dr anders ericsson

The Origins of Expert Performance

Is elite performance just a matter of how much and how well you practice? I interview a man known as the expert on experts, Dr Anders Ericsson and discuss the controversy surrounding Deliberate Practice.

World records are humanity’s scoreboard. They are broken every single day by people who push themselves further than any human being before them. 


Could I break a world record if I practiced enough?


The most push ups I’ve ever done is 60. The world record is 10,507.


In grade school I memorized 30 digits of pi. The record is over 67,000.


Can anyone achieve anything if you try hard enough?


My name is Lowell Brillante and this is Prodigy.




Dr. Anders Ericsson spent his entire adult life studying elite performance. He’s referred to as the expert on experts. 

Anders: [00:00:00] Well sort of, you know, I’m Swedish. So the way it’s pronounced in Sweden is Ondesh, but I’ve learned here that in the States that unless you’re born in Sweden, that’s hard. So pretty much anything is fine. 

Ericsson’s name might not be familiar to you, but his research probably is. It’s been cited over 11,000 times. I learned about him from the book “Outliers” by Malcolm Gladwell 

Anders: [00:00:53] I guess one of the questions that we were interested in was, the role of practice and sort of determining, who would be very successful as a violinist. 

Gladwell wrote that 10,000 is the magic number of hours it takes to master something. He came to this number from Ericsson’s study of classical musicians in 1993. Which showed a direct correlation between the amount of practice and achievement.

Anders: [00:00:53] And we found that, at the time, this was surprising, that sort of the most successful actually had practiced more during their development than those in the same program who were not as successful, in the music competitions.

Ericsson’s abstract said, “Many characteristics once believed to reflect innate talent are actually the result of intense practice extended for a minimum of 10 yrs.” 

Basically finding now, an interesting, kind of rank ordering here of the amount of practice you had engaged in and your success as sort of an adult. 

In Outliers, Gladwell defines practice as, “purposefully and single-mindedly, playing their instruments to get better.” 

There has been some controversy about what Ericsson called “deliberate practice” and we’ll get into that soon but let’s start at the beginning.

60 years ago, a Harvard psychologist published what became one of the most cited papers in psychology. It was about cognitive limitation, specifically related to memory span. 

Memory span is the max amount of items (like digits in a phone number) that one can repeat back immediately. You might know it as short-term memory. The items were read out loud to a subject at the speed of 1 per second. The list had to be recalled in the correct order and accomplished at least 50% of the time. 

The study showed that the average memory span for adults is 7 items.

I tested this on myself and I can usually recall 7 digits, but not 8. 

If you want to test your memory span, visit prodigypodcast.com/memory 

Here’s a list of 9(7) digits… 7,0,4, 1,9, 8, 5,3,5 

It’s difficult to hold those individual numbers in your working memory but it’s much easier if you use a mechanism called “chunking.” Chunking is the process of breaking down a data set and grouping the pieces together into meaningful chunks.

For the 9(7) digits I just read I would group them into 3(2) chunks 704-1985-35. These chunks make sense to me because it’s my hometown area code, the year I was born, and my age. 

As you can probably guess, chunks are based on an individual’s perception and past experiences. A different person may chunk them as 70-419-8535

Here’s Dr Scott Barry Kaufman. 

Scott: [00:04:38] Chunking is a term in the expertise literature, where once you get lots of complex information and you start looking at them as smaller patterns, you can really quite quickly appear quick and smart and talented in various, specific, forms of expertise. 

So 7 items was understood to be the average memory span. 

More than 30 years later a young postdoctoral researcher by the name of Dr Karl Anders Ericsson developed a study to determine if memory span could be improved. 

Their subject’s name was Steve Faloon who was cross country runner at carnegie mellon university. Ericsson would read him random digits at a rate of 1 per second, which is too fast to store in long term memory. If Steve recalled them correctly then Ericsson would add a digit. If he made an error then Ericsson would subtract one. 

Anders: [00:15:00] He initially did what a lot of people would do with phone numbers. You know, you would just kind of repeat them in your head, maybe grouping them. But basically that’s all you were doing. And he just found that when he did that, he pretty much plateaued. 

After several sessions, Steve didn’t improve, and became discouraged… then there was a breakthrough. 

