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.