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If someone was as rational as could be—with many accurate and trustworthy judgments about the world, and with sound decisions—would we recognize it? There are reasons to think the answer is “No”. In this piece, I aim to challenge prevailing intuitions about rationality: I will argue that the philosophy and science of judgment and decision-making reveal a number of ways in which what appears to be rational diverges from what actually is rational. 

This piece takes its title from Steven Covey’s well-known book “The Seven Habits of Highly Effective People”. I will argue that, similarly, there are seven habits of highly rational people—but these habits can appear so counter-intuitive that others label them as “irrational”. Of course, the rationality of these habits might be obvious to specialists in judgment and decision-making, but I find they are often not so obvious to others of the sort for whom this piece is written.

In any case, not only are these habits potentially interesting in their own right, but recognizing them may also help to open our minds, to help us better understand the nature of rationality and to better identify the judgments and decisions we should trust—or not trust—in our own lives.

Without further ado, then, I present…

 
​          1. Highly rational people are confident in things despite “no good evidence” for them

The first habit of highly rational people is that they are sometimes confident in things when others think there is “no good evidence” for them.

​We all need to form accurate judgments about the world in many diverse and important contexts. What is the correct diagnosis for someone’s medical condition? Does someone have a crush on you? Did the defendant kill the victim? Here, I will discuss how the evidence can reveal the truth about these questions--and potentially others which you might care about--but only if we think in the right ways.

It’s well-documented that various biases can hinder us in our quest for truth. In a recently published paper in Judgment and Decision Making (freely available here), I introduce a new cognitive bias: likelihood neglect bias. Understanding this bias, and how to overcome it, can help us recognize good evidence and find the truth in numerous cases where others might not.

To show this, though, I’ll use a well-known brain-teaser which reveals this bias—the Monty Hall problem—and then I’ll apply the emerging ideas to show how we can find the truth in other realistic cases—including medicine, law and more mundane topics. You might then want to apply these ideas to other cases which you might care about.

We all make countless judgments, and our important life decisions depend on them.  

My new book, “Human Judgment”, investigates these judgments, and it is now available to purchase online here.

The book concerns two topics to do with human judgment, as implied by the subtitle: How accurate is it, and how can it get better?

It has two somewhat newsworthy items, one bad and the other good.

The bad news is that the science suggests that human judgment is often much more inaccurate than we might hope or expect. For example, some researchers estimated as many as 40,000 to 80,000 US citizens will die because of preventable misdiagnoses—and that’s each year. If they are right, that’s a yearly death toll at least 13 times higher than the September 11th terrorist attacks. Unfortunately, medicine is not unique too: judgmental inaccuracy can afflict a number of other areas in society as well. As another example, some researchers estimate at least 4.1% of death sentence convictions in the US are actually false convictions; this implies that some people are trialed, convicted and executed for horrific crimes that they never actually committed. So that is a few of numerous studies painting a less than ideal picture of human judgment: we make inaccurate judgments about medical diagnoses, about criminal convictions and about a number of other areas.

We all make judgments every day. We all depend on them to make decisions and to live our lives. You might think someone is a good partner for you, and so you might marry them. Or you might think you will be happy in a particular career, and so you might spend countless hours of your life studying and working your way towards it.

But what happens if your judgments are wrong—if the person you married or the career you chose weren't good options?

We all know that this kind of thing happens: people make bad judgments and regret their decisions all the time. That is old news—and bad news, at that. What’s more, if we take a passing glance at the scientific study of reasoning, we’ll see that we are often biased in our judgments and we may not even realize it (check out Kahneman's fantastic book, for instance).

But there is good news: we can improve our judgments!
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Nowadays, we’re especially worried about risks—about the risk of getting COVID if we hop on a plane or go to an in-person class, or about the risk of dying if we get COVID. And some risks are worth taking, but others aren't; it depends partly on how we estimate the risks.

So, then, how good are we at estimating risk? And how should we estimate risks?