Normal is not the same as good

That's not normal.

Most of us learned what this phrase means long before we ever sat in a statistics class. We learned it from a subtly raised eyebrow when we say or do certain things, a pointed question from a well-meaning family member, or a friend's offhand remark that stings more than they meant it to. Without anyone spelling it out, normal came to mean good, and abnormal came to mean bad.

Later, in a statistics class, we learn a second meaning. Measure a trait like height across a population and most people cluster around the average, thinning out towards the extremes in the familiar bell curve. This is what's known as the normal distribution. Normal, in this context, describes how often something occurs, and nothing more.

However, the statistical meaning tends to stay in the classroom, used to pass an exam and rarely thought about again. In everyday life, we default to the assumption that what's common is what's right. And since we make our life decisions based on what we think is right, it's an assumption worth examining.

How ideas spread

Behind that assumption sits a quiet line of reasoning. If everyone does it, there must be a good reason.

There is a reason.

But it may not be the one we imagine.

To see why, we need to look at how memes spread. By memes, I don't mean the internet jokes, but rather the ideas, behaviours and traditions that spread from person to person.

Like genes, memes are in constant competition with each other for survival. What makes one meme spread more successfully than a rival isn't necessarily that it benefits the people who hold it, or even society as a whole, though it can. It's that holding it leads us to behave in ways that make it more likely to be passed on to others.

In The Beginning of Infinity, physicist and philosopher David Deutsch proposes two basic ways in which memes spread.

The first type, rational memes, spread because they benefit the holder by helping them solve a problem. Other people notice the idea is useful, examine it for themselves, and adopt it when it holds up to criticism. Every time someone challenges it, the errors they expose can be corrected, so the meme keeps getting better. And the better it gets, the more useful it becomes, and the more people adopt it in turn.

The second type, anti-rational memes, spread by doing the opposite. Rather than standing up to scrutiny, they disable the critical thinking of the people who hold them, so they can't be criticised, modified or abandoned even when their flaws are exposed. They tend to work by making questioning feel dangerous, disloyal or shameful. And because doubting them feels so costly, people keep following them and expect those around them to do the same, which is how they carry on spreading. Taboos and superstitions are classic examples.

Both types of memes can become the norm if they spread to dominate a society. A behaviour can become common because it serves the people who adopt it. But it can also become common because societies, schools, workplaces and families reproduce it, generation after generation, whether or not anyone stops to ask if it serves them well.

This means the prevalence of an idea doesn't tell us whether it's rational, or useful for our lives. It simply tells us that it was very good at spreading.

Common does not equal useful.

Socially acceptable does not equal rational.

Traditional does not equal infallible.

Asking why

If we can't rely on what's normal, we need another way to tell a rational meme from an anti-rational one. The easiest way is to see how it responds to rational criticism. We can test any norm we're about to adopt with a simple question.

Why do we do this?

Listen carefully to the answer that comes back, whether it's from the people around us or the narrator in our own heads. It tends to take one of three forms.

A good explanation. We get an explanation that tells us why and how the idea actually works and what problem it solves. The reasoning is specific such that we cannot arbitrarily change its components and still have it make sense. And when we challenge it, the explanation holds up to criticism. That's a strong sign we're looking at a rational meme.

A bad explanation. A bad explanation can take many forms, but when it comes to defending the norm, we tend to hear something like "that's how it's always been done" or "everyone does it." Answers like these could justify almost any practice, and basically explain nothing. The tricky thing here is that the idea could actually be useful, with a faulty explanation for why it works, or it may not be useful at all. So this answer alone can't tell us whether we're looking at a rational or an anti-rational meme. And if we never learn why a practice works, we can't spot when it stops working, or whether there's a better way.

No explanation. Instead, we hear some version of "who do you think you are?" or "what will people think?" The question itself gets treated as the problem, as an insult or a sign that something is wrong with us for even asking. We tend to feel guilt, shame or fear. When questioning an idea gets us psychologically or emotionally punished, we've found the signature of an anti-rational meme.

What we do next depends on which answer comes back. A good explanation gives us reason to adopt the norm, at least for now, while staying open to a better one. A bad explanation or no explanation doesn't mean the norm is necessarily wrong, but it does caution us to hold off. Rather than adopting it because it's normal, we keep looking for a better explanation.

Thinking for ourselves

None of this means we should default to rebelling against the norm and do the opposite of what everyone else is doing. Rejecting a norm without examining it is just another way of not thinking. What we're suggesting instead is applying our capacity to think critically, rather than outsourcing our thinking to the herd.

This matters in a life of finite resources. While we can't examine every norm, it's worth focusing on the ones that matter most. Every decision comes at an opportunity costThe lifetime value of the next best alternative forgone when expending life resources to improve or implement misconcepts.Full definition (opens in a new tab)→, and an unexamined norm we adopt can quietly shape the trajectory of our lives through thousands of seemingly inconsequential decisions, its effects compounding over a lifetime.

So the next time we catch ourselves thinking everyone does it, it's worth pausing to ask why we do this, and to notice which answer comes back. An explanation we can challenge and improve upon. A shrug and a reference to tradition. Or a guilt trip that makes us regret asking.

Normal only tells us which memes have been most successful at spreading. It doesn't tell us whether they're worth adopting.