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The human colon may represent the most biodense ecosystem in the world. Though many may believe that our stool is primarily made up of undigested food, about 75 percent is pure bacteria—trillions and trillions, in fact, about half a trillion bacteria per teaspoon.

Do we get anything from these trillions of tenants taking up residence in our colon, or are they just squatting? They pay rent by boosting our immune system, making vitamins for us, improving our digestion, and balancing our hormones. We house and feed them, and they maintain and protect their house, our body. Prebiotics are what feed good bacteria. Probiotics are the good bacteria themselves. And postbiotics are what our bacteria make.

Our gut bacteria are known as a “forgotten organ,” as metabolically active as our liver and weighing as much as one of our kidneys. They may control as many as one in ten metabolites in our bloodstream. Each one of us has about 23,000 genes, but our gut bacteria, collectively, have about three million. About half of the cells in our body are not human. We are, in effect, a superorganism, a kind of “human-microbe hybrid.”

Having coevolved with us and our ancestors for millions of years, the relationship we have with our gut flora is so tightly knit as to affect most of our physiological functions. Yet our microbiome is probably the most adaptable component of our body. Gut bugs like Escherichia coli (E. coli) can divide every twenty minutes. The more than ten trillion bugs we churn out every day can therefore rapidly respond to changing life conditions. Every meal, we have the opportunity to nudge them in the right direction.

Thousands of years ago, Hippocrates is attributed as saying that all diseases begin in the gut or, more ominously, “death sits in the bowels.” Of course, he also thought women were hysterical because of their “wandering uterus.” (“Hysteria” comes from the Greek husterikos for “of the womb.”) So much for ancient medical wisdom. The pendulum then swung to the point of incredulity when the medical community refused to accept the role of one gut bug, Helicobacter pylori, as the cause of stomach and intestinal ulcers. Out of frustration, one of the pioneers chugged a brew of the bugs from one of his ulcer patients to prove the point, before finally being vindicated with the Nobel Prize in 2005 for his discovery.

In some ways, the pendulum has swung back, with overstated causal claims about the microbiome’s role in a wide range of disparate diseases that are casually bandied about. Perhaps the boldest such claim dates back more than a century to Élie Metchnikoff, who argued that senility and the disabilities of old age were caused by “putrefactive bacterial autotoxins” leaking from the colon. He was the first to emphasize the importance of the gut microbiome to aging. He attributed healthy aging to gut bacteria that fermented carbohydrates into beneficial metabolic end products like lactic acid and associated unhealthy aging with putrefaction, the process in which bacteria degrade protein into noxious metabolites as waste products.

There is no shortage throughout history of oldtimey crackpots with quack medical theories, but Metchnikoff was no slouch. He was appointed Louis Pasteur’s successor, coined the terms “gerontology” and “probiotics,” and won the Nobel Prize in medicine to become the founding “father of cellular immunology.” More than a century later, some aspects of his theories on aging and the gut are now being vindicated.

Young at Gut

Full-term, vaginally delivered, breastfed babies are said to start out with the gold standard for a healthy microbiome, which then starts to diverge as we age. The microbiomes of children, adults, the elderly, and centenarians tend to cluster together, such that a “microbiomic clock” can be devised. Dozens of different classes of bacteria in our gut so reliably shift as we age that our age can be guessed based on a stool sample within about a six-year margin of error. If these changes turn out to play a causal role in the aging process, then, hypothetically, our future high-tech toilet may one day be able predict our lifespan as well.

The transition from adulthood into old age is accompanied by pronounced changes to the microbiome. Given large interpersonal differences, there is no “typical” microbiome of the elderly, but the trends are in the very direction Metchnikoff described: a shift from the fermentation of fiber to the putrefaction of protein. This deviation from good bugs to bad is accompanied by an increase in gut leakiness, the spillage of bacterial toxins into the bloodstream, and a cascade of inflammatory effects. This has led to the proposal that this microbiome shift is a “primary cause of aging-associated pathologies and consequent premature death of elderly people.”

The most important role a healthy microbiome has for preserving health as we age is thought to be the prevention of systemic inflammation.

As profound a change in microbiome composition from early adulthood into old age, there’s an even bigger divergence between the elderly and centenarians. When researchers analyzed centenarian poop, they found a maintenance of short-chain fatty acid production from fiber fermentation. For example, in the Bama County longevity region in the Guangxi province of China, fecal sample analyses found that centenarians were churning out more than twice as much butyrate as those in their eighties or nineties living in the same region. Butyrate is an anti-inflammatory short-chain fatty acid critical for the maintenance of gut barrier integrity. At the same time, there were significantly fewer products of putrefaction, such as ammonia and uremic toxins like p-cresol. The researchers concluded that an increase of dietary fiber intake may therefore be a path toward longevity. An abundance of fiber feeders also distinguished healthy individuals ninety years and older from unhealthy nonagenarians.

Centenarian Scat

Interestingly, the microbiomes of Chinese centenarians shared some common features with Italian centenarians, suggesting that there could be certain universal signatures of a longevity-promoting microbiome. For example, centenarians have up to about a fifteenfold increase in butyrate producers.

A study of dozens of semi-supercentenarians (those aged 105 to 109) found higher levels of health-associated bacteria, such as Bifidobacteria and Akkermansia. In vaginally delivered, breastfed infants,

Bifidobacteria make up 90 percent of colon bacteria, but the level may slip down to less than five percent in adult colons and even less in the elderly and those with inflammatory bowel disease. But centenarians carry more of the good bacteria in their gut.

Bifidobacteria are often used as probiotics, but anti-aging properties may exist in their postbiotics. Bifidobacteria are one of the many bacteria that secrete “exopolysaccharides,” a science-y word for slime. That’s what dental plaque is—the biofilm created by bacteria on our teeth. Exopolysaccharides produced from a strain of Bifidobacteria isolated from centenarian poop were found to have anti-aging properties in mice, reducing the accumulation of age pigment in their brains and boosting the antioxidant capacity of their blood and livers.

Akkermansia muciniphila is named after the late Dutch microbiologist Antoon Akkermans and from Latin and Greek for “mucus-lover.” The species is the dominant colonizer of the protective mucus layer in our gut that is secreted by our intestinal lining. Unfortunately, that mucus layer thins as we age, a problem exacerbated by low-fiber diets. When we eat a fiber-depleted diet, we starve our microbial selves. Our famished flora, the microbes in our gut, have to then compete for limited resources and may consume our own mucus barrier as an alternative energy source, thereby undermining our defenses. Mucus erosion from bacterial overgrazing can be switched on and off on a day-to-day basis in mice supplanted with human microbiomes with fiber-rich and fiber-free diets. You can even show it in a Petri dish. Researchers successfully recreated layers of human intestinal cells and showed that dripping fiber (from plantains and broccoli) onto the cells at dietary doses could “markedly reduce” the number of E. coli bacteria breaching the barrier. Aside from eating fiber-rich foods, A. muciniphila helps to directly restore the protective layer by stimulating mucus secretion.

A. muciniphila is a likely candidate for a healthy aging biomarker, as its abundance is enriched in centenarians and it is particularly scarce in elders suffering from frailty. A comparative study was undertaken of the microbiomes of people in their seventies and eighties experiencing “healthy” versus “non-healthy” aging, defined as the absence or presence of cancer, diabetes, or heart, lung, or brain disease. Akkermansia, the species most associated with healthier aging, were three times more abundant in the fecal samples of the healthy versus non-healthy aging cohort. Among centenarians, a drop in A. muciniphila is one of the microbiome changes that seems to occur about seven months before death, despite no apparent changes in the physical status, food intake, or appetite at the time. To prove a causal role in aging, researchers showed that feeding A. muciniphila to aging-accelerated mice significantly extended their lifespans.

Cause, Consequence, or Confounding

A recurring recommendation from centenarian poop studies is the promotion of high-fiber diets, one of the most consistently cited pieces of lifestyle advice in general for extreme longevity and health. An alternative proposal is a fecal transplant, from a cocktail of centenarian stool. Both approaches assume a cause-and-effect relationship between fiber-fueled feces and long lives, but there remains much controversy over whether age-related microbiome changes are cause, consequence, or confounding.

Aging is accompanied by dysbiosis, an unhealthy imbalance of gut flora characterized by a loss of fiber-fed species. Rather than a changing microbiome contributing to the aging process, it’s easier to imagine how aging could instead be contributing to a changing microbiome. Loss of taste, smell, and teeth with age could lead to decreased consumption of fiber-rich foods, replaced by salted, sweetened, easier-to-chew processed foods. The drop in the quantity and diversity of whole plant foods—the only naturally abundant source of fiber—could result in a dysbiosis that leads to early death and disability. Or, the decline in diet quality could directly dispose to disease, with the dysbiosis just an incidental marker of an unhealthy diet.

There are also ways aging can be connected to dysbiosis independent of diet. While the rates of antibiotic prescriptions in childhood and through middle age have dropped in recent years, prescription rates among the elderly have shot up. Even non-antibiotic pharmaceuticals can muck with our microbiome. A study pitting more than a thousand FDA-approved drugs against forty representative strains of gut bacteria found that 24 percent of marketed drugs inhibited the growth of at least one strain. Reduced physical activity could also contribute to sluggish, stagnant bowels that could leave our gut bugs no other choice but to turn to protein for putrefaction once preferred prebiotics are used up. Nursing home residents are often fed the kind of low-fiber diet that can contribute to the “decimation” of a healthy microbiome.

This article appeared in Skeptic magazine 28.4
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So, while researchers have interpreted the link between dysbiosis and frailty as a poor diet leading to poor gut flora leading to poor health, the arrows of causality could potentially go in every which direction. Maybe there’s even a chicken-or-the-egg feedback loop in play. With so many interrelated factors, you can imagine how hard it is to tease out the causal chain of events.

These questions crop up all the time in microbiome research. For example, the microbiomes of centenarians aren’t just better at digesting fiber. They’re better at detoxifying industrial pollutants, such as petrochemicals; food preservatives like benzoate and naphthalene, used in petroleum refinement; and haloalkanes, widely used commercially as flame retardants, refrigerants, propellants, and solvents. None of these detoxification pathways was found in the microbiomes of the Hadza, one of the last hunter-gatherer tribes in Africa. Did the enhanced detoxification in centenarian guts (compared to younger individuals) contribute to their longevity, or did their longevity contribute to their enhanced detoxification (given their longer lifetime exposure and accumulation of chemicals)?

The microbiomes of centenarians and semi-supercentenarians are better able to metabolize plant fats than animal fats, but maybe that’s just due to their eating more plant-based diets. The Bama County longevity region centenarians who had such an abundance of fiber feeders were eating more than 70 percent more fiber (38 g versus only 22 g per 2,000 calories) compared to those aged eighty through ninety-nine living in the same region. The only way to know if their longer lives eating more healthfully just led to a better microbiome or if their better microbiome actually contributed to their living longer is to put it to the test.

Fecal Transplant Experiments

Longevity researchers have good reason to suspect a causal, rather than bystander, role for age-related microbiome changes, given fecal transplant studies showing that the lives of old animals can be extended by receiving gut bugs from younger animals. Centenarian stool has anti-aging effects when fed to mice. Researchers fed mice fecal matter from a 70-year-old individual that contained Bilophila wadsworthia, a pro-inflammatory bacteria enriched by a diet high in animal products, versus feces from a 101-year-old containing more fiber feeders. Mice transplanted with the centenarian microbiome ended up displaying a range of youthful physiological indicators, including less age pigment in their brains. This raises the possibility that we will one day be using centenarian fecal matter to promote healthy aging. Why bathe in the blood of virgins when you can dine on the dung of the venerable?

Plugging Leaks with Fiber

One of the mechanisms by which intestinal dysbiosis may accelerate aging is a leaky gut. This can lead to tiny bits of undigested food, microbes, and toxins slipping through our gut lining and entering uninvited into our bloodstream, triggering chronic systemic inflammation. Thankfully, there’s something we can do about it.

