Journal Identification = NRP Article Identification = 0645 Date: June 16, 2021 Time: 5:11 pm
doi:10.1684/nrp.2021.0645
REVUE DE NEUROPSYCHOLOGIE
NEUROSCIENCES COGNITIVES ET CLINIQUES
94
Point of view
Rev Neuropsychol
2020 ; 12 (S1) : 94-6
Covid-19 epidemic and cognitive bias *
Épidémie de Covid-19 et biais cognitifs
Franc¸ois Sellal1,2, Geoffroy Hautecloque2
1Department of Neurology, Civil Hospitals of Colmar, 39 avenue de la liberté, 68000 Colmar, France
2Inserm U-1118, Faculty of Medicine, University of Strasbourg, France
<francois.sellal@ch-colmar.fr>
To cite this article: Sellal F, Hautecloque G. Covid-19 epidemic and cognitive bias. Rev Neuropsychol 2020;12(S1):94-6 doi:10.1684/nrp.2021.0645
I
n contrast to the flu epidemic of 1979-80, although of close seriousness, which had hardly moved its contem- poraries nor left an immovable memory, the COVID-19 will have greatly disrupted social and economic life on a planetary scale as soon as it was developed. What is more, it raised and continues to raise a large number of ques- tions, criticisms, debates and controversies where positions can be as clear-cut as they are versatile. One may even be astonished in hindsight that some mistakes may have been made and repeated from one country to another. Without wanting to play the role of censor, it seemed interesting to us to better understand how these errors could have been committed, by analyzing them from the perspective of the humanities. The different reactions or lack of reactions can be interpreted by relying on the work of the psychologist and Nobel Prize winner in economics, Daniel Kahneman, who has tried to explain certain tendencies towards irra- tional decisions in the economic field [1]. This is what Olivier Sibony, professor at HEC (Hautes Études Commer- ciales, Paris) in strategy and corporate policy, recently did in a remarkable seminar, which partly inspired this article[2].Cognitive bias is a systematic deviation of logical and rational thinking from reality. This distortion in the cogni- tive processing of information does not therefore correspond to a willingness to disguise reality, but to errors, gener- ally unconscious, which affect perception, evaluation and logical interpretation. These cognitive biases result schemat- ically from four main causes: too much information to be processed, lack of meaning, the need to act quickly, and the limits of memory. These biases can be illustrated by cur- rent events observed during the COVID-19 epidemic. They
∗This article is an English language translation of the following article:
Sellal F, Hautecloque G. Épidémie de Covid-19 et biais cognitifs.Rev Neuropsychol2020 ; 12 (2) : 218-20. doi:10.1684/nrp.2020.0575.
Correspondence:
F. Sellal
allow a better understanding of why the authorities did not quickly require containment.
Many commentators have criticized the authorities for taking too late the measures that would have allowed a better control of the epidemic. In the case of the Chinese authorities, it is known that this delay was initially encour- aged by a deliberate attempt to deny and mask this infection with a new virus, despite reports from doctors. The Chinese can be blamed for the surprise effect due to the novelty of the epidemic. However, the Europeans have hardly taken advantage of this to anticipate barrier measures. Thus the Italians let the epidemic develop in the Milanese, without even canceling or postponing the Bergamo-Valencia Cham- pions League match of February 19, 2020. While the Italian situation proved the rapid and uncontrolled spread of SARS- CoV2, the French people watched it in disbelief. It was heard that the high Italian mortality was due to the fact that the Italian population was very old (and therefore at risk); that the elderly were more contaminated because they lived in promiscuity with the rest of the family in the same house;
or that the state of Italian public hospitals could explain their overflow, forgetting that the most affected regions were among the richest in Italy, with a hospital level comparable to ours. Such a phenomenon occurred in France, where the behavior of Parisians was not affected by the outbreak of the epidemic in Alsace; but also in the United States, where the epidemic was described as “hoax” by President Trump, before the New York’s hecatomb forced him to react.
Several cognitive biases can explain this blindness and latency of reaction.
Endogroup and exogroup bias
It consists on believing that another group’s matters do not concern us and that we are intrinsically stronger. In an interview on January 21, 2020, Pr Didier Raoult mocked the alarmists: “There are three Chinese who are dying and it’s a worldwide alert, the WHO is getting involved, it’s
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being talked about on television and radio”. The Italians pointed this out to us, judging our behavior in mid-March to be “surreal”(“In France, more people in the squares than in the polling stations”titled Il Messaggero). The words of Brazilian President Jaïr Bolsonaro illustrate this even bet- ter, despite the declaration of the first case of Covid-19 as early as February 25, 2020 in Sao Paulo: “Brazilians are immune, here we see kids diving all day long in sewage without getting sick” and calling Covid-19 a “little flu”.
Mental model bias
At the beginning many experts pointed out that the epi- demic would not cause more deaths than a flu. This was expressed by one expert when he said, “I am surprised that we are talking about a very significant cause of mortality, and even the health crisis of the century, when in 2017 influenza and other respiratory infections killed between 14,000 and 20,000 people in France. (...) Today I don’t see any major problem in terms of mortality” (Pr Didier Raoult, March 16). This is also the reference to what we know. This was expressed by another expert explaining that “Covid-19 is just another coronavirus” (Pr Eric Caumes, interview of February 28). Faced with a new problem, one is tempted to make an analogical reasoning, to take advantage of our knowledge before deciding on an answer. Sometimes this analogical reasoning is effective, sometimes not. Thus the comparison with the flu, which affects children, is bad for SARS-CoV2 since it affects them surprisingly little. Above all, the use of respiratory resuscitation is also out of pro- portion between the two diseases, which has considerable health consequences. It was therefore probably a mistake to think that containment was only necessary in the case of influenza or should be limited to schools.
Exponential growth bias
On February 28, the French balance sheet communi- cated by the Ministry of Health reported a doubling of the number of cases, from 18 to 38, but this did not move anyone. On March 16, the Director of the DGS (Direction générale de la santé, General Board of Health), Jérôme Salomon, was alarmed that the number of cases was
“doubling every three days” and therefore justified the con- tainment measures. However, nothing has fundamentally changed in terms of the speed of growth. Here we are con- fronted with the fact that, in exponential growth, the first doubling of the workforce (from 1 to 2, then from 2 to 4) is perceived as derisory, whereas when the work force becomes large, there is a feeling of being overwhelmed.
This is the famous problem of Sissa’s chessboard. To thank him, King Belkib had proposed him to choose his reward, as expensive as it may be. Sissa chose to ask the king to take a chessboard and, on the first square, to put one grain of rice, then two on the second, four on the third,
and so on, doubling the number of grains of rice each time.
Everyone laughed at this seemingly insignificant demand, but it turned out that it amounted to: 264- 1, or more than 18 billions billions grains, which corresponds to more than 1000 years of world rice production!
The same problem arose in assessing the number of peo- ple affected by the epidemic, so that it was minimized at first and containment measures were delayed.
Overconfidence bias
This refers to the confidence one tends to have in one’s estimates, to the point of not measuring the uncer- tainties. During his seminar, O. Sibony used the patient forecasts made by the 18 best American epidemiologists on March 16-17 for March 29, i.e. a dozen days later. They averaged 19,000 cases (from 10,000 to 80,000 according to specialists), whereas this figure turned out to be 140,000, an error of a factor of 7[2]. Such overconfidence is reflected in Professor Raoult’s statement on April 21 “...if we conti- nue like this, we have the impression that what was one of the possibilities of this disease, namely a seasonal disease, is being realized and that it is reasonable to think that within a month there will be no more cases at all in temperate countries”.
The same overconfidence bias may apply to the treat- ment options proposed by some, despite their poor scientific validation. The passionate debates on hydroxychloroquine are an illustration of this. This overconfidence can also be explained by the wishful thinking bias.
