It’s as if some of the A students and B students trade places when it’s test time

Saturday, August 14th, 2021

In the ninth grade, all Taiwanese children take the Basic Competency Test (BCT), Top Dog: The Science of Winning and Losing explains, which determines if they’ll get to attend senior high school:

The questions are much harder than American SAT questions, perhaps more equivalent to what Americans might see during a college final exam. And the testing takes two days. Only 39% of all Taiwanese ninth-graders manage to pass. It’s enormously competitive and stressful.


In regular classroom work, on a daily basis, the Worriers have the advantage. Thanks to high dopamine levels, they have better memories and attention and a higher verbal IQ. They’re superior planners and can better orchestrate complex thought. But as the BCT nears, the pressure intensifies, and the hours spent studying grow.


The Worriers become distressed and frustrated: they become unable to switch strategies or see something in a new way. They have trouble integrating new information. They are prone to panic when given new directions, preferring to stick to familiar ways of solving problems.


The Worriers score about 8% lower than the Warriors. The Worriers struggle the most on the academic subjects that tax working memory the hardest: science, social science, and math.

It’s as if some of the A students and B students trade places when it’s test time.

The future elites actually practiced less on average in their eventual sport than the near-elites through most of childhood

Friday, August 13th, 2021

If you look at the average number of hours of deliberate practice between elite and near-elite athletes, David Epstein explains (in The Sports Gene), packing in practice is clearly important, but you need to look at the entire picture:

The future elites actually practiced less on average in their eventual sport than the near-elites through most of childhood. Only in the mid-teen years did they focus in on a single sport and begin racking up practice hours in earnest.

Age vs. Practice Hours per Week

It could be that some eventual elites were simply more gifted and didn’t have to focus in as early.

Or, given the circa-puberty timing of the crossover in the above chart, the future near-elites may simply have been early developers who ceased to stand out when peers caught up physically, and subsequently the near-elites started throwing in the metaphorical towel.

Another possible explanation for this pattern is that early specialization actually hinders development in some sports.


[NBA MVP Steve] Nash followed a pattern that shows up repeatedly in studies of the childhoods of elite athletes: he had a “sampling period” through about age twelve, where he tried a variety of sports, found the one that best suited him — physically and psychologically — and then focused in during his mid-teen years and got down to business.


A Swedish study of sub-elite and elite tennis players — five of whom were ranked top fifteen in the world — found that the eventual sub-elites dropped all sports other than tennis by age eleven, whereas the eventual elites continued playing multiple sports until age fourteen. Only at fifteen did the future elites begin to practice more than the future sub-elites.


A study of the childhoods of musicians shows a similar pattern. In a paper titled “Biological Precursors of Musical Excellence,” psychologists John A. Sloboda and Michael J. A. Howe found that teenagers in a competitive music school who were deemed of “exceptional ability” had, prior to gaining entry to the school, sampled instruments and practiced less and had fewer lessons than students who were deemed of “average ability.” The average students accumulated 1,382 hours of play and practice on their first instrument prior to entering the school, compared to 615 hours for the exceptional students, who only focused on one instrument and ramped up their practice activities later. The average players, the psychologists wrote, “spent more total time on instrumental activity, but devoted the vast majority of their effort to the first chosen instrument.” That is, they stuck rigidly to a single path rather than embracing the sampling period during which athletes and musicians alike apparently often find the route that best fits their inimitable bodies and minds.

This led Epstein to write his next book, Range, which I also recommend — and which I’ve mentioned here before a few times.

Wearing cloth masks outdoors, far from other people, in the wind, as is the fashion in Palo Alto

Thursday, August 12th, 2021

John Cochrane, the grumpy economist, can’t help but rant about covid incompetence:

Delta is the fourth wave of covid, and amazingly the US policy response is even more irresolute than the first time around. Our government is like a child, sent next door to get a cup of sugar, who gets as far as the front stoop and then wanders off following a puppy.

The policy response is now focused on the most medically ineffective but most politically symbolic step, mask mandates. All all-night disco in Provincetown turns in to a superspreader event so… we make school kids wear masks in outdoor summer camps? Masks are several decimal places less effective than vaccines, and less effective than “social distance” in the first place.* Go to that all night disco, unvaccinated, but wear a mask? Please.