To avoid gut dysbiosis, inflammation, and leakiness, plants should be preferred. The reason vegetarians tend to have a better intestinal microbiome balance, a high bacterial biodiversity, and enhanced integrity of the intestinal barrier, and also produce markedly less uremic toxins in the gut, is likely that fiber is the primary food for a healthy gut microbiome. Cause and effect was established in a randomized, double-blind, crossover study of pasta with or without added fiber.

Dysbiosis Inflammation Immunosuppression

The most important role a healthy microbiome has for preserving health as we age is thought to be the prevention of systemic inflammation. Inflammaging is a strong risk factor not only for premature death. Those with higher-than-average levels of inflammatory markers in their blood for their age are more likely to be hospitalized, frail, and less independent, and suffer from a variety of diseases, including common infections.

In Japan, for example, more than 40 percent of all centenarian deaths are due to pneumonia and other infectious diseases. In one of the largest studies, involving nearly 36,000 British centenarians, pneumonia was the leading identifiable cause of death. Inflammaging has not only been shown to increase susceptibility to coming down with the leading cause of bacterial pneumonia but older adults with more inflammation also tend to suffer increased severity and decreased survival.

As we age, our immune system macrophages (from the Greek for “big eaters”) start to lose their ability to engulf and destroy bacteria. The same happens in regular mice. But mice raised microbe-free don’t suffer from the leaking gut, subsequent inflammation, and loss of macrophage function. To connect the dots between the inflammation and loss of function, researchers found that the macrophage impairment could be induced in microbe-free mice by infusing them with an inflammatory mediator, which, when dripped on macrophages in a Petri dish, could directly interfere with their ability to kill pneumonia bacteria. Because our immune system is also responsible for cancer defense, immune dysfunction caused by the inflammation resulting from dysbiosis may also help explain why cancer incidence increases so steeply as we age (and why microbe-free mice have fewer tumors and live longer).

Avoiding Dietary Antibiotics

Other than getting enough fiber, what else can we do to prevent dysbiosis in the first place? There are a number of factors that contribute to microbiome imbalance. For example, on any given day, an average of about two and a half doses of antibiotics are consumed for every one hundred people in Western countries. The havoc this can play on our microbiome may explain why antibiotic use predicts an increased risk of cancer, though confounding factors, such as smoking, that are associated with both, could also potentially explain this link.

Up to three-quarters of antibiotic use is of questionable therapeutic value. Avoiding unnecessary use of antibiotics and using targeted, narrow-spectrum agents whenever possible can help protect our gut flora, but most people may not realize they’re consuming antibiotic residues every day in the meat, dairy, and eggs they eat. As much as 80 percent of the antibiotics used in the United States doesn’t go to treat sick people but rather is fed to farm animals in part as a crutch to compensate for the squalid conditions that now characterize much of modern agribusiness. But do enough antibiotics make it onto our plates to make a difference?

Infections with multidrug-resistant bacteria are on target to become the world’s leading cause of disease and death by the year 2050, poised to surpass even cancer and heart disease. Excessive antibiotic use can result in our guts becoming colonized with these superbugs, so researchers set out to calculate how many animal products one would need to eat to achieve antibiotic concentrations in our colon to give resistant bugs an advantage. Single servings of beef, chicken, or pork were found to contain enough tetracycline, ciprofloxacin, tilmicosin, tylosin, sarafloxacin, and erythromycin to favor the growth of resistant bacteria. One and a half servings of fish (150 g) exceeded minimum selective concentrations of ciprofloxacin and erythromycin. Two cups of milk could tip the scales for tetracycline, ciprofloxacin, tilmicosin, tylosin, and lincomycin. And, legal levels of erythromycin and oxytetracycline in two eggs could also exceed safe levels.

We need to stop squandering lifesaving miracle drugs just to speed the growth of farm animals reared in unhygienic conditions, and we also need to stop the reckless overuse in medicine.

Excerpted from How Not to Age: The Scientific Approach to Getting Healthier as You Get Older by Michael Greger. Copyright © 2023 by Michael Greger. Reprinted with permission from Flatiron Books. All rights reserved.

About the Author

Michael Greger, M.D. FACLM is a graduate of the Cornell University School of Agriculture and the Tufts University School of Medicine. He is a practicing physician and author of Bird Flu: A Virus of Our Own Hatching and Carbophobia: The Scary Truth Behind America’s Low Carb Craze. Three of his recent books—How Not to Die, the How Not to Die Cookbook, and How Not to Diet—became instant New York Times Best Sellers. Greger has lectured at the Conference on World Affairs and the National Institute of Health, testified before Congress, and appeared on shows such as The Colbert Report and Oprah Winfrey.

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As a society we are self-censoring at record rates. Say the wrong thing at the wrong moment to the wrong person and the consequences can be dire. Think that everyone should be treated equally regardless of race? You’re a racist who needs to be kicked out of the online forum that you started. Believe there are biological differences between men and women? You’re a sexist who should be fired with cause. Argue that people should be able to speak freely within the bounds of the law? You’re a fascist who should be removed from your position of authority. When the truth is no defense and nuance is seen as an attack, self-censorship is a rational choice. Yet, our silence comes with a price. When we are too fearful to speak openly and honestly, we deprive ourselves of the ability to build genuine relationships, we yield all cultural and political power to those with opposing views, and we lose our ability to challenge ideas or change minds, even our own.

In No Apologies, Katherine Brodsky argues that it’s time for principled individuals to hit the unmute button and resist the authoritarians among us who name, shame, and punish. Recognizing that speaking authentically is easier said than done, she spent two years researching and interviewing those who have been subjected to public harassment and abuse for daring to transgress the new orthodoxy or criticize a new taboo. While she found that some of these individuals navigated the outrage mob better than others, and some suffered worse personal and professional effects than others, all of the individuals with whom she spoke remain unapologetic over their choice to express themselves authentically. In sharing their stories, which span the arts, education, journalism, and science, Brodsky uncovers lessons for all of us in the silenced majority to push back against the dangerous illiberalism of the vocal minority that tolerates no dissent— and to find and free our own voices.

Katherine Brodsky is a journalist, author, essayist and commentator who has been taking an especially keen interest in emerging technologies and their impact on society. She has contributed to publications such as Variety, the Washington Post, WIRED, The Guardian, Esquire, Newsweek, Mashable, and many others. Over the years she has interviewed a diverse range of intriguing personalities including numerous Oscar, Emmy, Tony, Pulitzer, and Nobel Prize winners and nominees—including the Dalai Lama.

Shermer and Brodsky discuss:

• What it’s like growing up Jewish in the Soviet Union and Israel
• Why the Jews
• Why liberals (or progressives) no longer defend free speech
• Cancel culture: data and anecdotes
• Is Cancel Culture an imagined moral panic?
• Cancel Culture on the political Left
• Cancel Culture on the political Right
• Social media and Cancel Culture
• Free speech law vs. free speech norms
• Pluralistic Ignorance and the spiral of silence
• Solutions to cancel culture
• Identity politics
• Cancel culture, witch crazes, and virtue signaling
• Free speech, hate speech and slippery slopes
• How to stand up to cancel culture.

If you enjoy the podcast, please show your support by making a $5 or $10 monthly donation.

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If you could rewind your life to the very beginning and then press play, would everything turn out the same? Or could making an accidental phone call or missing an exit off the highway change not just your life, but history itself? And would you remain blind to the radically different possible world you unknowingly left behind?

In Fluke, myth-shattering social scientist Brian Klaas dives deeply into the phenomenon of random chance and the chaos it can sow, taking aim at most people’s neat and tidy storybook version of reality. The book’s argument is that we willfully ignore a bewildering truth: but for a few small changes, our lives—and our societies—could be radically different.

Offering an entirely new lens, Fluke explores how our world really works, driven by strange interactions and apparently random events. How did one couple’s vacation cause 100,000 people to die? Does our decision to hit the snooze button in the morning radically alter the trajectory of our lives? And has the evolution of humans been inevitable or are we simply the product of a series of freak accidents?

Drawing on social science, chaos theory, history, evolutionary biology, and philosophy, Klaas provides a brilliantly fresh look at why things happen—all while providing mind-bending lessons on how we can live smarter, be happier, and lead more fulfilling lives.

Brian Klaas grew up in Minnesota, earned his DPhil at Oxford, and is now a professor of global politics at University College London. He is a regular contributor for The Washington Post and The Atlantic, host of the award-winning Power Corrupts podcast, and frequent guest on national television. Klaas has conducted field research across the globe, interviewing despots, CEOs, torture victims, dissidents, cult leaders, criminals, and everyday power abusers. He has also advised major politicians and organizations including NATO, the European Union, and Amnesty International. His previous book, for which he appears on this podcast, was Corruptible: Who Gets Power and How it Changes Us. His new book is Fluke: Chance, Chaos and Why Everything We Do Matters. You can find him at BrianPKlaas.com and on X @brianklaas.

Shermer and Klaas discuss:

• contingency and necessity/convergence
• chance and randomness
• complexity and chaos theory
• Jorge Luis Borges “The Garden of Forking Paths”
• self-organized criticality
• limits of probability in a complex, ever-changing world
• frequency- vs. belief-type probability
• ceteris paribus, or “all else being equal” but things are never equal
• economic forecasting
• free will, determinism, and compatibilism
• Holy Grail of Causality
• Easy Problem of Social Research and the Hard Problem of Social Research
• Was the original theory wrong, or did the world change?
• When Clinton lost, Silver pointed to his model as a defense: 71.4 percent isn’t 100 percent! There was nearly a 30 percent chance of Clinton losing in the model, so the model wasn’t wrong—it was just something that would happen nearly a third of the time!
• Special Order 191 and the turning point of the Civil War
• Implicit in the baby Hitler thought experiment is the idea that without Hitler the Nazis wouldn’t rise to power in Germany, World War II wouldn’t happen, and the Holocaust would be avoided. It therefore assumes that Hitler was the sole, or at least the crucial, cause of those events. Many historians would take issue with that viewpoint, arguing that those cataclysms were all but inevitable. Hitler might have affected some outcomes, they’d say, but not the overall trajectory of events. The Nazis, the war, and the genocide were due to larger factors than just one man.
• weak-link problem
• complex world defined by tipping points, feedback loops, increasing returns, lock-in, emergence, and self-organized criticality
• QWERTY and path dependency, Betamax vs. VHS, cassette v. CD v. streaming.

If you enjoy the podcast, please show your support by making a $5 or $10 monthly donation.

Leonardo da Vinci was a man of many talents. He was one of the few individuals to have made contributions to both the arts and science. His work extends to civil engineering, chemistry, geology, geometry, hydrodynamics, mathematics, mechanical engineering, optics, physics, pyrotechnics, warfare, and zoology.

Da Vinci was one of the best artists of his generation and many of his paintings are greatly admired today and command astronomical prices (his Salvator Mundi fetched the highest auction price ever). He was also an extraordinary illustrator, leaving thousands of manuscripts full of drawings of machines, fluid mechanics, humans, and many other topics. In addition, he was also a sculptor, architect, and more. As the type specimen of a Renaissance man, he put his mind to many different subjects, and he excelled at most of them. He was generally considered a genius by his contemporaries. In addition to all of this, he was described as a handsome and charming man, who was able to convince a whole room of the feasibility of something impossible.1 However, as it is sometimes said of promising but lazy children, some said that he would have been capable of even more accomplishments had he put his focus on them for longer and worked harder.

Revealingly, in his time, Leonardo was not considered to be at the same level as Michelangelo or even Raphael, perhaps because his notebooks were not published until much later. However, today many consider him superior to all his peers and—in a few extreme cases—some people fall into what we might call the “cult of Leonardo,” whose adherents believe that his genius was almost superhuman.