He realized that if he concentrated on the first three digits and thought of them as a running time, he was a cross country runner. He could actually think of those numbers in a meaningful way. And then once he got further into the sequence, he could then maybe even do another group of three and interpret that. And some with some meaningful associations. So that’s kind of how he improved 

That session Steve was able to recall 11 digits for the first time. But it didn’t stop there.

What he did was to build like a hierarchy where he kind of had running times in a different place in the space.

Steve was learning to chunk chunks. 3 weeks later he was able to recall 20 digits. After 100 hours of training he was able to recall 40, which at the time was the most ever. And by the end of the study, he could recall a random string of 82 digits.

These were groundbreaking results. Now Ericsson needed to repeat it. He began with a 2nd subject but she ended up quitting. 

She did something quite different. So she actually tried to identify numbers and then make like a little meaningful story about the numbers, you know, so basically maybe, Oh six, I would be a six year old and then basically there would be another number and then she could make that into a date, you know, or at least part of the digits would match a date. So she kind of would generate these sort of little stories or scenarios. And we argue that that type of strategy it’s just not useful or possible to, to really, you know, keep improving. So it sort of sets a goal. I mean, she did, she was able to do, I guess at least 20 digits. So it’s pretty impressive, nonetheless.

Steve recruited his teammate, Dario Donatelli and taught him his method. Dario spent over 5 years in the study and at his peak was able to recall an incredible 113 digits. 

Practice is about building mental representations that form the connections in or between chunks. In the book “Peak” Ericsson defines mental representations as a structure that corresponds to an object, idea, or collection of information. 

Grandmaster chess players can memorize the positions of every piece in a game with just a quick glance.

They can even play a game without ever looking at the board. And not just 1. Some can play multiple games at the same time without seeing the board. The current record for simultaneous games played blindfolded is 48. With 35 wins, 7 draws, and 6 losses. 48 games of chess? I can’t even remember 8 numbers.

Everyone assumed grandmasters had photographic memories. Until a study was done where researchers showed them a chess board where the pieces were arranged in a way that couldn’t naturally occur in a game of chess. Now the grandmasters barely performed better than the average person.

Through thousands of hours of practice, grandmaster chess players build up mental representations for the arrangement of pieces on the board. 

I wanted to know, what is physically happening when we code these patterns into our long term memory? 

Anders: [00:30:50] Well, I think it’s very clear. Our body, including our nervous system, is basically engineered to kind of respond to challenges. 

So if you just kind of are in your comfort zone, you know, where you’re just walking down the street or doing things that don’t require any energy that basically will not now stimulate you to change. 

So for example, if we take something like, Long distance running the first two or three weeks when you actually are starting now to run, and it’s important here, you know, to pace herself. 

So you don’t try to do too much. but finding that stimulation, it seems like at that point, it’s more like the neurons in your legs are actually coordinating their activity.

But if you actually go beyond three weeks, then you can actually see that capillaries are growing because, you know, have such an effective way of using up the muscular energy, you know, have a depletion of oxygen and other things. So that’s. And that depleted state will now stimulate the growth of capillaries. 

So you will now have kind of an increased access to those ingredients. And with even more training, you will actually increase basically the heart. so it will actually be able to pump more blood. And also your arteries will be growing. And what’s interesting is that if you, for some reason, stop training, most of these changes will actually go back towards the normal state that you started out before training. 

Most people have experienced these types of physical effects on their body where it’s easy to recognize. But what about an area that’s harder to recognize. Like the brain. 

Anders: [00:32:51] Right. You basically can see these sorts of changes and there’s numerous different ways in which the brain can actually change. And one of the most noted ones is that you can grow myelin around certain nerve fibers. 

And that actually allows you to speed up the processing by an order of magnitude. You can also grow synapses to basically connect up various types of activities. I think we’re still, you know, the brain is so incredibly complex that people are still working on trying to come up with ways of measuring and quantifying, you know, I mean, we’re talking about, trillions of different nerve cells.

The brain is wired with nerve cell axons. Myelin insulates the wires and helps increase the rate at which electrical impulses are transmitted.

One of the books based on Ericsson’s research is “The Talent Code” by Daniel Coyle. 

