At the time we started working on this briefing, news that a new virus was claiming lives in the Chinese city of Wuhan was just breaking. By the time we completed it, the new coronavirus had spread across most of the world. Entire countries went on lockdown, with businesses shuttering up, and the public retreating indoors. But while things were coming to a standstill on the outside, the rumour mill went into overdrive. An avalanche of conspiracies, home-made remedies, and unsubstantiated DO’s and DON’Ts circulated across social, and some traditional, media. Much of it had the potential to cause real harm to people’s lives.

As we continue to face confusing and contradictory misinformation about Covid-19, the health research brief reviews findings from psychology and health communication to explain how health misinformation travels, and determine what we, and you, can do to fight it.

A long history of misinfodemics

In many respects, Covid-19 is unprecedented. The speed of its spread, and the impact it has had on lives and livelihoods around the world are extraordinary.

And yet, health myths are not unique to the new coronavirus. During the 2015 Zika outbreak, a post claiming that it was a man-made virus received over half a million views. It is not; it comes from the Aedes mosquitoes. When Ebola swept across West Africa from 2013 to 2016, unfounded rumours that medical staff were carriers of the disease dissuaded many from turning to treatment centres, leading to home remedies that thwarted efforts of containment, and even attacks on health facilities. Then there is the anti-vaccination argument – involving long-debunked, stubborn myths that just won’t go away. According to the World Health Organization, vaccine hesitancy is one of the world’s top 10 public health risks.

To make sense of the different ways in which health misinformation takes hold of the public imagination, the research brief distinguishes between three scenarios.

Crises, conspiracies, and everyday advice

Crises refer to moments of radical disruption and information overload. This is what happens during outbreaks and national emergencies, when even the simplest everyday routines are thrust into uncertainty. Covid-19 is no doubt one such crisis.

Conspiracies, by contrast, are wildly unsubstantiated allegations; narratives of secret deals and hidden intentions, which spread from groups of convinced believers on to the public. Anti-vaccination conspiracies are one of the best-known examples of this. Despite the overwhelming evidence that vaccines save millions of lives a year, a staggering 21% of people around the world have doubts about their safety.

Then there is what we call everyday misinformation. The realm of unsubstantiated advice, alternative cures, or even moral norms, which cause harm through setting unrealistic expectations of our bodies, and recommendations of unproven treatment.

There are ways to fight each one of them.

Crises: Use clear messaging to mitigate the information overload

Fighting misinformation in times of crisis takes clear, simple messaging, delivered early and regularly, using sources and channels that people trust. Think of messages like: “stay at home” or “wash your hands”.

This is because going through a crisis is a particularly stressful experience. We tend to actively look for information and try to make sense of the transformations around us. But paradoxically, we are less able to process complexity. The stress of a crisis, combined with a well-documented aversion towards uncertainty, makes it harder to distinguish information from the noise. This is why the US Centres for Disease Control and Prevention recommend simple, regular messaging, that leaves no room for interpretation.

Anti-vaccination conspiracies: focus on prevention to stop harmful narratives from gaining exposure

Anti-vaccination arguments, by contrast, are extremely difficult to correct. Experimental research has found that corrections to these arguments can make erroneous beliefs stronger in time. Notably, even in experiments which found a minor improvement in belief, there is no evidence that debunks improve intention to vaccinate.

We do not know with certainty why this happens. One explanation is that corrections increase the familiarity of myths – and with it, the public’s likelihood to believe them. We have looked at this in more depth in another briefing.

Another explanation is that readers who are already skeptical of vaccination may reject new information to protect prior beliefs. This is what psychologists refer to as motivated reasoning. Finally, anti-vaccination attitudes may also be difficult to correct because they represent an entire worldview, rather than the sheer absence of information.

A survey with over 5,000 respondents in 24 countries found that belief in conspiracy theories is the best predictor of vaccine hesitancy. This is not something one can easily change. Conspiratorial ideation is not a minor quirk like believing in star signs, but a person’s entire worldview, or way of interpreting events through filters of suspicion and mistrust. The World Health Organisation makes it clear that vaccine deniers are unlikely to change their minds.

When it comes to vaccine hesitancy then, prevention is better than cure. Marking a misleading anti-vaccination post as false via Facebook’s Third Party Fact Checking initiative, for instance, reduces the likelihood of it influencing new audiences, even though it is unlikely to change the views of existing believers. Similarly, health communicators can mitigate hesitancy by emphasising high safety, instead of low-risk, and avoiding fear inducing pictures of needles. The multi-country survey found that disgust towards needles is the third best factor which explains vaccine hesitancy.

In every case, fighting misinformation is a matter of truth and trust

Having the latest medical evidence is only half the fight against health misinformation. The other is about earning the public’s trust. This takes time, patience, and a long-term campaign that takes into account the media consumption practices and value systems of the public.

Research on everyday health behaviours finds that long-term interventions can improve health-seeking behaviours such as taking up walking, using protection, or accessing quit lines for smokers.  But this requires targeted, sustained intervention.

Take care over what you share

An experiment conducted in the US at the beginning of 2020, found that participants who were simply asked to choose which posts they would share from a list of 30 Covid-19 stories, selected false posts about as frequently as they selected true posts. This is a worrying finding. Focusing on what’s share-worthy, thinking about what’s likely to provoke the most intense reaction from our peers, can make us lose track of accuracy.

The same experiment found that participants who were first asked to think about accuracy were a lot more discerning with their selections.

Therefore, stop, take a second, and think about what you share.