In 1950, the United States Census Bureau estimated that approximately 2,300 Americans were aged 100 or older. The total population of the country at the time was approximately 152 million, which made centenarians one of the rarest possible demographic categories — approximately one in every 66,000 Americans had reached the age. By 1990, the centenarian count had risen to approximately 37,000. By 2020, it had reached approximately 92,000. By 2024, it had passed 101,000. The trajectory has been steep and accelerating, and the demographic shift now visible in the centenarian numbers is one of the larger long-term changes in the structure of the American population — a category that was statistically negligible at the end of World War II is now projected to become, within the lifetimes of most people reading this, a substantial demographic constituency in its own right.

According to the Pew Research Center’s January 2024 analysis of Census Bureau projections, the US centenarian population is projected to more than quadruple from approximately 101,000 in 2024 to approximately 422,000 by 2054 — meaning that within the next 30 years, the proportion of Americans aged 100 or older will rise from approximately 0.03 percent of the population to approximately 0.1 percent. This is the official Census base-case projection. Higher-end estimates developed by demographic researchers — including the MacArthur Foundation Research Network on an Aging Society — have projected substantially higher numbers under more optimistic mortality-improvement scenarios, with some estimates exceeding 1.8 million US centenarians by mid-century and substantially larger numbers by 2100. The range between the Census base case and the higher-end projections is large, and the actual outcome will depend on whether mortality improvements at older ages continue at recent rates, accelerate, or plateau.

What is driving the projected growth

The proximate driver of centenarian growth is not improving mortality among the young or middle-aged — those mortality rates are already very low and have only modest room to fall. The driver is sharply declining mortality among nonagenarians: people aged 90 to 99 who, in previous generations, would typically have died before reaching 100. The mortality rate among 90-year-olds has been falling steadily across developed countries for decades, with each successive cohort of nonagenarians surviving slightly longer than the previous one. The result is that the share of any given birth cohort that eventually reaches 100 has been rising, and the absolute number of centenarians is rising even faster because the population at risk (the 90-year-olds in the country) has also been growing rapidly.

Per a CEOWORLD analysis of the global centenarian surge, the same pattern is visible internationally. The United Nations estimated approximately 722,000 centenarians worldwide in 2024 and projects that the number will rise to approximately 4 million by 2054 — a nearly six-fold global increase in 30 years. By mid-century, the largest national centenarian populations are projected to be China (approximately 767,000), the United States (approximately 422,000), India, Japan, and Thailand, with several Southeast Asian countries and parts of southern Europe showing particularly rapid centenarian growth on a per-capita basis. Japan, currently the country with the world’s highest median age, is projected to have approximately 40 centenarians per 10,000 people by 2054 — meaning that roughly one in every 250 Japanese residents will be aged 100 or older. Thailand is projected to have an even higher ratio, at approximately 49 per 10,000.

The contested longer-term projections

The substantive disagreement among demographers is not about whether centenarian numbers will rise — that is now essentially settled — but about how far they will rise, and how soon a majority of births in low-mortality countries will produce people who eventually reach 100. The optimistic position, associated with the demographer James Vaupel and colleagues at the Max Planck Institute for Demographic Research, holds that life expectancy in the most advanced countries has been increasing by approximately three months per year for the past 150 years and shows no clear sign of slowing — and that this trajectory implies that the majority of children born in low-mortality countries today will live to see their hundredth birthday. The skeptical position, associated most prominently with the American demographer S. Jay Olshansky and his collaborators, holds that life expectancy gains are now slowing substantially in the United States and other developed countries, that the easy mortality reductions from infectious disease control, smoking declines, and cardiovascular medicine have largely been achieved, and that further gains will be substantially harder to obtain.

The empirical evidence for the slowdown position has become more visible in recent years. US life expectancy peaked at approximately 78.9 years in 2014 and then declined — partly because of the opioid crisis, partly because of rising obesity-related mortality, partly because of COVID-19 mortality during the pandemic, and partly because of slowing gains in cardiovascular medicine. The current US life expectancy of approximately 76 years is substantially below the trajectory that the Vaupel projections would have predicted. As covered by a foundational MacArthur Foundation Research Network paper on demographic forecasts for the United States in the 21st century, the higher-end centenarian projections depend on assuming that the recent slowdown is temporary and that the longer-run Vaupel-style trajectory will resume. Whether it does is one of the central empirical questions in contemporary demography, and the answer will substantially affect both the centenarian counts in 2054 and the much larger projections for 2100.

