(featured image: Thomas Quine/Flickr CC BY 2.0)
There is one heuristic we use a lot. We also misuse it quite a bit.
(Warning: this piece contains references to activities which may temporarily not be available in your area.)
Bedtime was not always quite sleep time, back when my age could still be expressed as a single digit. Often, my younger sisters and I (we all, conveniently, slept with our bedroom doors open) used to play a guessing game for as long as it took for us to finally doze off. Two of us needed to find out, by asking yes/no questions, what the third one was thinking of. This could be a person, an animal or an object, and the category had to be announced (this was also the symbolic start of the game).
Knowing the category in which to guess gave us a head start, but it also prevented us from making inadvertent category mistakes – a concept that was well beyond us at the time. Category mistakes are errors in which attributes and categories are mismatched. Asking whether my sister was thinking of a man or a woman would be a category mistake if she was thinking of the dining table downstairs, for example, for members of the category ‘object’ do not have the attribute man/woman. The canonical definition provided by Gilbert Ryle, the philosopher who coined the term, is that of a tourist who, after a tour of Oxford, asks where the university is. (The University of Oxford consists of several colleges, scattered over the city, without one main campus; the category error is therefore the assumption that a University is a member of the category “physical infrastructure”, instead of that of an “institution”.)
Categories as heuristics
Categories are an extremely useful concept, allowing us to make sense of the world. People, objects, abstract concepts – you name it – we place them all in categories, often in many categories simultaneously. For example, wellington boots can be a member of the category of footwear (along with flipflops, trainers and smart leather shoes), and at the same time also be in the categories “suitable for a walk on a wet day” (together with a waterproof jacket and a pair of old jeans), and “unsuitable for a black- tie event” (besides a t-shirt bearing a risqué pun and a swimsuit).
We widely use categories as a heuristic in making decisions: by verifying whether something is (or is not) a member of one or more categories, we can include it in (or exclude it from) a final set of options. We will, for instance, generally not even consider wearing sandals to a wedding reception, because while they are definitely a member of “footwear”, they do not belong to the “suitable for formal occasions” category.
Preferences (or aversions) can define categories too. A new movie may have your favourite actress or actor in the principal role, or may have been directed by someone whose previous films you liked a lot. Another one may be a musical, or a romantic comedy, and you happen to have a strong dislike of that kind of entertainment. Based on the categories a movie belongs to, you can skip finding and reading reviews, and simply use that heuristic for determining whether you’d enjoy it (and you would often be right).
You might reason in a similar way when you visit a restaurant you have not been to before. As you consult the menu, you spot a dish with some of your favourite ingredients. That is a category that might make the dish stand out, and influence your choice. Alternatively, if you feel adventurous, the category “have never had this before” might appeal to you and lead you to choose a very different dish. In either case, your decision is inspired by categories.
Unfortunately, efficient as they are, heuristics can tempt us into error, and two specific kinds of mistakes are closely associated with the concept of categories. When we reason that something that is true for a category as a whole, is also true for every member of the category, we commit the fallacy of division. The Dutch are the tallest people in the world, but it would be wrong to claim, on that basis, that any Dutch citizen is necessarily very tall. The converse is the fallacy of composition, which happens when you conclude that, because something is true for some member, it is also true for the whole category. We’d be committing it if we assumed that, because one multiple Tour de France winner was caught using illicit performance-enhancing substances, the whole sport is rife with doping.
Both these fallacies can be seen as instances of blurring the lines between two categories, and it is precisely this blurring that can mess around with our judgement.
Last weekend, the long-awaited Eurovision Song Contest, postponed from last year, took place. The most important rule in the voting mechanism is that both the professional jury and the audience cannot vote for the artist that did represents their own country (or at least the one from which they phone in their vote). It is not hard to see why: the category “represents my country” would, for many, be a heuristic so strong that it would replace a more objective judgement of the quality of the performance. This restriction may prevent the most egregious nationalist voting, but it does not remotely eliminate it, as a paper by Alex Mantzaris, a data scientist at the University of Florida, and colleagues suggests. They examined the votes between 1957 (when the event started) and 2017, and established strong evidence supporting the hypothesis of regional collusion (countries giving high scores to each other) and bias arising from factors like proximity or cultural affinity, instead of artistic merit.
We might dismiss favouritism in matters of entertainment as frivolous and nothing much to worry about, but the category heuristic lurks elsewhere too. We should, of course, judge a decision on the basis of the robustness of the logic and the strength of the evidence, but the category “decisions that are beneficial to us” might be a tantalizing heuristic to override that reasoning. When a new book is published in which the authors make far-reaching claims, we should evaluate these on the basis of the soundness of their argument, and our judgement should not be influenced by whether the authors belong to “smart people”, or “assholes”. Yet, isn’t it tempting to take the simple route of the category heuristic?
If a close colleague at work, belonging to the category “people towards whom I feel loyal” is accused of inappropriate behaviour, will we approach the affair with the same dispassionate attitude as if it concerned someone from the category “complete strangers”, or “people I don’t get along with for whatever reason”? The category heuristic beckons insistently. Should someone challenge us about whether we took the right action, might we be seduced into blurring the line between the categories “worked really, really hard” and “considered the trade-offs and made the right calls”?
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Like all heuristics, the category heuristic (which we use much more than we realize) can be a very useful shortcut – but only when it is used correctly. Ignoring the trade-offs involved in a choice or judgement and failing to engage in deliberate reasoning is a common error. In this particular case, however, the cardinal sin, the true category mistake, happens when we blur the lines between a category that is relevant, and one that is not.
When we blur those lines, we deservedly end up in the category of “people who misapply the category heuristic”.