If we’re going to do NPI (non pharmaceutical interventions), policy other than vaccines, the level of policy and public discussion has tragically regressed since last summer. Last summer, remember, we were all talking about testing. Alex Tabarrok and Paul Romer were superb on how fast tests can reduce the reproduction rate, even with just voluntary isolation following tests. Other countries had competent test and tracing regimes. Have we built that in a year? No. (Are we ready to test and trace the next bug? Double no.)

What happened to the paper-strip tests you could buy for $2.00 at Walgreen’s, get instant results, and maybe decide it’s a bad idea to go to the all night dance party? Interest faded in November. (Last I looked, the sellers and FDA were still insisting on prescriptions and an app sign up, so it cost $50 and insurance “paid for” it.) What happened to detailed local data? Did anyone ever get it through the FDA’s and CDCs thick skulls that even imperfect but cheap and fast tests can be used to slow spread of disease?

Last summer, we were talking about super-spreader events, and the idea that you don’t have to have disastrous lockdowns of everything but maybe packed all-night disco parties are a bad idea? (Reopen smart, I wrote at the time, for example here) Today, silence. Masks. Nice big symbolic masks. Period.

And then we indulge another round of America’s favorite pastime, answers in search of a question. Delta is spreading, so… extend the renter eviction moratorium.


In the talk “pandemic of the unvaccinated,” I hear, basically, resignation. We offered you vaccines. If you won’t take them, fine, we’re done. We’re back really to what quite a few people argued for and were pilloried for in March 2020. Let it sweep through, get to herd immunity, it peters out, bury the dead and go on with life.

The good news. A reproduction rate of 6 means Delta will spread really fast, peak really fast, and decline fast. The bad news: a lot of people will needlessly get sick and quite a few will die. The economy will slow down as people voluntarily pull back. Evolution got one more step ahead of bureaucratic bungling. A variant that transmits even more easily through vaccinated people can’t be far behind.

It did not have to happen. The vaccine was in hand, the lines were done, anyone could walk in and get the vaccine. All we had left to do was get pretty much everyone vaccinated before the new variant hit, and it would have been pretty much over. Something like $5 trillion dollars of extra debt, the economy closed for a year, thousands dead, thousands unemployed, huge pain and now we lose sight of the ball when all we had to do was pay a little attention, get some small incentives going for everyone to get vaccinated. (Aaron Stupple suggested, just pay people $1,000 to get vaccinated. 100 million people times $1,000 is $100 billion. Couch change in what the pandemic has cost us, or the upcoming $3.5 trillion “infrastructure” bill. That’s not much more than rail and transit subsidies alone.)


Of the many things we don’t know, just how much masks help or don’t help is one of them. You think with $42 billion dollars one could find out. Of the studies I have read and seen cited, I see a guesstimate of 20% reduction in reproduction rate. So if Delta has R0=6, masks might reduce that to 4.8. Even if a vaccine is only 50% effective in stopping transmission, then R0 among the vaccinated is 0.25.

Masks do much more to stop you from giving it to someone else than to protect you. Cloth masks are close to useless. Well-fitting N95 masks work much better in both directions. Neither comes close to vaccination. Wearing cloth masks outdoors, far from other people, in the wind, as is the fashion in Palo Alto, is just part and parcel of the pointless virtue-signaling so prominent here. If you do go to that crowded all-night disco, wearing an N95 mask might be a good idea. Of course if you’re even thinking about wearing a mask, you’re not going in the first place, which is why the whole mask-mandate business is a bit silly.

People whose enzymes work slowly can’t handle the stress

Tuesday, August 10th, 2021

A single letter in your genetic code determines whether your COMT enzyme is hardworking or lazy, Top Dog: The Science of Winning and Losing explains, and thus whether you are a Warrior or a Worrier:

The hardworking ones are precisely four times faster than the lazy ones. The hardworking enzymes are built with valine, the lazy enzymes with methionine.


In people of European descent, 50% have a combination of both slow and fast enzymes; 25% have only fast enzymes; and 25% have only slow enzymes.


For people whose enzymes work fast, their brains can handle the stress, because the enzymes can get rid of the extra dopamine.


People whose enzymes work slowly can’t handle the stress, because their enzymes can’t clear the dopamine. Their brains become overexcited, and they become overwhelmed.


The fast enzymes work so rapidly that when someone is not being stressed — when conditions are normal, and there’s just a normal dopamine turnover — the enzymes clear out too much dopamine.