The maximum lifespan question

As reported by a 2021 Bayesian analysis published in Demographic Research by Michael Pearce and Adrian Raftery at the University of Washington, the related question of what the maximum human lifespan will reach by 2100 is approachable with statistical methods even where the underlying biology is uncertain. The Pearce-Raftery analysis modelled the existing distribution of supercentenarians (people aged 110 or older) and the projected growth of that population through the rest of the century, and estimated that there is greater than 99 percent probability that the current record human lifespan — Jeanne Calment of France, who died in 1997 at 122 years and 164 days — will be broken before 2100. They estimate an 89 percent probability that someone will reach age 126, a 44 percent probability that someone will reach 128, and a 13 percent probability that someone will reach 130. These projections are not predictions about the typical lifespan but about the extreme tail of the survival distribution, which depends on the same nonagenarian mortality declines that drive the centenarian numbers.

The deeper question that the centenarian projections raise is the relationship between living longer and living well. The available evidence on healthspan — the proportion of life spent in good health, rather than in disability or substantial decline — suggests that healthspan has been increasing more slowly than lifespan. The result is that the gap between the two has been widening: people are living longer, but with more years of substantial disability, more years of cognitive decline, and more years of dependence on caregivers and the healthcare system. The economic implications are substantial. The current pension systems, healthcare systems, and family structures of most developed countries were built around assumptions about average lifespan and the typical duration of post-retirement life that no longer hold. The institutional response, across most of the developed world, has been slower than the underlying demographic shift. Whether the eventual centenarians — including, possibly, a substantial fraction of the children born this year — will arrive at their hundredth birthdays in good health, in supported decline, or somewhere in between will depend on whether the gains of the coming decades are made primarily in extending lifespan or primarily in extending healthspan. The two trajectories produce very different futures.

The post By the end of this century, the United States is projected to have more than one million centenarians — people aged 100 or older — for the first time in human history, in a demographic shift driven by sharply falling mortality among nonagenarians, and some demographers now believe that a majority of children born today in low-mortality countries can reasonably expect to reach their hundredth birthday appeared first on Space Daily.

Frances Gerety was a copywriter at the Philadelphia agency N.W. Ayer & Son when she sat down late one night in 1947, exhausted, and scrawled four words on a notepad before going to bed: A diamond is forever. She nearly forgot them by morning. The line would run on De Beers advertisements for decades, get crowned the greatest advertising slogan of the twentieth century by Advertising Age in 1999, and rewire the global engagement ritual so completely that the diamond ring became something close to a biological assumption. Gerety herself, who wrote the most successful marriage proposal in commercial history, lived alone and never married.

She worked at N.W. Ayer for her entire career, from 1943 until her retirement in 1973, on a single account: De Beers. For three decades, almost every piece of copy that sold a diamond in the United States passed through her typewriter. She was the only woman in the agency’s copy department when she was hired, and she stayed the only woman on the De Beers account for most of that run.

The night the line arrived

The story Gerety told later was unglamorous. She had a presentation the next morning and had not yet written a tagline for the new campaign. She was tired. She put her head down on her desk and asked, by her own account, for some help from above. Four words came. She wrote them on a slip of paper and went to sleep.

The agency’s creative director was unimpressed at first. The grammar bothered people — are forever, surely, not is. Gerety held the line. The singular verb gave the sentence the weight of a proverb instead of a sales pitch, and that was the whole point. De Beers signed off. The slogan ran for the first time in 1948.

What the line was actually doing

To understand why the four words mattered, you have to understand what De Beers was up against in 1947. Diamond sales had collapsed during the Great Depression. The average American engagement ring in the 1930s contained no diamond at all, or a small chip mounted in a thin band. The South African mining cartel, sitting on enormous stockpiles, hired N.W. Ayer in 1938 to do something unprecedented: not advertise a brand, but invent a custom.

