Cadets with lower grades improved academically if they socialized with cadets with high GPAs

Thursday, July 29th, 2021

Economists Scott Carrell and James West had noticed a pattern, a particular peer effect, at the Air Force Academy, Top Dog: The Science of Winning and Losing explains:

Cadets with lower grades improved academically if they socialized with, and spent more time around, cadet friends with high GPAs. The high-performers rubbed off on the low-performers, dragging them upward. Having friends whose SAT scores were 100 points higher than yours led to a half-grade improvement in GPA.

[...]

Carrell and West started by identifying which of the 1,314 incoming cadets had lower SAT scores and GPAs. These were the students most at risk of dropping out. They were assigned to special squadrons with a makeup of extra numbers of high-achievers. Compared with normal squadrons, these socially engineered squadrons had a few more low-performers, many more high-performers, and — to make room — fewer middle-performers.

[...]

More of the at-risk cadets were crumbling, not fewer.

[...]

Within a test squadron, the low-performers were self-segregating into cliques, to insulate themselves from the endless ranking and comparison.

[...]

Remember those squadrons comprised of leftover middle-performers? It turned out that their academic performance dramatically surpassed expectations.

[...]

When the field is too large, and the chance to be near the top is slim, people don’t try as hard.

Hyperactivity and impulsivity may have had advantages in the ancestral state of man in nature

Wednesday, July 28th, 2021

In The Sports Gene David Epstein reports on a “controversial” hypothesis about ADHD — or “hyperactivity”:

A set of scientists have proposed the controversial idea that hyperactivity and impulsivity may have had advantages in the ancestral state of man in nature, leading to the preservation of genes that increase ADHD risk. Interestingly, the 7R variant of the DRD4 gene is more common in populations that have migrated long distances, as well as those that are nomadic, compared with settled populations.

In 2008, a team of anthropologists genetically tested Ariaal tribesmen in northern Kenya, some of whom are nomadic and some recently settled. In the nomadic group — and only in the nomadic group — those with the 7R version of the DRD4 gene were less likely to be undernourished.

Centenarians had an “iAge” 40 years lower than their actual age

Tuesday, July 27th, 2021

The inflammatory ageing clock (iAge) is based on the idea that as a person ages, their body experiences chronic, systemic inflammation because their cells become damaged and emit inflammation-causing molecules;

To develop iAge, a team including systems biologist David Furman and vascular specialist Nazish Sayed at Stanford University in California analysed blood samples from 1,001 people aged 8–96 who are part of the 1000 Immunomes Project, which aims to investigate how signatures of chronic, systemic inflammation change as people age. The researchers used the participants’ chronological ages and health information, combined with a machine-learning algorithm, to identify the protein markers in blood that most clearly signal systemic inflammation. In particular, they pinpointed the immune-signalling protein, or cytokine, CXCL9 as a top contributor; it is mainly produced by the inner lining of blood vessels and has been associated with the development of heart disease.

[…]

After developing it, the researchers tested iAge by collecting the blood of 19 people who had lived to at least 99 years old, and using the tool to calculate their biological age. On average, the centenarians had an iAge 40 years lower than their actual age, according to a press release — aligning with the idea that people with healthier immune systems tend to live longer.

[…]

When examining CXCL9 as a biomarker of systemic inflammation, Furman and his colleagues grew human endothelial cells, which make up the walls of blood vessels, in a dish and artificially aged them by letting them divide repeatedly. The researchers saw that high levels of the protein drove the cells into a dysfunctional state. When the team silenced expression of the gene that encodes CXCL9, the cells regained some function, suggesting that the protein’s harmful effects might be reversible.

The travelling whale that reached the Pacific

Monday, July 26th, 2021

An ancient four-legged whale with hooves has been discovered:

The giant 42.6m-year-old fossil, discovered in marine sediments along the coast of Peru, appears to have been adapted for a semi-aquatic lifestyle. Its hoofed feet and the shape of its legs suggest it would have been capable of bearing the weight of its bulky four metre long body and walking on land. Other anatomical features, including a powerful tail and webbed feet similar to an otter suggest it was also a strong swimmer.

[…]

Previously, far older whale ancestors dating to about 53m years ago have been discovered in India and Pakistan. Until now scientists have disputed when and how whales first dispersed to the Americas and beyond.

