The Sports Gene: Inside the Science of Extraordinary Athletic Performance

“While physical hardware alone—like depth perception or visual acuity—is as useless as a laptop with an operating system but no programs, innate traits have value in determining who will have a better computer once the sport-specific software is downloaded.” 

Epstein uses the hardware/software metaphor throughout The Sports Gene, returning to it for purposes of explanation and articulation. It also takes on thematic importance, as the debate between “hardware” and “software” is unsettled and ongoing in much of the sports science world. In most cases, the simplest answer as to which gives a person his or her abilities is “both.”

“It’s always a hardware and a software story. The hardware is useless without the software, just as the reverse is true. Sport skill acquisition does not happen without both specific genes and a specific environment.” 

This passage is a clear distillation of one of Epstein’s main themes. It relies on a computer metaphor used throughout the book as a motif to articulate different aspects of the same idea. The tone is so confident as to almost sound weary or unsurprised by the fact that this one truth emerges in every sports gene study.

“The ‘practice only’ narrative to explain Tiger Woods has an obvious attraction: it appeals to our hope that anything is possible with the right environment, that children are lumps of clay with infinite athletic malleability. In short, it has the strongest possible self-help angle and it preserves more free will than any alternative explanation. But narratives that shun the contributions of innate talent can have negative side effects in exercise science.” 

This passage underscores one of the book’s main themes: that social narratives are often incompatible with scientific data. It’s also typical of Epstein’s style to discuss world-famous sports stars like Tiger Woods in the context of his research. Such examples allow for the reader to make connections between the material and his/her preconceptions.

“The trouble is that human biology simply does not break down into male and female as politely as sports governing bodies wish it would.” 

This quotation falls in a chapter about chromosomal abnormalities that resist binary sex classification. Epstein assumes a facetious tone here, understanding that science by its nature cannot be “polite” or convenient. His tone betrays a critical attitude toward “sports governing bodies” that have, as the chapter reveals, made numerous mistakes throughout history in this very area of sex classification, sometimes resulting in career-ending scandals for athletes.

“The reason we have females separated in sports is because in many sports the best female athletes can’t compete with the best male athletes. And everybody knows that but nobody wants to say it. Females are structured like a disabled class for all sorts of, I think, good reasons.” 

This quote comes from Alice Dreger, professor of clinical medical humanities and bioethics in the Feinberg School of Medicine at Northwestern University. That “everybody knows” and “nobody wants to say” is typical of the sports research world that Epstein critiques throughout the book. Here, though, Dreger makes the case that the sports world separates the sexes based on scientific “good reasons,” in spite of the social discomfort surrounding the subject.

This quote comes from Alice Dreger, professor of clinical medical humanities and bioethics in the Feinberg School of Medicine at Northwestern University. That “everybody knows” and “nobody wants to say” is typical of the sports research world that Epstein critiques throughout the book. Here, though, Dreger makes the case that the sports world separates the sexes based on scientific “good reasons,” in spite of the social discomfort surrounding the subject.

This quotation is characteristic of Epstein’s writing style and chapter structure. He presents evidence, summarizes it, arrives at what seems like a conclusion, and then launches an inquiry that he’ll pursue in subsequent paragraphs. The bluntness of this question (“Why are women athletic at all?”) is perhaps meant to raise eyebrows, as Epstein makes the point repeatedly that scientific inquiry owes no politeness.

“This is a story that plays out on every track in America—-similar boys and girls miraculously become less similar despite training similarly—albeit in far less dramatic fashion. In the absence of any biological explanation for these stories, we find other narratives to explain them, narratives that are not without consequences.” 

In Chapter 5, Epstein reflects on his college track-and-field training partner Scott and on the differences between them. Whereas his partner was once believed to be lazy or wasting his gift, Epstein now wonders if Scott’s genes made him a low responder to training. The theme of the interplay between social narratives and scientific explanations is on display in this passage. 

“The results evoke the American College of Sports Medicine’s new motto: ‘Exercise Is Medicine.’ Just as areas of the genome have been identified that influence how well different people respond to coffee, Tylenol, or cholesterol drugs, so does every individual seem to have a physiologically personalized response to the medicine of any particular variety of training.” 