The campaign that Gerety inherited and then defined had two jobs. First, convince young men that a diamond ring was the only acceptable way to propose. Second, convince young women that a ring without a diamond meant they were not truly loved. The slogan she wrote in 1947 accomplished both at once. If a diamond is forever, then so is the marriage it represents — and so is the reason you cannot resell it, which was the quiet commercial masterpiece of the line. A diamond you would never part with is a diamond that would never flood the secondhand market and crash De Beers’ carefully managed prices.

By the 1950s, the majority of American brides received a diamond engagement ring. The number kept climbing. By the late 1990s the practice had become standard in the U.S. and had spread to Japan, where the diamond engagement ring had been essentially unknown before Ayer’s campaign arrived in the 1960s. Within two decades, a majority of Japanese brides were also wearing diamonds.

The greatest slogan of the century

In 1999, as advertising trade publications compiled their end-of-century lists, Advertising Age ranked the top slogans of the twentieth century. A diamond is forever took first place. The judges noted that no other slogan had so thoroughly created the market it served. Most advertising sells a product into an existing desire. Gerety’s line manufactured the desire.

She was in her eighties and watched the announcement from her home in Philadelphia. She had retired three decades earlier. The line was still running, unchanged, on every De Beers campaign worldwide.

The copywriter herself

Frances Gerety was born in Philadelphia in 1916. She studied at Bryn Mawr College and joined N.W. Ayer in 1943, at a moment when wartime labor shortages had cracked open copywriting rooms to women who would have been turned away five years earlier. She kept the job after the war, which was less common, and her colleagues described her as quiet, professional, and obsessively careful about the cadence of a sentence.

She lived in a small house in Philadelphia. She kept dogs. She traveled. She did not, by every available account, ever come close to marrying. She told a colleague once, with characteristic dryness, that she had spent her career persuading other women to do something she had decided against.

The irony nobody made her explain

The temptation, looking back, is to read the gap between Gerety’s professional output and her private life as some kind of secret wound. The concept of achievement wounds tends to frame high-output creative careers as compensations for absences in personal life, and biographers love that frame because it gives a tidy arc. Gerety’s contemporaries did not describe her that way. They described someone who liked her work, liked her independence, and treated the De Beers account as a professional puzzle rather than a personal project.

Building on the distinction between achievement and accomplishment — achievement as the metric, accomplishment as the internal sense that the work was worth doing — Gerety, by every account from people who worked with her, had both, and never seemed to need her own life to mirror the lives she was selling.

The pull to read her biography as ironic comes from how people interpret others’ contradictions. Audiences see a single salient fact — copywriter sells marriage, copywriter never marries — and lock it into a narrative shape because the shape is more memorable than the messy truth. The truth is that Gerety was a working professional in a creative field who happened to be very good at one specific assignment and happened to live a private life that did not match the assignment.

Why the slogan stuck

Linguists and advertising scholars have spent decades trying to explain why four words written at the end of a long workday became one of the most replicated commercial sentences in history. Some of it is the grammar — the singular is, which Gerety insisted on, makes the sentence sound like an axiom rather than a claim. Some of it is the rhythm: three short syllables, a pause, three more. Some of it is the way the line refuses to mention the buyer, the seller, the price, or the act of purchase.

The slogans which embed themselves most deeply in memory tend to function as small proverbs — sentences that feel pre-existing rather than written. They borrow the cadence of folk wisdom. Gerety’s line does this almost perfectly. It sounds like something your grandmother might have said, even though your grandmother probably first heard it from a magazine ad in 1948.

The brevity of four-word phrases sits inside the comfortable range of working memory and can be retrieved with almost no effort. They become available as a kind of mental shortcut, which is exactly what an engagement ring shopper wants when standing in front of a jewelry counter trying to justify a purchase that costs two months of salary — another rule of thumb, incidentally, that N.W. Ayer invented.

The afterlife of four words

Frances Gerety died in 1999, the same year Advertising Age named her line the slogan of the century. She was 83. The obituaries described her as a pioneering woman in advertising and noted, almost as a footnote, that she had never married. De Beers, by then a global conglomerate, kept the slogan running. It still runs.

The diamond engagement ring, which did not exist as a near-universal custom before her campaign, is now worn by the majority of brides in the United States, Japan, China, and a growing list of other markets. Geologists will tell you that diamonds are not, technically, forever — under high enough temperature and pressure they convert back to graphite, and on long enough timescales even the stones in a setting are slowly losing carbon atoms. The line was always a small lie.