The Peruvian fossil suggests the first whales would have crossed the South Atlantic, helped by westward surface currents and the fact that, at the time, the distance between the two continents was half what it is today.

The last few tail vertebrae are missing and so it is not clear if the creature’s tail would have featured the large paddle, known as a fluke, that allows some modern whales to power themselves along at speeds of more than 30mph (48 km/h). But it must have been an accomplished swimmer to have survived for days or even weeks at sea.

The fossil was excavated in 2011 by an international team, including members from Peru, France, Italy, the Netherlands, and Belgium. It has since been named Peregocetus pacificus, meaning “the travelling whale that reached the Pacific”.

Competition facilitates improvement

Sunday, July 25th, 2021

A recurring note in Top Dog: The Science of Winning and Losing is that there are two kinds of people: those who need to avoid stress to do well, and those who actually need stress to perform their best:

If you go back to the first published research ever done in the field of social psychology, the year was 1898, and the author was a 37-year-old high school teacher named Norman Triplett, who had returned to Indiana University to pursue his master’s degree.

[...]

He concluded that competition against other cyclists took off five seconds per mile compared to racing alone against the clock.

[...]

He found a 50%/25%/25% split [when he tested children on his "competition machine"] — half the kids benefitted a lot from being made to compete. Another quarter of the kids were largely unaffected, barely lowering their times over the three competitive trials. The last quarter of the kids did not handle the competition trials well at all.

[...]

Competition facilitates improvement. But the tradeoff is that competition doesn’t benefit everyone.

Access to a health club had a comparatively puny influence

Saturday, July 24th, 2021

All sixteen human studies conducted as of the writing of The Sports Gene had found a large contribution of heredity to the amount of voluntary physical activity that people undertake, David Epstein reports:

A 2006 Swedish study of 13,000 pairs of fraternal and identical twins — fraternal twins share half their genes on average, while identical twins essentially share them all — reported that the physical activity levels of identical twins were twice as likely to be similar as those of fraternal twins.

[...]

But another, smaller study of twin pairs that used accelerometers to measure physical activity directly found the same difference between fraternal and identical twin pairs.

The largest study, of 37,051 twin pairs from six European countries and Australia, concluded that about half to three quarters of the variation in the amount of exercise people undertook was attributable to their genetic inheritance, while unique environmental factors, like access to a health club, had a comparatively puny influence.

It is entirely clear that the dopamine system responds to physical activity. This is one reason that exercise can be used as part of treatment for depression and as a method to slow the progression of Parkinson’s disease, an illness that involves the destruction of brain cells that make dopamine. And there is evidence that the reverse is true as well, that physical activity levels respond to the dopamine system.

If you can control your fear, then you can control your biology

Wednesday, July 21st, 2021

When people say that the difference between an elite competitor and an intermediate competitor is all mental, Top Dog: The Science of Winning and Losing explains, that’s accurate:

Becoming a better competitor is about controlling your psychological state, which in turn alters your underlying physiology. Most simply put, if you can control your fear, then you can control your biology, too.

Yet it’s a myth that remaining calm is the answer for everyone. Only some people need to remain calm; others conquer anxiety by going to the other end of the spectrum — by being highly aroused, animated, and even angry.

A recurring note in this book is that there are two kinds of people: those who need to avoid stress to do well, and those who actually need stress to perform their best. Being told to chill out, relax, and think positively is fundamentally counterproductive for some people.

I will face my fear. I will permit it to pass over me and through me. And when it has gone past, I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain.

Normal mice run three to four miles each night

Tuesday, July 20th, 2021

Scientists who bred rodents for their desire to run have proven that work ethic is genetically influenced, David Epstein explains (in The Sports Gene):

Normal mice run three to four miles each night.

[...]

Garland took a group of average mice and separated them into two subgroups: those that chose to run less than average each night, and those that chose to run more than average. Garland then bred “high runners” with other high runners, and “low runners” with other low runners. After just one generation of breeding, the progeny of the high runners were, of their own accord, running even farther on average than their parents. By the sixteenth generation of breeding, the high runners were voluntarily cranking out seven miles each night.

[...]

When mice are bred for endurance capacity — not voluntary running, but when they are forced to run as long as they physically can — successive generations have more symmetrical bones, lower body fat, and larger hearts.