They actually need the stress (and the dopamine) to get up to the optimal level of mental functioning.


On most days, having slow COMT enzymes is actually a good thing. But under stress and pressure, with that extra flood of dopamine, they crack.


The COMT gene for the fast-acting enzymes is one we share with chimps and apes — it’s been in human DNA forever. But the COMT gene for the slow-acting enzymes is ours alone; it’s a more recent entrant in the survival-of-the-fittest contest.


While you might think the Warriors are the aggressive ones, that’s not accurate. With higher levels of dopamine, the Worriers are always near the threshold for an aggressive response. It’s easy to set them off; they’re very temperamental. They get angry more easily and act out. But their aggression isn’t necessarily successful. The meaning of “successful aggression” is correctly reading and interpreting other people’s aggressive intentions, and matching them. Worriers tend to see aggression when it’s not there, and they miss it when it is. The Warriors are ready for the real thing.


For those with the “Warrior” gene, a majority had recovered from their PTSD. And after the researchers had reconstructed their history of trauma, the scholars learned that the Warriors had only developed PTSD after experiencing a number of traumatic incidents. For those with the “Worrier” gene, it was a different story. It had taken only a single traumatic event to cause severe PTSD symptoms. And the majority of the Worriers still had PTSD related to the trauma of the genocide. More than a decade later, they had not yet recovered.

Both warriors and worriers are needed in every society

Monday, August 9th, 2021

The gene that has been most studied for its involvement in pain modulation, David Epstein explains (in The Sports Gene), is the COMT gene, which is involved in the metabolism of neurotransmitters in the brain, including dopamine:

Two common versions of COMT are known as “Val” and “Met,” based on whether a specific part of the gene’s DNA sequence codes for the amino acid valine or methionine.


In both mice and humans, the Met version is less effective at clearing dopamine, which leaves higher levels in the frontal cortex. Cognitive testing and brain imaging studies have found that subjects with two Met versions — both animals and humans — tend to do better on and require less metabolic effort for cognitive and memory tasks, but that they are also more prone to anxiety and more sensitive to pain.

(Anxiety, or “catastrophizing,” is a strong predictor of an individual’s pain sensitivity.)

Conversely, Val/Val carriers seem to do slightly worse on cognitive tests that require rapid mental flexibility, but may be more resilient to stress and pain.

(They also get a better boost from Ritalin, which increases dopamine in the frontal cortex.)


David Goldman, chief of the Laboratory of Neurogenetics at the NIH’s National Institute on Alcohol Abuse and Alcoholism, coined the phrase “warrior/worrier gene” to describe the apparent tradeoffs of the two COMT variants.


In the United States, Goldman says, 16 percent of people are Met/Met; 48 percent are Met/Val; and 36 percent are Val/Val, leading him to suggest that both warriors and worriers are needed in every society, so there is widespread preservation of both forms of the gene.

I didn’t remember this passage from my original reading of the hardback edition back in 2013 — because it wasn’t in there:

So, I’ve included a relevant passage that didn’t make it past the first draft of this book.

It is about the BDNF gene, which codes for its namesake protein: brain-derived neurotrophic factor. The gene comes in two common varieties, known as “val” and “met,” and a National Institute of Mental Health study found that individuals with the met version performed more poorly on tests that asked them to recall scenes they had been shown. Follow up studies suggest that BDNF may also impact the kind of “muscle memory” involved in sport skill acquisition:

Bond’s beloved Bentley was his only personal hobby

Sunday, August 8th, 2021

Before James Bond was the dashing and debonair secret agent on the silver screen, Jordan Golson notes, he was the tormented and brooding assassin of Ian Fleming’s novels, and in those books, he drove a Bentley:

In Fleming’s first 007 novel, Casino Royale, published in 1953, Bond tooled around in a 1931 4.5 Litre Blower Bentley. It wasn’t so sleek or sexy as the Astons that Bond would come to be known for, but it was among the finest cars of its day and just the thing for getting around in all due haste with style.

Bond was, in Casino Royale, something of a car nut and his beloved Bentley was “his only personal hobby.” He bought it in 1933 and kept it in storage while serving in World War II. “Bond drove it hard and well and with an almost sensual pleasure.”

