Daniel Hannan is a writer and columnist. He was a Conservative MEP from 1999 to 2020, and is now President of the Initiative for Free Trade.

In a crisis, we reach for whatever feels most comforting. As the Titanic sank, its band leader, Wallace Hartley, played the hymn his father had introduced to the chapel where he had sung as a boy, “Nearer my God to Thee”.

More prosaically, a thousand pundits and politicians have responded to the COVID-19 outbreak by saying, in effect, “This just goes to show that we need to do whatever I happened to be banging on about before”. Anti-globalisers say that it proves we are too reliant on international trade. China hawks say we must ban Huawei. The GMB rails against the use of private hospital beds. Jeremy Corbyn blames Boris Johnson.

There was an eco-activist on the radio yesterday saying it proved the urgency of cutting carbon emissions – though I’m pretty sure that is already happening. Anti-Brexiteers demand an extension of the transition period. People who dislike capitalism argue that we mustn’t waste a good crisis.

The EU, too, has reverted to its most elemental impulses. In an extraordinary video clip, the President of the European Commission, Ursula von der Leyen, insisted that the Single Market be preserved while at the same time (and evidently oblivious to any contradiction) announcing an export ban on some forms of medical equipment. We’re all in this together; but only if we’re in the EU.

A visibly shaken Aleksandar Vučić, the President of Serbia, responded to Ms von der Leyen’s announcement with a televised statement in which he told his countrymen that China was their true friend. The EU, he said, having for years set conditions that effectively forced Serbia to bid for European rather than non-European contracts, had now thrown his country over. Only the Chinese would send medical equipment.

Now it is possible that Vučić, too, is reverting to his primal instincts. He started out as a hardline nationalist, though he is now a goody-goody EPP member. And it is equally possible that I am doing the same, identifying what I see as a clear case of EU hypocrisy but others might see as a justified response. All human beings suffer from confirmation biases.

There is nothing we can do about our neural wiring; but we can at least try to identify and allow for the various cognitive glitches that become especially pronounced when there is an elevated stress level.

For example, our instincts are likelier to push us into over-reacting than the reverse. When the UK government, acting in line with advice, responded in a phased and measured way to the outbreak, there was a general demand that it do more. I was reminded of a line from Harold Nicolson’s diary at the height of the 1938 Czech crisis: “Several people ring me up begging me ‘to do something’. They have no idea what they want me to do, but they are getting hysterical, and it is some relief to them to bother others on the phone”. For phone, these days, read social media.

One of the most dangerous sequences in politics goes like this. “Something must be done. Here’s something. Let’s do it.” It leads to all manner of needless and counterproductive decisions.

For example, it is hard to see any medical case for countries banning international travel, as the EU has just done – especially from places with infection rates similar to or less than their own. Nor can I see much rationale for closing schools and sending children, who seem mercifully to be the least at risk from the disease, into the care of their grandparents. But, as always in a crisis, people want action – big, visible, dramatic action. So my guess (and, I could, as I say, be subject to cognitive bias) is that governments the world over are doing more rather than less than is strictly demanded by the science.

What of the disease itself? Is it likely to be better or worse than the forecasts suggest? Obviously, it is impossible to know. When even my friend Matt Ridley – the brilliant Matt, who has made a career out of wisely and successfully debunking scare stories – says that this is the big one, there is plainly a genuine menace. Still, it is worth noting that the forecasts for both bird ’flu and swine ’flu were far too pessimistic. When I say “forecasts”, I mean the predictions of WHO officials, the Chief Medical Officer and the US government – the headlines, naturally, were even more wildly out.

Our pessimism has a solid evolutionary basis. Trusting and cheerful early hominids tended not to have as many surviving offspring as their suspicious kindred, and we carry the gloomy genes of the survivors. Pessimism has its uses; but we should be aware of how our instincts can mislead us.

It is at least possible that we will avoid some or most of the predicted catastrophes. The WHO says the illness has peaked in parts of East Asia, and the Chinese President has visited Wuhan without protective clothing. We need to think, not just about getting through the coming weeks, but about what comes afterwards.

It is inevitable that we will emerge from the crisis poorer, more indebted, with many businesses destroyed and with something close to a wartime command economy. But how high those costs are is at least partly discretionary. We – or at least our leaders – can dial them up or down. It is a hard thing, in politics, to act proportionately when public opinion demands drastic action. But doing so is the essence of statecraft.