If you’ve ever gotten a flu vaccine, you probably know the somewhat counterintuitive way it works: Your body gets a small dose of inactivated virus, so that if and when the real thing invades, your defenses are already up, prepared to quash the infection before it starts.
According to a study published today in the journal Global Challenges, a similar principle may help boost people’s immunity toward a different kind of plague: fake news. In the first part of the study, the authors tested out a handful of false statements about climate change on a nationally representative sample of volunteers, asking them how believable and convincing they found each one to be. For the second part, they picked the message that had been deemed most persuasive — the claim that scientists haven’t reached a consensus about whether climate change is man-made — and showed it to a new batch of participants, after first asking them to estimate the percentage of scientists that believed it was.
In some cases, people saw only the lie. Others viewed a chart showing that 97 percent of scientists agreed climate change was man-made (a figure generally agreed upon in climate research), or saw both the chart and then the lie, in that order. Within that third group, some people were also part of the more nuanced “inoculation” condition, reading a warning alongside the chart that “some politically motivated groups use misleading tactics to try and convince the public that there is a lot of disagreement among scientists” before proceeding to the false claim.
When the study authors then asked their subjects to estimate how much scientists actually agreed on climate change, those who had read only the lie, unsurprisingly, lowered their guess of how many believed it to be man-made, while those who had only seen the chart raised their estimate. Those who had seen both items without the so-called “inoculation” didn’t change their opinion. For the volunteers who were inoculated against falsehoods, though, the strategy worked: Their belief in the widespread acceptance of climate change was stronger at the end of the study, even though they’d also seen inaccurate information arguing against it.
“Misinformation can be sticky, spreading and replicating like a virus,” lead study author Sander van der Linden, a social psychologist at the University of Cambridge in the U.K., said in a statement. To stop it, then, you treat it like a virus: Increase the defenses of people likely to be infected by fake news. “The idea is to provide a cognitive repertoire that helps build up resistance to misinformation, so the next time people come across it they are less susceptible” — and, in turn, less likely to spread it to others.