In a Ted Talk Coyle actually called the idea of people being born with talent, the greatest story ever told. And he called it that because it had magic babies in it. Coyle quite literally referred to genetic predisposition as magic.


He wrote on his website his opinion of genes. “They matter, but not nearly as much as we think. Scientists have sequenced the human genome, but they can’t locate the genes for musical talent. Or math. Or art. Or sports. Mostly because genes don’t work that way.”

Here’s what Dan Coyle believes is the science behind skill acquisition.

“To put it in construction terms, genes are the blueprint for our bodies. But the skill circuits that allow those bodies to perform complex skills are built through deep practice”

Coyle suggests that what he calls “deep practice” causes new nerve cells to fire which increases myelin and establishes a strong skill circuit.

I asked Dr Brooke Macnamara what is happening in the brain when we learn. She is a professor at Case Western Reserve University where she investigates complex human performance. She got her PHD from Princeton on the subject so I figured she might be a better source than journalist Dan Coyle.

Brooke: [00:32:21] That is something that we’re still figuring out. So we know of some sort of physical, structural changes in terms of more processing changes. Really. It’s a bit more on the theory side at this point. So for example, If you say, okay, well, how do people recognize something new versus something that they’ve learned and can apply. While there’s some theories that say that a new neural trace is put down whenever you experience a new stimulus.

And then when you experience that same stimulus again, you either sort of try to figure it out how you did the first time, where you go back to that neural trace and some theories say the neural trace is strengthened. There’s other theories that say a new neural trace is laid down and eventually you can kind of shift based on the strength of the neural trace or the strength of multiple neuro traces.

You begin to recognize that stimuli. You don’t have to try to figure it out, but you, you go, Oh, right. I remember that. And I know the response to it. So you start recalling it directly from memory. But even that depends on the stimuli. So those types of theories seem to hold for verbal tasks and mathematical tasks, but they don’t seem to hold for dynamic spatial tasks, like returning a serve in tennis.

And so we don’t actually even know exactly what’s going on with the brain. There’s lots of both neuroscience, cognitive neuroscience, and cognitive psychology, left on the table for people to discover more about how the brain works.

The brain is incredibly complex and difficult to study. We have some methods but they’re relatively rudimentary. 

Here is Psychiatrist and Nuclear Medicine specialist Dr Rob Tarzwell. He uses radioactive tracers to study activity in the brain. 

[00:28:47] It’s just something that with our current state of science and technology is pretty difficult to see. So the kind of imaging I’m working at is at about a four to six millimeter scale. And. Within a four to six millimeter cube. there’s about 80 to a hundred million neurons.

[00:29:12] So in a sense, we’re trying to figure out whether Joe Biden or Donald Trump is gonna win the election by watching voters in lines from satellites in orbit. It tells you something, but it’s not drilling down fine enough to give you the kind of information you really need.

For some reason Dr Macnamara and Tarzwell didn’t know that Coyle had this all figured out 11 years ago when his book was published. (sigh)  I didn’t have the heart to tell them.

But joking aside. Dan Coyle is an environmentalist who clumsily rebranded Ericsson’s theory of deliberate practice to sell books. Disregard simple explanations, especially ones that turn a profit.

Alright we’re going to dive into Deliberate practice and the 10,000 hour rule right after this quick break.


Welcome back to prodigy. You can find source material and test your memory span at prodigypodcast.com. Alright back to the show.

So now that we’ve covered how practice improves ability.  Let’s look at Ericsson’s research which altered the perception of expert performance.

In his 1993 paper, Ericsson denied that innate talent determined the level of one’s performance. 

I’m going to paraphrase a quote from the paper that described this belief. 

We agree that expert performers have abilities outside the range of normal adults. However we deny that these differences are due to genetic talent. Only a few exceptions, like height are genetically prescribed. We argue that the difference between expert and normal performers is a life long period of deliberate effort to improve in a domain.

Ericsson’s data showed that the only determining factor of expert performance is the amount of time spent practicing. But not just any type of practice. A specific type he referred to as “deliberate practice.”  

In Malcolm Gladwell’s best-selling book titled “Outliers: The Story of Success”  he defines practice as, “purposefully and single-mindedly, playing their instruments to get better.” 

