Some of these new rules are nigh impossible not to adhere to – if there are no planes from where we are to where we want to go, then we cannot fly, and if the pubs are closed, we cannot go for a pint. Others seem more a question of discretion. British Prime Minister Boris Johnson is, as of Tuesday, March 24th, the latest country leader who has imposed strict curbs on public life, apparently because the more advisory, nudgy, framework that was in force until now was widely ignored. The Sunday before, Mother’s Day in the UK, people traveled in their tens of thousands to seaside towns and inland beauty spots, utterly disregarding the requirement to keep 2 meters distance.

Do we need rules?

Will these new rules work, unless they are accompanied by tough enforcement? Such a forcible lockdown goes against the Nudge philosophy, with which Behavioral Science has become closely identified. Rules have no place in libertarian paternalism, where neither material incentives, nor the elimination of options are acceptable.

It’s not that rules cannot be an effective mechanism to influence people’s behavior. We are expected to drive on a specific side of the road, and the vast majority of the people never question or break this rule. Some rules are not even written down. When I visited the UK for the first time, as a 15-year-old, I was taken aback by the way people stood in a disciplined queue at bus stops in London – from punks with a swastika t-shirt and a Mohican coiffure, to city types with a pinstripe suit, from parents with babies to old-age pensioners. They all queued as if it was the most natural thing.

So why was the lightweight advice not to travel, attend social gatherings or go to the pub, so comprehensively flouted? One explanation, observes economist and founder of the Cognitive Economics Society, Leigh Caldwell, is a tendency he calls “institutional licence”. On the one hand, the government told us to stay away from pubs and public transport, but on the other hand, they did not actually order the pubs to close or the underground to stop operating. How strictly should such a rule then be adhered to? Not very, is the – quite defensible – conclusion of many people. This approach gives us a licence to deviate. If we actually want to go to the pub, we reason that the rule is perhaps intended for a very specific category of people, e.g. the elderly and vulnerable. But we are neither, so it’s not for us, really.

Another explanation is a behavioral propensity called “reactance”, which Syon Bhanot, a professor of economics, describes as follows: “when you tell me what to do, a part of me feels compelled to do the opposite”. If you are, or have been, a parent of young children, you will undoubtedly recognize this. Tell them not to touch something, and faster than you can mumble “reverse psychology” you will see it covered in smudgy fingerprints. The instinct to respond in an adversarial manner to any attempts to curb our liberty goes back to our earliest years.

And while we seem quite happy to accept that we need to stick to the agreed (and prescribed) side of the road, we are not necessarily so obedient when it comes to other rules of the road. Many among us (and I count myself as one) will occasionally treat the permitted maximum speed as a guideline, rather than a hard limit. The same applies to parking “just for 2 minutes” where we shouldn’t, and even accelerating as a traffic light goes amber. Rules that are not enforced, when it serves us, can be treated as optional, it seems.

I don’t think it is necessarily reactance or institutional licence that makes us ignore these rules, or the rule that we should stay at home, and really, really, don’t come closer than 2 meters from each other. We don’t need a rule telling us we need an oven glove to retrieve a gratin that has been baking for 30 minutes at 200 degrees: it is pretty clear and certain that if we attempt to take it with our bare hands, we’d quickly, regret it very much, and for a long time. But the behavior that some rules seek to regulate often seems perfectly fine. Breaking the speed limit is often without consequence (other than, occasionally, a penalty ticket). Compared with the salient benefits of speeding – whether it is the thrill of seeing the scenery whizz past or the fact that we can still arrive on time despite leaving too late – the vague and unlikely consequences are small.

The message challenge

And so, as the tentative early spring sunshine begins to warm up and beckons us to go out and meet our friends in the park, appeals to stay indoors and keep our distance – because doing otherwise may ultimately cost someone their life – have limited impact. They are often vague, and appear to leave a lot to individual interpretation. We don’t have a formal, strict definition of ‘social distancing’, so we construct our own, and we do so in a self-serving manner.

What should the authorities appeal to in order to make us change our ways? Many researchers have been studying attitudes and responses to messaging. One study, by Jocelyn Raude and colleagues, involving over 4,000 people in France, Italy, the UK and Germany in February found that we are overoptimistic, estimating the chance of catching the disease very low (nearly 80% thought it was less than 1/100), and thought they were a lot less likely to be infected than others. With such optimism, people simply don’t pay much attention to warnings.

Would it be better nevertheless to appeal to people’s self-interest, than to their altruistic nature? The evidence is mixed.

US-based research using about 1,600 participants, carried out by Toby Wise and colleagues, found that proper social distancing and hand washing was most strongly predicted by a perceived likelihood of being infected oneself, rather than a perceived likelihood of infecting others. In contrast, a wider study by Stefan Pfattheicher and colleagues, with over 2,000 participants from the US, the UK, and Germany concluded that empathy for the vulnerable is a basic motivation for physical distancing, and that inducing this empathy promotes compliant behaviour. Yet another, more specific study by Benjamin Oosterhoff and Cara Palmer, focusing on 770 US adolescents, suggests that higher levels of self-interest correlate with less social distancing, although, if that coincided with a belief the condition is severe, there was more social distancing and protective behavior.

Perhaps the tone of the message plays a part? Jim Everett and colleagues investigated the effectiveness of four types of messages with 1000 participants in the US: