(featured image: Gerd Altmann via Pixabay)
Not the most obvious kind of decision, but arguably the most important one
I was only about this tall when I was first told this riddle, but straight away I thought it was fascinating. My father asked me, what weighs more, a kilo (I grew up in metric) of feathers, or a kilo of lead? My intuition immediately suggested the kilo of lead would weigh more – everyone knows lead is heavier than feathers, right? Subsequently being told the right answer – and worse, having to admit it! – made it stick with me all these years.
I was reminded of this a few days ago, when reading an article discussing research by Kaitlin Woolley and Peggy Liu, marketing professors at Cornell and Pittsburgh universities respectively, which looked at people’s ability to estimate the calories of the food on their plate. It seems we are not really much good at doing so.
Health experts suggest two distinct approaches to people who want to control their calorie intake by evaluating what they eat. One is to make a quantitative estimate of the calories in the food, the other is to simply rate it qualitatively, e.g., on a nine-point scale from “very few” to “very many”. The argument in favour of the latter is that it is much easier to manage for the lay person, while leading to very similar decisions as the more precise one.
Woolley and Liu presented their subjects with two snack plates: one with 33g of plain roasted almonds, and one with 20g of chocolate coated ones, respectively with a calorific content (unbeknownst to the participants) of 200kcal and 100kcal. One group of subjects used the qualitative scale, and thought the plate with the plain almonds contained fewer calories (by about 1.5 points on the nine-point scale); also, when they were asked to choose a low-calorie snack, almost all went for the plate with the plain almonds. The other ‘quantitative’ group got the difference right (117kcal vs 111kcal), but clearly failed to realize that the plate with the roasted almonds contained twice as much energy as the one with the chocolate covered ones.
The authors believe these mistakes stem from a qualitative perception. Plain almonds are “very healthy”, while chocolate ones are “unhealthy”, therefore a plate of one is healthy, and a plate of the other is not (just like the mistake with the lead that is heavy, and the feathers that are not). We consider the inherent characteristics of two categories, but fail to take into account that these are not absolute ones. There is an amount of feathers that is heavier than a given amount of lead; there is an amount of plain almonds that contains more calories than a given amount of chocolate almonds.
The most important kind of decision
Surprisingly, this phenomenon relates closely to decision-making in a much more general context. In the class in Ethical and Evidence-Based Decision Making that a colleague and I teach, we consider three basic kinds of decisions. The whether (or not) decision is perhaps the most common one – with examples like the decision whether we should take an umbrella, whether we should have another glass of wine, whether we should write an angry letter of complaint, or whether emigrating to Chile is a good idea. The which decision compares different possibilities, and works out the most suitable one, given a set of criteria. After having come down in the affirmative on the decision whether you should buy a new kitchen, you then need to decide which kind of worktop you will get, which finish on the units, which type of refrigerator and so on.
The third type, the when decision, seems relatively trivial in comparison. At the surface, it simply relates to the timing of a decision – when to get up in order not to miss your flight, or when to start saving for your retirement. But it can also indicate when you change your mind about something and decide to pursue a different course of action. This is precisely where the same kind of absolutist thinking – lead heavy, feathers light; plain almonds healthy, chocolate almonds unhealthy – can trip us up.
As the number of COVID-19 cases is rising in many countries, we hear conflicting arguments as to what to do (or not to do). Some people argue that schools should close and switch to distance learning. Early this week, London mayor Sadiq Khan was strongly urging the government to shut all secondary schools and colleges ahead of the Christmas break. The UK education secretary, Gavin Williamson, is of a different opinion, and told a London council, which had already ordered schools to move the majority of pupils to remote learning, to keep them open, or face legal action. In Belgium, a similar controversy arose later in the week: on Wednesday, immunologist Hans-Willem Snoeck advocated closing all schools until the end of January (and extend the school year by one month). Education secretary Ben Weyts vigorously rejects the idea.
How would approaching this as if it were a when decision help? The positions of either side seem as absolutist as the plain=healthy/ chocolate=unhealthy views in the Woolley and Liu experiment. If one is an expert in one domain or one has responsibility for a domain, then one can be very tempting to focus exclusively on the consequences of a decision within that domain.
The decision which of the two plates provided lowest-calorie snack should not be made on the basis of which of the two kinds of almonds are healthiest. Instead, it should be treated as a when decision: when, i.e., with what quantity of almonds would a plate of the plain variety be less healthy than one with the chocolate-coated one? That is a good way to come to an evidence-based conclusion.
It should be similar with the question whether or not the schools should remain open. The proponents of closure should establish when, i.e., with what consequences on, say, the educational disadvantage to pupils, or their mental health, would they change their mind and conclude that it is indeed preferable to keep the schools open, given the consequences on case numbers, hospitalizations and deaths this would bring about. Likewise, those who argue the schools must remain open should explain, when, i.e., with what consequences on case numbers, intensive care occupancy and COVID-19 deaths, they would agree that closing the schools would be the lesser of two evils.
A when decision compels those who might be prejudiced by their own expertise in one domain, or those who are bound by their political responsibilities and allegiances, to face the actual trade-off. It leaves no room for absolutist thinking – for any of us. That is why it is, perhaps, the most important kind of decision.