CRITICS claim the UK Government’s relaxed response to the coronavirus is a dangerous experiment based on the advice of behavioural scientists.

They believe it has been developed from “nudge theory” and could go terribly wrong.

Westminster has denied the accusations but there is growing concern the UK is not following the lead of other countries by taking more drastic action to prevent the spread of the virus.

Richard Horton, the editor of the world’s oldest and most well-known medical journal, The Lancet, has accused the government of lying when it claims its approach is based on medical science.

“The UK Government – Matt Hancock and Boris Johnson – claim they are following the science,” he said. “But that is not true. The evidence is clear. We need urgent implementation of social distancing and closure policies. The Government is playing roulette with the public. This is a major error.”

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The chair of the health select committee, Jeremy Hunt, said the failure of the Government to take stronger measures could lead to more people becoming infected. He said the UK’s reaction made it an “outlier” when compared with other countries.

“It’s extremely grave,” he said. “We are in a national emergency. You would have thought every single thing we do would be designed to slow the spread of people catching the virus.”

Jimmy Whitworth, a professor of international public health at the London School of Hygiene and Tropical Medicine, also said he was surprised stronger measures had not been introduced.

“Based on evidence from other countries, the most realistic approach to this is to initiate the strongest public health measures that will be supported by the general British public,” he said.

“I am surprised that stronger measures haven’t been introduced at this stage.”

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Devi Sridhar, professor of global public health at University of Edinburgh, agreed: “Now is the time for the UK Government to ban large gatherings, ask people to stop non-essential travel, recommend employers shift to home working and ramp up the response. The curve can be shifted (like South Korea and Singapore) but only with government action.”

However experts from the Government’s Behavioural Insight Team, unofficially known as the Nudge Unit, have been involved in the plans, according to the Institute for Government think tank.

Nudge is a concept in behavioural science which proposes that positive reinforcement and indirect suggestions can influence the behaviour and decision making of individuals or groups. Putting fruit at eye level close to a check-out in a shop counts as a nudge.

The Government’s strategy of telling people to keep calm and wash their hands is based on nudge theory, according to the Institute for Government.

“The most visible manifestation of its influence to date is in the communication around hand-washing and face touching – in particular the use of ‘disgust’ as an incentive to wash hands and the suggestion of singing Happy Birthday to ensure hands are washed for the requisite 20 seconds,” said a spokesperson.

The theory is that the longer people are asked to self-isolate the less effective this will be. “Behavioural science shows that people start off with the best of intentions, but enthusiasm at some point lags,” said Chris Whitty, England’s chief medical officer.

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However, others are wondering why, if the nudgers are right, so many other countries are taking a completely different view of the “science”.

“The predictions about fatigue setting in, on the face of it, seem dubious,” said Tony Yates, former professor of economics at the University of Birmingham.

“If we are prone to fatigue, why rely on the one thing we can ignore – advice about hand washing?

“The Government’s predictions are based on analysing past episodes of human behaviour, a process that is often fraught with error.”

The Nudge Unit was established in the Cabinet Office in 2010 by David Cameron’s Government to apply behavioural science to public policy. Now owned partly by the Cabinet Office, by Nesta and by employees, it has operations across the world. Its chief executive is Dr David Halpern.