Choose a card, any. It is a staple of traditional magic tricks. But if you choose the three of diamonds, chances are that you have been “primed” by the magician to choose this card without even realizing it. Indeed, some subtle verbal and gestural cues can unconsciously influence decision-making, according to a recent article in the Proceedings of the National Academy of Sciences (PNAS).
There is a degree of well-founded skepticism around visual or verbal priming studies. There was, for example, a famous “experiment” in 1957 by a market researcher named Vicar of James McDonald, involving subliminal advertising. Vicary claimed to have conducted an experiment in which some 45,000 people attended screenings of the film Picnic at a theater in Fort Lee, New Jersey, brief advertisements (“Drink Coke” or “Hungry? Eat Popcorn”) were repeatedly shown in the theater for just 1/3,000th of a second during the film – thanks to a tachistoscope Vicary said he installed in the projection booth. It reported an 18.1% increase in Coca-Cola sales and a surprising 57.8% increase in popcorn sales as a result.
The concept of subliminal advertising then spread like wildfire, featuring in a 1973 episode of Colombo and even prompting the CIA to issue a cautionary report. There was just one problem: Vicary was a fraud. No one has ever been able to replicate these results – including Vicary himself – and Vicary eventually admitted that he had falsified his data, and that the story had been a gimmick to prop up his struggling marketing business. . It’s possible he never even conducted the original experiment.
While more recent, non-fraudulent studies have suggested that priming can influence people’s choices, these studies have limitations. For example, the choices subjects can make are usually limited to two or three options, and experiments are usually performed in a tightly controlled laboratory environment, rather than a more natural real-world environment. But there is substantial anecdotal evidence that the forcing techniques used by magicians are effective; it just hadn’t been studied scientifically. And unlike typical free-choice paradigms tested in the lab, these techniques are subtly integrated into performance.
Alice Pailhès, a psychologist at Goldsmiths University in London and co-author of the PNAS paper, is well aware of the checkered history and longstanding difficulty in replicating social psychology experiments on priming effects. But she feels confident in using magicians’ techniques in her own work on how unconscious factors can influence choice, as they rely on tightly controlled scripts and actions, while being embedded in a natural environment and conversational. She started performing magic tricks while still a graduate student in France. “I love magic and soon realized that magicians are the best at influencing choices,” she told Ars.
Pailhès found inspiration for his most recent research in the British illusionist Derren Brown. Brown uses mental priming and coercion techniques (among other tools) involving verbal and visual cues in his performances, tricking someone, for example, into thinking about the three of diamonds card. (Apparently the three of diamonds is an unlikely card that people pick at random in a 52-card deck.)
Brown’s method involves having an audience member try to “mentally convey” the image of a playing card, asking the viewer to “make the color bright and vivid”. This should make the spectator think of a red-colored card, as opposed to a black-colored card. Next, Brown asks the viewer to imagine a screen, mimicking the shape of a diamond with their hands to trick the viewer into thinking about the diamond suit.
To get the viewer thinking about the number 3, Brown asks them to imagine the “little numbers in the corner of the card and on top”. As he does so, he quickly draws three in the air, as on an imaginary map, with his index finger. Finally, he asks the viewer to imagine the “things in the middle of the card, the boom, boom, boom, the costumes” while pointing to three imaginary symbols in the air. The whole priming exercise only lasts 15 seconds.
Pailhès and his co-author, Gustav Kuhn, recruited 90 volunteers and randomly divided them into two groups: one group that watched a live performance of the experiment and one group that watched a videotaped version. Pailhès did the priming herself, using Brown’s method to focus on the card number she wanted the contestants to choose (three) and color (diamond). Rather than doing it in the lab, she sat at a table in the Goldsmith cafeteria, facing the subjects, and asked them to either watch her for instructions or watch a video of her giving the same instructions on a laptop with headphones.
Next, participants wrote down the card they chose and rated how free and in control they felt of their choice. “Participants’ sense of freedom is one of the key elements of a successful forcing technique,” the authors wrote. “If the magician manages to force a card, but this person feels constrained and not free in their choice, the trick no longer works[s]These measures also allowed the researchers to assess the extent to which participants were aware of attempts at manipulation of their choice by asking them if they had noticed any gestures from the performer.
The authors found that 17.8% of the subjects chose the three of diamonds, while 38.9% chose a three (among the four suits) and 33.3% chose a diamond (among all the cards available in this color). Subjects most often chose the three of diamonds, followed by the three of hearts. As a control, the experiment was repeated by having the participants watch a video of the same performer (Pailhès) and the same scenario, without the priming gestures. Subjects chose the three of diamonds, or a three, significantly more often with priming than without, or in a random distribution. Choosing a diamond alone showed no statistically significant difference between priming, no priming, and a random distribution.
Among the subjects (16) who chose the three of diamonds, only three of them stated that they knew the reason for their choice. Similarly, only seven of the 35 participants who chose a three-way card said they knew the reason for their choice – and even then, only three of those seven subjects specifically mentioned the performer’s gestures. The others said they chose it randomly, or made up a confabulation to explain their choice, for example, “I always feel like I’m counting by three” or because it was their favorite number. “Our results are consistent with findings from the choice blindness literature, which illustrates that people often do not know the real reason for their choice,” the authors wrote.
“I find it incredible that so many people have no idea that I’m influencing them with my actions.”
About 72% of subjects noticed at least some of the priming features, but this was independent of whether or not they chose the Three of Diamonds, and their descriptions of the gestures were vague. Pailhès and Kuhn found that it made no difference whether priming was via live performance or video, which went against their pre-experimental predictions. Pailhès was also pleasantly surprised that her priming performance actually worked on so many topics, especially since she is by no means a professional magician or performer. “I find it incredible that so many people have no idea that I’m influencing them with my actions,” she said.
Admittedly, a 17.8% success rate in getting subjects to choose the three of diamonds doesn’t exactly speak to the robustness of the technique – which is why professional magicians rarely rely on priming methods alone. . But it remains clearly higher than the percentage of subjects who would choose this card at random. Brown, according to Pailhès, is likely to have a higher success rate. He is a gifted illusionist with a noted knack for spotting sensitive people, and he usually performs these sorts of tricks in the context of reinforcing previous tricks or audience interactions.
Understanding the underlying cognitive mechanism – the next step in Pailhès’ research – is important because such techniques could be used for more nefarious purposes to influence other mental processes, according to the authors. Previous studies, for example, have shown that subtle hand gestures and similar priming methods can influence eyewitness testimony and even implant false memories.
“If you witness a crime and I question you, and I ask what kind of jewelry the suspect was wearing, if I just touch my finger, chances are you will remember that the suspect was wearing a ring,” explained Pailhès. “Even if it wasn’t true. So it could have a big impact on the criminal justice system. If you know you can be influenced in that way, you might be more careful.”
DOI: PNAS, 2020. 10.1073/pnas.2000682117 (About DOIs).