Gerety knew. She had written it as a closing argument, not a scientific claim. She went home to her small house in Philadelphia, fed her dogs, and went to sleep, having that morning convinced several million strangers to spend several months of income on a piece of carbon she would not, herself, ever wear.

The post Frances Gerety, the copywriter who coined ‘A diamond is forever’ in 1947, wrote the line judged the greatest slogan of the 20th century — yet she herself never married appeared first on Space Daily.

A copywriter named Frances Gerety working at the Philadelphia advertising agency N.W. Ayer created the line A Diamond Is Forever for a client called De Beers, the South African mining cartel. The slogan would run on De Beers advertising for decades, and the campaign it anchored would invent, almost from scratch, the idea that an engagement ring should cost a man two months’ salary — a number that had no basis in tradition, etiquette, or jewelry industry practice.

The figure started smaller. In the early twentieth century, diamond engagement rings were relatively uncommon among American brides, and rings cost less than they would later.

By the 1980s, De Beers had pushed the American benchmark to two months. In Japan, where the company began advertising in the 1960s, it set the figure at three.

The slogan that ran for 75 years

Gerety worked at N.W. Ayer for her entire career. A Diamond Is Forever became one of the most recognized advertising slogans of the twentieth century. The line did two things at once. It implied that a diamond, like the marriage it symbolised, was eternal — and it discouraged resale, because a stone you would never part with did not need a secondary market that might reveal how little used diamonds were actually worth.

De Beers did not sell diamonds directly to consumers. It sold rough stones to a tightly controlled group of cutters and wholesalers, and it needed to keep demand high enough to absorb the supply coming out of mines in South Africa, Botswana, and later Russia. Advertising was the lever.

Inventing a tradition that had not existed

The two-months-salary rule was not handed down from a Victorian etiquette guide. It was tested in print ads through the 1970s and 1980s, raised from one month to two as inflation and rising incomes allowed, and reinforced through magazine spreads featuring couples whose ring size was implicitly tied to the groom’s professional success. The company eventually stopped suggesting specific salary multiples in U.S. advertising, but by then the figure had embedded itself in popular memory as if it had always been there.

The campaign worked because it tied a luxury purchase to a social fear. A man who spent less risked appearing cheap or uncommitted; a man who spent more signalled devotion. The metric was self-reinforcing because almost no one resold the ring afterward, so the market never had to absorb the secondhand stones that would have exposed the inflated retail markup.

Repeated messaging can convert a manufactured benchmark into a perceived custom, particularly when the purchase is rare, emotionally loaded, and hard to comparison-shop.

The Japan campaign of 1967

Japan was the harder case. Diamonds were largely absent from Japanese weddings before De Beers began its campaign. Engagement gifts followed a traditional custom called yuino, which involved exchanges of symbolic items between the two families. Brides did not typically wear rings. Diamonds, when they appeared at all, were associated with Western excess and were considered ostentatious.

De Beers worked with advertising agencies to change that. The campaign placed diamond rings on young Japanese women photographed in Western settings — skiing, sailing, driving sports cars — surrounded by Western boyfriends and husbands. The visual argument was that diamonds belonged to a modern, internationally mobile, economically successful Japan, and that a man who proposed without one was clinging to a prewar past.

The salary benchmark in Japanese ads was set at three months’ salary, higher than the American figure. Japanese household savings rates were high at the time, and the campaign calibrated the ask accordingly.

How fast the custom took

The numbers shifted faster than almost any comparable case in consumer history. When the campaign launched in the late 1960s, few Japanese brides received diamond engagement rings. Within a few years, the figure began climbing rapidly. By the early 1980s, the majority of Japanese brides were receiving diamond engagement rings. By the late 1990s, the practice had become widespread, and Japan had become the second-largest diamond market in the world after the United States.

Within roughly thirty years, a country with no diamond tradition had adopted one as if it were ancient. Older relatives at weddings began to assume their granddaughters would receive a stone. Wedding magazines printed guidance on ring selection alongside articles on traditional kimono. The yuino ceremony itself often absorbed the ring as one of its exchanged items, blending the new custom into the old form so seamlessly that the seam disappeared.

