps they felt forced, but watch again the video in the link provided here, and review the first three forces, and notice that in every case the spectator rates his freedom of choice at the maximum of 10.

    Now watch it again, and see if you can figure out, without googling 'how do magicians force cards on spectators' or something similar, and ask yourself how hundreds of participants all chose the forced card, yet felt as if they had complete freedom in choosing?

    That's the magic of magic. It absolutely is based in psychology, and better understanding of psychology can lead to better magic tricks, just as some of the very best magic tricks can perhaps open doors into a better understanding of psychology. There is plenty of merit to the study, because it exposes how easily we can be manipulated, and not knowing that is how we readily accept things like 'Fat Free!' as a positive message on a package of Twizzlers. We're duped into forgetting that of course Twizzlers don't contain fat, they're made of sugar and gelatin and flavors. That's just one obvious merit to better understanding the psychology of misdirection. If you think there's no point to that, well, then you've missed something.

  4. One of the first things I taught my daughter was, "There's no such thing as magic; just cheating." She's gotten pretty good at misdirection while pick-pocketing, but I'm not sure that's where I wanted this to end up.

  5. What's utterly amazing is that you forced LemoUtan to pick three of clubs a full eight hours before you even performed the trick. This magic stuff is way over my head.

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