Blower Bently 4.5-Litre Inline

Built by Sir Henry “Tim” Birkin, one of the famous “Bentley Boys” who raced the cars at Le Mans, the supercharged, two-ton Blower was based on the brand’s 24 Hours of Le Mans race car. It produced 240 horsepower from a 4.4-liter inline-four motor with a four-speed unsynchronized manual transmission. The supercharger, which forced more air into the engine to generate more power (thus “Blower”) was gigantic and easily spotted at the front of the car, between the headlights. Top speed was in the 120 mph range, impressive for the era. Just 55 supercharged units of the car were produced between 1929 and 1931.

They waste that money on bad haircuts and pop stars, making them ripe for Communist picking

Saturday, August 7th, 2021

Scott Bradfield of The New Republic reviews Oliver Buckton’s new Fleming biography, The World Is Not Enough:

After he lost his father, his overbearing mother dominated his life and prevented him from marrying the first woman with whom he formed an engagement. And his brothers (especially the elder, Peter) achieved greater successes in their studies and occupations than Ian ever did. Like many middle children who feel lost, Ian retreated into a love of writers who transported him into extreme landscapes of love and adventure — such as Robert Louis Stevenson, Jules Verne, H. Rider Haggard, and those early spy novelists who depicted tough-talking, well-bred men willing to fight for God and country, John Buchan and Sapper (the pseudonym of H.C. McNeile).

It’s surprising how little Fleming’s view of international politics differs from that of Sapper, even though they lived and wrote nearly half a century apart. Like Bulldog Drummond, who frets about those international forces who want to “Bolshevize” England by empowering “members of the Do-no-work-and-have-all-the-money Brigade,” the characters in Bond are filled with suspicion of working-class agitators and foreigners. As General G. brags in From Russia With Love, the Russian state is “quietly advancing” on the West through “strikes in England” and the “great political gains” of liberal governments in Europe. And as Bond reflects early in Thunderball, this postwar liberalizing of Britain is leading to a generation of soft-shelled young people who don’t understand how hard their parents worked before the war. (From Fleming’s spotty employment record, he probably wouldn’t have understood this, either.) On a taxi ride, Bond notices his taxi driver playing with a comb and takes it as a mark of disrespect. “It was typical of the cheap self-assertiveness of young labor since the war,” he thinks to himself. For the young man “born into the buyer’s market of the Welfare State,” he fulminates, “life is easy and meaningless.”

In Bond’s view, the problem with postwar British youth is that they expect good pay for their not-hard work; and they waste that money on bad haircuts and pop stars, making them ripe for Communist picking. At the same time, there are isolated, patriotic types like Bond himself, capable of rising above the world’s naturalistic soup by knowing what to wear, what to eat, and how to best serve the desires of a woman. Beneath the high-gloss glamor of his novels, Fleming’s disdain for the working class veiled his frequent bouts of incompetence, just as it masked his concerns about the country that was changing around him, turning into a place that was no longer entirely his.


What most distinguishes Fleming is how adroitly he adapted these adolescent power fantasies to his job in British Naval intelligence, where he was recruited after failing a Foreign Office civil service exam and after lackluster stints at Reuters and in the City. (His business partner famously called him “the world’s worst stockbroker.”) In the Navy, Fleming was best known for creating Assault Unit 30, also dubbed “Ian Fleming’s Commandos” or “Fleming’s Red Indians.” And while Fleming’s unit (which he directed from afar, since his superiors considered Fleming too knowledgeable to be captured) achieved several successes, many of Fleming’s wild imaginings never survived their earliest brushes with reality.

For example, there was Operation Ruthless, a plan to repair a captured German plane, fill it with British soldiers dressed in German uniforms, crash land in the Channel, capture a German U-boat, and bring home the Enigma machine. Or another one code-named Operation Goldeneye, which involved digging an underground bunker in Gibraltar, filling it with British intelligence agents and their equipment, and fighting off a predicted occupation by Germans (which never materialized). After the war, Goldeneye provided the name of Fleming’s beloved home in Jamaica, where he often went to write the first drafts of his novels (and to escape his quickly failing marriage); and the idea of an underground spy network was used in his short story, “From a View to a Kill.”

Fleming preferred fiction to reality; and whenever he could put fiction to use in real life operations, he did. Inspired by a detective novel, Basil Thomson’s The Milliner’s Hat Mystery, Fleming is credited with proposing Operation Mincemeat, in which Naval Intelligence attached an identikit of fake documents to a dead body and released it from a submarine into Spanish waters; the Spanish, as expected, passed on the false information to the Germans, causing them to leave Sicily unprotected against Allied invasion.

