A year ago, just a few weeks after the World Health Organization declared that Covid-19 was a global pandemic, UN secretary-general António Guterres announced a campaign to tackle another emerging threat to society. This new epidemic was not medical, however, but digital: misinformation and ‘wild conspiracy theories’ surrounding Covid-19 were going viral online. To combat this infection of information the UN planned to ‘flood the internet with facts and science’. Yet the ‘misinfodemic’ remains a persistent problem, contributing to vaccine hesitancy and resistance to public health measures that threaten our ability to control Covid-19 around the world.

Conspiracy theories are not a modern phenomenon, but as our feature explores, their modern manifestations have traits that give them more serious consequences. The internet and social media have been valuable communication tools during the pandemic, but they have also enabled fringe views and falsehoods masquerading as truth to reach large audiences far faster than they can be debunked.

Studies on the psychology of conspiracy theory believers show that, ironically, they have something in common with scientists: our curiosity and desire for answers; our need to understand and explain. Wherever these epistemic needs are unfulfilled, conspiracy theories can fill the gap – and in times of crisis those needs are especially acute. That’s a problem for science because the answers it can provide often exist behind barriers that put them beyond reach of the general public. Also, science has done some pretty incredible things that are, at times, straight out of science fiction, so being able to spot truly outlandish claims can require a high degree of science literacy. And of course there have been genuine cover-ups where science has been misused or evidence concealed, and science has been tarred by those episodes.

Even the scientific method, a prophylactic against our tendency to tell ourselves stories that might not be true, can be corrupted. The philosopher Karl Popper first defined conspiracy theories in the early 20th century and noted that they appear to be scientific by selecting evidence and proof that seem to support their narratives – a veneer that it can be hard for the uninitiated to penetrate.

It is seldom sufficient to simply disprove a specious claim, because those who believe in it can exhibit a plasticity of thought that reconciles refuting evidence. And it’s more difficult still to predict how public opinion will be swayed by a claim. The mishandling of the narrative around GM foods, for example, is generally considered a textbook example of PR failure. However, it’s worth noting that the much-publicised study claiming to show harm in mice fed on GM potatoes was recommended for publication despite being regarded as flawed by some of its reviewers, partly because rejecting the paper might raise suspicions of a conspiracy. The attempt to be transparent instead made the issue murky in the public consciousness and GM became more contentious. 

The conspiracy theory phenomenon also tells us something about our society. Social scientists have found that conspiracy theories tend to take hold where society is fragmented – by inequality in wealth, education and opportunity, for example. Individuals who feel failed by society are more likely to seek alternatives to the consensus, and are less likely to have the inoculation of education against false narratives. And nowadays, those fragments then further disintegrate across a smörgåsbord of choose-your-own-reality social media circles – echo chambers where suspicion and fear are amplified and monetised.

Part of the solution to both Covid-19 and its misinfodemic is therefore an immunisation programme. Education, critical thinking and science communication can give people resistance to the threat, but if broader societal problems are not also addressed, then the threat remains. Ideas are powerful things – and they do not have to be real to cause real harm.