Consider a recently published article titled “Leonardo da Vinci’s Visualization of Gravity as a Form of Acceleration” by Morteza Gharib, Chris Roh, and Flavio Noca (henceforth GRN).2 In it, the authors propose that Leonardo understood gravity in a way that was not surpassed until the works of Galileo, Newton, and even Einstein. Had GRN presented their ideas in a less spectacular way, their article could have been a flawed, but mainly harmless one. Unfortunately, they chose to take the more risky path of venturing unfounded, under-researched, mind-blowing claims under the guise of solid scholarship, starting with the assertion that Leonardo saw gravity not as a force, but as an acceleration:

About 500 years ago, Leonardo da Vinci tried to uncover the mystery of gravity and its connection to acceleration through a series of ingenious experiments guided only by his imagination and masterful experimental techniques.

The shocking revelation that they put forth is that Leonardo “almost” (bit of wiggle room there) anticipated Einstein’s General Theory of Relativity, in particular, the so-called “Equivalence Principle” (see Figure 1):

As with Galileo, Leonardo’s geometrical representation of the equation of motion is as insightful as Newtonian mechanics’ representations of equations of motion. […] After Newton, Albert Einstein referred to the equivalency of gravity and acceleration, when he introduced the principles of “strong equivalency” while developing his theory of relativity in the early twentieth century.

Figure 1. (Click image to enlarge) Einstein’s equivalence principle states that gravity is indistinguishable from being in an accelerated system of reference. This was famously illustrated by Einstein using a thought experiment: imagine we are in a closed room. Is there any way we can know if the down force that we feel is due to gravity? Maybe the room is in a spaceship, away from big masses and accelerating upwards with acceleration g. Einstein concluded that both situations are equivalent.

Considering gravity as an acceleration instead of a force is indeed a crucial difference between Einstein’s and Newton’s conceptions. The assertion that Leonardo could have hit upon this insight centuries before Einstein is the most preposterous claim in GRN’s article and likely what has made it so ballyhooed in the popular press. To give just a couple of examples of some of those reviews, here is one from Ars Technica:

[Leonardo attempted] to draw a link between gravity and acceleration—well before Isaac Newton came up with his laws of motion, and centuries before Albert Einstein would demonstrate the equivalence principle with his general theory of relativity.3

Here’s another one from CNET:

Before Galileo, Newton, and Einstein, it seems to be Leonardo da Vinci who started piecing together the gravity puzzle […] Rather, it’s kind of the same thing as acceleration…. [Einstein] called it the equivalence principle, and soon, this eye-opening concept would blossom into the mind-bending theory of general relativity. The rest, as they say, is history.4

Let’s summarize GRN’s argument. First, they assert that Leonardo had a good understanding of how objects fall with constant acceleration under the effect of gravity. Second, they present a thought experiment devised by Leonardo that, they claim, shows he understood that gravity is equivalent to being in an accelerated frame of reference. Finally, they present a quantitative model, purportedly based on Leonardo’s manuscripts, and they compare it against Newtonian mechanics. Let’s consider each of these points.

Acceleration of Falling Objects

To support their claim that Leonardo understood that gravity produces a constant acceleration on falling objects, GRN provide the following quote from Leonardo’s M manuscript: “a weight that descends freely in every degree of time acquires…a degree of velocity”5 (ellipsis in their article). They further tell us that “many scholars of Leonardo note that this statement indicates that Leonardo correctly understood that the velocity of a falling object is a linear function of time.”

Now consider Leonardo’s quote in full: “The free-falling body acquires a degree of displacement over each degree of time, and over each degree of displacement it acquires a degree of velocity.”6 It is not completely clear what Leonardo meant by this, since the original sentence can be translated in slightly different ways; but the simplest interpretation is that Leonardo didn’t have a full understanding of acceleration. He repeats similar ideas in various places,7 including in drawings and calculations.8 For the full quote, I have used a translation from Prof. Enzo Macagno, one of the scholars that GRN cite in support of their hypothesis. Macagno has this to say about Leonardo’s understanding of gravity relative to this quote:

what Leonardo is trying to express is that over equal intervals of time there are constant increments for both distance traversed and for velocity. If this is understood, we may study critically what Leonardo said to detect how far he went in his descriptions of motion during free fall. Even if he did not add anything new to this question, or actually detracted from it, it is still important to know his “degree” of understanding.9

However, Macagno then notes that, “In his descriptions of an accelerated motion, which could not be correct because of an intrinsic inconsistency between velocity and displacement,” an observation that is hardly in support of GRN’s claim.

Another point to consider is the concept of “free fall.” Today we apply it to objects moving exclusively under the influence of the Earth’s gravity. However, when Leonardo talks about free fall (“discienso libero”), he was probably referring to something different. Da Vinci was very conscious of the effect of air drag. In almost every case where he talks about falling objects, he mentions the effect of air and he even includes it in his simplified calculations.10 In his manuscripts, he has many things to say about the effect of air on falling objects and vice versa. To me, it is much more likely that for Leonardo, free fall meant something closer to what we now call “terminal velocity”— that is, that constant velocity which a falling object reaches due to the balance between gravity and air resistance.

Further, Leonardo mentions several times that, on sunny clear days, the air is lighter at higher altitudes, so that the air becomes thicker as the object falls. This means that he thought that, at terminal velocity, objects decelerate as they fall. This is actually true, although the effect is probably much weaker than what Leonardo implies. None of these considerations discussed at length by Da Vinci in his manuscripts are mentioned in GRN’s article.

Leonardo’s Thought Experiment

Having argued that Leonardo thought that objects fell with constant acceleration, the next step in GRN’s article is to “prove” that Leonardo had a deeper understanding, namely that he was somehow aware that gravitation was not a force, but an acceleration in a manner similar to Einstein’s equivalence principle (see Figure 1). To do this, GRN analyze a thought experiment that Leonardo described in slightly different forms in various parts of his manuscripts.

Figure 2. Leonardo’s thought experiment. The jar moves from left to right releasing beads as it moves (Manuscript M, 143r).

The experiment consists of an open “container” (a jar, a funnel, and even a cloud in his various descriptions) that moves horizontally as it allows some particles to fall (beads or hail grains). Leonardo then considers the geometry of the system, giving special consideration to the case where the jar moves horizontally at the same speed as the first released bead falls vertically. This can be seen in Figure 2 as drawn by Leonardo, where he explains that, in this particular case, the trajectory of the first bead, the one of the jar, and the line that connects all beads, form an isosceles right triangle.

Figure 3. GRN’s interpretation of the experiment. All movements are accelerated, and the beads follow parabolas.

GRN analyze this problem using a more modern Newtonian approach. As is commonly done in high school physics problems, they start by simplifying away the effect of the air—an unusual assumption in this case—given that Leonardo constantly talks about the effect of air on falling objects. They also use the perhaps more reasonable assumption that particles leave the jar at the same speed as the jar itself, not considering that they must be moving with some relative speed out of it. They show their results in a graphic similar to Figure 3.

Figure 2 is not identical to the one drawn by Leonardo, but some salient features are still there: an isosceles right triangle, abn, defined by the movement of the jar (an), the falling trajectory of the first bead (ab), and the straight line that connects all the beads (bn). GRN assert that this is what Leonardo had in mind and they use the fact that, in both cases, the line formed by the falling beads is a straight line as proof that their assumptions are correct. They contrast it against the case in which the jar moved at constant velocity while the beads fall accelerated by gravity, in which case the beads align, but in a vertical line. They never entertain the more logical possibility: that Leonardo thought that the beads fell vertically at more or less constant velocities.

Then GRN go on to explain that this system can be better understood from the point of view of the accelerated frame of reference of the moving jar, a technique not available in Leonardo’s time but in the toolbox of Newtonian mechanics. Probably, they do this to remind us of Einstein’s Equivalence Principle, wherein the connection between gravity and acceleration is deeper and where accelerated frames of reference are equivalent to gravity fields. To me, it is clear that GRN’s ulterior and ultimate motivation is to establish a connection with the General Theory of Relativity. Throughout the article they leave small hints of this; for example, they say that “Leonardo’s studies of objects in free fall demonstrate that gravitational and pseudo-acceleration fields are indistinguishable locally when their magnitudes are the same.” Here, the words “fields” and “indistinguishable locally” have nothing to do with anything Leonardo writes, but GRN say it anyway because it is a language that feels more Einsteinian. In another part of the article, they say: “in other words, he [Leonardo] switched time with space to be able to conduct this experiment,” which is a thinly veiled way of suggesting that Leonardo was wise to the space-time continuum.

Of course, Einstein’s Equivalence Principle is deeper than just comparing accelerations. That could have been done in Newtonian mechanics. The crucial point that Einstein understood is that the mass of an object subjected to a gravitational field plays no role in its dynamics. All objects are accelerated equally, even light! Leonardo never says that all objects fall at the same speed independently of their weight; quite the contrary. Leonardo gives various examples where they don’t, although he mentions air resistance as one reason. Famously, Galileo was the first person to prove that all objects fall at the same speed (not including the effect of air), and there is no reason to believe that Leonardo knew that before Galileo.

Figure 4. Leonardo’s Manuscript M 217r (left), and my translation (right). The image above has been mirrored from the original for ease of understanding. Leonardo wrote from right to left, using his left hand, to prevent smudging the ink as he wrote.

I have translated the page where Leonardo presents the experiment of the hail cloud (see Figure 4). My translation is quite literal, except that I have simplified the third paragraph which, to me, was a little bit reiterative and confusing. It is clear that Leonardo thought that hail grains fell mostly vertically, without any appreciable horizontal velocity, as indicated by the vertical lines that connect every grain with the location at the moment it was released. Leonardo thought that the effect of the air would make objects quickly stop any horizontal movement (see Figure 5). The fact that he also thought that this experiment could be performed substantiates the assumption that he was considering objects falling at constant velocity. Should we believe Leonardo was thinking that clouds could be seen accelerating to absurdly great speeds or that hail grains were not affected by air resistance?

Figure 5. Objects thrown at different angles. The image has been mirrored for ease of understanding (Codex Arundel 92v).

Simply by inspecting Figure 4 and the other pages that Leonardo devoted to this problem, it is clear that he was interested in a simpler geometrical problem: two things that start moving from the same point at the same constant speed but in perpendicular directions will have trajectories that define the two legs of an isosceles right triangle. And the trivial corollary is that if the velocities are different, the triangle will not be isosceles. Da Vinci draws examples of each of these cases and explains how this can be used to estimate the speed of the clouds.

If Leonardo really thought that the particles were following the beautiful parabolic trajectories shown in Figure 3, why didn’t he draw them that way rather than drawing, as he did, vertical lines of no clear meaning? GRN never comment on this obvious weakness in their claim.

Leonardo’s Model?

The next section in GRN’s article is truly strange. In what seems like a misguided attempt to perform a quantitative validation of Leonardo’s ideas on gravity, they make extraordinary assumptions and take huge leaps of faith. They interpret the line in Figure 4 labeled “equation of movement” (it can also be translated as “balanced movement”) as meaning that this figure encodes the actual physical equation of movement. After observing that Leonardo seemed to have bisected the axes, they decide that “presumably, the distance between consecutive bisecting locations represents the distance the object traveled during a fixed time step,” although Leonardo says nothing of the sort. He very clearly says that these bisections represent possible speeds of the cloud, relative to the speed of the hail. According to the supplementary materials provided by GRN, it seems that they came up with “Leonardo’s model” for gravity acceleration by looking at the figures, which may explain their misunderstanding.

GRN claim that “Leonardo’s model” is given by the formula: z(t) ∝ 2(t-1)n, where z is the vertical location of the object, t is time, n is the number of bisections, and ∝ means “proportional to.” It is a strange mixture of a discrete description in terms of bisections (n) and a continuous one in time (t). They recognize that this model is incorrect, but after a few additional assumptions which I will not discuss here, they realize that it is not as bad as it might seem initially. In fact, they say that in certain circumstances it is quite good. They write: “Leonardo’s gravitational constant is 0.9774 (95 percent confidence interval, 0.8535, 1.101), which is close to the nondimensional gravity of 1. These two observations suggest that Leonardo’s model of natural motion, while imperfect, was an accurate representation of his observation of falling objects.”