Sometimes it really helps to have a loved one there to support you, and sometimes it doesn’t

Friday, August 6th, 2021

Researchers at the University of Trier, Top Dog: The Science of Winning and Losing explains, had young adults give a speech about why they were the best candidate for a job — either with or without their boyfriend or girlfriend there:

The scholars had entirely expected that having a supportive partner there would diminish the stress of giving a speech. And that did happen for the men; having their girlfriend or wife there calmed them considerably.

But to the researchers’ surprise, it was the exact opposite for the women.


[S]ometimes when you’re performing or competing, it really helps to have a loved one there to support you. And sometimes it doesn’t.


The workplace has its version of this same conundrum: sometimes, employees’ effort level goes up if a boss frequently monitors them. But it’s also true that being monitored can stress out employees and become a distraction, causing them to lose concentration and be less productive.


In 1965, Robert Zajonc, then at the University of Michigan, resuscitated the question. He noticed a dividing line in all the research, a consistency that explained when being watched helped or hurt performance. He theorized that the key variable was whether people were in a learning phase or had already mastered the skill. If they were learning the skill, the presence of spectators hampered performance. If they had mastered it, the presence of spectators improved performance.


The idea that novices and experts respond to an audience divergently is consistent with other work that shows that novices get the most out of positive feedback, but experts benefit from criticism — they need that discerning scrutiny in order to improve.


Jack Aiello of Rutgers University has shown that simple tasks improve under supervision. But the more complicated the job, the worse people perform when being monitored.


The short answer is that Aiello and his team have found that intermittent supervision works even better than continuous supervision.

They could twist their bodies into positions that you and I can’t

Thursday, August 5th, 2021

Collagen is sometimes referred to as the body’s glue, David Epstein explains (in The Sports Gene), holding connective tissues in proper form:

Biologists at South Africa’s University of Cape Town have been leading the way in identifying genes that predispose exercisers to injuring tendons and ligaments. The researchers focused on genes like COL1A1 and COL5A1 that code for the proteins that make up collagen fibrils, the basic building blocks of tendons, ligaments, and skin.


People with a certain mutation in the COL1A1 gene have brittle bone disease and suffer fractures easily. A particular mutation in the COL5A1 gene causes Ehlers-Danlos syndrome, which confers hyperflexibility. “Those people in the old days of the circus who used to fold themselves into a box, I bet you in most cases they had Ehlers-Danlos syndrome,” says Malcolm Collins, one of the Cape Town biologists and a leader in the study of collagen genes. “They could twist their bodies into positions that you and I can’t because they’ve got very abnormal collagen fibrils.”

Ehlers-Danlos syndrome is rare, but Collins and colleagues have demonstrated that much more common variations in collagen genes influence both flexibility and an individual’s risk of injuries to the connective tissues, like Achilles tendon rupture. Using that research, the company Gknowmix offers collagen gene tests that doctors can order for patients.

David Brooks reconsiders Bobos in Paradise

Tuesday, August 3rd, 2021

David Brooks looks at the recent social phenomenon of the populist regatta and reconsiders Bobos in Paradise:

They are doing pretty well but see themselves as the common people, the regular Joes, the overlooked. They didn’t go to fancy colleges, and they detest the mainstream media.


You can see this phenomenon outside the United States too. In France, the anthropologist Nicolas Chemla calls this social type the “boubours,” the boorish bourgeoisie. If the elite bourgeois bohemians — the bobos — tend to have progressive values and metropolitan tastes, the boubours go out of their way to shock them with nativism, nationalism, and a willful lack of tact. Boubour leaders span the Western world: Trump in the U.S., Boris Johnson in the United Kingdom, Marine Le Pen in France, Viktor Orbán in Hungary, Matteo Salvini in Italy. How could people with high-end powerboats possibly think of themselves as the downtrodden? The truth is, they are not totally crazy. The class structure of Western society has gotten scrambled over the past few decades. It used to be straightforward: You had the rich, who joined country clubs and voted Republican; the working class, who toiled in the factories and voted Democratic; and, in between, the mass suburban middle class. We had a clear idea of what class conflict, when it came, would look like — members of the working classes would align with progressive intellectuals to take on the capitalist elite.

