A brief, up-front description of the arguments used by climate-change deniers makes people less susceptible to believing them, according to a study published recently in Global Challenges.
The researchers liken this approach to a kind of psychological immunization. “We wanted to see if we could find a ‘vaccine’ by preemptively exposing people to a small amount of the type of misinformation they might experience. A warning that helps preserve the facts,” says University of Cambridge social psychologist Sander van der Linden, the study’s lead author.
Van der Linden and his collaborators at Yale and George Mason Universities recruited 2,167 people in the US via the online platform Amazon Mechanical Turk. They asked these study participants to estimate the level of scientific agreement about climate change, on a scale of 0 to 100 percent, before and after being presented with various combinations of climate-change messages.
The study is among the first to look at how a barrage of conflicting information about climate change affects people’s perceptions of the issue.
One group of participants was told that 97 percent of climate scientists agree that human-caused climate change is happening. This consensus message increased study participants’ assessment of scientific agreement by about 20 percentage points.
A second group was told about claims from a climate-denial organization that over 31,000 American scientists have signed a petition stating human release of carbon dioxide is not a problem for the earth’s climate. These individuals decreased their rating of scientific agreement about climate change by 9 percentage points after learning about the petition.
When people were presented with information about about both the consensus and the countermessage, the two canceled each other out completely. “A lot of people’s attitudes toward climate change aren’t very firm,” says van der Linden. “They are aware there is a debate going on, but aren’t necessarily sure what to believe. Conflicting messages can leave them feeling back at square one.”
But hearing about the tactics used by climate deniers can ‘inoculate’ people against misinformation, the researchers found.
Among study participants who were given a general warning that “some politically motivated groups use misleading tactics to try to convince the public that there is a lot of disagreement among scientists,” the overall perception of scientific agreement on climate change went up by about 6.5 percentage points at the end of the experiment.
Among those who also got a more specific message pointing out the problems with the petition (the signatories include obviously false names like Charles Darwin and members of the Spice Girls, and fewer than 1 percent have a background in atmospheric or climate science), the estimate of scientific agreement went up by nearly 13 points.
In other words, the general and specific ‘inoculation’ messages preserved 1/3 and 2/3, respectively, of the effect of the climate consensus message, even in the face of climate-denial misinformation.
The strategy is effective across the political spectrum, the researchers say. They argue that this inoculation approach should be used regularly in public discussions of climate change.
“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,” van der Linden says.