Gladwell then describes the Beatles playing hundreds of shows in Hamburg as a reason why they became so good. But this example doesn’t fit the definition of deliberate practice. 

Ericsson describes 3 types of activities. Work, Play and Deliberate Practice. Work includes public performances and other activities motivated by external rewards. Play has no explicit goal and is enjoyable. Deliberate Practice is activities specifically designed to improve performance.

So according to Ericsson, Gladwell’s example of the Beatles, would be defined as work. The reason Ericsson made this distinction is because during a show, your focus is on performing at your highest level. While deliberate practice is focused on increasing your highest level. 

Anders: [00:27:06] If you want to dunk a basketball, I think most people would think, well, you know, I’m just gonna keep stretching myself and trying to get a higher jump. and basically that’s the way I’m going to, you know, improve my ability to dunk. And it turns out that it’s well known now that there are other ways in which you can actually improve your jumping ability so much more than actually just trying to dunk. 

So for example, one thing is weightlifting. So if you basically look at the stimulation of your legs, when you’re actually lifting a weight, That is so much more intense than the stimulation that you get from actually trying to jump towards the hoop, and, and, you know, reach a higher level. Another thing that’s been demonstrated to also be far superior to just doing the thing is, basically jumping from a height. 

So if you’re basically standing on a table, And then you jump down, the stimulation that you get on your legs when they have to absorb your body. Weight is actually much more intense and therefore will lead to the development and the strengthening of your legs and the much more effective way than, you know, just trying to jump up towards the hoop.

The general idea is to focus your efforts on improving specific areas of weakness that will increase your overall performance. 

He also said that it should include a coach to provide feedback and design the training. Whether or not it must include a coach wasn’t clear, which brings me to Dr Hambrick.  

Here’s a clip from one of his lectures.

[00:07:00] Now, in the mid two thousands, this, you entered the popular imagination. Who has read the book? Outliers. Okay. Chapter two is called the 10,000 hour rule.

And in chapter two of this book, Gladwell describes Ericsson’s research and calls 10,000 hours. The magic number of true expertise. 

In 2013 researchers Hambrick, Macnamara and Oswald published a meta-analysis of deliberate practice. A meta-analysis examines multiple scientific studies that address the same question. In this case, how effective is deliberate practice? They include more data than a single study so they’re expected to be more accurate.

Brooke: [00:25:07] So meta analysis takes all relevant studies or data sets and synthesizes across them looking for patterns. 

That’s Dr Brooke Macnamara again, she works with Dr Hambrick a lot.

So meta-analyses are important because with any one study, You could find any effect. Right? There’s randomness. So randomness is lumpy. It’s called sampling error. So if I sample a hundred people, I might find something, but unless I replicated it, I can’t be too confident in that result. I, I have a result and it’s interesting and I’ll probably put it forth. But until I get some confirmation of that, I don’t know if it just happened to be those 100 people I sampled that seemed to give that effect.

So either through replication, especially if you have multiple replications or if you have a meta analysis. So instead of that one study that gives me this one result. If I have 20 studies, Then I can see, well, how many of these 20 studies give me the same result? Now that’s somewhat simplified.

It’s a bit more computationally intensive where a fancier weighted mean essentially of the effects across studies. And it also looks at the variance across studies and says, okay, well, on average meta analytic average, but on average, what is the effect?

So the more studies that you have included the better and that in a meta analysis will give you a better estimate than any one study could provide

They agreed that practice is critical and accurately predicts how much an individual person improves.

David: [00:10:00]I mean, we aren’t born. Literally born as experts, you have to acquire skill and knowledge

However, they determined that deliberate practice is not as important as Ericsson claimed. 

What we argued and thought based on what we understood his perspective to be was that practice is not as important as he had originally claimed, not to say that it was unimportant. It’s just that there were additional pieces to the puzzle. 

They weren’t saying that deliberate practice doesn’t matter. It’s necessary for improving your skill, however they found that it wasn’t a major factor in explaining the skill differences between people.

So the more you practice the better you’ll be but that doesn’t guarantee you’ll be better than someone else who has practiced less. 

Here’s another clip from Hambrick’s lecture.