Why the persuasion worked

Repeated exposure to a single visual framing — a young couple, a small velvet box, a specific cut of stone — establishes the diamond as the default object in the scene. Once the default is set, alternatives feel like deliberate refusals rather than neutral choices.

Purchases tied to identity transitions — marriage, parenthood, graduation — are especially susceptible to manufactured tradition, because the buyer is also performing a social role for an audience of family and peers.

The Japanese campaign exploited that exactly. A bride showing the ring to her mother was not just displaying a stone; she was confirming that the marriage met a modern standard.

The royal accelerant

One outside event amplified the campaign more than any single ad. In 1981, Prince Charles proposed to Lady Diana Spencer with a 12-carat oval Ceylon sapphire surrounded by 14 diamonds — a ring that broke generations of royal tradition by being chosen from a commercial Garrard catalogue rather than commissioned bespoke. The wedding drew a global television audience, including a substantial viewership in Japan, where the broadcast aired with translation.

Diana’s ring was not a solitaire diamond, but the broader visual — a Western royal bride wearing a serious gemstone — fed directly into the framing De Beers had been building. Sales accelerated in both markets through the 1980s.

What the campaign is doing now

The structure has begun to wobble. Lab-grown diamonds, chemically identical to mined stones, now sell at substantially lower prices than natural equivalents, and younger buyers in the United States and East Asia have proved willing to choose them. De Beers spent decades insisting that synthetics were not real diamonds, then launched its own lab-grown brand called Lightbox, and has since pulled back.

In October 2025, the company launched a campaign called Desert Diamonds, its largest in a decade, aimed at re-establishing the cultural premium of natural stones. A separate rebrand of the De Beers jewelry line features the model Adwoa Aboah and a new Paris flagship, framing natural diamonds as heritage objects rather than commodity purchases.

Japan’s diamond market has softened since its peak, partly as marriage patterns have shifted. The three-months-salary rule is now treated by many younger couples as a vintage idea rather than a binding one. The custom is no longer growing. It is also not disappearing — the wedding ring section of any department store in Tokyo still displays solitaires under the same lighting used in the original campaign.

What Frances Gerety left behind

The slogan Gerety wrote had been printed in more languages than almost any other piece of commercial copy in history, and the salary multiples it anchored — two months in America, three in Japan — had reshaped how hundreds of millions of people thought about the moment of proposal.

The diamonds themselves were chemically the same carbon they had always been. The forever was the advertising.

The post The idea that a man should spend two months’ salary on an engagement ring was invented by De Beers marketing — in Japan the campaign set the figure at three, rewriting wedding customs where diamond engagement rings had barely existed appeared first on Space Daily.

The self-help shelf in any bookshop is a monument to overcomplication. Forty-seven habits, twelve rules, seven levels, a morning routine that begins at half past four and involves cold water and a gratitude journal. I have read a depressing number of these, mostly in airports, and retained almost none of it past the departure gate.

Then Neil deGrasse Tyson, the astrophysicist, was asked on a Reddit thread in 2012 what drives him, and he gave an answer short enough to fit on the back of a receipt. Two philosophies, he said. Know more today about the world than you knew yesterday, and lessen the suffering of others. You would be surprised how far that gets you.

My first reaction was the one you are probably having. Lovely. Goes nicely on a mug. My second reaction, a few years later, was that the man had calmly described the only two things that have ever worked for me, and that the second one once stopped me making the stupidest decision of my career.

Know more today than you knew yesterday

The first one is the scientific method pointed at your own life, and it is far more modest than it sounds.

It does not ask you to be a genius, or to ever finish. It asks you to be slightly less wrong tonight than you were this morning. That is more or less the whole engine of science. Nobody in a serious lab is trying to be right in some final, permanent way. They are trying to be marginally less mistaken than the last person, write it down, and let someone else chip a bit further along.

The humility runs deeper than people outside science tend to assume, too. We have been studying gravity for three centuries and still only know Newton’s constant to three significant figures. Around ninety-five percent of the universe is made of things we have politely named dark matter and dark energy, mostly so we do not have to say out loud that we have very little idea what they are. The best-informed species on the only planet known to carry one spends most of its day confidently not knowing things.