I don’t think this section requires detailed commentary. GRN start with their wrong interpretation of Leonardo’s manuscripts, invent a model based on what they think a figure means, make some unsupported assumptions, and end up with something that has nothing to do with what Leonardo might have had in mind. One could imagine that they wanted to end their article with some hard numerical results, and they distorted Leonardo’s meaning until it yielded something they could use.

This article appeared in Skeptic magazine 28.3
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There is, however, an additional point I would like to mention. The model they attribute to Leonardo is invalid for times close to zero (ironically, the only ones for which air drag is insignificant). The plot of z against t that they show in their article and in the supplementary materials does not begin at the origin. The object starts falling only after it is already eight percent of its way down!

* * *

As we have seen, there is no basis to believe that Leonardo da Vinci, genius though he undoubtedly was, had a knowledge of gravity ahead of his time, much less at the level of Newton or Einstein. Every year, thousands of articles are written with the only intention of entertaining casual readers. Their flaws are obvious to most knowledgeable readers. However, this article was published in a peer-reviewed journal by a well-known academic institution. The authors claim to have studied the topic scientifically and their conclusions are not easy to dismiss. One must dig into Leonardo’s large corpus of manuscripts to be able to properly analyze their claims, and few are willing or have the language skills to do so. I have tried my best to examine GRN’s claims carefully. After looking at all the evidence, I remain unconvinced.

Leonardo da Vinci was one of the greatest minds in history. He is unrivaled in having made significant contributions to both science and the arts. There is simply no need for GRN’s hyperbole that Leonardo was a genius who foresaw relativity theory centuries ahead of his time. Their claim is not supported by any fair reading of the original manuscripts. Rather, their paper is a generator of disinformation that has helped to decrease the already too low signal-to-noise ratio in public conversations about science.

About the Author

José María González Ondina is an Associate Researcher at the University of Florida. He received his PhD from Cornell University. He spent most of his career as an ocean modeler, studying underwater sound propagation and sediment transport at the Plymouth Ocean Forecasting Centre. He also spent a decade at the Ocean & Coastal Research Group (University of Cantabria, Spain) developing numerical models for coast engineering.

References

1. Giorgio, V. (1550) Lives of the Most Excellent Painters, Sculptors, and Architects.
2. https://rb.gy/7sfix
3. https://rb.gy/8lhni
4. https://rb.gy/wvnhr
5. Manuscript M, folio 45r, folio 43r.
6. I am using the translation of Enzo Macagno from Leonardian Fluid Mechanics in the Manuscript M, page 18.
7. For example here: “Hence, in each doubling of the quantity of time the body doubles the length of fall and the velocity of its motion.” from Manuscript M, folio 44v.
8. Manuscript M, folio 45r.
9. Enzo Macagno, Leonardian Fluid Mechanics in the Manuscript M, page 18.
10. Manuscript M, folio 44v.

https://traffic.libsyn.com/secure/sciencesalon/mss399_Chris_Anderson_2024_01_17.mp3 Download MP3

As head of TED, Chris Anderson has had a ringside view of the world’s boldest thinkers sharing their most uplifting ideas. Inspired by them, he believes that it’s within our grasp to turn outrage back into optimism. It all comes down to reimagining one of the most fundamental human virtues: generosity. What if generosity could become infectious generosity? Consider:

• how a London barber began offering haircuts to people experiencing homelessness—and catalyzed a movement
• how two anonymous donors gave $10,000 each to two hundred strangers and discovered that most recipients wanted to “pay it forward” with their own generous acts
• how TED itself transformed from a niche annual summit into a global beacon of ideas by giving away talks online, allowing millions access to free learning.

In telling these inspiring stories, Anderson has given us “the first page-turner ever written about human generosity” (Elizabeth Dunn). More important, he offers a playbook for how to embark on our own generous acts—whether gifts of money, time, talent, connection, or kindness—and to prime them, thanks to the Internet, to have self-replicating, even world-changing, impact.

Chris Anderson has been the curator of TED since 2001. His TED mantra—“ideas worth spreading”—continues to blossom on an international scale. He lives in New York City and London but was born in a remote village in Pakistan and spent his early years in India, Pakistan and Afghanistan, where his parents worked as medical missionaries. After boarding school in Bath, England, he went on to Oxford University, graduating in 1978 with a degree in philosophy, politics and economics. Chris then trained as a journalist, working in newspapers and radio, and founded Future Publishing that focused on specialist computer publications but eventually expanded into other areas such as cycling, music, video games, technology and design. He then built Imagine Media, publisher of Business 2.0 magazine and creator of the popular video game users website IGN, publishing some 150 magazines and websites and employed 2,000 people. This success allowed Chris’s nonprofit organization to acquire the TED Conference, then an annual meeting of luminaries in the fields of Technology, Entertainment and Design held in Monterey, California. He expanded the conference’s remit to cover all topics, and now has TED Fellows, the TED Prize, TEDx events, and the TED-Ed program offering free educational videos and tools to students and teachers. Astonishingly, TED talks have been translated into 100 languages and garner over 1 billion views a year. His new book is Infectious Generosity: The Ultimate Idea Worth Spreading.

Shermer and Anderson discuss:

• how his life turned out (genes, environment, luck)
• what makes TED successful while other platforms failed or stalled
• TED talks go public for free vs. paying customers
• power laws and giving: do 10% donate 90%?
• Amanda Parker gave away her music and asked people to pay: survival bias—how many people have tried this and failed?
• blogs, podcast, Substack … saturation markets
• changing business landscape of charging vs. giving away
• What makes things infectious?
• What is generosity? Idea vs. character trait—virtue ethics
• altruism and reciprocal altruism, reputation and self-reputation
• religion and morality: do we need an “eye in the sky” to be good?
• Can people be good without God?
• philanthropy: 2700 billionaires have more wealth than 120 poorest countries combined
• giving & philanthropy seems like a rich-person’s game. How can average people participate?
• incentivizing giving as a selfish act: why “pay it forward”?
• public vs. private solutions to social problems
• How can one person make a difference?
• The Mystery Experiment
• Ndugu Effect
• donor fatigue
• Giving What We Can.

If you enjoy the podcast, please show your support by making a $5 or $10 monthly donation.

The practice of discussing educational testing in the same sentence with the term “war” is not necessarily new or original.1 What may be new to readers, however, is to characterize current debates involving educational testing as involving a war against: (1) accurate perceptions about the way things really are (reality), and (2) sound judgment in practical matters (common sense).

Education, Testing, and the Real World

Education is compulsory in American society, and no one escapes testing—whether standardized or unstandardized—in their schooling experience, even before entering school. As newborns, infants are given Apgar scores to assess their overall health.2 When a child is ready to enter preschool, s/he may be assessed with a standardized test to determine school readiness in understanding basic concepts, cognitive and language development, and early academic achievement.

As children matriculate through the primary school years, they are required to pay attention to teacher lessons; resist natural impulses to fidget, talk out of turn, or bother one’s neighbor; complete worksheets quietly at one’s desk; complete and return homework assignments; and complete national or state-mandated standardized academic achievement tests that measure “what students know and can do.”3 In some cities, students must complete tests to determine eligibility for entrance into elite or specialty high schools,4 and students in some states must successfully complete tests in order to graduate high school.5 Well before students are scheduled to graduate, they have, until recently, been required to complete standardized college admissions tests in order for their applications to be competitive for colleges of their choice.6

Enter Basic Common Sense

When enough years are spent surrounded by age peers in schools, everyone—regardless of background, race, ethnicity, or socioeconomic status—intuitively understands that comparatively, some peers are intellectually smarter, other peers are roughly the same, and others are intellectually slower. These differences are most determinative of one’s overall level of academic achievement from kindergarten to high school graduation and beyond. Some pupils have a natural proclivity to be voracious readers and progress successfully through their academic programs much more quickly than others. They are able to grasp and understand difficult and abstract academic material more quickly, have a wide range of intellectual interests and hobbies, and are much more likely to be selected for admission to programs for the gifted and talented. These are generally the A and B students and tend to enroll in advanced foreign languages, trigonometry, pre-calculus, chemistry, and other advanced placement (AP) classes in high school.

Then there are students who struggle with school—particularly as the curriculum becomes more conceptual, complex, and abstract. These students have often been identified as “slow learners,” and school generally becomes a profoundly aversive experience. In higher grades, many tend to select vocational courses or may sometimes drop out of school before graduation, and these are generally known as the C and D students in their classes. The majority of pupils, however, fall somewhere in between those two extremes.7

When interacting with curricula, brighter students can generalize learning more easily to new classes of similar information never before encountered, while slower students have more difficulty in remembering what has been previously learned. Using a simple illustration from the early elementary school years (and barring specific reading disabilities), teachers can teach brighter students the phonetic rules for sounding out words such as “groan” and “moan.” Later, when these students encounter similar words that they have not seen before, such as “Joan” or “loan,” they can more easily apply what they have previously learned and correctly sound out these new words as well as understand their meaning. In contrast, when slower students encounter new words that have the same phonetic spelling and pronunciation as previously learned words, they find it more difficult to spontaneously apply what they have previously learned to sound out these new words, and consequently, word identification mastery takes them more time.8

Similarly, slower students will be easily confused over the rules that govern the correct pronunciation of words with the same “ei” letter combination but different pronunciations, e.g., neighbor, heist, and weird. In contrast, brighter students will internalize these nuances more quickly, readily identify these words correctly, and so move on to master more complex words. These differences in word identification skills also influence reading comprehension.

To be sure, slower students will eventually learn how to pronounce correctly similar words governed by different phonetic rules, but teaching such students requires instruction where broader learning objectives are broken down into smaller hierarchical steps, teaching is much more intentionally explicit, and greater amounts of time are devoted to learning and practice.9 If you learned academic subjects more quickly than other students, you probably have found other areas (e.g., art, music, athletics, home and auto repair, cooking, or just learning to get along with others) that took you longer than others, including those who took longer than you on the purely academic subjects.

Regardless of grade level brighter students can more quickly internalize and consolidate the required mental schemata for representing material that is learned, and then use this knowledge as a foundation upon which to build new schemata.10 Slower students have more difficulty consolidating information to be learned, or at least it requires more time to consolidate prerequisite information compared to brighter age peers. When slower peers attempt to mentally consolidate new information built on a shaky foundation, new information is poorly understood.

Brighter students can generally follow along at the pace of regular instruction, while slower students cannot, and eventually fall further and further behind as they get older. The older pupils are, the more they begin to self-select into secondary school tracks that are more suitable to their intellectual capabilities and interests, resulting in extremely wide individual differences in academic performance at higher grades. By the time students reach 11th and 12th grades, for example, brighter students are able to solve complex mathematical equations while slower students still struggle with mastering elementary fractions. As a result, the brightest students in high school tend to enroll in advanced placement courses such as foreign languages, pre-calculus, chemistry, and physics, while slower students gravitate to vocational courses.

Anti-testing hostility has found a powerful, organized voice whose prime directive is to diminish the influence—if not the outright banishing—of standardized testing.

Psychologists refer to this basic phenomenon as “individual differences in mental ability and learning potential,”11 and no one knows this better than teachers. In the elementary grades, for example, teachers regularly come into contact with wide individual differences in performance on standardized achievement tests, despite all students being taught the same material under the same teacher. That’s why it is a bit unfair to hold teachers solely responsible for the achievement test performance of their students, since students can perform poorly on achievement tests despite exemplary teaching, and can also perform well on achievement tests despite mediocre teaching.

Enter Painful Realities

There are no racial, ethnic, language, or socioeconomic subpopulation groups, anywhere on any continent on the globe, that display equal means in their respective distributions of mental test scores.12 These individual differences in mental test scores, when consolidated and averaged, will inevitably result in statistically significant average differences in academic achievement across subpopulation groups. Of course, there is also significant overlap among these groups. Although the full range of test scores and performance—from severe intellectual disability to mental genius—can be found within all racial and ethnic subpopulation groups,13 it is nevertheless true that these abilities are not equally distributed across such groups. Group differences have been observed since the beginning of standardized testing. In fact, they begin as early as three years of age, remain consistent over decades, and have proven stubbornly resistant to intervention.14 The largest gaps between subpopulation groups in both mental test scores and the achievement outcomes that result from such scores will be most noticeable at the extremes of their respective distributions.15 Because this is such a sensitive subject it should be noted that these are average differences between groups and tell us nothing about the ability of any single member of any group.

