Elite-level performance can leave us awestruck. This summer, in Rio, Simone Biles appeared to defy gravity in her gymnastics routines, and Michelle Carter seemed to harness super-human strength to win gold in the shot put. Michael Phelps, meanwhile, collected 5 gold medals, bringing his career total to 23.

In everyday conversation, we say that elite performers like Biles, Carter, and Phelps must be “naturals” who possess a “gift” that “can’t be taught.” What does science say? Is innate talent a myth? This question is the focus of the new book Peak: Secrets from the New Science of Expertise by Florida State University psychologist Anders Ericsson and science writer Robert Pool. Ericsson and Pool argue that, with the exception of height and body size, the idea that we are limited by genetic factors—innate talent—is a pernicious myth. “The belief that one’s abilities are limited by one’s genetically prescribed characteristics....manifests itself in all sorts of ‘I can’t’ or ‘I’m not’ statements,” Ericsson and Pool write. The key to extraordinary performance, they argue, is “thousands and thousands of hours of hard, focused work.”

To make their case, Ericsson and Pool review evidence from a wide range of studies demonstrating the effects of training on performance. In one study, Ericsson and his late colleague William Chase found that, through over 230 hours of practice, a college student was able to increase his digit span—the number of random digits he could recall—from a normal 7 to nearly 80. In another study, the Japanese psychologist Ayako Sakakibara enrolled 24 children from a private Tokyo music school in a training program designed to train “perfect pitch”—the ability to name the pitch of a tone without hearing another tone for reference. With a trainer playing a piano, the children learned to identify chords using colored flags—for example, a red flag for CEG and a green flag for DGH. Then, the children were tested on their ability to identify the pitches of individual notes until they reached a criterion level of proficiency. By the end of the study, the children had seemed to acquire perfect pitch. Based on these findings, Ericsson and Pool conclude that the “clear implication is that perfect pitch, far from being a gift bestowed upon only a lucky few, is an ability that pretty much anyone can develop with the right exposure and training.”

This sort of evidence makes a compelling case for the importance of training in becoming an expert. No one becomes an expert overnight, and the effects of extended training on performance can be larger than might seem possible. This is something that psychologists have long recognized. In 1912, Edward Thorndike, the founder of educational psychology, wrote that “we stay far below our own possibilities in almost everything that we do….not because proper practice would not improve us further, but because we do not take the training or because we take it with too little zeal.” And, in Peak, Ericsson and Pool write that in “pretty much any area of human endeavor, people have a tremendous capacity to improve their performance, as long as they train in the right way.”   

But does the fact that training leads to improvements—even massive improvements—in skill level mean that innate talent is a myth? This is a much harder scientific argument to make, and is where Peak runs into trouble. Ericsson and Pool gloss over or omit critical details of research they review that undermine the anti-talent argument. As one example, although they claim that the results of Sakakibara’s training study imply that “pretty much anyone” can acquire perfect pitch, the sample in that study did not include pretty much anyone. It included children who had been enrolled in a private music school from a very young age (the average age at which training began was 4). It does not seem likely that this non-random sample was representative of the general population in music aptitude or interest—factors that are known to be influenced by genetic factors. It’s also not clear whether the children had acquired true perfect pitch, because there was no comparison of the children after training to people who possess this rare ability—for example, in terms of speed of identifying notes or neural correlates of performance.

As another example, describing the results of a study of ballet dancers by Ericsson and colleagues, Ericsson and Pool claim that “the only significant factor determining an individual ballet dancer’s ultimate skill level was the total number of hours devoted to practice” and that there was “no sign of anyone born with the sort of talent that would make it possible to reach the upper levels of ballet without working as hard or harder than anyone else.” Not mentioned is the exact magnitude of the correlation—a value of .42, where 1.0 is perfect. The fact that the correlation was modest in magnitude means that factors not measured in the study—including heritable aptitudes—could have actually accounted for more of the differences in ballet skill than deliberate practice did. As it always is in scientific debates, the devil is in the details in the debate over the origins of expertise.