I got this wrong for years in a particular way. I thought “know more” meant collect facts and deploy them to win. I was the man at the table with the correction loaded and ready. What I was doing was the precise opposite of the rule, because a person busy being right learns nothing. The truer version is duller and harder. Assume, every single day, that there is a fact you do not yet have. Above all about a person.

The cook I nearly sacked

That stops being abstract very quickly in a kitchen.

Years ago I had a line cook, a quiet lad called Tomas, who started arriving late. Ten minutes, then twenty, then a morning he missed altogether. In the economy of a busy kitchen that is close to a capital offence. The prep does not do itself, and one slow start poisons the entire service behind it. I had the conversation drafted in my head, the regretful, businesslike one that ends with a final pay packet. By the cold numbers, he had to go.

What stopped me was a flat, almost accidental question. I asked him, with no great warmth, what was actually going on. And it came out that his mother had been taken into a hospital on the far side of the city, that he was sitting with her until the small hours, and then walking ninety minutes to my door because the night buses did not connect and the fare, on a cook’s wages, was a genuine decision every morning.

None of that was visible from where I stood, which was the whole point. I had a full and confident model of Tomas, the unreliable cook, and it was missing the single fact that explained all of it. I knew less than I believed I did, which is the standard human condition and the exact thing the first rule is trying to beat out of you.

So I did something small. I shifted his start to the evening, which suited the kitchen anyway, and stopped docking him for the lost mornings. It cost me close to nothing. He stayed four years, became the steadiest pair of hands in the building, and covered for me more times than I can count when my own life later fell apart. You would be surprised, as the man said, how far that got me.

Lessen the suffering of others

People hear the second philosophy as the soft one. The charity bit, bolted on after the clever bit, to make the clever bit look kind. I think that is exactly the wrong way round.

They are the same engine. Knowing more about Tomas was worthless as trivia. Its only value was that it let me take a little weight off him at almost no cost to me. And easing what he carried was not me playing the saint. It was the most clear-headed thing I did that year, because it kept a good cook and bought a loyalty that no bonus on earth would have. Knowledge without the second philosophy is just cleverness, which is cold and gets you avoided at parties. Kindness without the first is good intentions fired blindfold, which mostly miss the target. You need the two of them aimed together.

That is what Tyson tucks into that last offhand line. He does not promise you enlightenment, or wealth, or a flat stomach by June. He promises only that two ordinary habits will carry you “surprisingly far,” which may be the single most honest sentence in the entire self-improvement trade. Nobody can tell you how far. You would be surprised. That is the whole claim, and it happens to be true.

I walked away from the restaurants a few years after Tomas, and I have since forgotten most of what I once knew about margins and stock rotation and the correct way to close down a kitchen at midnight. What stayed was the picture of a tired young man crossing a sleeping city on foot to stand at my stove, and the small, unheroic discovery that the cheapest thing I ever did, ask one question and move one shift, turned out to be the cleverest entry in the books. Two rules, typed into a website by a stargazer at his keyboard. They really will carry a person an absurd distance, though their author had the good manners not to say how far. He left you to walk it and find out.

The post Quote by Neil deGrasse Tyson: “For me, I am driven by two main philosophies: know more today about the world than I knew yesterday and lessen the suffering of others. You’d be surprised how far that gets you.” appeared first on Space Daily.

The quote has a clean, precise quality that most observations about fear do not. Reid Wiseman posted it to Twitter in October 2014, a few days after completing the first spacewalk of Expedition 41 aboard the International Space Station: “While #spacewalking I realized something: I used to think I was scared of heights but now I know I was just scared of gravity.”

He was floating outside the station at roughly 400 kilometres above Earth, working with European Space Agency astronaut Alexander Gerst for six hours and thirteen minutes on cooling pump relocation and external robotics work. The spacewalk was conducted on 7 October 2014. At that altitude, with nothing below and the planet curving away at the edge of peripheral vision, Wiseman noticed the absence of something he had expected to find: the fear he thought he had.

The quote has resurfaced in the months around the Artemis II mission, for which Wiseman serves as commander. On 1 April 2026, he launched as part of the first crewed mission to the Moon since Gene Cernan commanded Apollo 17 in December 1972. The insight is more than a decade old. It reads differently now, from a trajectory that takes Wiseman and his crew past the Moon and back.