[00:21:00, video] People vary widely in the amount, but deliberate practice it takes them to reach a given level of skill. Let me give you a couple of illustrations of this.

This is a study done in Buenos Aires. my colleague jeremo camp, it’s Ellie. He recruited 90 chess players, Buenos Aires chess club. They completed a survey to assess the amount of deliberate practice in the finding. Was that number one, practice and [00:22:00] chess rating correlated 0.42. That’s not. Trivial, nothing to see that, but there was still a massive amount of variability in the amount of deliberate practice.

It took the players to reach a, given a level of skill masters fast, to be exact. And here we can see this, we see a large amount of variability within skill level. some never reached master level, despite over 20,000, 25,000 hours of deliberate practice. 

The results of the meta-analysis showed that deliberate practice contributed to a 14% difference in performance. This differed by domain. So deliberate practice contributed to 26% difference in games but just 1% for professions.

Ericsson said that performance was 100% related to the amount of deliberate practice spent. What was the cause for such a wide discrepancy in findings?

Anders: [00:11:01] Their definition of basically the study. So practice that they included really failed to meet those standards that we were pointing out of actually having activity with training activities, where you get immediate feedback. So you can actually monitor how you get better. They included one estimate of having adolescents watch sports on television. I think that’s fundamentally different.  

So Ericsson said they didn’t use the correct criteria for choosing studies. Let’s look at the description in the meta-analysis. They define it as quote “engagement in structured activities created specifically to improve performance in a domain.”

So those activities are very different from the way we define deliberate practice. There’s not a teacher who is actually assessing your given individual and then posing appropriate training activities that would allow that individual to improve from the current performance.

And they included times, like, for example, scrimmaging where, you know, you just have the team split up into two groups and them playing against each  other. Again. That’s very, very far from the criteria that we established for deliberate practice.

So the meta-analysis included studies that didn’t meet Ericsson’s definition of deliberate practice. I asked Dr Hambrick what criteria they used. 

David: [00:20:49] There were a number of criteria, but the main one was that the studies reported a measure of performance in a domain and a measure interpretable as deliberate practice. 

And what is deliberate practice? Well this was at least to us, was unclear. In terms of specifics, one thing that a consistent point that Ericsson’s colleagues made all along was that it’s an activity that’s been designed to elevate a performance. There were elements of the definition where we saw inconsistencies in his writings, for example, whether or not a coach or a teacher is required, whether it can be group or whether it can be individual.

So we cast a wide net and used a broad definition of deliberate practice. That of course is, as you probably know, was where some of the debate, focused, was whether or not we had used the right definition of deliberate practice. And that was one of the reasons that we made all our data available. So that people could reanalyze our data using their own definition or what they believe to be the correct definition.

Ericsson took that available data and reanalyzed it according to his definition of deliberate practice.

Anders: And when we select another, now these studies that met these criteria, we found substantially higher estimates than they did.

Why would an intelligent person like Hambrick misinterpret the definition?

David: [00:23:03] Right. I mean, that, that is certainly, particularly recently, actually at the beginning and then pretty recently, his colleagues did emphasize the importance of having a coach. At other times as we noted in the literature. And actually as we note in the paper, was that he also at points said that deliberate practice could be designed by the performers themselves. 

Hambric, and colleagues released an article in august explaining the source of the confusion.

Quote, “Ericsson and colleagues have been inconsistent on critical elements of the definition of deliberate practice and consequently it has been unclear what activities do and do not qualify as deliberate practice.”

Hambrick then provides a timeline over the course of 27 years where Ericsson has given 3 different definitions of deliberate practice regarding who designs the training program. 1. The teacher alone. 2. Typically the teacher and 3. The teacher or performers themselves.

Hambrick’s issue is not with the evolution of the definition. He states that revising a theory as new evidence is accumulated is not only normal, it’s expected. But the revisions must be explained so they can be evaluated. If the revisions are not transparent then they can be altered in order to stay relevant. This is what’s referred to as “post hoc interpretation of data.”

Sadly we’ll hear no response. The day after our interview. Dr Karl Anders Ericsson passed from heart complications. 

David: [00:02:20] It is really difficult to overstate the influence that he had on the field of expertise. I mean, his ideas and his perspective shaped the trajectory of research on expertise for decades. It inspired a whole generation of researchers.

