Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Leveling Up Or Leveling Off? Understanding The Science Behind Skill Plateaus, published by lynettebye on June 16, 2023 on LessWrong.

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If you’re going into surgery, you want the youngest operating surgeon available.

This is a slight exaggeration – you don’t want a doctor in their first year out of medical school.[1] After that, it’s less clear. One review found thirty-two studies indicating that the older a doctor was, the worse their medical outcomes; that review only found one study indicating that all outcomes got better with increasing age.[2] Other analyses suggest that middle-aged doctors might do better than younger doctors (though the effect is not statistically significant)[3], but older doctors are still clearly worse than middle-aged doctors.[4]

It’s not like doctors become terrible with more experience, but they are measurably worse. In one study, an extra twenty years of experience translated to about one additional elderly patient dying out of every hundred treated.[5] Why would twenty extra years of practice make a doctor worse at helping people?

Similarly, some research on famous painters, writers[6], and composers[7] found that it’s most common for these artists to produce their best work before the age of 45. A famous composer is more likely to have written their best piece of music in their 20s than their 40s, and they’re almost twice as likely to have written their best piece in their 30s instead of their 50s.[8]

Again, creatives are doing worse after a couple of extra decades of experience. This phenomenon is called skill plateaus. The idea is that performance stops improving after a relatively short time. After that, putting in thousands more hours on the job won’t reliably make you much better.

What’s going on here?

Deliberate practice

Anders Ericsson thought he had the answer. Ericsson was a psychologist famous for his research on expertise and human performance. He claims that most people practice a new skill until they can perform it adequately for their purposes.

For example, someone might practice tennis until they’re good enough to play with their friends. At that point, they stop practicing to just enjoy the casual games. Many people assume that they’ll continue to slowly get better just by playing games. However, that doesn’t seem to be the case. If they just play games using the skills they already know, they stagnate or even get worse over time.[9]

Ericsson sought to study what separated the truly outstanding top performers from those who were merely good. He concluded that the key factor was a particular approach to improvement, which he called “deliberate practice”.

Deliberate practice is not just any focused practice.

Deliberate practice is breaking your work down into individual steps, finding the optimal technique for each step, and practicing each technique until you execute it automatically. It requires clear, rapid feedback so that you know what you’re doing right and what you need to work on (this feedback usually comes from a coach).

Say our amateur tennis player wanted to continue improving. They might get a tennis lesson. The coach would identify what is holding the player back -- perhaps they hold the racket poorly. Here the coach breaks tennis down into individual subskills and identifies which are making their performance worse.

So, the coach demonstrates a better way to grip the racket and marks their racket at the correct place to grip. Here the coach gives the player a better technique and a training method to practice it.

The player practices gripping the racket correctly, takes one swing, and then stops to check their grip. Here the player repeatedly pra...