False claims about COVID-19 must be repeatedly debunked, study finds

Researchers at the University of Toronto, Dartmouth College, the University of Exeter and the University of Kent have found that fact checking can quickly correct misperceptions about COVID-19 – but that beliefs in wrong information often return.

The study, published in the journal Nature Human Behaviour, asked respondents from the United States, Great Britain and Canada 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.

They found that fact checks did indeed reduce people’s misperceptions, but that the changes did not persist over time.

“Our findings suggest that fact checks can successfully reduce misperceptions about COVID-19 immediately after people read them,” said study co-author Peter Loewen, director of U of T’s Munk School of Global Affairs & Public Policy and a professor in the department of political science in the Faculty of Arts & Science.

“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.”

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 study’s findings have implications for how we dispel misinformation around the coronavirus pandemic.

“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 political science 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 U of T, 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 U of T’s Faculty of Arts & Science .

With files from Amy Olson / Dartmouth.