Researchers have questioned the effectiveness of using certain 'nudges' to change attitudes or behaviour in relation to COVID-19.


Nudge theory is an area of behavioural science that uses subtle psychological cues to influence the people's behaviour, particularly around public health.

In a series of experiments, scientists from King’s College London tested nudges that have previously been shown to encourage people to think or act in desired ways. But they found that, when used in the context of the coronavirus outbreak, they did not have the expected effects.

Dr Michael Sanders, reader in public policy at the Policy Institute, King’s College London, said: “Controlling the spread of the coronavirus pandemic is as much about human behaviour as it is about the medical facts or government rules, so it’s no surprise that governments have turned to behavioural scientists for insights.

“Across two papers and six studies, our new findings cast doubt on the actual impacts of some of the most commonly used tools in the context of this crisis.”

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In the first study, published in the peer-reviewed journal Economic Letters, researchers tested so-called loss aversion messages. They say that one of the most robust findings in social psychology is that people value losses more than they do gains of equivalent size.

Therefore, a message highlighting the potential lives lost without a well-managed extension to lockdown would be expected to make respondents more cautious about COVID-19 than a message highlighting potential lives saved by a well-managed extension.

In the study, 500 people were randomly assigned to be shown one of the two messages, which were presented as government information posters. They were then asked how long the lockdown should last for schools, offices and different types of businesses.

The participants were also asked about their intention to comply with public health guidelines, such as washing their hands more frequently and for longer, and maintaining social distancing.

Contrary to literature on loss aversion, the researchers found that highlighting potential lives lost did not make people more cautious about ending lockdown or more likely to say they would follow the guidelines.

They said this may be because the participants were already familiar with the anticipated death toll for COVID-19 with and without lockdown measures.

Another reason could be that as so many people had already died in the UK at the time of the experiment on 19 May, the participants were effectively choosing between two very large losses, rather than a loss or a gain.

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We can only conclude that nudges activate good intentions, but people find it hard to follow through because of all the other influences on their behaviour that crowd out nudges on this occasion

In a second study, published as a working paper and currently under peer review, the researchers carried out a series of experiments testing a different set of nudges in April, May and June.

According to the research, while nudges increased respondents’ intention to comply with guidelines to tackle COVID-19, they did not have the expected result of actually changing their behaviour.

Participants were randomly assigned to read one of three mocked-up online news articles about coronavirus. The articles were identical except for their titles and opening paragraphs, with two containing messages informed by behavioural science research, and one containing a control message.

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The first nudge message focused on high levels of compliance with the lockdown among the UK public, while the second focused on an older person particularly at risk of COVID-19 and unable to leave their home at all.

Highlighting positive behaviour as a widespread norm has been found to encourage others to engage in it, and previous research has found that people are more willing to make sacrifices when there is an identifiable beneficiary.

The third message, which was presented to the control group, contained general guidance on how to maintain mental and physical wellbeing during lockdown.

A COVID-19 advice poster © Niall Carson/PA
The nudges used in the context of the COVID-19 outbreak did not have the expected effect © Niall Carson/PA

Participants were then randomised to receive an extra nudge, in which they were asked to reflect on someone they knew who was more likely to be affected by COVID-19 and then provide a written explanation of the steps they were taking to stop the spread of the virus.

Finally, they were asked to rate their intention of leaving their home in the next five days, as well as their intention to follow public health guidelines.

After reading the messages, participants who received the nudges were significantly more likely to say they would comply with the lockdown and follow the guidelines, researchers found.

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But when asked again in follow-up experiments – one and two weeks later – there was no difference in intention to comply among those who had been nudged and the control group.

Asked to recall their behaviour in the intervening weeks, the groups who had received nudges were no more likely than the control group to report following the rules.


The study states: “We can only conclude that nudges activate good intentions, but people find it hard to follow through because of all the other influences on their behaviour that crowd out nudges on this occasion.”

How can I protect myself from the coronavirus when shopping?

You’ll have seen signs in your local supermarket advising you to keep two metres from others while moving around the store. This is key to reducing your chances of catching the virus while shopping.

The coronavirus SARS-CoV-2 is spread through respiratory droplets that leave our mouth and nose when we cough, sneeze, or sometimes even talk. The droplets sprayed out by an infected person will contain the virus, which could then enter your body via your mouth, nose or eyes (this is why you shouldn’t be touching your face).

Respiratory droplets don’t usually travel more than one metre, so by keeping two metres from others, you’ll reduce the likelihood of being in the firing line. To make it easier to keep your distance, try to shop during off-peak hours, choose a store that’s limiting the number of people who can be inside at any one time, and use self-checkout if you can.

Keeping your hands clean is the other main thing you can do. If possible, wipe the trolley or basket handles with a disinfectant wipe when you arrive at the store. When you get home, wash your hands or use hand sanitiser before and after unpacking your bags.

A US study found that the coronavirus can survive for up to 24 hours on cardboard, and up to three days on hard, shiny surfaces such as plastic, so wiping down your purchases with a disinfectant spray or a soapy cloth before you put them away is another good habit to get into.

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Sara RigbyOnline staff writer, BBC Science Focus

Sara is the online staff writer at BBC Science Focus. She has an MPhys in mathematical physics and loves all things space, dinosaurs and dogs.