When someone falls down the conspiracy rabbit hole, there are very few proven ways to get them out, according to a new analysis.

The study is a review of research into attempts to counter conspiracy thinking, and it shows that common strategies, including counterarguments and fact-checking, largely fail to change people’s beliefs. The most promising ways to combat conspiracy thinking seem to involve prevention, either by warning people ahead of time about a particular conspiracy theory or explicitly teaching them how to spot false evidence.

“Unfortunately, we are still in the early stages of developing a silver bullet that will fight disinformation in general,” says Cyan O’Mahony, a psychology doctoral student at University College Cork in Ireland, who led the study. What’s this published today in PLOS ONE magazine.

Countering conspiracy beliefs is important because conspiracy beliefs can motivate people to act in detrimental ways, says Kathleen Hall Jamison, professor of communication and director of the Annenberg Center for Public Policy at the University of Pennsylvania, who was not involved in the new review. For example, the people who stormed the US Capitol on January 6, 2021 believed that the results of the 2020 presidential election had been stolen. And COVID vaccine conspiracy advocates are putting themselves at risk of disease by not getting vaccinated. But the field is so young that trying to compare individual studies is risky, Jamison says.

“There are so many different definitions and specifications of what is conspiracy belief and conspiracy thinking that it is very difficult to collect this data in any way that allows for generalization,” she says. Jamison adds that the comparisons in the new review are a suggestive starting point, but should not be seen as the last word in counter-conspiracy interventions.

Research often blurs the lines between conspiracy theory, misinformation, and disinformation, O’Mahony says. Disinformation is simply false information, and disinformation is intentionally misleading. Conspiracy beliefs, as O’Mahony and colleagues define them, include any belief that involves intruders involved in a conspiracy to explain a major event. Such beliefs are not necessarily false—real conspiracies do happen—but there are many erroneous conspiracy theories, from the idea that the moon landing was rigged to the notion that COVID vaccines cause mass death that the authorities cover up.

O’Mahony and colleagues focused on research aimed at conspiracy beliefs rather than disinformation or misinformation. They found 24 studies in 13 articles. Most of these articles were conducted in the US or UK, although some were conducted in other countries, and most of them included online sampling, which often included participants from different countries. In nearly two-thirds of these studies, researchers tried to change people’s general willingness to believe in conspiracies, while the rest were about individual beliefs.

There were several categories of interventions. One of them consisted of preliminary studies that used an unrelated task to change someone’s mindset. For example, participants may be asked to read a passage written in hard-to-read type, which requires extra work to process the information and encourages analytical thinking. The researchers can then present the participants with a conspiracy theory to see if the task reduces belief. These studies showed that priming mostly worked, but had little overall effect. Another strategy for challenging conspiracy theories with facts has also shown very little effect. The least effective arguments were to appeal to the believers’ feelings of empathy or ridicule them for their beliefs.

More promising were the vaccine studies, which warned people ahead of time that they might encounter conspiracy theories and argued against them. This had a medium to large effect in reducing conspiracy belief. However, vaccination can have unpleasant consequences. One study found that if a conspirator warns against vaccination, that the vaccine no longer works. Politicians use this “vaccination versus vaccination” strategy in the real world, says Joseph Uscinski, a University of Miami political scientist and co-author of American Conspiracy Theories (Oxford University Press, 2014), who was not involved in this study or the new analysis. For example, Florida Gov. Ron DeSantis began to accompany his arguments about teachers indoctrinating students with a “wake up” agenda with phrases such as “Anyone who tells you it’s not happening is lying to you“.

Another challenge is figuring out whether the vaccine or any other strategy works in the long run, says Karen Douglas, a social psychologist at the University of Kent in England, who was not involved in the new review. In many of the studies examining this method, scientists measure immediate effects but do not observe over days, weeks, or months. “For something to be effective in tackling a larger problem,” Douglas says, “we need to know that the intervention will continue over time.”

The best opportunity to avoid conspiratorial thinking may be the most time-consuming. In the new analysis, one of the biggest effects came from A study that involved a three-month university course purpose of distinguishing science from pseudoscience. For the study, three instructors taught students the critical thinking skills needed to understand common human errors of perception and logic. The result was a reduction in conspiracy beliefs. “This was a unique study, but it focused on teaching these skills,” says O’Mahony.

While it’s hard to change ingrained beliefs about conspiracies, the upside is that it’s also hard to get people to believe in conspiracies, contrary to popular belief, Uschinski says. In 2022, he and his colleagues published a study in PLOS ONE that found no evidence that conspiracy beliefs are growingdespite their visibility on social media. It is difficult to change ingrained beliefs of any kind, Ushchinsky says, especially if those beliefs are closely tied to one’s worldview. “Sometimes people choose the beliefs they need and do what they want based on who they are,” he adds.

For those who want to challenge conspiracy thinking, the authors of the new review offer some advice:

1. Don’t appeal to emotions. Research shows that emotional strategies don’t work on budget.
2. Don’t get fooled by factual arguments. The authors found that controversy about the facts of a conspiracy theory or the consequences of believing in a particular conspiracy also did not matter much.
3. Focus on prevention. The best strategies seem to include helping people recognize unreliable information and unreliable sources before they are confronted with a particular belief.
4. Support education and analysis. Making people analytical and explicitly teaching them how to evaluate information seems to be the most effective defense against conspiracy rabbit holes.