The distinction itself

The difference between fearing heights and fearing gravity sounds like wordplay until you hold it carefully. Both terms are commonly used to describe the same cluster of behaviour: the discomfort on balconies, the reluctance to stand near the edge of a cliff, the particular unease of a glass floor above a long drop. The behaviours are consistent. What Wiseman is questioning is the diagnosis.

A fear of heights, understood as a response to elevation and exposure, locates the problem in the altitude. But what most people are responding to in those situations is not the height in any abstract sense. It is the fall. It is gravity’s action on the body in the event of a slip. It is the trajectory the body would follow if the ledge gave way, and the irreversibility of what that trajectory leads to. The height is the setup. Gravity is the mechanism.

In microgravity, the mechanism has been removed. There is no directional pull toward a surface that recedes infinitely. There is no trajectory the body would follow if it lost contact with the station. An astronaut outside the ISS is not high in the sense that a person on a balcony is high, because the relationship between position and consequence that produces the fear of heights has been cancelled. Wiseman was in the most extreme version of elevation a human can occupy, and the thing he expected to feel was not there.

He worked backward from that absence to what it meant. The fear he had carried was not of heights. It was of gravity.

What reclassification does

This kind of revision is harder than it sounds. Most people who believe they fear heights have arranged something around that belief: the avoidance patterns, the decisions about which windows to stand near, the self-description offered when explaining a refusal. The label has become load-bearing. It organises behaviour.

What Wiseman found was that the label was describing a proxy rather than the cause. The altitude was consistently present when the fear appeared, so the altitude got named. But the consistent presence of altitude was itself a consistent presence of gravity’s consequences. The two variables had never been separated. Spacewalking separated them.

The implication is not that people who fear heights are wrong about their fear. The fear is real and the behaviour it produces is real. What shifts is the precision of the account. Someone who understands their discomfort as being about gravity’s consequences, rather than about altitude per se, has a different description of where the sensitivity lives. That description may or may not change anything practical about what they avoid. But it is more accurate, and accuracy in these matters has a certain value even when it is not immediately actionable.

Wiseman did not overcome a fear. He reclassified one. The distinction matters because overcoming implies confronting the same situation repeatedly until the response diminishes. Reclassification involves recognising that the situation you have been avoiding is not quite the thing you thought it was.

Twelve years and a lunar trajectory

Wiseman is 50 years old, a retired United States Navy captain and test pilot. As of April 2026, he is the commander of a mission carrying him further from Earth than any human since the Apollo programme. His crew includes NASA astronauts Christina Koch and Victor Glover and Canadian Space Agency astronaut Jeremy Hansen.

Artemis II is a circumlunar flyby, not a landing. The crew will loop around the Moon and return. The distances involved, the communication delays, the duration, make any analogy between this and an ISS spacewalk look quite small. The environment Wiseman occupied in 2014 was far more controlled than the one he entered in April 2026.

The 2014 insight does not become more or less true in this context. It is not predictive of how Wiseman or anyone else experiences the Artemis II mission specifically. But the Artemis II frame does something to the quote: it makes the scale of what he has learned to not be afraid of more visible. The man who discovered in 2014 that his fear was of gravity, not altitude, is now travelling to a distance at which Earth’s gravity is a much smaller presence.

There is a version of this story that treats it as an arc of overcoming, each mission more extreme than the last, the fear perpetually shrinking. That is not what Wiseman is describing. He is describing a single clarification, arrived at empirically, during six hours of work outside a space station. The rest followed from that, or did not.

The question the observation leaves open

Wiseman’s observation raises a question that has no clean answer: when we say we fear something, how often are we naming the right thing?

The fear of heights is a durable shorthand, but it collapses a set of variables that could in principle be separated. The height. The exposure. The lack of handholds. The awareness of what would happen if the body fell. The mental simulation of the fall itself. These are not identical. They would, if separated, suggest different things about where the sensitivity lives. Most people never encounter the conditions that would separate them. Wiseman did.

There is no general lesson here that applies predictably from person to person. What seems clear is that the precision of Wiseman’s account is a function of the specificity of the test. An environment that removed gravity as a variable allowed him to see that gravity was the variable that mattered. Ordinary environments, which almost always include gravity as a background constant, do not offer the same diagnostic clarity.

