Wooden squares with letters on them are partially rotated to spell fake and fact
Global governance, Munk School

Fact checks work best on loop: New study shows false claims about COVID-19 must be repeatedly debunked

As COVID-19 continues to spread, so does misinformation about the disease and measures to contain it. Despite efforts by authorities, the medical community and credible media to debunk false and misleading claims, it’s been unclear before now how effective fact checks are as a tool to respond to misinformation.

A new study from researchers at the University of Toronto, Dartmouth, the University of Exeter and the University of Kent suggests that, while fact-checking can quickly correct misperceptions about COVID-19, beliefs in wrong information often return.

During the study, respondents from the U.S., Great Britain and Canada were asked to rate the perceived accuracy of four claims on COVID-19 that have been debunked by scientific and public health authorities: that the Chinese government created the coronavirus as a bioweapon; that a group funded by Bill Gates patented the coronavirus; that antibiotics are effective in preventing and treating COVID-19; and that the medication hydroxychloroquine is proven to cure or prevent COVID-19.

Study participants shared political and demographic information about themselves and rated the accuracy of both true and false claims about COVID-19. They were then randomly assigned to receive fact-checked or unrelated placebo articles. The research team then compared belief in the claims over time between respondents who were shown the fact checks and those who weren’t.

The results, published today in the journal Nature Human Behaviour, have implications for how we dispel misinformation around the coronavirus pandemic. “Our findings suggest that fact checks can successfully reduce misperceptions about COVID-19 immediately after people read them,” said co-author Peter Loewen, director of the Munk School of Global Affairs & Public Policy and a professor in the department of political science.

Headshot of Peter Loewen
Peter Loewen, by Alexis MacDonald

“Now that we know those misperceptions often return, we can expect that convincing someone to adopt new understanding about COVID-19 may include setbacks. We also know that frequent exposure helps so what this tells us is that the best approach is a long term strategy.”

“Our results suggest that effectively addressing misbeliefs about COVID-19 will require repeatedly debunking false claims about the coronavirus. Otherwise, people will tend to revert back to the level of belief that they had before,” says co-author Brendan Nyhan, the James O. Freedman Presidential Professor in the department of government at Dartmouth.

“Fact checks were most effective among people who are more vulnerable to misperceptions of COVID-19 at baseline,” said Nyhan. These groups included supporters of conservative leaders, those with high conspiracy predispositions and those with low trust in health institutions. However, these effects did not persist over time in follow-up surveys conducted in the U.S. and Britain.

“By comparing U.S. data on the effects of COVID-19 fact checks to that of Great Britain and Canada, we found that our results are parallel across all three countries, which suggests that the effects are not an artifact of polarization over COVID-19 in the U.S.,” says co-author Jason Reifler, a professor of politics at University of Exeter.

The study is the first to estimate the effects of fact checks on COVID-19 misperceptions over time and across countries. The results provide evidence that COVID-19 fact checks can be effective but that frequent exposure is necessary for addressing misinformation during the pandemic.

John M. Carey from Dartmouth, Andrew M. Guess from Princeton University, Eric Merkley from the University of Toronto, and Joseph B. Phillips from the University of Kent also contributed to the study, which was supported by the National Science Foundation, the Economic and Social Research Council, and the Munk School of Global Affairs & Public Policy and the Dean of the Faculty of Arts & Science at the University of Toronto.

With files from Amy Olson / Dartmouth.