The research reveals 'key predictors' for susceptibility to fake pandemic news, and finds that a small increase in the perceived reliability of conspiracies equates to a larger drop in the intention to get vaccinated.
Scientists from the University of Cambridge gathered data from national samples in each country, and asked participants to rate the reliability of several statements, including six popular myths about COVID-19.
While a large majority of people in all five nations judged the misinformation to be unreliable, researchers found that certain conspiracy theories have taken root in significant portions of the population.
The conspiracy deemed most valid across the board was the claim that COVID-19 was engineered in a Wuhan laboratory. Between 22-23% of respondents in the UK and United States rated this assertion as "reliable". In Ireland this rose to 26%, while in Mexico and Spain it jumped to 33% and 37% respectively.
This was followed by the idea that the pandemic is "part of a plot to enforce global vaccination", with 22% of the Mexican population rating this as reliable, along with 18% in Ireland, Spain and the US, and 13% in the UK.
The notorious 5G conspiracy - that some telecommunication towers are worsening COVID-19 symptoms - holds sway over smaller but still significant segments: 16% in Mexico, 16% in Spain, 12% in Ireland, and 8% in both the UK and US. The study is published today in the journal Royal Society Open Science.
"Certain misinformation claims are consistently seen as reliable by substantial sections of the public. We find a clear link between believing coronavirus conspiracies and hesitancy around any future vaccine," said Dr Sander van der Linden, co-author and Director of the Cambridge Social Decision-Making Lab.
"As well as flagging false claims, governments and technology companies should explore ways to increase digital media literacy in the population. Otherwise, developing a working vaccine might not be enough."
Earlier this week, the Social Decision-Making Lab launched a project with the UK Cabinet Office: Go Viral!, a short online game that helps 'inoculate' players against fake news by lifting the lid on common misinformation techniques.
For the new study, the team - including Cambridge's Winton Centre for Risk and Evidence Communication - looked at correlations between certain beliefs and demographic categories and the perceived reliability of misinformation.
Scoring highly on a series of numeracy tasks given as part of the study, as well as declaring high levels of trust in scientists, are 'significantly and consistently' associated with low levels of susceptibility to false information across all nations.
"Numeracy skills are the most significant predictor of resistance to misinformation that we found," said Dr Jon Roozenbeek, lead author and Postdoctoral Fellow in Cambridge's Department of Psychology.
"We all now deal with a deluge of statistics and R number interpretations. The fostering of numerical skills for sifting through online information could well be vital for curbing the 'infodemic' and promoting good public health behaviour."
Moreover, and despite 'boomer' memes, the team found that being older is actually linked to lower susceptibility to COVID-19 misinformation in all nations except Mexico (where the opposite is true).
Identifying as more right-wing or politically conservative is associated with higher likelihood of believing COVID-19 conspiracies and falsehoods in Ireland, Mexico and Spain - but less so in the UK or US.
Trusting that politicians can effectively tackle the crisis predicts higher likelihood of buying into conspiracies in Mexico, Spain and the US, but not in the UK and Ireland. Exposure to information about the virus on social media is linked to misinformation susceptibility in Ireland, the UK and US.
Researchers asked participants about their attitude to a future coronavirus vaccine. They were also asked to rate the reliability of conspiratorial COVID-19 claims on a scale of one to seven.
On average, an increase by one-seventh in someone’s perceived reliability of misinformation is associated with a drop of almost a quarter - 23% - in the likelihood they will agree to get vaccinated.
Similarly, a one-point increase on the conspiracy reliability scale is linked, on average, to a 28% decrease in the odds of someone recommending vaccination to vulnerable friends and family.
Conversely, on average, a one-seventh increase in trust in scientists is associated with a 73% increase in the likelihood of getting vaccinated and a 79% increase in the odds of recommending vaccination to others.
The researchers controlled for many other factors - from age to politics - when modelling levels of 'vaccine hesitancy', and found the results to be consistent across all countries except Spain.
Jon Roozenbeek, Claudia R Schneider, Sarah Dryhurst, John Kerr, Alexandra LJ Freeman, Gabriel Recchia, Anne Marthe van der Bles, Sander van der Linden.
Susceptibility to misinformation about COVID-19 around the world.
R. Soc. Open Sci., 2020, doi: 10.1098/rsos.201199