Dichotomous Thinking

Heel-Strikers Versus Forefoot Runners

This morning I read an article in The Guardian about proper running form. Author Sam Murphy sets the stage:
A few weeks back, this blog ran a feature on running form and how to improve it. It included the oft-repeated advice about avoiding overstriding, which “causes the foot to land too far in front of the knee and encourages heel striking – and increases injury risk”. A reader commented that they’d “like to see a blog on whether heel striking really is a bad thing”, which spurred me to investigate.
Murphy then goes on to discuss the influence of the book Born To Run (I reviewed it on the blog here) and its role in promoting "barefoot running." Much of the remainder of the article discusses the evidence of whether "heel-striking" is bad, compared to "forefoot running."

The problem with such an article is that, aside from a small number of people with very extreme running form, almost no one is a pure "heel-striker" or "forefoot runner." Most of us fall somewhere on a continuum, where we tend more toward one direction than the other. For some, the tendency is quite mild. Still others land exactly in the middle of their foot.

In short, the problem with the article was dichotomous thinking.

"Cognitive Distortion"

Why is this a problem? Summer Beretsky at PsychCentral.com breaks it down for us:
...[U]sing dichotomous language boosts dichotomous thinking, and the latter is a type of cognitive distortion that can negatively influence the way you feel about yourself. If you’re dealing with anxiety, casual usage of extremely polar words can lead you to magnify thoughts and events through a distorted lens that can ultimately make you more anxious.
So the problem is twofold: First, dichotomous thinking is distorted, and therefore less accurate than having a more nuanced perspective. Second, and perhaps more importantly, dichotomous thinking can make you unhappy.

Murphy herself seems partially aware of this, as she writes that she has recently "begun to feel a little like someone who was converted to a religion by zealots." I can understand this, because when I finished reading Born To Run, I also gave barefoot running a try. It was consistently the one question that everyone asked me when they learned I had read or was reading the book.

When one watches racing events, one is typically struck by the same fact that McDougall reports in his book: good runners tend toward a similar running form. This is not altogether surprising since running is a natural human activity and all human bodies are built more or less the same with respect to musculo-skeletal structure.

That so many great runners have similar form is not a cognitive distortion. However, the insistence  that all runners should adopt the same set of practices to run well or run comfortably, is.

Anti-Vaxxers And Climate Deniers

In an article aimed at promoting the scientific validity of childhood vaccinations, Amy Parker succumbs to dichotomous thinking. While she opens her article with carefully worded sentences laying out the perspective of those who oppose childhood vaccinations, by her final paragraph, she is talking about all people as though the belong to one of two camps:
Those of you who have avoided childhood illnesses without vaccines are lucky. You couldn’t do it without us pro-vaxxers. Once the vaccination rates begin dropping, the drop in herd immunity will leave your children unprotected. The more people you convert to your anti-vax stance, the quicker that luck will run out.
Ah, yes. "Anti-vaxxers." Many commentators at Slate.com pointed out that "anti-vaxxers" are quite similar to "climate deniers" because both groups of people are opposed to the latest scientific research on the subject in question. This claim alone is somewhat dubious, since people who oppose vaccination don't typically feel that the science behind vaccines is bunk, but just that the risks outweigh the benefits. I disagree, but it is a value judgment based on information they have deemed important to them. As for "climate deniers," few if any openly disagree with the idea that climate doesn't change - the question is whether one believes specifically in the climate forecast models of those scientists who believe that anthropogenic global warming is a risk to the survival of the human species.

But just look at all those words. Why bother with all that nuance and fairness when we can simply engage in dichotomous thinking, box people into "camps" or "groups" or "sides," and then declare one group wholesale wrong?


Much has been written and said by many intelligent people about the "state" of political discourse today. We hear a lot about how polarized people have become, and this seems to suggest that dichotomous thinking is a rampant social problem. When was the last time you heard or read a political opinion that you didn't subsequently place into some kind of ideological box? 

In the political sphere, when people try to regain control of all this cognitive distortion, many of them fall into the logical fallacy that "the truth lies somewhere in the middle." The problem with this line of reasoning is that it accepts a dichotomous framing of issues and attempts to reconcile that dichotomy. In reality, dichotomous thinking is dangerous because it doesn't describe reality accurately at all.

For example, most of your day is probably spent indoors, at room temperature, i.e. neither hot nor cold. You wouldn't even think to describe this temperature. Temperature only becomes an issue when you find it either too hot or too cold, and suddenly we are confronted by an extreme from the dichotomy of hot versus cold. Never mind the fact that the vast majority of time spent indoors is spent at a temperature we don't really have linguistic terms to describe. The point being this: our reality is neither hot nor cold, it's room temperature. Framing things in terms of hot and cold doesn't adequately describe the majority of our day!

Meanwhile, at Cato Unbound, Kevin Vallier engages in some tetrachotomous thinking, boxing all possible viewpoints about religion in politics into four boxes. The reader may determine for him-or-herself whether Vallier's point resonates; my only point here is to remark that perhaps there are a few more possible ways to look at it. 


The philosophical concept of "difference" is a powerful one. It is one of the first things we learn as infants, and it forms the basis on which we build the knowledge that guides us for the rest of our lives. To that extent, some elementary form of dichotomous thinking will always be a part of human cognition.

But if we think rationally, then as we apply "difference" to our experiences and observations, we will start to uncover the inadequacy of dichotomy. We start to learn that life consists of more than just conceptual poles. We start to reject dichotomous thinking, and we gain a perspective that is at once more accurate and more curious.