Why getting it wrong in a quiz makes you smarter

You know the moment. The quizmaster reads out a question and you're certain you've got it, bet-your-life certain.

You say it out loud, maybe a bit smugly, and wait for the nod. Instead there's a pause, and then: "No."

Funny thing is, years later that's the answer from the night you'll still remember. You'll have forgotten the dozen you got right, but not the one you got so confidently, so embarrassingly wrong.

That isn't just a quirk of memory. Quizzes don't only measure what you know; they change what you remember, and there's solid research to back that up.

Why rereading fools you

Most of us study the same way: read it, read it again, highlight, read once more. It feels productive.

In 2006, psychologists Henry Roediger and Jeffrey Karpicke put that habit to the test. Students read a short passage. Some kept rereading it, while others read it once and then repeatedly tried to recall it without looking.

When they were tested five minutes later, the rereaders came out ahead, 83% to 71%. A week later it was a different story: the students who had tested themselves remembered about 61% of the passage, and the rereaders only about 40%.

What I find most interesting is that the rereaders felt more confident they'd remember it. That makes sense when you think about it. Rereading feels easy because everything looks familiar, while trying to recall something feels like hard work, and it's that hard work that makes it stay.

Psychologists call this the testing effect. Every quiz you've ever played was quietly doing it to you.

Why confident mistakes stick

So why does a wrong answer stick so well? In 2001, psychologists Brady Butterfield and Janet Metcalfe asked people a set of general-knowledge questions and had them rate how sure they were of each answer. Then they showed everyone the correct answers and tested them again.

You'd expect the mistakes people were surest about to be the hardest to shake off. It turned out to be the other way round: the answers people had been most confident about, and still got wrong, were the ones they were most likely to get right the second time. The researchers called this the hypercorrection effect.

The likely reason is surprise. When you're sure of something and find out you're wrong, it catches you off guard, and you pay far more attention to the right answer. In a follow-up study, people had to listen out for a tone while they read the corrections, and they were more likely to miss it during the correction to a confident mistake, because their attention was busy elsewhere.

There's one catch: if you later forget the correction, that confident wrong answer is the one most likely to creep back. So it's worth going over your mistakes once more a few days later.

Even a wild guess helps

It isn't only confident mistakes that help, either. In 2009, psychologists Nate Kornell, Matthew Hays and Robert Bjork had people guess answers they couldn't possibly know, then showed them the right one. In one version, people saw a word like "pond" and had to guess the word it was paired with (it was "frog").

The guessers remembered more than people who had simply studied the correct pairs for the same amount of time. So when you scribble down a total shot in the dark before the reveal, you're not wasting the question. You're giving the right answer somewhere to land.

Curiosity does the rest

A good quiz also does something a textbook usually doesn't: it makes you want the answer before you get it.

In 2014, neuroscientist Matthias Gruber and his colleagues scanned people's brains while they waited for the answers to trivia questions. When people were really curious about a question, activity rose in the midbrain and the nucleus accumbens, parts of the brain's reward circuit. They also remembered those answers better, both straight away and a day later.

Here's the strange part. While people waited for each answer, a photo of a random stranger's face flashed on the screen. When people were curious, they remembered those faces better too, even though they had no reason to care about them. The people who got the biggest boost were the ones whose midbrain and hippocampus, a region central to forming memories, were most active while they waited. Once curiosity kicks in, your brain seems to soak up whatever comes next.

So that dramatic pause before the quizmaster reveals the answer is doing more work than it looks.

How to use it

If you want to make the most of all this, it's simple. Commit to an answer before the reveal, even if it's a guess. Notice when you were sure and still wrong, because that's the one your brain will hold on to. And when you study, close the book and try to recall instead of reading the same page a fourth time.

The next time you get an answer wrong, don't sulk. That wrong answer, especially the one you were sure about, can do more for your memory than the ones you got right.

The right answers feel good. The wrong ones make you smarter.

Want to put this to the test? Try a round of The Trivia League, and don't worry about getting a few wrong.