Differences in academic achievement are not equally distributed across socioeconomic groups or across communities and school districts, as these have more or less different concentrations of low to high performing students. Studies consistently show that even massive allocation of funds to school districts, without other interventions, has no significant effect on raising academic achievement.16 School systems are keenly aware of this, which is why comparisons of achievement test scores across school districts are careful to use race, ethnicity, and socioeconomic status as a covariate in comparing scores. That is, schools having similar concentrations of students from particular racial/ethnic groups and socioeconomic backgrounds are compared to other schools with similar backgrounds. This way, when schools having concentrations of students from similar backgrounds show significantly different levels of academic achievement, higher performing schools can be studied intensively to determine the key factors that are responsible for their relative success.17

For purposes of this analysis, the term education establishment refers to the constellation of education school professors, teacher education textbooks and journals, teacher certification training programs, and professional teaching associations (e.g., the American Educational Research Association, or AERA; the National Education Association, or NEA) that dominate thought and opinion within the education and teaching professions. Within that group, there are four arguments held by anti-testing critics that are given prominence that far outweighs their scientifically demonstrated validity.

Claims That Testing Harms Students

Eighteenth Century social philosopher Jean-Jacques Rousseau’s notion of children born in freedom and innocence, but eventually corrupted and enslaved by society,18 is the basic assumption that undergirds hostility toward standardized testing among many educators. According to critics, standardized testing places undue emotional stress on students due to test scores’ relation to important outcomes. They argue that testing fails to measure accurately the capabilities of students with different learning styles and penalizes pupils who are not good test takers.

Another common argument is that standardized testing fails to account for language deficiencies, empty stomachs, learning disabilities, difficult home lives, or cultural differences.19 The tests are said not to measure student progress or improve student performance, but rather penalize students’ critical thinking and creativity due to the multiple-choice testing format (or its opposite), namely, that tests confer an unfair advantage to students who perform well on multiple-choice tests by learning test-taking strategies without having deep knowledge of the subject matter.

Anti-testing hostility has found a powerful, organized voice in numerous movements whose prime directive is to diminish the influence—if not the outright banishing—of standardized testing in pre- and post-higher education. The opt-out movement, for example, began in New York in 2014 among mostly White, highly-educated, and politically liberal parents who were united in their refusal to have their children sit for standardized testing in schools.20 They claimed that judging teacher performance by students’ test scores is unfair and that testing unduly narrows the school curricula by creating a “teaching-to-the-test” instructional ethos. Some stated they were in outright opposition to the implementation of Common Core State Standards.21

It would not be an overstatement to say that certain criticisms have their origin in various neo-Marxist ideologies. There, standardized tests are portrayed as instruments of oppression designed by capitalistic test-construction companies to crush students’ dreams of a better life and trap them in the social classes in which they were born. One such critic writes:

Rather than providing for an objective and fair means of social mobility, the tests were a tracking mechanism limiting the odds of improving on one’s family’s economic and social position in America…. The SAT aptitude test in particular was designed from the beginning to facilitate social Darwinism, selecting for White Anglo-Saxon males; Jim Crow segregation, eugenics, and protecting the Ivy League’s racial stock provided the legal and cultural context in which the SAT was born.22

These criticisms are feeble, shallow, and above all, dishonest. Rebuttals to these fallacies, patiently documented and dissected by recognized testing scholars, are readily available to anyone with a fair and open mind.23

Claims of Cultural Bias in Tests

The critically acclaimed 1991 film Boyz N the Hood told the tale of three Black youths growing up in a South Central Los Angeles ghetto, and the differences in their eventual life outcomes as a function of having (or not having) a strong father figure. One of the boys has a strict but caring father figure (named Jason “Furious” Styles), while the other two do not. In numerous spots throughout the movie, Mr. Styles imparts pithy pearls of wisdom to the boys, intended to guide them throughout life. In one such sequence, he opines on the SAT requirement for college:

Most of those tests are culturally biased to begin with. The only part that is universal is the Math.24

Wrong. Although popularly believed, the claim that contemporary standardized mental testing is culturally biased is patently false, as revealed in hundreds of empirical studies.25 When critics accuse standardized tests of cultural bias, they typically mean that a test includes words, concepts, or ideas that are perceived to be more familiar to White middle-class examinees compared to other groups, or that a test’s standardization samples fail to include sufficient representation of non-White, lower socioeconomic status (SES) persons.26

Both of these conditions are alleged to foster an unfair disadvantage to lower SES non-White examinees, purporting to cause them to have lower average scores relative to more advantaged White test takers. While some critics may not be familiar with the content of tests or the racial/ethnic makeup of standardization samples, they nevertheless believe that standardized tests are biased simply because the average scores achieved by different subpopulation groups are not equal. Such a definition of test bias is widely rejected by contemporary testing experts.27

The cold reality, however, is that test companies, like all other companies that must be profitable in order to stay in business, routinely and carefully examine their test items for any evidence of statistical bias in the production phase, before any updated test revisions are published. Items that show actual evidence of statistical bias (i.e., items that statistically perform differently for test takers of different racial/ethnic groups) are discarded, and the results of statistical tests for biased test items are typically published in test manuals for open review by the general public.28

Crying Racism

Whenever attempts to tar and feather tests with charges of cultural bias fail, the next step is to simply smear them with the charge of racism. In today’s heated political climate few things are more effective in attracting panicked attention than labeling persons, organizations, or products as “racist.” In the 1990s, test critics began to point out that the term “aptitude” in the (then-called) Scholastic Aptitude Tests (SAT), could be perceived as measuring something innate that is impervious to effort or instruction.29 This, coupled with the fact that these tests reflect the significant subpopulation group differences in mean scores discussed above, prompted the College Board to change the middle word of the SAT from “aptitude” to the more bland descriptor “assessment” in 1993.30 That euphemism, however, did little to quell the ire of critics, who continued to accuse standardized college testing of being racist.31

In today’s heated political climate few things are more effective in attracting panicked attention than labeling persons, organizations, or products as “racist.”

To be fair, it is relatively easy to locate offensive quotes by 19th and early 20th-century testing supporters who freely ascribed the adjectives “inferior” and “superior” to racial groups on the basis of significant mean differences in IQ scores.32 It comes as little surprise, therefore, when Ibram X. Kendi, founder and director of the Center for Antiracist Research, declares that:

Standardized tests have become the most effective racist weapon ever devised to objectively degrade Black and Brown minds and legally exclude their bodies from prestigious schools.33

Kendi and many others never doubt that contemporary testing must be racist, based on the false belief that such testing was birthed out of a history of racism.34 There is no doubt that these types of claims are very effective in poisoning contemporary public discourse, but such invective does not hold up under critical examination or hard evidence.

First, many early researchers were extremely cautious about, and resistant to, interpreting group differences in text performance as ironclad indicators of any innate inferiority/ superiority of groups. While racist attitudes were certainly more prevalent a century ago compared to today, many early American IQ test researchers were keenly aware of racial discrimination and unequal social circumstances of racial groups during the times in which they wrote, and so urged their peers to avoid hasty and intemperate generalizations from performance on tests until environmental disadvantages could be properly ruled out.35

Second, not a few early 20th-century researchers intentionally showcased the exceptional IQ test performance of high-scoring non-White (particularly African-American) students, who achieved scores several standard deviations above the general mean.36 Their writings disprove the assertion that there is something intentionally nefarious deeply embedded within mental tests that unfairly suppresses the intellectual capabilities of examinees who are not White and/or middle class.

Third, one study using a large and representative dataset of school-aged students in California, analyzed the sources that account for IQ test score variance (using Analysis of Variance, a long-standing, well-established, and widely-used statistical method), and demonstrated that the largest sources of IQ test score variability are within and between families that in many cases share the same racial group and social class.37 If two members of this same dataset are selected at random (regardless of race, ethnicity, social class, or family) and the difference in their IQ scores are calculated and averaged and the procedure repeated an infinite number of times, the average difference between randomly selected pairs of IQ scores is 17 points.

Given that the mean of modern IQ tests is 100 and its standard deviation is 15, this average 17-point difference between such randomly chosen pairs exceeds the average score differences between Black and White students in the dataset (i.e., 12 points). Simply stated, the average IQ point difference between siblings in the same family exceeds the average test score difference between African Americans and White Americans. Taken together, these findings demonstrate the oft-repeated claims that IQ and other mental tests are inherently flawed and discriminate unfairly along racial lines, are simply false. This won’t convince Ibram X. Kendi, however, since his definition of racism is any group difference of any kind anywhere, thereby rendering the concept unfalsifiable.

Lowering Standards

Whenever two or more subpopulation groups achieve unequal means in their test score distributions, any set cutoff score that a college or university uses to determine acceptance or rejection for admission will display unequal percentages across groups as to who is selected or rejected. That is a statistical reality. For admissions committees that champion Diversity, Equity, and Inclusion (DEI) mandates, standards must be lowered for members of lower-scoring groups in a manner that camouflages what is actually being done.

Researchers have long acknowledged that obtaining data on college admissions decisions is an uphill battle, as colleges strive to prevent access to the criteria on which acceptance decisions are made. When such information is obtained, the results confirm what many have always suspected.

That is to say, Black and Latino applicants are admitted with test qualifications that are as much as one standard deviation or more below the average test scores of White and Asian applicants,38 and this practice has predictable consequences. To illustrate, many Black and Hispanic students find themselves on academic probation or switch majors (from the major into which they were initially admitted) to enter disciplines that are less demanding.39 Many of those so admitted will simply drop out and fail to graduate, creating “artificial failures” that would have been successful if properly matched to institutions that enroll students with comparable qualifications.40

This observation was solidly reinforced in Richard Sander and Stuart Taylor’s 2012 book Mismatch: How Affirmative Action Hurts Students It’s Intended to Help, and Why Universities Won’t Admit It. In it, the authors examined and compared enrollment, graduation rates, and doctorate/STEM graduate degrees of Black and Hispanic students in the state of California in the eras before and after Proposition 209 was passed in that state. Proposition 209 (Prop 209, also known as the California Civil Rights Initiative, or CCRI), was a ballot proposition approved in 1996, which prohibited state governmental institutions from considering race, sex, or ethnicity in public employment, contracting, and education.

When comparing the pre-Prop 209 to the post-Prop 209 eras, the number of Black students receiving bachelor degrees from University of California (UC) schools, the number of UC Black and Hispanic freshmen who went on to graduate in four years (as well as graduate with STEM degrees), and the number of graduates with GPAs of 3.5 or higher all significantly rose. This hard data was used to support the general thesis that when students are matched (through objective standardized test scores) to institutions where all students are admitted under the same standards (and standards are not artificially lowered to satisfy diversity goals), minority students benefit significantly.

These practices are so pervasive, that Black students who meet the same college admissions requirements as their peers often write of their frustration and resentment at being unfairly judged by other students as having been admitted solely because of their race and under lower standards.41 In one particularly heartbreaking account, a successful Black journalist wrote of his frustrations taking two years out of his professional life to teach journalism to Black students, admitted under lowered academic standards, at a small, historically Black college. He writes of his reluctant efforts to repeatedly lower basic academic expectations in order to accommodate a critical mass of students whose attitudes, values, achievement motivation, academic preparation and qualifications, and intellectual capabilities demonstrated that they had no business being at an institution of higher learning.42

One strategy for justifying lowering standards is for college admissions committees to claim that their admission standards are “holistic.”43 That is, criteria for admission presumably must take into account a wide range of factors that provide a more “three-dimensional picture of the whole person,” as opposed to the more “narrow” consideration of standardized test scores. Yet critics charge that the deep subjectivity of such practices represents little more than academic flimflam.44

The oft-repeated claims that IQ and other mental tests are inherently flawed and discriminate unfairly along racial lines, are simply false.

