After receiving misinformation from the anti-vaccine movement, including its founder Andrew Wakefield, immunization rates plummeted in a community of Somali immigrants in Minnesota, causing a measles outbreak among their children. It’s a disturbing trend on the rise in America that shows the importance of immunization and the dangerous power of misinformation.

A new paper published in PLOS One by John Cook, Stephan Lewandowsky, and Ullrich Ecker tests the power of inoculation; not against disease, but against the sort of misinformation that created the conditions leading to Minnesota measles outbreak. Inoculation theory suggests that exposing people to the tricks used to spread misinformation can equip them with the tools to recognize and reject such bogus claims.

The study focused specifically on misinformation about climate change. The scientists wanted to determine if inoculation could boost peoples’ resistance to false balance in the media, and efforts to cast doubt on the 97% expert consensus on human-caused global warming.



The two issues are connected – in climate stories, journalists will often present arguments by climate scientists and climate deniers with equal weight, creating the perception of a 50/50 split when in reality, 97% of experts are on one side, as elegantly illustrated by John Oliver in this clip with over 7 million views from his HBO program Last Week Tonight :

Facebook Twitter Pinterest Last Week Tonight with John Oliver - a statistically representative climate debate.

In one experiment, before showing people a media story with this sort of climate false balance, the study authors first provided a group with information about the 97% expert consensus, and delivered an “inoculation” explaining the misleading effects of false balance media coverage.

They found that in the group that was only exposed to the false balance story, average perceived consensus, acceptance of human-caused global warming, trust in climate scientists, and support for climate policy all fell. When subjects were first inoculated against false balance and told about the expert consensus, these factors instead all increased. The authors concluded:

In sum, the effect of false-balance media coverage had the greatest effect on perceived consensus among the various climate attitudes measured. However, a consensus message presented with the false-balance message was effective in increasing perceived consensus, thus neutralizing the negative influence of the misinformation. In addition, we found that an inoculation message was effective in neutralizing the effect of misinformation on perceived consensus.

In a second experiment, they exposed participants to consensus misinformation via the infamous Oregon Petition, explained in the video below, and again inoculated one group against the misinformation

Facebook Twitter Pinterest John Cook Denial101x lecture on climate consensus and the Oregon Petition misinformation.

The inoculation this time consisted of a mixture of text and a figure of a tobacco ad with the text “20,679 Physicians say ‘Luckies are less irritating’” to show participants a similar previous example of the fake experts technique employed in the Oregon Petition.



As in the first experiment, exposure to only the misinformation decreased participant perception of the expert consensus, acceptance of human-caused global warming, and support for climate policies. However, exposure to the inoculation offset the effects of the misinformation.

I asked lead author John Cook how these findings can be implemented in the real world where misinformation about subjects like climate science and vaccines is pervasive.

One of the unique elements of the inoculation we tested in our study is that we never actually mentioned the myth that we were inoculating against. Instead, we explained the general fallacy that the misinformation employed - the technique of using fake experts to cast doubt on expert agreement on a scientific topic. This tells us that explaining the techniques of denial can help people spot attempts to mislead them, hence neutralizing misinformation that uses those techniques. Arguably, the most effective way to practically implement inoculation is in the classroom. Decades of research have found that one of the most powerful ways to teach science is through misconception-based learning: teaching science by directly addressing misconceptions and misinformation about the science. Two ways we’ve put this into practice is through a Massive Open Online Course on climate science denial that uses the misconception-based-learning/inoculation approach and a college textbook that teaches climate science while debunking common climate myths.

In short, the more we explain the techniques of science denial and misinformation, the more people will become inoculated against them. When we’re exposed to examples of people using cherrypicking or fake experts or false balance to mislead the public, it becomes easier to recognize those techniques, and we’re less likely to fall for them in the future. Teaching people to recognize those techniques is a primary goal of the Denial101x free online course mentioned by Cook.

When anti-vaxxer Andrew Wakefield was confronted with the consequences of misinforming the Somali immigrants in Minnesota, he told a Washington Post reporter “I don’t feel responsible at all.” One wonders whether we’ll be hearing those words from climate deniers in the coming years.

Hopefully it won’t come to that, if we can avoid the worst consequences of human-caused climate change. Inoculating people against the techniques used by climate deniers and misinformers can help us achieve that goal.

