The Other Subject Nobody Teaches

In my last post I argued that epistemology, the study of how we know what is true, is the most important subject missing from school. This post is its mirror image. Knowing how to find the truth is only half the job. The other half is knowing all the ways our own minds get in the way. That, too, is never taught to children.

To know what is true, I need to know my own failures of thinking. If I know where my mind tends to go wrong, I can correct for it. If I don't, I will go wrong with complete confidence.

Three ways our minds fail us #

There are well over a hundred named cognitive biases, and listing them would make this post endless. More useful is to sort the hindrances into a few groups, because they are not all the same kind of thing.

Biases #

These are systematic distortions in judgment. They push our thinking in a consistent direction. We notice evidence that confirms what we already believe and ignore what contradicts it. We judge how likely something is by how easily an example comes to mind, so one plane crash on the news can make flying feel more dangerous than driving.

Loyalty over truth #

This one is deeper, and research over the last couple of decades has made it hard to ignore. We are tribal animals. For most of human history, staying in good standing with your group mattered far more for survival than being right. So our minds evolved to protect our loyalties, and we often reject evidence when it threatens the group we belong to.

The sunk cost effect makes this worse. People join a movement, invest years in it, and then stay loyal even after they notice it going astray. Admitting the movement was wrong would mean admitting those years were wasted. This has direct political consequences: whole populations follow leaders and parties long after the evidence has turned against them.

This is not really a malfunction. It is our psychology working exactly as evolution built it. It just wasn't built for finding the truth.

The limits of intuition #

Some failures are not biases at all. Our brains simply were not built for mathematics. There was never any selective pressure that made mathematically gifted people leave more offspring, so evolution gave us a rough sense of quantity and little more.

The result is that most people struggle with statistics. Many cannot tell the difference between a mean and an expected value. Our intuition has no resolution at extreme scales. A probability of 10⁻¹² and one of 10⁻¹⁵ both feel like "basically zero," even though one is a thousand times larger than the other. A million and a billion both feel like "a lot." These are not distortions in one direction. They are places where our intuition gives no reading at all, and the only fix is training.

Why this belongs in elementary school #

None of this is taught to children. We teach them facts, and sometimes we teach them to check facts, but we never teach them how their own minds will mislead them while they do it.

Yet this is among the most teachable material there is. Children love catching each other in mistakes, and they can learn to catch themselves. A teacher could:

• Run a simple guessing game, then show the class how their guesses clustered around the first number they heard.
• Show what a million grains of rice look like next to a billion, so the difference between orders of magnitude becomes something they have seen.
• Ask the class to argue the side of a debate they disagree with, and talk about how hard it felt.
• Discuss why people stay loyal to a team, a group or a cause even when it is losing, and when that loyalty is worth it and when it isn't.

How it is taught matters. Psychologists describe a "bias blind spot": people who learn about biases often get better at spotting them in others, not in themselves, and sometimes use the new vocabulary to dismiss opponents. Lectures about biases do little. What works is practice, where children make the mistake themselves and then catch it. There is evidence this can last: Finland teaches media literacy throughout its schools, and a 2015 study by Morewedge and colleagues found that a short training game reduced biases for months afterward. That is another reason to start early, before the habits of belief harden.

These lessons don't need a new department. They fit into maths, history and social studies, and they reinforce the epistemology I argued for last time.

We should not be naive about this. As with epistemology, there are powerful forces in society that will actively work against such an initiative, because they have no interest in people finding out the truth. Religious institutions, politicians, propagandists and advertisers all depend on exactly the weaknesses described here: loyalty that outweighs evidence, fear driven by a single vivid example, and numbers too large or too small for anyone to feel. A population that understands its own biases is much harder to manipulate, and that is precisely why it will be resisted. Today the threat is not only domestic. Foreign states run organized influence campaigns through social media, using fake accounts and targeted content designed to exploit these same biases and to turn citizens of other countries against each other. And not every bad actor is a state. Many are simply misinformed people who sincerely believe what they spread, or people out to make a quick buck. My own social media feed is full of ads for astrology, an entire industry that lives off our tendency to see patterns and to accept vague statements that seem to fit us personally. Every such ad is a small lesson in the opposite of everything argued here.

Two halves of one skill #

Epistemology teaches how to find the truth. Knowing our biases, our loyalties and the limits of our intuition teaches what stands in the way. A child who learns only the first will still be fooled, mostly by themselves. A child who learns both has a real chance of thinking clearly as an adult, as a voter and as a citizen.

We are not born knowing either one. Both have to be taught, and school is the place to teach them.