Recently, testing companies have come to serve as enablers of lowered college admissions standards. For example, the College Board spent two years (2017–2019) creating an “adversity index,” a 100-point scale that provides a rough measure of the degree of adversity versus privilege in the life of a prospective applicant. In theory, adversity index scores could be used to balance lower standardized test scores in an effort to justify lower admissions standards. Ultimately, however, these efforts of testing companies to placate their critics once again proved futile.45

Another strategy is to claim that empirical research supports the benefits of having diverse academic settings compared to those not as diverse. For example, a DEI advocate cited research support for claims that students who enroll in more diverse classrooms earn higher GPAs, more diverse college discussion groups generate “more novel and complex analyses,” and that greater exposure to diversity in college settings increases civic attitudes and engagement.46

However, studies of such an important topic as the benefits of diversity in college admissions require at minimum systematic replication as well as hundreds of studies by independent researchers (conducted at a wide variety of institutions) if they are to yield results that can be subjected to appropriate meta-analyses.

One study, however, is notable for its elegance, clarity, and simplicity. In 2002, researchers specifically evaluated the claim that increased racial diversity in college enrollments enriches students’ educational experience and improves relations between students from different cultural groups.47 They argued that prior self-report data claimed to demonstrate support for this notion were misleading, as they suffered from biased item wording, methodological flaws, and the tendency for responses to reflect social desirability effects.

To correct for these flaws, the researchers analyzed self-report data from a random sample of more than 4,000 American college students, faculty, and administrators who were asked to simply evaluate various aspects of their educational experience and campus environment, but without any direct references to racial/ethnic diversity. They then correlated their data with the percentage of Black student enrollment in predominantly White student bodies. They found that, contrary to what diversity advocates would predict, no consistent positive correlation was found between increased diversity and respondents’ assessments of educational satisfaction.

Delete Standards Altogether

Eventually, what was previously unthinkable, has now become unavoidable: objective standards in and of themselves are seen as an impediment to the goals of achieving diversity, equity, and inclusion. Hence, testing necessary for demonstrating mastery of taught subject matter must itself be abolished.

This article appeared in Skeptic magazine 28.3
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In one example, the Oregon state legislature eliminated (for two years, until the state can re-evaluate its graduation policies) the long-standing requirement that students successfully pass a high school exit exam in order to demonstrate proficiency in reading, mathematics, and writing. This was done in response to criticisms that the testing requirement was inequitable because higher percentages of Black and Hispanic students failed the test.48

Various anti-testing writers and organizations applaud the news that more and more institutions of higher education no longer require standardized test scores as a condition for selection,49 under the pretense that “the social and academic costs of continuing to rely on…tests outweigh any possible benefits.”50

Where are we headed?

At the time of this writing, the U.S. Supreme Court has ruled that the admissions programs at Harvard University and the University of North Carolina (where race is used as one of many factors in student admissions) violate the equal protection clause of the 14th Amendment of the United States Constitution, which guarantees equal protection for all U.S. citizens.51 In a videotaped reaction to the decision, President Biden stated that the decision “effectively ends affirmative action in college admissions,”52 a sentiment echoed by many who support the continued and fair race-neutral use of standardized tests. Nevertheless, many commentators have also suggested ways in which admissions committees can circumvent the decision by no longer requiring standardized testing, or by changing the manner in which applicants write their college essays to signal their racial group membership.53

There is simply no way to produce a mental test that effectively measures the abilities and skills needed to predict success in educational programs but at the same time satisfies the political goals of racially proportional representation as demanded by DEI advocates.54 Given this reality, the war involving standardized testing has by no means ended, but rather is just beginning.

About the Author

Craig Frisby is Associate Professor Emeritus in School Psychology from the University of Missouri, Columbia. He has served as an Associate Editor for School Psychology Review, the official journal of the National Association of School Psychologists, and Associate Editor for Psychological Assessment, a journal published by the American Psychological Association. He currently serves as Associate Editor for the Journal of Open Inquiry in the Behavioral Sciences. He is the author of Meeting the Psychoeducational Needs of Minority Students: Data-based Guidelines for School Psychologists and Other School Personnel and co-editor of the recently published Ideological and Political Bias in Psychology: Nature, Scope and Solutions. Watch him on C-SPAN discussing education reforms to benefit the African American community

References

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3. https://rb.gy/2247j
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7. Frisby, C.L. (2013). General Cognitive Ability, Learning, and Instruction. In C.L. Frisby, Meeting the Psychoeducational Needs of Minority Students, 201–266. Wiley.
8. Ibid.
9. Ibid.
10. Jensen, A.R. (1993). Psychometric G and Achievement. In B.R. Gifford (Ed.), Policy Perspectives on Educational Testing, 117–227. National Commission on Testing and Public Policy. Springer.
11. https://rb.gy/row4i; Jensen, A.R. (1987). Individual Differences in Mental Ability. In J.A. Glover & R.R. Ronning (Eds.), A History of Educational Psychology, 61–88. Plenum.
12. Lynn, R. & Vanhanen, T. (2006). IQ and Global Inequality. Washington Summit Publishers; Rushton, J.P. & Jensen, A.R. (2005). Thirty Years of Research on Race Differences in Cognitive Ability. Psychology, Public Policy, and Law, 11(2), 235–294.
13. Gottfredson, L.A. (1997). Mainstream Science on Intelligence: An Editorial With 52 Signatories, History, and Bibliography. Intelligence, 24(1), 13–23.
14. Rushton, J.P. & Jensen, A.R. (2005). Thirty Years of Research on Race Differences in Cognitive Ability. Psychology, Public Policy, and Law, 11(2), 235–294; Gottfredson, L. (2005). Implications of Cognitive Differences for Schooling Within Diverse Societies. In C.L. Frisby & C.R. Reynolds (Eds.), Comprehensive Handbook of Multicultural School Psychology, 517–554. Wiley.; https://rb.gy/24n08
15. Ibid.
16. https://rb.gy/pvhup; Greene, J.P. (2005). Education Myths: What Special Interest Groups Want You to Believe About Our Schools—and Why It Isn’t So. Rowman & Littlefield.; https://rb.gy/65e0w
17. https://rb.gy/jpry7; Whitman, D. (2008). Sweating the Small Stuff: Inner–City Schools and the New Paternalism. Thomas B. Fordham Institute Press.
18. Rousseau, J. (2019). The Social Contract, or Principles of Political Right. (Trans. by G. Cole) Compass Circle.
19. https://rb.gy/bdg1d
20. https://rb.gy/l8bls
21. https://rb.gy/r8xlx
22. Soares, J.A. (Ed.) (2020). The Scandal of Standardized Tests: Why We Need to Drop the SAT and ACT (p. ix). Teachers College Press.
23. Phelps, R.P. (2003). Kill the Messenger. Transaction; Phelps, R.P. (2005). Defending Standardized Testing. Erlbaum; Phelps, R.P. (2009). Educational Achievement Testing: Critiques and Rebuttals. In R.P. Phelps (Ed.), Correcting Fallacies About Educational and Psychological Testing, 89–146. American Psychological Association; https://rb.gy/8b1mv
24. https://rb.gy/r449n
25. Camara, W.J. (2009). College Admissions Testing: Myths and Realities in an Age of Admissions Hype. In R.P. Phelps (Ed.), Correcting Fallacies About Educational and Psychological Testing, 147–180. American Psychological Association.; Reynolds, C.R., Altmann, R.A., & Allen, D.N. (2021). Chapter 15: The Problem of Bias in Psychological Assessment. In C.R. Reynolds, R.A. Altmann & D.N. Allen, Mastering Modern Psychological Testing: Theory and Methods (2nd Ed.), 573–614. Springer.; Jensen, A.R. (1980). Bias in Mental Testing. Free Press.
26. Jensen, A.R. (1980). Bias in Mental Testing. Free Press.
27. Warne, R.T., Yoon, M. & Price, C.J. (2014). Exploring the Various Interpretations of ‘Test Bias’. Cultural Diversity and Ethnic Minority Psychology, 20(4), 570–582.
28. Ibid.
29. https://rb.gy/btc99
30. https://rb.gy/4ixp7
31. https://rb.gy/hvz82
32. Galton, F. (1870). Hereditary genius: An Inquiry Into Its Laws and Consequences. Appleton.; Brigham, C. (1923). A Study of American Intelligence. Princeton University Press.; Gould, S.J. (1996). The Mismeasure of Man (revised and expanded). W.W. Norton & Company.
33. https://rb.gy/foaup
34. https://rb.gy/nk8fu; https://rb.gy/3ec9n; https://rb.gy/3gnwb
35. Bond, H.M. (1924). What the Army ‘Intelligence’ Tests Really Measured. Opportunity, 2, 197–198.; Canady, H.G. (1942). The American Caste System and the Question of Negro Intelligence. The Journal of Educational Psychology, 33(3), 161–172.; Canady, H.G., Buxton, C. & Gilliland, A.R. (1942). A Scale for the Measurement of the Social Environment of Negro Youth. The Journal of Negro Education, 11(1), 4–13.; Klineberg, O. (1934). Cultural Factors in Intelligence Test Performance. The Journal of Negro Education, 3(3), 478–483.; Long, H.H. (1925). On Mental Tests and Racial Psychology—a Critique. Opportunity, 134–138.
36. Bond, H.M. (1927). Some Exceptional Negro Children. The Crisis, 34(8), 257–259, 278, 280.; Bousfield, M.B. (1932). The Intelligence and School Achievement of Negro Children. The Journal of Negro Education, 1(3/4), 388–395.; Jenkins, M.D. (1939). Psychological Study of Negro Children of Superior Intelligence. The Journal of Negro Education, 5(2), 175–190.
37. Jensen, A.R. (1980). Bias in Mental Testing (p. 43). Free Press.; Jensen, A.R. (1998). The G Factor: The Science of Mental Ability (p. 357). Praeger.
38. Murray, C. (2021). Facing Reality: Two Truths About Race in America, 67–71. Encounter Books.; Riley, J.L. (2014). Chapter 6: Affirmative Discrimination. In J.L. Riley, Please Stop Helping Us: How Liberals Make It Harder for Blacks to Succeed, 141–168. Encounter Books.
39. https://rb.gy/9zbnl
40. Riley, J. (2014). Please Stop Helping Us: How Liberals Make It Harder for Blacks to Succeed. Encounter Books.; Sander, R.H. & Taylor, S. (2012). Mismatch: How Affirmative Action Hurts Students It’s Intended to Help, and Why Universities Won’t Admit It. Basic Books
41. Carter, S.L. (1992). Reflections of an Affirmative Action Baby. Basic Books.; https://rb.gy/18cbl
42. https://rb.gy/h1olw; https://rb.gy/4e8sn
43. https://rb.gy/xkcte
44. https://rb.gy/xlr6p
45. Soares, J.A. (2020). The “Landscape” or “Dashboard Adversity Index” Distraction. In J.A. Soares (Ed.), The Scandal of Standardized Tests: Why We Need to Drop the SAT and ACT, 76–94. Teachers College Press.
46. https://rb.gy/b884w
47. Rothman, S., Lipset, S.M., & Nevitte, N. (2002). Does Enrollment Diversity Improve University Education? International Journal of Public Opinion Research, 15(1), 8–26.
48. https://rb.gy/sw9u8; https://rb.gy/xqvc9
49. https://rb.gy/oa9o4; https://rb.gy/md53l; https://rb.gy/1qw9z
50. Schaeffer, R.A. (2020). The SAT/ACT Optional Admissions Growth Surge: More Colleges Conclude “Test Scores Do Not Equal Merit”. In In J.A. Soares (Ed.), The Scandal of Standardized Tests: Why We Need to Drop the SAT and ACT, 97–113. Teachers College Press.
51. https://rb.gy/za7v3
52. https://rb.gy/z22hf
53. https://rb.gy/r4k0d
54. Gottfredson, L. (2000). Skills Gaps, Not Tests, Make Racial Proportionality Impossible. Psychology, Public Policy, and Law, 6(1), 129–143.

https://traffic.libsyn.com/secure/sciencesalon/mss398_Paul_Halpern_2024_01_02.mp3 Download MP3

Our books, our movies—our imaginations—are obsessed with extra dimensions, alternate timelines, and the sense that all we see might not be all there is. In short, we can’t stop thinking about the multiverse. As it turns out, physicists are similarly captivated.