Ericsson helped define the optimal way to improve skills. His research was so groundbreaking that it transformed our understanding of potential. Transformation of a field is the metric that psychologists use to define a genius. Anders was a genius… and a genuinely good human being. 

Anders: [00:46:22] I love people to raise difficult questions because I think that’s a little bit, the way I view kind of purposeful practice for a scientist is, you know, the more that you can find the best, most challenging questions, that allows you to get ahead, start thinking about things, and are hopefully being able to understand them better.

David: [00:06:56] He was such an engaging person to be around. I remember going in the first time in Ander’s office. And it was just filled with papers and books as if they’d been just kind of shoveled in there.

And he was just really warm and friendly and, and we stayed in touch for a good amount of time. He had a great sense of humor, and was a voracious reader. He would go to conferences. And he would take a, or maybe you would buy them once he got their trunks. And he would, if there was a great bookstore at a con one of the conference cities, he would fill the trunk full of books and ship it back to his home. And speaking of his home, he had a library in his home, a full wall, a full on library with, you know, Stacks like Rose and it was, it was pretty cool. Cool to see that.

It’s obvious how much Hambrick respected Ericsson and valued his contribution to the field.  

I’ve been. Critical of it.

This is what happens in a scholarly area. People have different perspectives and critique has his work and his view.

He forced me to think carefully about my perspective and to try to put my best case forward. And our examination of his perspective has led to my colleagues and I to offer an alternative perspective.

His work, his influence has been on the field has been profound and he certainly had a huge influence on my own work. I’ve spent a lot of time thinking about his work and critically examining it and assumptions about the origins of expertise. And so it’s, it’s, uh, I have to say, it’s just, it’s really weird to think about him no longer being around. His ideas of course will live on and they’ll continue to inspire debate and in scholarship. And, I think that this will move us ever closer towards a full understanding of expertise and expert performance.

In 2010 a study was published proving the existence of extra sensory perception, or ESP. We’ll explore that, after a quick break.


Welcome back to Prodigy. Pam Peacock is the talented designer of our cover art. You can see more of her work on instagram at the voyager peacock. Ok back to the show.

This issue with the definition of deliberate practice is fairly common. Social sciences had been suffering from something known as the “replication crisis.” Researchers found that many studies are difficult or impossible to reproduce. Here’s Dr Macnamara. 

Brooke: [00:01:28] It began with a study on ESP that got published and this outraged a number of psychologists thinking, what have we come to when we know that this can’t exist?

In 2011 Daryl Bem published the results of a 10 year study on extrasensory perception. The data seemingly showed that time flowed in 2 directions allowing people insight into the future. Bem’s research appeared to be done correctly. But his peers knew that ESP couldn’t exist.

Or if it could, then that the evidence should be really strong and you read this paper and you realize that. That it’s not, and that there’s problems with it. And that surely if any other psychologist tried to conduct this experiment, they would not find significant effects. So this led people to start really thinking about replication and how many of the effects that we see in the published literature.

So how can we avoid confusion like this moving forward?

Brooke: [00:03:42]  We want to see larger samples. We want to see rigorous methods. And so. What is acceptable practice has changed quite a bit. Something else that has really changed the landscape quite a bit is pre-registration. 

Very simply, pre-registration is submitting a document explaining what research they plan to do and how.

So we know for medicine that things changed a lot in the year 2000. This is when it became required for any clinical trial to be pre-registered.

And all of the sudden from that date forward, there were way fewer successful attempts at a new drug or a new clinical trial. So, iff you think about that and think, well, you know what, I want to be treated by a doctor using a study before 2000 or after 2000, the answer is probably after 2000. 

It used to be was that if there was no pre-registered plan, people would treat the data, however, could get them an effect.

But now if it’s documented how you’re going to do it, then you can actually confirm hypotheses  as opposed to just trying to find something from the data

There’s even a society for the improvement of psychological sciences. It’s focused on transparency, open data and methodological rigor. So I think things are just changing and the journals are changing. What they find acceptable peer review is changing, so everything is shifting towards more rigor.


If deliberate practice is not the primary predictor of expert performance, then what  is? Hambrick and Macnamara propose something called the multifactorial model.