Ericsson and Pool also leave out a good deal of evidence that runs counter to the anti-talent argument. For example, they claim that professional baseball players have “no better eyesight than an average person,” but there is evidence to suggest otherwise. In a study published in the American Journal of Ophthalmology, Daniel Laby and colleagues assessed the vision of major and minor league baseball players in the Los Angeles Dodgers organization over the course of four spring training seasons. As David Epstein recounts in his book The Sports Gene, in the first year of the study the researchers used a standard test of visual acuity, and it turned out to be too easy. Over 80% of the players got a perfect score of 20/15, meaning that they could see at 20 feet what an average person can see at 15 feet. In the following seasons, using a custom test, Laby and colleagues found that 77% of the 600 eyes tested had visual acuity of 20/15 or better, with a median of about 20/13. Even for young adults, this is excellent vision. Overall, Laby and colleagues concluded that “[p]rofessional baseball players have excellent visual skills. Mean visual acuity, distance stereoacuity, and contrast sensitivity are significantly better than those of the general population.”

Another notable omission from Peak is a study of 18 prodigies by Joanne Ruthsatz and colleagues—to date, the largest study of the intellectual abilities of prodigies. (Given the rarity of prodigies, a sample size of 18 is very large in this area of research.) The researchers gave the prodigies a standardized IQ test, and found that all scored very high on working memory (most were above the 99th percentile, and the average score for the sample was in the top 1%). A major factor underlying the ability to acquire complex skills, working memory is substantially heritable. There is also no discussion of the landmark Study of Mathematically Precocious Youth, started in the 1970s by the Johns Hopkins psychologist Julian Stanley and now co-directed by Camilla Benbow and David Lubinski at Vanderbilt. Now in its forty-fifth year, this longitudinal study has revealed that, even in the top 1%, cognitive ability in childhood is a significant predictor of objective occupational achievements in adulthood, such as earning advanced degrees, publishing scientific articles, and patent awards.

Based on our own evaluation of the evidence, we argue in a recent Psychological Bulletin article that training is necessary to become an expert, but that genetic factors may play an important role at all levels of expertise, from beginner to elite. There is both indirect and direct evidence to support this “multifactorial” view of expertise. (We call the model the Multifactorial Gene-Environment Interaction Model, or MGIM.) The indirect evidence comes in the form of large individual differences in the effects of training on performance. In other words, some people take much more training than other people to acquire a given level of skill. As it happens, Sakakibara’s pitch training study provides some of the most compelling evidence of this type. There was a large amount of variability in how long it took the children to pass the test for perfect pitch—from around 2 years to 8 years. As Sakakibara notes in her article, this evidence implies that factors other than training may be involved in acquiring perfect pitch, including genetic factors. This finding is consistent with the results of recent reviews of the relationship between deliberate practice and skill, which include numerous studies Ericsson and colleagues have used to argue for the importance of deliberate practice. Regardless of domain, deliberate practice leaves a large amount of individual differences in skill unexplained, indicating that other factors contribute to expertise.

The more direct evidence for the multifactorial view of expertise comes from “genetically informative” research on skill—studies that estimate the contribution of genetic factors to variation across people in factors that may influence expert performance. In a study of over 10,000 twins, two of us found that music aptitude was substantially heritable, with genes accounting for around half of the differences across people on a test of music aptitude. As another example, in a pioneering series of studies, the Australian geneticist Kathryn North and her colleagues found a significant association between a variant of a gene (called ACTN3) expressed in fast-twitch muscle fibers and elite performance in sprinting events such as the 100 meter dash. There is no denying the importance of training for becoming an elite athlete, but this evidence (which is not discussed in Peak) provides compelling evidence that genetic factors matter, too.

Based on this sort of evidence, we have argued that the experts are “born versus made” debate is over—or at least that it should be. There is no doubt that training is required to become an expert. Notwithstanding a report by North Korea’s state-run news agency that Kim Jong-il made five holes-in-one his first time playing golf and rolled a perfect 300 his first time bowling, no one is literally born an expert. Expertise is acquired gradually, often over many years. However, as science is making increasingly clear, there is more to becoming an expert than training. Moving ahead, the goal for scientific research on expertise is to identify all of the remaining factors that matter.