In The Allure of the Multiverse, physicist Paul Halpern tells the epic story of how science became besotted with the multiverse, and the controversies that ensued. The questions that brought scientists to this point are big and deep: Is reality such that anything can happen, must happen? How does quantum mechanics “choose” the outcomes of its apparently random processes? And why is the universe habitable? Each question quickly leads to the multiverse. Drawing on centuries of disputation and deep vision, from luminaries like Nietzsche, Einstein, and the creators of the Marvel Cinematic Universe, Halpern reveals the multiplicity of multiverses that scientists have imagined to make sense of our reality. Whether we live in one of many different possible universes, or simply the only one there is, might never be certain. But Halpern shows one thing for sure: how stimulating it can be to try to find out.

Dr. Paul Halpern is the author of 18 popular science books, exploring the subjects of space, time, higher dimensions, dark energy, dark matter, exoplanets, particle physics, and cosmology. The recipient of a Guggenheim Fellowship, a Fulbright Scholarship, and an Athenaeum Literary Award, he has contributed to Nature, Physics Today, Aeon, NOVA’s “The Nature of Reality” physics blog, and Forbes “Starts with a Bang!” He has appeared on numerous radio and television shows including “Future Quest,” “Science Friday,” “Radio Times,” “Coast to Coast AM,” “The Simpsons 20th Anniversary Special,” and C-SPAN’s “BookTV.” He appeared previously on the show for his book Synchronicity: The Epic Quest to Understand the Quantum Nature of Cause and Effect. His new book, The Allure of the Multiverse, describes the controversial history of higher dimensional and parallel universe schemes in science and culture. More information can be found at: allureofthemultiverse.com

Shermer and Halpern discuss:

• universe and multiverse meaning
• Is the multiverse science, metaphysics, or faith?
• theists claim the “multiverse” is just handwaving around the God answer
• types of multiverses
• many worlds interpretation of quantum mechanics?
• inflationary cosmology and eternal inflation
• Darwinian cosmology
• infinity and eternity
• multiple dimensions and the multiverse
• string theory and the multiverse
• cyclical universes and multiverses (the Big Bounce)
• Anthropic Principle (weak, strong, participatory)
• time travel and the multiverse
• sliding doors, contingency, and the multiverse.

If you enjoy the podcast, please show your support by making a $5 or $10 monthly donation.

Institutionalized experiments take a while to fail so fully as to be discredited. The 1917 Russian Revolution put its people “seventy years on the road to nowhere,” three generations of poverty, fear, and violence (as the news media, quoting protesters, declared in the regime’s last year).1 Poles who survived communism dismissed it as something that “looks good on paper.”

The situation with schools or colleges of education—a division within a university devoted to teaching its students to be teachers and school leaders, commonly called, “ed schools”—is not nearly so bad. While elite ed schools have been and often are steeped in the political/cultural ideology of the day, whatever that might be, non-elite ed schools are less radical. Most education professors at state universities bearing directional names, such as Southern Mississippi, North Texas, and Central Michigan—who train the bulk of teachers and principals—actually have worked in schools, an experience that tends to instill more pragmatism than ideology. Most educational leadership professors are former principals with backgrounds as athletic coaches, and accordingly less fans of Critical Theory than of the Friday Night Lights. Those with real-world experience have taught me the most about our schools.

Yet a skeptical examination of ed schools reveals a century-plus experiment that failed, harming millions of students, particularly the disadvantaged. The best education professors should go back to leading or teaching in schools rather than keeping afloat insular, often arrogant institutions. Especially as regards the teaching of reading, the failings of ed schools are painfully obvious and, unfortunately (and ironically), it is illiterate students who pay the price for their failure.

As the Chair in Leadership at the Department of Education Reform at the University of Alabama, it is my contention that American ed schools were bad from the beginning, spreading academic mediocrity and compliance mindsets that left K-12 educators ill-suited to resist the various deeply flawed fads and fallacies that came their way. Worse, long before the rest of higher education, ed schools succumbed to the lure of the big bottom line, focusing on raising revenue rather than mentoring young minds.

Yet you can’t replace something with nothing, so I will end my analysis with ideas about how we could have different and far better ed schools, in part by creating education markets, coupling school choice with varied alternatives for educator training and certification.

Bad From the Beginning

You can’t understand an institution without knowing its history. Reporting for my school newspaper in 1976, I asked retiring Baltimore County school superintendent Dr. Joshua Wheeler, known for his progressive policies, why our 110,000-student system did not require proficiency tests since, as everyone knew, some students graduated even though they were illiterate. Dr. Wheeler explained that, “the purpose of public education is not to educate students. The purpose of public education is to provide an education for those few who want it.” In that case, I suggested, everyone including taxpayers might be happier if we let students drop out. Dr. Wheeler retorted, “we can’t do that. Crime would go up. Unemployment would go up. Parents would be angry…and whenever we do require more homework and start failing kids, parents complain that their kids are working too hard.”2

From the beginning, such anti-learning mindsets have dominated ed schools. As scholars such as David F. Labaree3 and Raymond E. Callahan4 detail, in the late 1800s and early 1900s, what were termed “normal schools,”5 which had trained teachers, were repackaged as teachers colleges and, eventually, middling universities. Elite institutions such as Columbia University developed their own ed schools (which Columbia segregated from the rest of campus), in response to political demands to produce greater numbers of teachers and school leaders to meet expanding demand.6 From 1900 to 1940 the percentage of high school-aged children actually in high schools grew from 11 percent to 73 percent, fundamentally changing the institutions. Local businesses wanted these new high schools to produce compliant factory workers and to improve their community’s reputation. Further, as Dr. Wheeler suggested, keeping children in school and out of the workforce looked like a good idea, since a teen sleeping on a school desk is a student, while the same teen sleeping on a park bench is an unemployment statistic.

Two ed school ideologies exploded in popularity, even while eroding standards. As E.D. Hirsch chronicles in The Schools We Need and Why We Don’t Have Them,7 idealistic progressives (Hirsch terms them “romantics”) such as John Dewey, argued that emphasizing content meant deemphasizing children, so he viewed memorization and book learning as dehumanizing and interfering with children’s natural curiosity. Such misguided idealism has done enormous damage to schooling, enabling the adoption of failed techniques, such as whole language to teach reading (more on that below).

Though the idealists (whom Labaree terms “pedagogical progressives”) get more attention, “administrative progressives” had more impact. Administrative progressives agreed with pedagogical progressives that traditional book learning (“to educate students” as Dr. Wheeler put it) should be marginal in school. Yet in contrast to the idealists, administrative progressives wanted schools to serve the purpose of social utility rather than individual fulfillment, so they created schools that were bureaucratic, not organic. All too many administrative progressives believed that few students (and fewer still among minorities) had the capacity to learn much, thus making academic achievement inherently elitist.

One sees this in the 1918 Cardinal Principals of Secondary Education issued by the National Education Association, then an administrator organization rather than a teachers’ union. The Cardinal Principals lists seven goals for schooling, with a single goal—Command of Fundamental Processes—covering nearly all scholarly disciplines. (The other goals were health, worthy use of leisure, citizenship, worthy home membership, vocation, and ethical character.) As Labaree notes:

If school subjects have to be adjusted to the capacities of the students and to the requirements of the job market, and if most students have modest capacities and most jobs have modest skill requirements, then only a few classes need provide a rigorous academic content for the college bound elite, while most students need classes that are less academic, less demanding, and better suited to their modest future roles in society. This is a straightforward prescription for diluting academic content.8

While few educators have ever heard of the Cardinal Principals, the document’s ideas defined education for generations of educators and remain dominant today. As critics Hirsch and Diane Ravitch9 detail, contempt for knowledge meant freedom: both in ed schools and real schools, teachers can do what they want in a way that engineers cannot. After all, it is tougher to cover up a fallen bridge than an illiterate graduate.

Institutions define themselves by what they are not. From the beginning, ed schools distinguished themselves from the rest of academia by their indifference to academic content: after all, the teacher’s job was not to educate children. Other professors noticed. The doctorate in education, the EdD, has never carried much respect in academic circles. Labaree, who taught in Stanford’s ed school concludes:

Those teaching in the university think of those in ed schools as being academically weak and narrowly vocational. They see ed school teachers not as peers in the world of higher education but as an embarrassment, who should not be part of the university at all. To them the ed school looks less like a school of medicine than a school of cosmetology.10

As Jonathan Wai (another contributor to this issue) and I have detailed, ed schools have low standards and give out high grades. Both undergraduate and graduate ed students average lower intelligence test scores than other students, and elite universities do not pick EdDs to be their chancellors.11

Further, as American Enterprise Institute scholar Rick Hess and former Columbia ed school (Teachers College) dean Art Levine demonstrate,12, 13 there is little evidence that earning graduate degrees makes either teachers or their leaders better at their jobs; indeed, when surveyed, they say as much. The same holds for teacher certification.14

Yet graduate degrees in education serve important economic and symbolic purposes. K–12 educators get pay raises for obtaining graduate degrees, and their tuition (usually paid by their employers) produces a cash stream for colleges. Symbolically, many administrators claim authority over parents and teachers by invoking their first name, “Dr.” I have never met a physics PhD who insisted on being called “Doctor,” and seldom met an EdD who didn’t. In this sense, education graduate degrees recall Lord Farquaad’s giant, somewhat phallic castle, which led Shrek to ask, “do you think maybe he’s compensating for something?”

There are (at least) two other unfortunate legacies of administrative progressives, sexism and compliance cultures, each reinforcing the other.15 Administrative progressives bureaucratized, consolidating small schools where many principals still taught (and which were often led by women) into large, differentiated bureaucracies. Encouraged by school boards, emulating the business best practices of 1918 scientific management methods, administrative progressives transformed schools into factories where the workers (teachers) batch-process students under the direction of professional managers (principals and superintendents) who prize compliance and uniformity.

At a time when “professional” meant male, administrative progressives hit upon athletic coaching as a career path to attract men into teaching, with the prospect of fast promotion into administration. By the middle of the 20th century, it seemed only natural that in schools male administrators would boss around female teachers, who were expected to be compliant, not self-directed. Even today, while most teachers are women, most principals and superintendents are still men. Most male principals are former coaches who stress teamwork and compliance over integrity, covering up rather than exposing scandals to protect schools’ reputations, and showing loyalty to colleagues who have strayed.16 For women, the plurality fast track into administration is to become a curriculum specialist. As in education generally, this subfield possesses no specific scientific knowledge, so its “experts” stress compliance to rules and regulations, while showing loyalty to higher-ups. Generally, neither male nor female school leaders focus very much on academic learning beyond basic minimum requirements.

The Decline and Fall of Schools, But Not Ed Schools

Despite ed school deficiencies, public schools held together until 1970 or so, chiefly because of discrimination in the workplace. The fact that college-educated Blacks and women had few career paths other than teaching, ironically enabled schools to hire high talent for low wages. Smart teachers often kept schools from straying too far into intellectual vacuity. And ironically, civil rights laws (and social norms) changed all that. From 1970 to 2005, among female high school graduates in the top tenth of cognitive ability, the proportion entering teaching fell from roughly a quarter to a tenth, with similar changes among African Americans.17 The daughters of teachers went into more prestigious, more lucrative fields; in the case of two of my relatives, college teaching and investment banking.