But somehow when the class conflict came, in 2015 and 2016, it didn’t look anything like that. Suddenly, conservative parties across the West — the former champions of the landed aristocracy — portrayed themselves as the warriors for the working class. And left-wing parties — once vehicles for proletarian revolt — were attacked as captives of the super-educated urban elite. These days, your education level and political values are as important in defining your class status as your income is. Because of this, the U.S. has polarized into two separate class hierarchies — one red and one blue. Classes struggle not only up and down, against the richer and poorer groups on their own ladder, but against their partisan opposite across the ideological divide.

The home advantage is an evolutionary one

Monday, August 2nd, 2021

The home advantage is an evolutionary one, Top Dog: The Science of Winning and Losing explains, rooted in territorialism:

University of British Columbia professor Graham Brown once asked pairs of college students to take part in a mock contract negotiation. But he staggered the arrival of the students, taking early-arriving students to an unused office. There, Brown handed the early bird a key to the office, told her she was free to use the computer, even encouraged her to hang up a poster or two as decoration. Then he gave the early bird 20 minutes to get comfortable in the space. Once the other student arrived, they proceeded with the negotiation. It wasn’t even close. The students who made themselves at home in the office got everything they wanted, and more.

Brown concluded that those who are on their home turf receive a huge windfall. Their takeaway may be worth up to 160% more than what the away-team opponents will bring home.


When two teams at a firm work together on a project, the team hosting the coffee and bagels in their conference room is more likely to take charge of the entire endeavor.


[T]he home team in a NBA game wins about 63% of the time.


In studies of collegiate and professional basketball teams, the home teams are led by centers and forwards. The home teams are better at blocks, steals, turnovers, and have more successful field-goal attempts. The away team is led by guards’ defensive tactics: they are better at assists, three-point shots, rebounds, and intentional fouls.


Statistician Richard Pollard looked at the win-loss records of 37 professional teams that moved to shiny new stadiums across town. You’d think that the new and improved facilities help the teams, but Pollard’s results show that, at least at first, teams are actually less likely to win in the new stadium than they were at the old park.


A few years ago, violence in the stands of Italian soccer games became so pronounced that some teams chose to play in empty stadiums: not a single fan was allowed in to watch the game. But the home teams still kept winning.


Given findings such as these, researchers have increasingly come to the conclusion that the home advantage is an evolutionary one, rooted in territorialism — a deeply rooted, innate need to control one’s own space. And once this sense of territorialism is activated, you become more competitive; you’re more willing to challenge potential intruders. You’re more confident, more motivated, and more aggressive when you perceive a potential threat. You have a higher sense of self-efficacy, controlling the environment in a way that best suits your needs.

Far Side Territory

In video game experiments, if a player arrived at the game’s target destination just ten seconds before his opponent, he was more likely to win the game.


People accept others’ sense of ownership just as quickly: late arrivals accept that they are the visitors and usually defer to this prior residency. Latecomers are the ones more likely to flee than stand their ground. Territorialism explains why pedestrians naturally say, “Excuse me,” when walking past a perfect stranger. On a subconscious level, it feels as if the other person already “owns” the sidewalk in front of him, and someone needs permission to take the sidewalk away.


If another car was waiting for the space, people took twice as long to exit.

Boxers with an ApoE4 copy scored worse on tests of brain impairment

Sunday, August 1st, 2021

The apolipoprotein E gene comes in a number of common variants, and a single copy of the Apo4 variant is associated with a threefold increased risk of Alzheimer’s, David Epstein explains (in The Sports Gene), but it also extends beyond Alzheimer’s to how well the brain recovers from any injury:

A 1997 study determined that boxers with an ApoE4 copy scored worse on tests of brain impairment than boxers with similar length careers who did not have an ApoE4 copy. Three boxers in the study had severe brain function impairment, and all three had an ApoE4 gene variant. In 2000, a study of fifty-three active pro football players concluded that three factors caused certain players to score lower than their peers on tests of brain function: 1) age, 2) having been hit in the head often, and 3) having an ApoE4 variant.


What went entirely unmentioned in media coverage, though, was that five of nine brain-damaged boxers and football players who had genetic data included in the report had an ApoE4 variant. That’s 56 percent, between double and triple the proportion in the general population.