This quotation supports a category of findings Epstein presents in the book that have to do with a genetic predisposition to respond to stimulus in a certain way. This genetic response to training upends traditional notions about practice in sports. It doesn’t undermine the role of training but rather incorporates it into the genetic story.

“The more that elite sports markets have shifted from participatory affairs to events for bulging masses of spectators, the more rare the bodies required for success have become, and the greater the money needed to attract those rare bodies to a particular sport.”

Here, Epstein pinpoints a significant change in the cultural role of sports, from a “participatory affair” to a spectator event. The physiology of an eligible professional athlete changed based on the financial incentives of the market around the sport. This quotation is emblematic of the way Epstein draws lines from culture to economics to sports to science.

“‘We can see differences in the strength of bones in different populations already at one year of age,’ Cowgill says. ‘What I’ve found indicates that these differences are just there. They are exacerbated over the course of growth based on what you’re doing, but it looks like people are born with genetic propensities to be strong or to be weak.’” 

This statement comes from University of Missouri anthropologist Libby Cowgill. She studied skeletons to determine whether children develop strong bones due to physical activity after they’re born or due to genetic sequencing before they’re born. It’s an example of a finding, like so many in the book, that emphasizes the astounding power of genetics (even as environment plays a part).

“In just three years following the new labor agreement, the proportion of seven-footers in the NBA more than doubled, reaching 11 percent, where it has essentially remained ever since. ’What it means is that basically everyone in the world who is seven foot tall and can play basketball is part of the game,’ Olds says. ‘We’ve kind of reached a population limit.’” 

This quotation refers to the labor agreement struck between the NBA and its players in 1983 that allowed players to profit in “licensing agreements, ticket sales, and television contracts” (132). It’s an example of how the economics and cultural role of a sport impacted the genetic diversity within the sport. Researcher Timothy Olds, who co-authored the term “Big Bang of Body Types,” puts the statistics about height in the NBA in blunt, humorous terms.

“If you want to know if your kid is going to be fast, the best genetic test right now is a stopwatch. Take him to the playground and have him race the other kids.” 

This quotation comes from Carl Foster, an author of several studies on ACTN3, or the “gene for speed.” It’s a simplistic answer coming from a genetic specialist, and it’s an example of a message Epstein delivers again and again in the book, which is that the search for sports genes occasionally overcomplicates what is already knowable. 

“‘The concept that physical superiority could somehow be a symptom of intellectual inferiority only developed when physical superiority became associated with African Americans […] That association did not begin until about 1936.’ The idea that athleticism was suddenly inversely proportional to intellect was never a cause of bigotry, but rather a result of it. And Cooper implied that more serious scientific inquiry into difficult issues, not less, is the appropriate path.” 

Epstein understands that research into ethnic groups and their genetic advantages in sports, particularly when these groups have recent African ancestry, can scare scientists away. He, like Patrick Cooper (whom he quotes here), believes this is the wrong way to approach science that pertains to sensitive subjects. This quotation also speaks to theme, as it describes a damaging social narrative that arose merely to denigrate black athletes, absent of scientific evidence. 

“For certain sports, it’s obvious and uncontroversial that particular populations will have a greater or lesser frequency of gifted prospective athletes. Pygmy populations have an average adult male height of around five feet. So, while they may produce an NBA player someday, a basketball scout taking a random sample from a Pygmy population will discover fewer athletes who, given the proper training, might make the NBA than if the sample were taken in Lithuania.” 

Epstein explains how certain traits confer obvious advantages in certain sports. Height and basketball, for example, is not a controversial relationship, perhaps because it's visible, whereas subtler traits advantageous in running, and associated with certain ethnic groups, make for a far more controversial discussion (though Epstein doesn’t believe it should be this way). This quotation is also an example of how Epstein distills complex information about genetics and statistics into simple, tangible terms. 

“In these days of computer games, sedentary pursuits, and driving our children to school—it is the ‘hungry’ fighter or the poor peasant who has the endurance background, and the incentive to work on it, who makes the top distance runner.” 