This did not seem to trouble ed schools, nor the school leaders they trained. Both my experiences as a school board member (when I once had to explain to an award-winning principal why he should hire math teachers who know math) and the empirical evidence indicate that in hiring teachers, the leaders trained by ed schools prefer compliance over intelligence.18 Political leaders are only now realizing that we cannot get better schools without raising pay for new teachers in order to get more of the most talented people to give teaching a try; some will like it and stay.19

Contempt for academic knowledge likely explains an interesting conundrum exposed by the rise of homeschooling. Parents untrained in medicine could not remove their children’s tonsils. Parents untrained in law could not capably represent their children in court. Yet currently, the bulk of the empirical evidence indicates that on both student achievement and socio-emotional skills, students homeschooled by parents do as well as or slightly better than those taught by certified teachers (even in calculus!).20 Granted, homeschooling families tend to have relatively high motivation and are thus a self-selected sample, but mere enthusiasm would not close the gap that separates amateurs from professionally trained doctors or lawyers. The fact that it does for education undermines the claim that ed schools produce education professionals.

The compliance-oriented, intellectually mediocre school bureaucracies developed by schools of education have cost trillions of dollars, while simultaneously damaging equity, higher education, and democracy.

Compliance-oriented, intellectually mediocre school bureaucracies developed by schools of education have cost trillions of dollars, while simultaneously damaging equity, higher education, and democracy.

Regarding equity, the flight of the bright from teaching came at a time when schools needed them most. Schooling began bureaucratizing in the early 20th century, at a time of stable two-parent and extended families, unlike today. From 1960 to 2010, the percentage of children spending substantial periods either without parents or in single-parent homes skyrocketed from under a tenth to about half, and far more in disadvantaged communities. Statistically, this likely explains the academic achievement and wealth gaps separating Asian Americans from White Americans, and in turn, White Americans from African Americans.21 Family fragility requires smarter, more innovative teachers than ed schools produce, ones attuned to the needs of these children.

The success of certain charter schools that have closed achievement gaps, staffed by teachers trained outside schools of education, demonstrates that most disadvantaged children can master the material when educators keep order, build relationships with parents and students, and set measurable, achievable goals to get kids reading at grade level before leaving elementary school. The successful methods used by such poverty-high achievement schools were consistently resisted by ed schools, even before Critical Race Theory could be invoked to cast teaching disadvantaged children math and standard English as culturally insensitive, despite parental objections.22

Even mainstream journalists, who normally defend ed schools, are starting to agree. For over a half-century, armies of education professors, paid consultants, and for-profit publishers dissuaded teachers from using phonics to teach reading, as journalist Emily Hanford details in her six-part podcast, “Sold a Story: How teaching kids to read went so wrong.”23 They dismissed decades of empirical research that demonstrated that phonics works far better for the vast majority of students as being “reactionary,” instead requiring the use of progressive methods such as “three cueing,” in which students guess what a word is without understanding how its letters sound. (There are superb professional musicians who play only “by ear,” or even teach students to start out by imitating what the teacher plays before learning to read sheet music. But no one teaches music by having their student first begin by guessing at what a song or passage of written music sounds like, even though music notation is much more intuitively obvious than writing).

Steeped in compliance to authority, many teachers assumed that the education professors knew best because they were professors, and then blamed themselves for not doing it right. When the George W. Bush administration and some state governments legally mandated phonics-based reading instruction, certain education professors and their allies sabotaged implementation. This harmed everyone, but particularly disadvantaged students, whose families were less likely to teach phonics at home (as my dad did) or employ tutors.

Regarding higher education, ed schools have been part of a broader movement to make universities more bureaucratic and less intellectual, in effect, more like K-12 schools. Since 1990, administrative staff (who often make more than teachers), frequently with doctorates in education, have outnumbered college professors and usurped faculty governance, as Benjamin Ginsberg details in The Fall of the Faculty: The Rise of the All-Administrative University and Why it Matters.24 A large literature suggests that the habits of schools of education—batch-processing students and boosting their bottom line while shorting academic standards—have in recent years become the norm in most non-STEM departments throughout higher education. Empirical studies by Richard Arum and Josipa Roksa25 find little measured academic learning in college, with unfortunate later-life outcomes.26 In short, in terms of their academic rigor, higher education institutions have increasingly become like ed schools, emphasizing social utility in ways that undermine it.

There is a second huge cost to higher education, with implications for free speech, critical thinking, and democratic governance. Increasingly, administrators impose compliance to “best practices,” even when, in the case of sexual matters27 and race relations, empirical evidence indicates the new orthodoxies are unscientific and ineffective, failing to lessen conflict, diversify leadership, or fit scientific evidence.28 In Woke Racism: How a New Religion has Betrayed Black America,29 the African American Columbia University linguistics professor John McWhorter makes a compelling case that Anti-Racist higher education and corporate bureaucrats have imposed ineffective practices, while terminating their critics and blocking practices (including teaching phonics) that would reduce real inequities.

What is to be done?

Ed schools operate in a monopolistic manner and under the direction of bureaucratic experts. But what if the bureaucratic experts are wrong about the techniques of schooling? Or what if many parents want their children to get more out of school than mere social utility? As the history of ed schools, and of large and powerful organizations in general demonstrates, one shouldn’t rely on the “experts” to self-correct.30 Even with the of best intentions, what if what the experts dictate works for some students but not others? Montessori schooling—a method of education that is based on self-directed activity, hands-on learning, and collaborative play—might be best for some students, especially those from socially and economically advantaged homes who receive content knowledge at home and become bored or frustrated with normal classroom routines. A more disciplined school experience might work better for those from less fortunate circumstances. And every student works best at the speed appropriate to their development.

So should we simply defund ed schools and pension off their professors? As noted, teacher and leader certification from ed schools does not seem to produce more effective educators. Yet policymakers, parents, and prospective educators are used to ed schools; and for the latter, they do enable valuable networking. The bottom line is that you can’t replace something with nothing. If we defunded ed schools, they would likely reappear, just under a new name or in a different form.

One alternative, advanced by my collaborators and myself, would be to restructure ed schools around actual academic disciplines that have demonstrated rigor and scientifically established bodies of knowledge. And there’s an instructive precedent. Long marginal members of academia, in the 1960s business schools reformed with a focus on applied mathematics, economics, and behavioral science, gaining more respect and more students. Today, an MBA often helps get a well-paying job. Ed schools could likewise reform by offering their students content that teachers and school leaders really need. Psychology (especially learning theory), biology, statistics, and content knowledge in the disciplines taught in K–12 schooling would make good candidates.31 Unfortunately, ed school professors, even if informed and well-intentioned, are not incentivized to do this; indeed, existing certification and accreditation organizations (whose approval is required for federal funding) would likely derail such efforts.

A broader answer would be to replace the existing bureaucratic mindset with pluralistic ones.32 The prevailing systems of teacher certification and school accreditation encourage uniformity precisely where variety is needed. If there’s one thing true about students it is that they vary: one size never fits all. The current system is hamstrung by the way it empowers a small number of nontransparent state bureaucrats and accreditors whose “best practices” fail to reflect either public goals or scientific knowledge about how to achieve those goals.33 And there are better ways.

This article appeared in Skeptic magazine 28.3
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Mehta and Teles34 have shown that successful professions build, select, and train for knowledge and independent judgment rather than mere compliance to rules and deference to superiors. Only a professional– rather than a compliance-based human capital model (along with higher pay) seems likely to build respect for teachers as professionals. Further, education models that work well for certain students and teachers fail for others, leading Mehta and Teles to question the wisdom of a single uniform certification system as opposed to multiple systems (such as for Montessori schooling, the high performance-oriented No Excuses schooling, and Classical schooling), each with their own training and distinct certification pathways, as is the case in more rigorous fields such as architecture and psychotherapy, where the clients legitimately want and need different things.

Coupled with school choice that provides a range of options, as is the case in countries such as Belgium and the Netherlands (which have better schools than the United States), such systems could incentivize schools of education to reform and so produce the educators parents really want for their children…or else lose market share to those institutions that do. Despite having been trained by certified teachers, most parents, regardless of socioeconomic or demographic particulars, actually want math teachers who actually know math. Therein lies hope and a pathway to the future.

About the Author

Robert Maranto holds the 21st Century Chair in Leadership at the Department of Education Reform at the University of Arkansas. He has written widely on civil service reform, higher education reform, and K–12 school reform, particularly on charter schools. He has served on his local school board, and a board governing a charter school in another state. With others, he has produced sixteen scholarly books so boring his own mother refused to read them, including President Obama and Education Reform, Beyond a Government of Strangers, School Choice in the Real World: Lessons From Arizona Charter Schools, and Radical Reform of the Civil Service. In 2009 he co-edited both the conservative-leaning The Politically Correct University, and the liberal-leaning Judging Bush.

References

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3. Labaree, D.F. (1995). The Trouble with Ed Schools. Yale University Press.
4. Callahan, R.E. (1962). Education and the Cult of Efficiency. University of Chicago Press.
5. The name derives from the French “école normale,” meaning a “model school,” with no reflection on the students or their abilities.
6. Pawlewicz, D.D. (2020). Blaming Teachers: Professionalization Policies and the Failure of Reform in American History. Rutgers University Press.
7. Hirsch, E.D. (1996). The Schools We Need and Why We Don’t Have Them. Doubleday.
8. Labaree, D.F., Hirsch, E.D., & Beatty, B. (2004). The Ed School’s Romance with Progressivism. Brookings Papers on Education Policy, 7, 89–130.
9. Ravitch, D. (2000). Left Back: A Century of Battles Over School Reform. Simon & Schuster.
10. Ibid., p. 91.
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12. Hess, F.M. (2013). Cage-Busting Leadership. Harvard Education Press.
13. Levine, A. (2006). Educating School Teachers. The Education Schools Project.
14. Stotsky, S. (2015). An Empty Curriculum: The Need to Reform Teacher Licensing. Rowman and Littlefield.
15. This paragraph and the next two summarize https://rb.gy/dffow
16. Maranto, R. (2020). Why American School Corruption Remains Hidden: Diagnoses and Prescriptions for Reform. International Journal of Education Law and Policy. Vol. 15 (2019, but publication in 2020), 55–66.
17. Gastic, B. (2014). Closing the opportunity gap: Preparing the next generation of effective teachers. Teacher Quality, 2, 91–108.
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20. Maranto, R., & Bell, D.A. (Eds.). (2018). Homeschooling in the 21st Century: Research and Prospects. Routledge.
21. This has been widely documented empirically, and almost completely ignored by the American Educational Research Association, which is to say, research oriented ed school professors. See https://rb.gy/tyyr7. For nuanced, updated treatments with ideas for serving children with unstable family structures, see Rowe, I.V. (2022). Agency. Templeton Press; Cheng, A.A., & Maranto, R. (2023). Parent Involvement, Family Structure, and Children’s Economic Outcomes. In G. Brown & C.A. Makridis (Eds.), The Economics of Equity in K–12 Education: A Post-Pandemic Policy Handbook for Closing the Opportunity Gap and Using Education to Improve the American Economy. Rowman & Littlefield.
22. Maranto, R. & Ritter, G. (2014). Why KIPP Is Not Corporate: KIPP and Social Justice. Journal of School Choice. 8: 2(April–June), 237–57; Maranto, R. and Shuls, J.V. (2011). Lessons from KIPP Delta. Phi Delta Kappan 93: (November) 52–56. I speak from personal experience as one who tried to create a partnership between a successful high poverty charter school and an ed school.
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27. Melnick, R.S. (2018). The Transformation of Title IX. Brookings Institution Press.
28. For details, see works within Frisby, C.L. & Maranto, R. (Eds.) (Forthcoming, 2023). Social Justice Verses Social Science: White Fragility, Implicit Bias, and Diversity Training. National Association of Scholars.
29. McWhorter, J. (2021). Woke Racism: How a New Religion Has Betrayed Black America. Penguin.
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34. Mehta, J., & Teles, S. (2014). Professionalization 2.0: The Case for Plural Professionalism in Education. In McShane, M., & Hess, F. (Eds.), Teacher Quality 2.0: Will Today’s Reforms Hold Back Tomorrow’s Schools? Harvard Education Press.