The trick, as strange as it may sound, is to make people believe the opposite opinion was their own to begin with.

The experiment relies on a phenomenon known as choice blindness. Choice blindness was discovered in 2005 by a team of Swedish researchers. They presented participants with two photos of faces and asked participants to choose the photo they thought was more attractive, and then handed participants that photo. Using a clever trick inspired by stage magic, when participants received the photo it had been switched to the person not chosen by the participant—the less attractive photo. Remarkably, most participants accepted this card as their own choice and then proceeded to give arguments for why they had chosen that face in the first place. This revealed a striking mismatch between our choices and our ability to rationalize outcomes. This same finding has since been replicated in various domains including taste for jam, financial decisions, and eye-witness testimony.

While it is remarkable that people can be fooled into picking an attractive photo or a sweet jam in the moment, we wondered whether it would be possible to use this false-feedback to alter political beliefs in a way that would stand the test of time.