Vaccination

The vast majority of methods for quashing belief in conspiracy theories have little or no effect and the ones that do work are impractical. That is the conclusion of a review of 25 studies assessing various methods of tackling unfounded beliefs in secret plots.

Methods such as offering ridicule, presenting rational counterarguments or labelling conspiracy theories as such are ineffective at countering specific conspiracy theories or people’s general tendency to believe them, the review concludes. In fact, one study found that the labelling method backfired by slightly increasing conspiracy beliefs.

Priming methods that aim to boost people’s critical thinking before they are exposed to conspiracy theories did work, but not very well – the effects were usually small.

What did work well was prebunking or informational inoculation, in which people
are told why a conspiracy theory isn’t true before being exposed to it. All studies testing inoculation found medium-sized or large effects.

The most effective method reported so far involved a three-month university course with weekly sessions in which students looked at the differences between sound science and pseudoscience. This course comes closest to what is needed: a kind of broad-spectrum vaccination against conspiracy theories based on teaching people how to think rather than what to think, according to O’Mahony.