Daniel Lemire's blog

, 6 min read

Expert performance and training: what we really know

Movies such as Good Will Hunting tell beautiful stories about young people able to instantly master difficult topics, without any effort on their part.

That performance is unrelated to effort is an appealing belief. Whether you perform well or poorly is not your fault. Some go further and conclude that success and skill levels are primarily about genetics. That is an even more convenient observation: the quality of your parenting or education becomes irrelevant. If kids raised in the ghetto do poorly, it is because they inherited the genes of their parents! I personally believe that poor kids tend to do poorly in school primarily because they work less at it (e.g., kids from the ghetto will tend to pass on their homework assignments for various reasons). A recent study by Macnamara et al. suggests that practice explained less than 1% of the variance in performance within professions, and generally less than 25% of the variance in other activities. It is one of several similar studies attempting to debunk the claim popularized by Gladwell that expert performance requires 10,000 hours of deliberate training.

Let us get one source of objection out of the way: merely practicing is insufficient to reach world-expert levels of performance. You have to practice the right way, you have to put in the mental effort, and you have to have the basic dispositions. (I can never be a star basketball player.) You also need to live in the right context. Meeting the right people at the right time can have a determining effect on your performance. But it is easy to underestimate the value of hard work and motivation. We all know that Kenyan and Ethiopian make superb long-distance runners. Right? This is all about genetics, right? Actually, though their body type predispose them to good performance, factors like high motivation and much training in the right conditions are likely much more important than any one specific gene. Time and time again, I have heard people claim that mathematics and abstract thinking was just beyond them. I also believe these people when they point out that they have put many hours of effort… However, in my experience, most students do not know how to study properly. You should never, ever, cram the night before an exam. You should not do your homework in one pass: you should do it once, set it aside, and then revise it. You absolutely need to work hard at learning the material, forget it for a time, and then work at it again. That is how you retain the material on the long run. You also need to have multiple references, repeatedly train on many problems and so on.

I believe that poor study habits probably explain much of the cultural differences in school results. Some cultures seem to do a lot more to show their kids how to be intellectually efficient.

I also believe that most people overestimate the amount of time and effort they put on skills they do not yet master. For example, whenever I face someone who failed to master the basics of programming, they are typically at a loss to describe the work they did before giving up. Have they been practicing programming problems every few days for months? Or did they just try for a few weeks before giving up? The latter appears much more likely as they are not able to document how they spent hundreds of hours. Where is all the software that they wrote?

Luck is certainly required to reach the highest spheres, but without practice and hard work, top level performance is unlikely. Some simple observations should convince you:

  • There are few people who make world-class contributions at once… there are few polymaths. It is virtually impossible for someone to become a world expert several distinct activities. This indicates that much effort is required for world-class performance in any one activity. This is in contrast with a movie like Good Will Hunting where the main character appears to have effortlessly acquired top-level skills in history, economics, mathematics.

A superb scientist like von Neumann was able to make lasting contributions in several fields, but this tells us more about his strategies than the breadth of his knowledge:

Von Neumann was not satisfied with seeing things quickly and clearly; he also worked very hard. His wife said “he had always done his writing at home during the night or at dawn. His capacity for work was practically unlimited.” In addition to his work at home, he worked hard at his office. He arrived early, he stayed late, and he never wasted any time. (…) He wasn’t afraid of anything. He knew a lot of mathematics, but there were also gaps in his knowledge, most notably number theory and algebraic toplogy. Once when he saw some of us at a blackboard staring at a rectangle that had arrows marked on each of its sides, he wanted to know that what was. “Oh just the torus, you know – the usual identification convention.” No, he didn’t know. The subject is elementary, but some of it just never crossed his path, and even though most graduate students knew about it, he didn’t. (Halmos, 1973)

  • In the arts and sciences, world experts are consistently in their 30s and 40s, or older. This suggests that about 10 years of hard work are needed to reach world-expert levels of performance. There are certainly exceptions. Einstein and Galois were in their 20s when they did their best work. However, these exceptions are very uncommon. And even Einstein, despite being probably the smartest scientist of his century, only got his PhD at 26. We know little about Galois except that he was passionate, even obsessive, about Mathematics as a teenager and he was homeschooled.
  • Even the very best improve their skills only gradually. Musicians or athletes do not suddenly become measurably better from one performance to the other. We see them improve over months. This suggests that they need to train and practice.

When you search in the past of people who burst on the scene, you often find that they have been training for years. In interviews with young mathematical prodigies, you typically find that they have been teaching themselves mathematics with a passion for many years.

A common counterpoint is to cite studies on identical twins showing that twins raised apart exhibit striking similarities in terms of skills. If you are doing well in school, and you have an identical twin raised apart, he is probably doing well in school. This would tend to show that skills are genetically determined. There are two key weaknesses to this point. Firstly, separated twins tend to live in similar (solidly middle class) homes. Is it any wonder that people who are genetically identical and live in similar environment end up with similar non-extraordinary abilities? Secondly, we have virtually no reported case of twins raised apart reaching world-class levels. It would be fascinating if twins, raised apart, simultaneously and independently reached Einstein-level abilities… Unfortunately, we have no such evidence.

As far as we know, if you are a world-class surgeon or programmer, you have had to work hard for many years.

Credit: Thanks to Peter Turney for telling me to go read Carse.