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Scientists are testing a “vaccine” against climate change denial

“Inoculating” people against misinformation may give scientific facts a shot at survival.

It may be possible to metaphorically “inoculate” people by addressing the misinformation about climate change alongside the facts.

In the battle between facts and fake news, facts are at a disadvantage. Researchers have found that facts alone rarely dislodge misperceptions, and in some cases even strengthen mistaken beliefs.

That’s just as true for climate change as it is for any other politically polarized issue in the US. The theory of identity-protective cognition, developed by Yale Law professor Dan Kahan, holds that we subconsciously resist any facts that threaten our defining values — and better reasoning skills may make us even better at resisting. People who are more scientifically literate, for instance, are even more divided about the risks of climate change than those who are less scientifically literate.

Deliberate campaigns against climate change science — like the one launched by the American Petroleum Institute in the late 1990s that’s been much imitated since — have taken advantage of this tendency, encouraging resistance to the facts by exaggerating the uncertainty inherent in the science.

But two recent, preliminary studies suggest there’s hope for the facts about climate change. Borrowing from the medical lexicon, these studies show that it may be possible to metaphorically “inoculate” people against misinformation about climate change, and by doing so give the facts a boost. What’s more, these researchers suggest, strategic inoculation could create a level of “herd immunity” and undercut the overall effects of fake news.

“Nobody likes to be misled, no matter their politics”

Psychologists have known for decades that people are more resistant to misinformation if they’re warned about it beforehand. Teens who are warned about the dangers of smoking are less likely to succumb to their friends’ arguments in favor of it; people who are warned about pro-sugar campaigns by soda companies are less likely to fall for them. These “inoculation messages” can even work retroactively, changing the minds of those who have already been influenced by misinformation.

John Cook, a cognitive scientist at the Center for Climate Change Communication at George Mason University in Virginia, recently tested the strength of inoculation messages against the notorious Oregon Petition, which uses fake experts to cast doubt on the scientific consensus on climate change.

In the journal PLOS One, Cook and his colleagues reported that when about 100 study participants were presented with the misinformation alone, their views did further polarize along political lines. But when another group of participants were first warned about a general strategy used in misinformation campaigns — in this case, they were told that fake experts had often been used by the tobacco industry to question the scientific consensus about the effects of tobacco on health, and were shown an ad with the text “20,679 physicians say ‘Luckies are less irritating’” — the polarizing effect of the misinformation was completely neutralized.

“Nobody likes to be misled, no matter their politics,” says Cook. He suggests that inoculation messages may serve to put listeners on alert for trickery, making them more likely to scrutinize the information they receive.

Cook’s research complements findings by Sander van der Linden, a psychology professor at Cambridge, who has also tested the strength of inoculation messages against the Oregon Petition. In a study published in the journal Global Challenges earlier this year, van der Linden and his colleagues presented more than 2,000 participants of varying political beliefs with one of two inoculation messages. The first, shorter message stated that “some politically motivated groups use misleading tactics to try to convince the public that there is a lot of disagreement among scientists.” Participants were then told that among climate scientists, there is virtually no disagreement that humans are causing climate change. The longer message specifically debunked the Oregon Petition before informing participants about the scientific consensus.

Both messages were equally effective across the political spectrum; the shorter message protected the effects of the scientific consensus on participants by one-third, while the longer one protected by about two-thirds. Inoculation, in other words, doesn’t insulate the facts from damage, but it does give them a shot at survival.

Come hither, climate skeptic, and listen to this tall tale.

Start with the facts, then debunk the myth

Both Cook and van der Linden say that while we do tend to resist facts that challenge our defining values, that defensive reaction can be circumvented. Previous studies by van der Linden and others show that the scientific consensus on the magnitude and causes of climate change can serve as what van der Linden calls a “gateway belief,” in that its acceptance can be a first step toward a more comprehensive change of views.

“Consensus messages don’t ask people to change their beliefs — they ask them to change their opinion about what other people believe, so they’re not a direct threat to their identity,” says van der Linden. “We’ve found that they’re one way to get people more aligned on the side of climate science.” Because consensus opinions from a respected group tend to be accepted as much if not more readily by conservatives than liberals, he says, they appear to decrease rather than increase polarization.

For Cook, who founded the Skeptical Science blog 10 years ago and is still actively combating misinformation about climate change, the results of the inoculation studies are immediately applicable. He used to try to avoid mentioning the misinformation when trying to debunk it, but now he confronts the fakery with an inoculation message. “You can’t talk around it; otherwise it persists,” he says. “What’s important is to lead with the facts — the facts are the headline — then introduce the myth, and then explain why it’s wrong.”

Earlier this month, Cook deployed this strategy in a response to a National Review article that used his own work to question the scientific consensus on climate change. “There is a consensus of evidence that human activity is causing all of recent global warming. Not some of it. Not even most of it. All of it,” his 1,000-word critique begins. Not until the sixth paragraph does he begin the inoculation: “Unfortunately, it’s all-too-easy to mislead people into thinking that experts disagree on human-caused global warming,” he writes. “If you want to work out whether you’re getting taken in with the fake-expert strategy, take a closer look at the ‘experts’ who are being cited.”

He then outlines the typical strategies used by climate deniers, such as the use of fake experts, logical fallacies, and conspiracy theories to undermine the scientific consensus, before moving on to a critique of the original article.

Of course, we can’t always deploy such lengthy and detailed debunkings. But Cook points out that even very brief, general warnings about science denialism strategies appear to have a significant inoculation effect — suggesting that they may work as wide-spectrum “vaccines” against many kinds of misinformation. He’s also heartened by the possibility that inoculation messages could create a kind of herd immunity: Other researchers have found that when people receive inoculation messages against public health misinformation, they spread their immunity to misinformation through conversation.

In the US in particular, climate change has become so politicized that what Cook calls “climate silence” is often observed in polite company. “It’s become this taboo topic that people are reluctant to talk about,” he says. “But when people understand both sides of a controversial topic, they’re more confident in talking about it. So inoculation can encourage people to break climate silence.”

“Teaching the controversy” isn’t such a bad idea — as long as you distinguish fact from fiction

While even brief inoculation messages can have lasting effects, permanent immunity requires repeated treatments — preferably starting with kids. Former climate denialists who have “converted” to support of the scientific consensus, such as Jerry Taylor of the Niskanen Center, often point to an informal inoculation message as the beginning of their reconsideration of the issue, but say their transformation took years to accomplish.

When Cook started Skeptical Science in 2007, he thought that climate denialism — and his blog — would disappear within a few years. Now he’s convinced that inoculation messaging needs to be used more widely and systematically in education, and he’s incorporated it into his own university and online courses. One unexpected benefit, he reports, is that addressing the misinformation alongside the facts doesn’t confuse, but instead adds interest.

“Because inoculation presents both the facts and the myths, it creates this conflict — students want to know how these two things can exist together,” he says. “So you have to resolve it, and that turns into a compelling story.”

Inoculating Republican leaders and Republican voters against the climate misinformation in their own party platform would surely take time, especially since so many are constantly exposed to new misinformation. But Cook is encouraged, both by his results and by his personal experience: When the right message is combined with the right messenger — one who shares the values of his or her audience — the facts have a fighting chance.

Michelle Nijhuis (@nijhuism) writes about science and the environment from Washington state.

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