In his voluntary-runner breeding program, Garland saw body changes, “but at the same time,” he says, “clearly the brains are very different.” Like their hearts, the brains of the high runners were larger than those of average mice. “Presumably,” Garland says, “the centers of the brain that deal with motivation and reward have gotten larger.”

[...]

Whatever Ritalin does in the brains of normal mice is already occurring in the brains of the high-running mice.

Patients have stayed at home for a year and suffered dramatically fewer asthma attacks

Saturday, July 17th, 2021

Doctors have spent the pandemic wondering why their patients with asthma were suddenly doing so well:

Asthma attacks have plummeted. Pediatric ICUs have sat strangely empty. “We braced ourselves for significant problems for the millions of people living with asthma,” says David Stukus, Scarlett’s doctor at Nationwide Children’s Hospital. “It was the complete opposite. It’s amazing.” (Fears about people with asthma getting more severe COVID-19 infections haven’t been borne out either.) Studies in other countries, including England, Scotland, and South Korea, also found big drops in hospital and doctor’s-office visits for asthma attacks.

The massive global experiment that is the pandemic is now leading doctors to rethink some long-held assumptions about the disease. Asthma is a chronic condition that occasionally flares up, leading to 3,500 deaths and 1.6 million emergency-room visits a year in the United States. These acute attacks can be triggered by a number of environmental factors: viruses, pollen, mold, dust mites, rodents, cockroaches, pet dander, smoke, air pollution, etc. Doctors have often scrutinized allergens that patients can control at home, such as pests and secondhand smoke. But patients have stayed at home for a year and suffered dramatically fewer asthma attacks — suggesting bigger roles for other triggers, especially routine cold and flu viruses, which nearly vanished this year with social distancing and masks.

Where are the runners from Nepal?

Friday, July 16th, 2021

Kenya’s long-distance runners live at altitude, David Epstein notes (in The Sports Gene), but some people ask, “If it’s just the altitude, where are the runners from Nepal?”:

The “Nepali runners” question, though, is actually irrelevant to the Kenyan and Ethiopian running phenomena, and not only because the Himalayan climate does not foster a narrow body type. One clear point of science is that the genetic means by which people in different altitudinous regions of the world have adapted to life at low oxygen are completely distinct. In each of the planet’s three major civilizations that have resided at high altitude for thousands of years, the same problem of survival is met with different biological solutions.

[...]

By the late nineteenth century, scientists figured they understood altitude adaptation. They had studied native Bolivians, living in the Andes at higher than thirteen thousand feet. At that altitude, there are only around 60 percent as many oxygen molecules in each breath of air as at sea level. In order to compensate for the scarce oxygen, Andeans have profuse portions of red blood cells and, within them, oxygen-carrying hemoglobin.

[...]

Andeans have so much hemoglobin that their blood can become viscous and unable to circulate well, and some Andeans develop chronic mountain sickness.

Nineteenth-century scientists also saw that Europeans who traveled from sea level to altitude responded the same way, by producing more hemoglobin.

[...]

Cynthia Beall, an anthropology professor at Case Western Reserve University in Cleveland, started visiting to study Tibetans and Nepalese Sherpas who can live as high as eighteen thousand feet. To her surprise, Beall found that Tibetans had normal, sea-level hemoglobin values, and low oxygen saturation, lower than people at sea level.

[...]

Most Tibetans have a special version of a gene, EPAS1, that acts as a gauge, sensing the available oxygen and regulating the production of red blood cells so that the blood does not become dangerously thick. But it also means Tibetans don’t have the increase in oxygen-carrying hemoglobin that Andeans do.

[...]

Eventually, Beall determined that Tibetans survive by having extremely high levels of nitric oxide in their blood. Nitric oxide cues blood vessels in the lungs to relax and widen for blood flow. “The Tibetans have 240 times as much nitric oxide in the blood as we do,” Beall says. “That’s more than in people at sea level who have sepsis,” a life-threatening medical condition. So Tibetans adapted by having very high blood flow in their lungs, and they also breathe deeper and faster than native lowlanders, as if they’re in a constant state of hyperventilation.

[...]

In 1995, Beall and a team moved on to the remaining population in the world that has lived at high altitude for thousands of years: Ethiopians, and specifically the Amhara ethnic group living at 11,600 feet along the Rift Valley. Yet again, she found an altitude biology unique in the world. The Amhara people had normal, sea-level allotments of hemoglobin and normal, sea-level oxygen saturation.

[...]

But Beall has preliminary data on Amhara Ethiopians that shows they move oxygen unusually rapidly from the tiny air sacs in their lungs into their blood.

Kenyan runners outperformed all other nations by 1,700-fold

Monday, July 12th, 2021

David Epstein explores (in The Sports Gene) Kenya’s dominance in long-distance running:

In the 1964 Olympics, just the third ever in which Kenya competed, a Kipsigis runner named Wilson Kiprugut won bronze in the 800-meters. Four years later, in the altitude of Mexico City, Kenya was the dominant distance running power, winning seven medals in middle- and long-distance events.

[..]

“The conventional wisdom was that blacks could sprint, but that anything that required tactical sophistication, or discipline, or training,” he says, “this was the white man’s province.”

[...]

The 4.9 million Kalenjin people represent about 12 percent of Kenya’s population, but more than three quarters of the country’s top runners.

[...]

Manners wrote that a part of traditional life for Kalenjin warriors was the practice of cattle raiding. Essentially, it entailed stealthily running and walking into the land of neighboring tribes, rounding up cattle, and escorting them back to Kalenjin land as quickly as possible. Cattle raiding was not considered theft so long as the raiders weren’t filching the cattle from the same subtribe within the Kalenjin. “The raids were conducted largely at night,” Manners wrote, “and sometimes ranged over distances as great as 100 miles! Most raiding parties were group ventures but each muren [or warrior] was expected to at least do his share.”

[...]

A muren who brought back a large number of cattle from a raid was hailed as a courageous and athletic warrior and could use his cattle and prestige to acquire wives.

[...]

Korir was thrust into the 3,000-meter steeplechase — a race just shy of two miles that includes hurdles — and in his third-ever attempt at the event won the national junior college championship. Four years later, Korir was the third-ranked steeplechase runner in the world.

[...]

Or the one about Julius Randich, who arrived at Lubbock Christian University in Texas a heavy smoker with no competitive running background. By the end of his first year, 1991–92, Randich was the national small-colleges (NAIA) champion in the 10K. The following year, Randich set NAIA records in the 5K and 10K and was named the outstanding athlete in any sport in the NAIA.

Kalenjin runners became all the rage among NAIA coaches, and several others would win the 10K national championships after Randich, including his younger brother Aron Rono, who won it four straight times.

Rotich, the son of a prosperous Kalenjin farmer, arrived at South Plains Junior College in Texas in 1988, having lived a “comfortably sedentary” life, as Manners describes it. Rotich, a stout 5’8″ and 190 pounds, quickly burned through most of the $10,000 his father had given him for two years of living expenses and tuition. “But rather than return home in disgrace,” Manners wrote, “Paul . . . decided to train in hopes of earning a track scholarship.” Rotich trained at night to avoid the embarrassment of being seen. That concern would be short-lived, as he made the national junior college cross-country championships in his first season. He went on to become a ten-time All-American in cross-country and indoor and outdoor track. As Manners reported, when Rotich returned to Kenya and detailed his running exploits to a cousin, the cousin replied: “So, it is true. If you can run, any Kalenjin can run.”

[...]

Consider this: seventeen American men in history have run a marathon faster than 2:10 (or a 4:58 per mile pace); thirty-two Kalenjin men did it just in October 2011.

[...]

For example: five American high-schoolers have run under four minutes in the mile in history; St. Patrick’s High School, in the Kalenjin training town of Iten, once had four sub–four milers in school at the same time.

[...]

Wilson Kipketer, a former St. Patrick’s student who became a Danish citizen and held the 800-meter world record from 1997 to 2010, does not hold his own high school’s record.

[...]

The kids in his time trials generally come from elite, highly selective, government-funded boarding schools, and essentially none of them have any racing experience.

[...]

Each year, about half of the boys in the time trial will run faster than 5 minutes and 20 seconds in the 1,500-meter time trial, on a shoddy dirt track, above seven thousand feet. (The 1,500 is about 100 meters shy of a mile, and 5:20 translates to a mile time just over 5:40.)

[...]

In the tryout in 2005, a boy named Peter Kosgei ran 4:15 with no real training. Kosgei was accepted to Hamilton College in Clinton, New York, and quickly became the best athlete in the college’s history. In his freshman year, Kosgei won the Division III 3,000-meter steeplechase national title. By the end of his junior year, he had compiled eight more national titles in cross-country and track.

[...]

Evans Kosgei — no relation to Peter — held down a 3.8 GPA in computer science and engineering at Lehigh University and, after adjusting to life in America for a year, decided to go out for cross-country in his sophomore year. He struggled even to finish his five-mile tryout. But, in short order, Kosgei was running at the Division I national championships in both cross-country and track. In 2012, he was named Lehigh’s Graduating Scholar-Athlete of the Year.

[...]

As expected from their latitudes of ancestry, though, the Kalenjin and Danish boys did display body type differences. A greater portion of the body length of the Kalenjin boys was composed of legs. The Kalenjin boys were, on average, two inches shorter than the Danish boys, but had legs that were about three quarters of an inch longer.

The scientists’ most unique finding, though, was not the length of the legs, but their girth. The volume and average thickness of the lower legs of the Kalenjin boys was 15 to 17 percent less than in the Danish boys. The finding is substantial because the leg is akin to a pendulum, and the greater the weight at the end of the pendulum, the more energy is required to swing it.

[...]

Compared with the Danish runners, the Kalenjin runners tested by the Danish scientists had nearly a pound less weight in their lower legs. The scientists calculated the energy savings at 8 percent per kilometer.

[...]

Some anthropologists actually refer to the extreme of a slender body build as the Nilotic type — “Nilotic” refers to a set of related ethnic groups residing in the Nile Valley — and, it so happens, the Kalenjin are a Nilotic people.

The Nilotic body type evolved in low latitude environments that are both hot and dry, because the long, thin proportions are better for cooling.

(Conversely, the extreme of the short, stocky build was historically known as the Eskimo type, though the term “Eskimo” has been replaced in some countries, where it is considered derogatory.)

[...]

Anthropologist Vincent Sarich used world cross-country championship results to calculate that Kenyan runners outperformed all other nations by 1,700-fold. Sarich made a statistical projection that about 80 out of every 1 million Kenyan men have world-class running talent, compared with about 1 out of every 20 million men in the rest of the world.

A 1992 Runner’s World article noted, based purely on population percentages, the statistical chances of Kenyan men having won the medals they did at the 1988 Olympics was 1 in 1,600,000,000.

Sickle-cell trait and low hemoglobin are evolutionary adaptations to malaria

Thursday, July 8th, 2021

Allen’s rule of body proportions dictates that people from low latitudes and warm climates have long limbs, and Bergmann’s rule dictates that they have narrower builds with slimmer pelvic bones, David Epstein explains (in The Sports Gene), but there’s another, less anatomical reason for western African sprinting dominance:

In 2006, Morrison, with Patrick Cooper, proposed in the West Indian Medical Journal that rampant malaria along the west coast of Africa, from where slaves were taken, led to specific genetic and metabolic alterations beneficial for sprint and power sports. The hypothesis: that malaria in western Africa forced the proliferation of genes that protect against it, and that those genes, which reduce an individual’s ability to make energy aerobically, led to a shift to more fast-twitch muscle fibers, which are less dependent upon oxygen for energy production. Morrison helped with the biology details, but the fundamental idea originally came from Cooper, a writer and childhood friend of Morrison’s.

Cooper was a polymath who had professional success in jobs ranging from music recording to writing speeches for Norman Manley, an architect of Jamaica’s independence, and then for his son, Prime Minister Michael Manley. Early in his career, Cooper had been a reporter for The Gleaner, Jamaica’s largest newspaper. Working at The Gleaner’s sports desk, he first surmised that white athletes had historically dominated sprint and power sports only by systematically excluding or dodging black athletes, like boxing champion Jack Johnson. In later writing, Cooper meticulously documented the fact that athletes with western African heritage become highly overrepresented in sprint and power sports almost immediately once they are allowed a fraction of their white counterparts’ access to sports.

At every Olympics after the U.S. boycott of 1980, every single finalist in the men’s Olympic 100-meters, despite homelands that span from Canada to the Netherlands, Portugal, and Nigeria, has his recent ancestry in sub-Saharan West Africa.

(The same has been true for women at the last two Olympics, and all but one female winner since the U.S.-boycotted 1980 Games has been of recent western African descent.)

And there has not been a white NFL player at cornerback, football’s speediest position, in more than a decade.

[...]

Cooper found the famous body types study of 1968 Olympians, and he latched on to a curious side note recorded by the scientists. The researchers had been surprised to find that “a sizeable number of Negroid Olympic athletes manifested the sickle-cell trait.”

[...]

In 1975, the year after the Mexico City Olympics data was published, another study appeared that Cooper would dissect two decades later, this one showing naturally low hemoglobin levels in African Americans.

[...]

Using data from nearly 30,000 people in ten different states, with ages ranging from the first year to the ninth decade, it reported that African Americans have lower hemoglobin levels at every stage of life than white Americans, even when socioeconomic status and diet are matched.

[...]

Like sickle-cell trait, genetically low hemoglobin — all else being equal — is a genetic disadvantage for endurance sports. Runners of recent western African descent are very much underrepresented at high levels of distance running. (The Jamaican record in the 10K would not even have qualified for the 2012 Olympics)

[...]

And then Cooper found just the potential “compensatory mechanism” he was looking for, in a 1986 study from Laval University in Quebec published in the Journal of Applied Physiology and coauthored by Claude Bouchard, who would go on to become the most influential figure in the field of exercise genetics, and the leader of the HERITAGE Family Study that documented aerobic trainability differences among families.

Bouchard and colleagues took muscle samples from the thighs of two dozen sedentary Laval students, primarily from countries in western Africa, as well as from two dozen sedentary white students, who were identical to the African students in age, height, and weight. The researchers reported that a higher proportion of muscle in the African students was composed of fast-twitch muscle fibers, and a lower proportion was slow-twitch muscle fibers compared with the white students. The African students also had significantly higher activity in the metabolic pathways that rely less on oxygen to create energy and that are engaged during an all-out sprint.

[...]

In his 2003 book, Black Superman: A Cultural and Biological History of the People Who Became the World’s Greatest Athletes, and then in his 2006 paper with Morrison, Cooper first made the argument that West Africans evolved characteristics like a high prevalence of the sickle-cell gene mutation and other gene mutations that cause low hemoglobin for protection from malaria, and that an increase in fast-twitch muscle fibers followed from that, providing more energy production from a pathway that does not rely primarily on oxygen, for people who have reduced capacity to produce energy with oxygen.

The former part of Cooper’s hypothesis — that sickle-cell trait and low hemoglobin are evolutionary adaptations to malaria — now seems undeniable.

In 1954, the same year Sir Roger Bannister broke the four-minute mile, British physician and biochemist Anthony C. Allison, who had been raised on a farm in Kenya, showed that sub-Saharan Africans with sickle-cell trait have far fewer malaria parasites in their blood than inhabitants of the same region who do not have sickle-cell trait.

[...]

Cooper and Morrison’s suggestion that low hemoglobin in African Americans and Afro-Caribbeans is a second adaptation to malaria has been proven true as well, in a deadly manner.

Even as evidence mounted that low hemoglobin levels in Africans native to malarial zones is at least partly genetic, aid workers in Africa looked upon low hemoglobin as a sign purely of a diet with too little iron. In 2001, the United Nations General Assembly charged the world with reducing iron deficiency among children in developing nations. And so, in a well-intended effort to improve nutrition, health-care providers descended on Africa with iron supplements, which raise the hemoglobin levels of those who consume them.

[...]

The problem was that doctors who studied malarial regions saw increased cases of severe malaria wherever iron supplements were dispensed. Since the 1980s, scientists working in Africa and Asia had documented lower rates of malaria death in people with low hemoglobin levels. In 2006, following a large, randomized, placebo-controlled study in Zanzibar that reported a stark increase in malaria illness and death among children given iron supplements, the World Health Organization issued a statement backtracking from the earlier UN position and cautioning health workers about giving iron supplements in areas with high malaria risk. Low hemoglobin, like sickle-cell trait, is apparently protective against malaria.

[...]

About 12 percent of Ivorian citizens are sickle-cell carriers, and in the early 1980s Le Gallais noticed that the top three female Ivorian high jumpers (one of whom won the African championship) became abnormally exhausted during workouts. Le Gallais tested the athletes and found — “surprisingly,” he wrote in an e-mail — “these three athletes were sickle cell trait carriers, despite originating from different ethnic groups in the country.”

[...]

In 1998, he reported that nearly 30 percent of 122 Ivorian national champions in explosive jumping and throwing events were sickle-cell trait carriers, and that they collectively accounted for thirty-seven national records. The top male and female in the group were both sickle-cell carriers.

The team is defeated by bureaucracy, indecision, complacency and malaise

Monday, July 5th, 2021

As you might expect from Michael Lewis, his Premonition is terribly well done, Alex Tabarrok says, if formulaic and over-the-top:

But Lewis has a bigger problem than over-the-top writing.

The heroes were defeated. Lewis likes to tell stories of brilliant mavericks like Billy Beane and Michael Burry who go against the grain but eventually, against all odds, emerge victorious. But six hundred thousand people are dead in the United States and whatever victory we have won was ugly and slow. Indeed, Lewis assembles his mighty team but then The Premonition trails off as the team is defeated by bureaucracy, indecision, complacency and malaise before they even have a chance to enter the real battle against the virus.

[…]

If there is one central villain in The Premonition, it’s the CDC. Lewis acknowledges that his perspective has changed. In The Fifth Risk, the system (the “deep state” used non-pejoratively if you will) is full of wisdom and power but it’s under threat from Trump. In The Premonition, Trump is an after-thought, at best a trigger or aggravating factor.

[…]

Lewis’s most sustained analysis comes in a few pages near the end of The Premonition where he argues that the CDC became politicized after it lost credibility due to the 1976 Swine Flu episode. In 1976 a novel influenza strain looked like it might be a repeat of 1918. Encouraged by CDC head David Sencer, President Ford launched a mass vaccination campaign that vaccinated 45 million people. The swine flu, however, petered out and the campaign was widely considered a “debacle” and a “fiasco” that illustrated the danger of ceding control to unelected experts instead of the democratic process. The CDC lost authority and under Reagan the director became a political appointee rather than a career civil servant. Thus, rather than being unprecedented, Trump’s politicization of the CDC had deep roots.

Today the 1976 vaccination campaign looks like a competent response to a real risk that failed to materialize, rather than a failure. So what lessons should we take from this? Lewis doesn’t say but my colleague Garett Jones argues for more independent agencies in his excellent book 10% Less Democracy. The problem with the CDC was that after 1976 it was too responsive to political pressures, i.e. too democratic. What are the alternatives?

The Federal Reserve is governed by a seven-member board each of whom is appointed to a single 14-year term, making it rare for a President to be able to appoint a majority of the board. Moreover, since members cannot be reappointed there is less incentive to curry political favor. The Chairperson is appointed by the President to a four-year term and must also be approved by the Senate. These checks and balances make the Federal Reserve a relatively independent agency with the power to reject democratic pressures for inflationary stimulus. Although independent central banks can be a thorn in the side of politicians who want their aid in juicing the economy as elections approach, the evidence is that independent central banks reduce inflation without reducing economic growth. A multi-member governing board with long and overlapping appointments could also make the CDC more independent from democratic politics which is what you want when a once in 100 year pandemic hits and the organization needs to make unpopular decisions before most people see the danger.

Legs got longer faster than torsos

Sunday, July 4th, 2021

Repeatedly, studies of families and twins find the heritability of height to be about 80 percent, David Epstein explains (in The Sports Gene):

For much of the twentieth century, denizens of industrialized societies were growing taller at a rate of about one centimeter per decade. In the seventeenth century, the average Frenchman was 5’4″, which is now the average for an American woman. The first generation of Japanese born to immigrant parents in America, known as the Nisei, famously towered over their parents.

In the 1960s, growth expert J. M. Tanner examined a set of identical twins that suggested the range of height variability caused by the environment. The identical boys were separated at birth, one brother raised in a nurturing household, and the other reared by a sadistic relative who kept him locked in a darkened room and made him plead for sips of water. In adulthood, the brother from the nurturing household was three inches taller than his identical twin, but many of their body proportions were similar. “The genetic control of shape is more rigorous than that of size,” Tanner wrote in Fetus into Man. The smaller brother was an abuse-shrunken version of the bigger brother.

[...]

Similarly, female gymnasts delay their growth spurt with furious training, but that does not diminish their ultimate adult height.

[...]

In World Wars I and II, European children were exposed to brief periods of famine during which their growth ground almost to a halt. When food again became plentiful, their bodies put the growth pedal to the metal such that adult height was not curtailed.

[...]

Consider that children grow more quickly in spring and summer than in fall and winter, and that this is apparently due to sunlight signals that enter through the eyeballs, since the growth of totally blind children consists of similar fluctuations but are not synchronized with the seasons.

The height that inhabitants of urban societies gained over the twentieth century came principally from increased leg length. Legs got longer faster than torsos. In developing countries that have gaping nutritional and infection-prevention disparities between the middle class and poor, the difference in height between the comfortable and the afflicted is all in the legs.

Japan displayed a startling growth trend during its “economic miracle” period following World War II. From 1957 to 1977, the average height of a Japanese man increased by 1.7 inches, and of a woman by an inch. By 1980, the height of Japanese people in Japan had caught up with the height of Japanese people in America. Amazingly, the entire height increase was accounted for by increased leg length. Modern Japanese people are still short compared with Europeans, but not as short as they once were. And they now have more similar proportions.

[...]

Every study that has examined race differences in body types has documented a disparity between black and white people that remains whether they reside in Africa, Europe, or the Americas. For any given sitting height — that is, the height of one’s head when one is sitting in a chair — Africans or African Americans have longer legs than Europeans. For a sitting height of two feet, an African American boy will tend to have legs that are 2.4 inches longer than a European boy’s. Legs make up a greater proportion of the body in an individual of recent African origin.

[...]

In their summary of the measurements of 1,265 Olympians from the 1968 Olympics in Mexico City, the scientists state that the successful body types within a sport are much more similar than body types between sports, regardless of ethnicity, but that “the most persistent of these differences” within sports are the narrow hip breadths and longer arms and legs of athletes with recent African ancestry.

[...]

In NBA predraft measurements for active players, the average white American NBA player was 6’7½” with a wingspan of 6’10″. The average African American NBA player was 6’5½” with a 6’11″ wingspan; shorter but longer.

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“So maybe it’s not so much that white men can’t jump. White men just can’t reach high.”

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In 1877, American zoologist Joel Asaph Allen published a seminal paper in which he noted that the extremities of animals get longer and thinner as one travels closer to the equator.

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A 1998 analysis of hundreds of studies of native populations from around the world found that the higher the average annual temperature of a geographic region, the proportionally longer the legs of the people whose ancestors had historically resided there.

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Africans with ancestry in southern regions of the continent, farther from the equator, do not necessarily have especially long limbs.

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Nonetheless, the researchers reported that, compared with white adults of a given height, black adults have a center of mass — approximately the belly button — that is about 3 percent higher.

They used engineering models of bodies moving through fluids — air or water — to determine that the 3 percent difference translates into a 1.5 percent running speed advantage for athletes with the higher belly buttons (i.e., black athletes) and a 1.5 percent swimming speed advantage for athletes with a lower belly button (i.e., white athletes).

Leonardo da Vinci’s Vitruvian Man has an arm span equal to his height

Wednesday, June 30th, 2021

Leonardo da Vinci’s Vitruvian Man has an arm span equal to his height, David Epstein explains (in The Sports Gene):

So do I. So, probably, do you, or very nearly so. Nate Robinson, on the other hand, is 5’7¾” and his arm span is 6’1″. He is, effectively, not as short as he is. Actually, almost none of the players in the NBA are as short as they seem, including the ridiculously tall ones.

The average arm-span-to-height ratio of an NBA player is 1.063. (For medical context, a ratio of greater than 1.05 is one of the traditional diagnostic criteria for Marfan syndrome, the disorder of the body’s connective tissues that results in elongated limbs.) An average-height NBA player, one who is about 6’7″, has a wingspan of seven feet.

Vitruvian-Man-Dunking

An NBA general manager who wants to increase his team’s blocked shots would be better off signing a player with an extra inch of arm than an inch of height.