The illusion of knowledge and the flashback effect
Faced with an epidemic, a first reflex is to turn to what the pharmacopoeia allows to be used to prevent the infec- tious agent or to counteract its pathogenicity. It is striking to see how easily the population, including doctors, has been able to adhere to a treatment, hydroxychloroquine, even though numerous factual elements cast doubt on this (uncontrolled studies on small numbers of people, with con- tradictory results). Even after the publication of inconclusive results of this treatment, including in randomized studies, its defender contests their validity in favor of studies[3]that are methodologically much lighter but consistent with it.
On May 25, 2020, he did not hesitate to launch, on his YouTube channel: “I don’t know if hydroxychloroquine kills elsewhere, but here it saves lives” or, on the same day: “At the IHU (University Hospital Institute) we trust in reality, not badly controlled big data”, while remaining supported by his followers.
There are many reasons why this therapeutic option has met with great success. Among them is undoubtedly the fact that a treatment presented as being able to stop the disease
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when prescribed at the first signs of it, offers a more tempting option than containment or hospitalization, without alter- native treatment. But there is also a group thinking effect [3], with people living in the south of France (i.e.near Mar- seilles, where this idea of treatment originated) adhering to it more than those living in the north (i.e.near Paris). People claiming to be “anti-systemic” are also more favorable to hydroxychloroquine[4].
Focus bias
When the question arose as to whether the munici- pal elections should be maintained, all the political parties militated, sometimes in strong terms, for them to be held on March 15. Containment was decided on March 16. As early as March 22nd, the Doctors’ Unions filed complaints with the Council of State because they felt that the mea- sures adopted were insufficient, even though their effect could not be felt for about two weeks, given the incubation period of the disease. On the other hand, while in Germany the Bundesliga soccer matches had just resumed in the evening, several news channels stressed that this resump- tion of matches (behind closed doors) had not had any deleterious consequences on the Covid epidemic, which for the same reasons is nonsense. This impatience to have results as soon as the measures have been taken is a mis- take of focus and can contribute to multiplying initiatives or even changes of perspective before even judging the effect of the first decisions, in this case containment then end of lockdown.
Retrospective bias
The option of confining the population was taken hesitantly by governments because it had serious socio- economic consequences that we are beginning to glimpse.
Moreover, even if the measure seems a priori relevant to limit the spread of the virus, which seems to be confirmed by the drop in Ro and then Re (number of cases infected by an individual), it remains contested and has not been
adopted in some countries, such as Sweden and Brazil, or to a lesser extent in other countries such as the Netherlands or Denmark. This containment measure has a very good chance of remaining contested, whatever the outcome of the pandemic, because each opponent will be able to ret- rospectively find arguments that support his or her initial visions[2, 5]. Thus, if the number of deaths is close to that of the 2003 heat wave (about 20,000 deaths), it will be easy to say that it was not necessary to confine (“all for that!”), since the number of deaths is modest considering the different causes of excess mortality, forgetting that the limited value of the deaths may have been favorably influ- enced by the containment measures. If the number of deaths approaches that of the already high number of deaths from the Asian flu of 1957 (about 100,000), it can be argued that this figure was reached without containment and that the latter therefore hanged nothing. Worse, if we wait for the figures of the Spanish flu of 1919 (>400,000 deaths), we can retort that confinement was useless (“What’s the point of all this?”).
By way of conclusion
Faced with an event characterized by its novelty and the many inherent uncertainties, we can see that many cogni- tive biases can disturb our analyses and behavior. Cognitive bias is a mistake we are not aware of when we commit it.
Cognitive biases are not necessarily harmful, because under specific conditions heuristics can help avoid an imminent pitfall. In a situation as complex as the management of an epidemic, they are much more likely to be detrimental to logical behaviour. This is why it is safer to analyze the facts as a group, to compare one’s opinions with those of others, before making decisions with far-reaching consequences.
Acknowledgments
We thank Moana Jardin for editing support.
Conflict of interest None.
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