I.

There’s been renewed debate around Bryan Caplan’s The Case Against Education recently, so I want to discuss one way I think about this question.

Education isn’t just about facts. But it’s partly about facts. Facts are easy to measure, and they’re a useful signpost for deeper understanding. If someone has never heard of Chaucer, Dickens, Melville, Twain, or Joyce, they probably haven’t learned to appreciate great literature. If someone can’t identify Washington, Lincoln, or either Roosevelt, they probably don’t understand the ebb and flow of American history. So what facts does the average American know?

In a 1999 poll, 66% of Americans age 18-29 knew that the US won independence from Britain (as opposed to some other country). About 47% of Americans can name all three branches of government (executive, legislative, and judicial). 37% know the closest planet to the sun (Mercury). 58% know which gas causes most global warming (carbon dioxide). 44% know Auschwitz was a concentration camp. Fewer than 50% (ie worse than chance) can correctly answer a true-false question about whether electrons are bigger than atoms.

These results are scattered across many polls, which makes them vulnerable to publication bias; I can’t find a good unified general knowledge survey of the whole population. But there’s a great survey of university students. Keeping in mind that this is a highly selected, extra-smart population, here are some data points:

• 85% know who wrote Romeo and Juliet (Shakespeare)

• 56% know the biggest planet (Jupiter)

• 44% know who rode on horseback in 1775 to warn that the British were coming (Paul Revere)

• 33% know what organ produces insulin (pancreas)

• 31% know the capital of Russia (Moscow)

• 30% know who discovered the Theory of Relativity (Einstein)

• 19% know what mountain range contains Mt. Everest (Himalayas)

• 19% know who wrote 1984 (George Orwell)

• 16% know what word the raven says in Poe’s “The Raven” (“Nevermore!”)

• 10% know the captain’s name in Moby Dick (Ahab)

• 7% know who discovered, in 1543, that the Earth orbits the sun (Copernicus)

• 4% know what Chinese religion was founded by Lao Tse (Taoism)

• <1% know what city the general Hannibal was from (Carthage)

Remember, these are university students, so the average person’s performance is worse.

Most of these are the kinds of facts that I would expect school to teach people. Some of them (eg the branches of government) are the foundations of whole subjects, facts that I would expect to get reviewed and built upon many times during a student’s career. If most people don’t remember them, there seems to be little hope that they remember basically anything from school. So what’s school even doing?

Maybe school is why at least a majority of people know the very basics - like that the US won independence from Britain, or that Shakespeare wrote Romeo and Juliet? I’m not sure this is true. Here are some other questions that got approximately the same level of correct answers as “Shakespeare wrote Romeo and Juliet”:

• What is the name of the rubber object hit by hockey players? (Puck, 89%)

• What is the name of the comic strip character who eats spinach to increase his strength? (Popeye, 82% correct)

• What is the name of Dorothy’s dog in The Wizard of Oz? (Toto, 80% correct)

I don’t think any of these are taught in school. They’re absorbed by cultural osmosis. It seems equally likely that Romeo and Juliet could be absorbed the same way. Wasn’t there an Academy-Award-winning movie about Shakespeare writing Romeo and Juliet just a decade or so before this study came out? Sure, 19% of people know that Orwell wrote 1984 - but how many people know the 1984 Calendar Meme, or the “1984 was not an instruction manual!” joke, or have heard of the reality show Big Brother? Nobody learned those in school, so maybe they learned Orwell’s name the same place they learned about the other 1984-related stuff.

Okay, so school probably doesn’t do a great job teaching facts. But maybe it could still teach skills, right?

According to tests, fewer than 10% of Americans retain PIIAC-defined “basic numeracy skills”, even though in theory you need to know algebra to graduate from most public schools.

I took a year of Spanish in middle school, and I cannot speak Spanish today to save my life; that year was completely wasted. Sure, I know things like “Hola!” and “Adios!”, but I also know things like “gringo” and “Yo quiero Taco Bell” - this is just cultural osmosis again.

So it seems most people forget almost all of what they learn in school, whether we’re talking about facts or skills. The remaining pro-school argument would be that even if they forget every specific thing, they retain some kind of scaffolding that makes it easier for them to learn and understand new things in the future; ie they keep some sort of overall concept of learning. This is a pretty god-of-the-gaps-ish hypothesis, and counterbalanced by all the kids who said school made them hate learning, or made them unable to learn in a non-fake/rote way, or that they can’t read books now because they’re too traumatized from years of being forced to read books that they hate.

II.

Step back a bit. Why should any of this be true? That is:

• Why would most students forget things that schools teach many times?

• Why would they remember it when it’s learned through cultural osmosis (eg Popeye, “yo quiero Taco Bell”)?

• Don’t children do okay on standardized tests? Why shouldn’t they remember that information later?

• If you can forget something that a professional teacher teaches you, and which you study intently for a high-stakes test on, then how do you remember anything at all?

Here’s the Ebbinghaus Forgetting Curve:

For our purposes, it’s a bit stylized - what does it mean to remember 20% of your American History lesson? The point is, you remember much less after some period of time.

The forgetting curve focuses on abstract, unconnected emotionless knowledge - you’ll remember the name of the man who killed your family for longer than it predicts - but it’s an okay approximation for the sorts of things you learn in school. I can’t find anything that investigates longer than a month, but probably after ten years or something it’s really low. So if you poll an adult on electrons ten years after their last high school science class, they’ll remember nothing.

