How our ‘free’ choices can be manipulated

A common trick by magicians is to riffle a deck of cards in front of someone so that the person gets a view of cards as they rapidly pass by their gaze, and ask them to choose one. The magician then produces that same card from elsewhere, say out of their pocket. How is that done?

David Robson explains how magicians persuade you to pick the card they had already selected.

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.

What was also interesting was that the card pickers were firmly convinced that they had made a free choice and even manufactured reasons for it.

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.

The article looks at the implications for what may be really happening in other situations where we think we are making free choices.

Consider when you go to a restaurant for a meal. Olson says you are twice as likely to choose from the very top or very bottom of the menu – because those areas first attract your eye. “But if someone asks you why did you choose the salmon, you’ll say you were hungry for salmon,” says Olson. “You won’t say it was one of the first things I looked at on the menu.” In other words, we confabulate to explain our choice, despite the fact it had already been primed by the restaurant.

The article also provides suggestions to resist this kind of manipulation.


  1. Pierce R. Butler says

    … Olson managed to direct 103 out of 105 of the participants.

    I can’t help but wonder whether the other two had poor vision, or maybe blinked at the key moment.

  2. Jim B says

    There are a few books that deal with phenomena like this. I’m reading one right now, called “You are not so smart” by David McRaney. Each chapter lists a category of logical failure (eg, confirmation bias, normalcy bias, priming, etc) and gives familiar examples of each, as well as citing studies which explore that type of failure. I’m only four chapters in, but so far it isn’t as compelling as I had hoped it would be.

    I loved reading books like The Man Who Mistook His Wife for a Hat (Sacks) because it clearly showed how people with severe damage to one part of their brain but otherwise fulling functioning in intelligence would use their powerful rationalization skills to cover up their deficits. For example, a man who denied that he had become blind after a stroke, despite being blind as a bat. If they can believe their own BS in a situation like that, how hopeless is it for us to recognize it in ourselves with much more subtle deficits?

    I think the fact that every decision we make, conscious or not, is just some weighted integral of a lifetime of priming is not appreciated at all. Free will is a strong illusion because we are all so good at confabulating the reasons for what we do, when mostly we are just observing our own behavior and rationalizing it after the fact. Even very deliberate decisions, such as ones we research for days before making a decision, falls into the same category.

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