People fixate on a false solution to a magic trick even after they recognise this solution is impossible, a scientific study led by Goldsmiths, University of London has shown.

The findings give an insight into how exposure to ideas we know to be false, such as demonstrably fake news, can continue to affect our reasoning capacity.

A report of the research is published in the Quarterly Journal of Experimental Psychology.

The researchers investigated a misdirection principle commonly used by magicians called ‘the Theory of False Solution’: this involves magicians giving audiences a potential, yet false, solution to a trick before demonstrating that this solution is wrong.

For the new study the researchers recruited 120 volunteers who were randomly selected to watch one of three versions of a card trick. The trick involved the magician showing the audience the queen of clubs, placing it face down on a pack of cards held in his right hand, then reaching with his left to produce the queen from his back pocket.

In one version of the trick the magician gestured with his closed left hand as if he was palming the queen (‘false solution’). In another he kept the fingers of his left hand open to show it was empty (‘no false solution’). In the final version he began as if palming the queen but then opened his fingers to show this was impossible (‘false solution extinction’). Participants were asked after each demonstration how they thought the trick was done.

The experiment showed that gesturing a palming action triggered the false solution in people’s minds (they thought the magician had palmed the card). More importantly, the researchers found that while with the no false solution trick 87.5% of participants discovered the correct solution (the magician had a duplicate queen of clubs in his back pocket) only 60% managed it with the false solution extinction version.

Dr Gustav Kuhn, Reader in Psychology at Goldsmiths and co-author of the study, said:

“Our findings show that being exposed to a false solution can continue to prevent people from reasoning their way to the right answer even after they recognise this false solution is impossible. It’s as if, having made the effort to construct a solution, people become stuck on it and less able to ‘think outside the box’ and come up with a new solution that abandons their original assumptions.”

The team believes that magic tricks are a good way of exploring ‘mind-fixing’ effects that play a role in everyday reasoning. These new findings raise an important issue: that it might be possible for ideas to continue to constrain our ability to discover the truth behind a magic trick or a news story long after those ideas have been exposed as wrong or ‘fake’.

A report of the research, entitled ‘It is magic! How impossible solutions prevent the discovery of obvious ones?’, is published in the Quarterly Journal of Experimental Psychology.