So how come anyone remembers anything at all? Here’s the forgetting curve’s more optimistic cousin, the spaced repetition curve:

The optimistic take is that presumably you study the things you learn in class. If you’re lucky, your teacher next year reviews on them and builds on them. So you get dozens of well-spaced reviews, until you reach a point where it’s with you for life.

Okay, now we’re back to not understanding why only 19% of people know about the Himalayas.

I can’t find any great research for the forgetting and repetition curves over years or decades, but one spaced repetition site recommends the following schedule:

• Day 0: Initial learning

• Day 1: First repetition within 24 hours

• Day 6: Second repetition in about one week

• Day 14: Third repetition in about two weeks

• Day 30: Fourth repetition in about a month

• Day 66: Fifth repetition in about two months

• Day 150: Sixth repetition in about five months

• Day 360: Seventh repetition in about a year

7 repetitions usually suffice to remember information for life. Also notice that after the second repetition, the next interval can be calculated by multiplying the previous interval with a factor of around 2.2. This number is called the ease factor, and depending on your implementation, it is usually set between 2 and 2.5.

So either people didn’t get 7 optimally-spaced repetitions of the Himalayas in school, or this very optimistic website is wrong and seven repetitions don’t suffice to remember information “for life”. I’m betting it’s the latter - for example, I’ve forgotten the names of some of my college professors, even though I would have seen them almost daily for a year.

Suppose that no reasonable amount of repetition is enough to remember an abstract fact of this sort for more than a decade. Then it’s not surprising that people forget most of the facts they learn in school.

But suppose that once you learn something to a school-test-passing level, approximately once-yearly repetition is enough to make you remember it. That would explain why we remember things like Shakespeare’s name - just going about our everyday lives, we probably hear him talked about more than once a year.

How strong is this cultural repetition effect? In order to settle a bet, I asked ACX survey respondents whether they had thought about the Roman Empire in the past 24 hours. About 45% had done so. Although we can’t make any formal estimates, it seems most likely that most people in this distribution think about it at least once a week, and overwhelmingly many think about it at least once a month. So no matter how bad your history teacher was, you will never forget the Roman Empire.

How often do people think about the Songhai Empire? I definitely learned about this one in 7th grade - it was part of the “It’s Very Important That All Of You Know That Africa’s History Existed And Was Very Glorious, Please Believe This” unit. But I forgot about its existence until it got featured in one of the Civ games - I think Civ V. After that I guess I played enough Civilization that it got imprinted in my memory for at least another few years. I think this is a better explanation for why most people remember things about Rome but not Songhai than how many hours their history teacher spent talking about each.

In this model, the reason smarter people remember more stuff than duller people is partly a differently-shaped forgetting curve. But mostly it’s that intellectuals put themselves in situations where they hear about things more often. If you remember that George Orwell wrote 1984, it’s probably because you read the newspaper or blogs or whatever and hear some government program described as “Orwellian”. But if you’re watching TikToks on your cell phone all day, maybe you don’t hear that, and then you join the 81% of college students who have forgotten that name.

(full list of things I remember about 1984: the author was George Orwell. There were three countries called Eurasia, Eastasia, and Oceania. Britain was part of Eurasia and called “Airstrip One”. Every so often the countries would shift alliances, and the government would lie and say “we have always been at war with Eastasia”. There was an evil totalitarian government with a possibly-fake leader named Big Brother, and a possibly-fake rebel with a Jewish-sounding name. It divided people into Inner Party, Outer Party, and proles. There was a language called “Newspeak” with neologisms like “doubleplusgood” that made it hard to question authority. There were characters named Winston and Julia. Winston sort of tried to be against the evil government; he got tortured through some horrifying thing involving rats; at the end he said he loved Big Brother and 2+2=5. Something was weird about Julia and maybe she was an agent of the evil government or something. I think these are all facts that I might encounter in the wild once every few years.)

III.

This model makes it hard for school to be useful. If school teaches you some fact, then either you’ll never encounter it again after school, in which case you’ll quickly forget it). Or you will encounter it again after school, in which case school was unnecessary; you would have learned it anyway.

Can we rescue some kind of value for school? One option might be that school starts a virtuous cycle by helping you learn something long enough that you can put yourself in situations where you can re-encounter it in the future. For example, consider reading. If you learn to read, you’ll probably read every day. Then you’ll remember how to read. But if you never learn to read, you might never try and never learn.

(this example is somewhat frustrated by the fact that many middle-class children learn to read before entering school - apparently you’ve got to teach them at two to keep up with the Joneses now. But at least it probably helps the lower-class kids.)

The same could be true of some kinds of math - even if only 10% of Americans have basic numeracy as defined by PIIAC, there are probably some kinds of sub-basic numeracy, like simple addition, which most people remember because they learned it in school and then kept using it forever.

Okay, so that maybe justifies up to fourth grade. Are there any examples from later schooling that could work like this?

You could imagine some equivalent where, for example, you need to know a certain amount about Roman history before you can enjoy books, movies, podcasts, etc on Roman history. But then once you know that amount, it’s a ratchet and you’ll keep learning more and reinforcing that knowledge. I think this is mostly false, considering how many things that people don’t learn about in school - eg coding, or cooking, or the history of their favorite fantasy world, or so on - they still manage to learn. Still, it’s a theory that you could have.

Otherwise - aside from being a place to warehouse children while their parents are away - I’m not sure how you rescue the usefulness of most schooling.

(on a purely theoretical basis, of course)