Irrational optimism in the time of COVID-19

Irrational optimism in the time of COVID-19

As I write this, the COVID-19 epidemic has taken a firm hold in many countries around the world. Now, one of the critical elements for containing the epidemic or delaying its peak, is the commonsense protection measures that individuals take. But for individuals to wholeheartedly adopt these measures, they will need to believe that the threat posed by this virus is real. Thankfully, many people do understand this. The German Chancellor realizes that given what we know at this stage, two-thirds of the population is likely to be infected. Many ordinary folks do too (Dude! We’re all getting it. Geography irrelevant. Pandemic). And many others have reacted disproportionately.

This piece is not intended to cause more anxiety to the general reader, but is mainly addressed to a recalcitrant group of people, constituting perhaps about 20% of the population, some of them in influential positions. Less than uniform adoption of self-protective measures can thwart containment measures, and have implications for all the rest of us. These otherwise intelligent folks don’t seem to appreciate the gravity of the situation. And here I am not referring to the worthies in high office who view quarantine as a conspiracy, or those who believe that large social gatherings are fine, and incantations to the coronavirus will convince it to leave us alone! I am talking about well-educated people, including some physicians. One colleague indicated that he would continue business as usual because he had “never taken a flu vaccine in his life and had never had influenza”, and was convinced that he was somehow immune! The fact that this virus was new to the human race did nothing to dent his belief. Another believed that people in northern Italy were in a bad way because they “drink less water” unlike the rest of us (and the disease would be less severe elsewhere)! Such irrational assumptions of immunity among influential people may be part of the reason why many countries have not taken adequate measures to contain or delay the peak of the epidemic.

Unrealistic optimism regarding risk to self

Underestimating susceptibility to health problems is a well known phenomenon. A good example of this is the failure of people to refrain from clearly harmful behaviors such as smoking. This is often the result of misplaced optimism in one’s resistance to disease relative to peers. Several cognitive errors may lead to such optimistic biases. Two are of particular relevance to the ongoing epidemic. The first is our inability to dispassionately assess the probability of events. Given the infectivity of COVID-19, it is expected that about 60% of the susceptible population will be eventually infected.* Therefore, you are more likely to be infected than not, and it is unrealistic to expect that you have a lower risk unless you live in a bubble. Second, we place disproportionate reliance on past experience to predict future vulnerability. Psychologists call this the absent/exempt heuristic. In the context of chronic non-communicable diseases, these cognitive errors have consequences only for the individual (and indirectly to their immediate family). But unrealistic optimism can have devastating consequences for the containment of an epidemic.

Public health messaging should therefore unequivocally dispel any illusion of immunity: the human immune system has never seen COVID-19 before, so every single one of us is vulnerable. The information for the public provided by both the CDC and the NHS are excellent, but do not categorically state this. Neither do the full page newspaper ads put out by the government in India. This central message needs reiteration to curb irrational optimism.

And once again, dear reader, this is not to get you to go into hiding. Universal vulnerability aside, there are grounds for rational optimism. Most infections with COVID-19 are mild, and the death rate is likely to be about 1 in a 100. Though this is many times higher than that due to seasonal influenza, it is not as high as originally feared. And most importantly, several countries have shown that with self-discipline, and state support, it is possible to contain the epidemic.

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* This figure is an estimate from the reproductive number (R₀) of COVID-19. Roughly, the proportion of the susceptible population which will be affected is calculated as p=1-1/R₀. For COVID-19, current data suggest an R₀ of about 2.5. Hence the 60% figure.