This quotation comes from track-and-field statistician Peter Matthews. It refers to the decline of first-world countries’ dominance in long-distance running and the increased dominance of countries like Kenya, as a dynamic dictated by incentive. It’s a perfect illustration of the theme of how economics and culture impact the sports world and the individuals who populate it.

“The human body is centuries in advance of the physiologist, and can perform an integration of heart, lungs, and muscles which is too complex for the scientist to analyze.” 

This quote comes from Sir Roger Bannister, “a world-renowned neurologist and the first man to break four minutes in the mile” (222). It articulates a sentiment Epstein shares, which is that the search for a single sports gene is futile. It’s also a subtle expression of awe for the complexities of the human body, a sentiment that likely drives Epstein’s research.

“Genetic variation among individuals, it seems, ensures that none of us can truly know another’s physical pain.” 

This revelation comes in “The Heartbreak Gene” and is based upon Epstein’s findings that genes influence how pain is perceived. Epstein uses the wording of a common saying and makes it literal. It’s a rare example of a social narrative that’s backed up by scientific data.

“Under conditions of acute stress the brain inhibits pain, so you can fight or flee without worrying about a broken bone.” 

This quotation is from psychologist Wendy Sternberg from a lecture on “stress-induced analgesia.” It’s one of the many fascinating facts about human physiology Epstein learns in his research. Epstein habitually connects human biology to evolution, and this is no exception: Once a survival mechanism, this particular brain response now enables athletes to play through pain.

“Like most traits discussed in this book, an athlete’s ability to deal with pain is a braid of nature and nurture so intricately and thoroughly intertwined as to become a single vine. As one scientist told me, without genes and environments, there are no outcomes.” 

At the same time Epstein unearths genetic components of pain, he also discovers that pain is learned and is therefore influenced by environment. This quotation reinforces the thematic idea that there is not one single influential element in an athlete’s abilities. It departs from the more common machine metaphor and uses an image from nature.

“It reinforces the idea that any notion of finding an ‘athlete gene’ was a figment of the era of wishful thinking that crested a decade ago with the first full sequencing of the human genome, before scientists understood how much they don’t understand about the complexity of the genetic recipe book. What, exactly, most human genes do is still a mystery. Sure, the ACTN3 gene may tell a billion or so people in the world that they won’t be in the Olympic 100-meter final, but chances are they all already knew that.” 

Epstein knowingly undercuts the book’s title here. He understands that the story of the human genome is so complex, and the pool of testable athletes alive on the planet so small, as to make a pointed search for a particular gene futile. He reminds the reader that much of what people wish to know about the supposed secret to being great at sports is already knowable.

“If not for a batch of curious scientists who were familiar with Mäntyranta’s exploits and invited him to their lab twenty years after his retirement, his story might have remained a pure triumph of nurture. But illumined by the light of genetics, Mäntyranta’s life tale looks like something entirely different: 100 percent nature and 100 percent nurture.” 

This quotation refers to Eero Mäntyranta, the Finnish skier with a genetic mutation that gave him extraordinary levels of hemoglobin and an advantage in endurance sports. Mäntyranta’s story is also a 10,000-hour story of training and environment. Epstein distills how scientific inquiry into his genetics does not detract from Mäntyranta’s life of training but rather adds new, equally important information to the story.

“In all likelihood, we over ascribe our skills and traits to either innate talent or training, depending on what fits our personal narratives.” 

This quotation underscores one of Epstein's main themes, that scientific fact gets selected and sometimes warped to fit social narratives. This time, he places the narrative-making in the individual’s hands, rather than the media’s or sports organizations’. In doing so, he subtly asks the reader to examine his or her own narratives surrounding ability and personality.

“Essentially everybody falls in or near the muddled middle, differing by only a handful of genes. It’s as if we’ve all played genetic roulette over and over, moving our chips around, winning sometimes and losing other times, all of us gravitating toward mediocrity.” 

In a book that focuses on and celebrates the extreme examples of athletes, this quotation stands out. It refocuses the reader’s attention away from the margins and toward the middle, where most people’s bodies and abilities reside. The use of the gambling metaphor re-emphasizes Epstein’s sentiment that searching for perfection from a genes-first perspective is a foolhardy way to think about streamlining excellence in sports.