Brooke: [00:18:45] So the multifactorial model is essentially saying that we can’t rely on the single cause fallacy that deliberate practice or even practice, however, it’s defined, can’t fully account for individual differences in performance.

In fact, it doesn’t even account for the majority of it.  

The single cause fallacy occurs when it is assumed that there is a single, simple explanation for an outcome when in reality it’s a combination of factors.

So we need to start thinking of these other factors and figuring out how they predict performance directly. Uh, or indirectly. And so it’s based on the idea of gene environment interactions and that those are going to feed into types of experience, opportunity, um, cognitive abilities, which are some mostly heritable.

But certainly hasn’t have environmental components and that there’s. A lot happening, uh, within the person that is going to predict performance, right? So we are not all the same. If we were all the same, then we would be able to very simply say what predicts it. But we each come to the table with unique characteristics and unique characteristics around us that are going to predict that, um, also the deliberate practice view.

Not only sort of thinks of people all the same. Um, and so that we can have this one explanation, but tasks as all the same, well tasks have different demands. Um, and, and what someone is good at is going to depend on the task because tasks will demand different things from the person. So for example, if you have, um, a fairly simple task or to use the, you know, kind environment type task, um, practice is going to explain a lot more.

Then, if you have something that’s a complex or wicked environment where you’re going to need more reasoning and creativity and diversity of experiences to maybe tackle that problem. So the type of task environment and the demands of the task, maybe physically, maybe emotionally or cognitively, are all going to interact and there really needs to be a broader picture taking into account multiple factors to begin to explain human performance in a real way.

One question that I’ve been wanting the answer to is where does the motivation to spend thousands of hours on a single domain come from? 

[Hambrick Video 00:40:00] We analyze data from the national merit twins study of 800 twin pairs identified from 400,000 high school juniors taking the sat. And these twins were given a large survey of interests, attitudes, preferences, accomplishments, and so on. And we found a heritability of a 26% for music accomplishment as indexed by things like winning an award in a music competition or regional or national music competition, things of this sort, and then 38% for self-reported music practice. In Sweden, my colleagues, Frederick Ulan and Miriam Mosen. In a much larger sample, they replicated this, they had 2,569 full, twin pairs, heritability of lifetime hours of music practice was on average, about 50%, 41% for males, 69% for females.

Now in the expertise literature, this is a head-scratcher cause wait, how could practice be heritable? [00:41:00] That doesn’t compute, it’s a purely environmental variable, but this is readily explained in terms of the concept of gene environment correlation. This is the idea that the environments that we seek out and create for ourselves, are in part influenced by our genes.VV

This gene environment correlation is extremely interesting. The idea that people who have genetic traits that fit a domain, may actively seek it out. So if you’re tall and agile, you might be drawn to play basketball. To understand this better I speak with Dr. Robert Plomin, a famous geneticist and psychologist who did a massive twin study. Twin studies provide unique insights because the pair shares an environment. You can learn a lot by comparing the difference between identical twins which are like clones and fraternal twins which are like siblings.

Next episode we’re going to dig into these details and a lot more.  I have so many questions to answer, and a ton of really interesting topics to cover. So subscribe to the show, because I’ll be back next week, with another episode of Prodigy. 

Prodigy was created and produced by me, Lowell Brillante. I’m very fortunate to have the brilliant former magic baby, Tyler Klang as my executive producer.

If you want to measure the quantity of your myelin, then take the memory test at  prodigypodcast.com

Dr Anders Ericsson was the expert on experts and will be sorely missed.

Dr David Hambrick runs the expertise lab at Michigan state which focuses on the origins of skill. You can find more info at scienceofexpertise.com

Dr Brooke Macnamara is a professor at Case Western Reserve University where she investigates complex human performance. Follow her on twitter @brookemacnamara


Dr Scott Barry Kaufman is host of the psychology podcast and has a new book out. Visit scottbarrykaufman.com for details


Dr Rob Tarzwell is a nuclear medicine scientist


If you like the artwork, check out Pam Peacock on instagram @thevoyagerpeacock


Special thanks to Camille Dizon, Ben Kuebrich, Tristan McNeil, Terri Myher,, Allyson Cantor and Alex Cardinale.