He has not said whether the reclassification changed anything else. He has said that he now knows which word to use.

The post Artemis II astronaut Reid Wiseman on spacewalking: “I used to think I was scared of heights — now I know I was just scared of gravity” appeared first on Space Daily.

A few months ago, I found myself deep in a conversation about Mars colonization timelines. The other person — a software engineer, genuinely enthusiastic, not naive about the engineering — was walking me through radiation shielding approaches, the habitability of lava tubes, the logistical case for SpaceX’s Starship architecture. It was fascinating. He clearly knew far more than I did about the technical specifics. But somewhere in the middle of it, a question started forming that I couldn’t quite place, until eventually I did: we hadn’t once asked whether any of this was a good idea.

We had been talking about how for an hour, and neither of us had said the word why.

That conversation has been sitting with me since. Not because the technical questions aren’t important — they’re genuinely hard, and the people working on them are doing serious work. But there is a gap between “this is technically possible” and “this is what we should do,” and that gap tends to close faster in the Mars discourse than it does almost anywhere else. The survival problem gets all the oxygen. The ethical one gets treated as settled — as if the answer to “should we go?” is obviously yes, and the only thing left to figure out is the radiation shielding.

I’m not a space scientist and I don’t have a strong stake in any particular answer here. What I do have is a persistent discomfort with how questions get framed — with the way the tractable problem has a tendency to absorb all the attention that the harder one deserves.

The question we’re not asking

The survival discourse is, in its way, extraordinary. Cosmic radiation at the Martian surface running at roughly six to seven chest X-rays per day under normal conditions — and significantly higher during transit and solar storm events. An atmosphere that amounts to about one percent of Earth’s. Temperatures swinging 70 degrees Celsius or more between day and night. The progressive bone density loss from low gravity that compounds across months into something that isn’t easily reversed. These are real problems, and the engineers working on them deserve the coverage they get. None of that is what I’m questioning.

What I’m questioning is the habit of treating “can we survive there?” as a proxy for “should we go?” — as though answering the first settles the second. It doesn’t. They are different questions that require different kinds of thinking, and we have, for the better part of a decade, let the excitement and tractability of the first crowd out serious engagement with the second.

The life question nobody wants to stop for

One of the more uncomfortable things I’ve come across in reading about this is the planetary protection question — specifically, the possibility that Mars might not be as empty as the colonization narrative tends to assume. The debate about whether Mars currently harbors microbial life, perhaps in briny subsurface water or in the recurring slope lineae that have been periodically interpreted as evidence of seasonal liquid water, remains genuinely open. No confirmed biology has been found. But “not yet confirmed” is not “not there,” and the question of what we would do if we found it — before or after we arrived — seems to get less serious treatment than it warrants.

NASA’s planetary protection guidelines exist precisely because this uncertainty is real. They were built around the concern that Earth microbes carried on spacecraft could contaminate Mars and compromise any future ability to find or study native life there — or vice versa. The protocols apply most strictly to robotic missions, which can be sterilized. They apply far less cleanly to humans, who exhale, shed skin cells, and carry an internal ecosystem of trillions of organisms that are not optional passengers. A crewed mission, by design, cannot be managed the same way a probe can.

What this means, if taken seriously, is that any crewed mission to Mars before we have higher confidence about the biological status of the planet carries a non-trivial risk of introducing an extinction event for whatever might be living there. Carl Sagan, who spent his career both advocating for space exploration and urging caution about it, made this point repeatedly — that introducing Earth organisms into a low-diversity Martian ecosystem, if one exists, could eliminate it entirely before we ever knew it was there. The argument has not aged out. If anything, growing scientific interest in Martian subsurface habitability has made it more pressing, not less.

We have spent years asking whether humans can survive on Mars. We have spent much less time asking what Mars might be surviving from, if we arrived.

The backup civilization argument and its hidden premises

The most common justification offered for Mars colonization at the level of civilizational stakes is the backup argument: a multi-planetary species is an insurance policy, and the cost of not going is existential risk to the entire human project. Stephen Hawking made this argument in his final years. Elon Musk has built it into the explicit ideological foundation of SpaceX’s long-term mission — a self-sustaining city on Mars as a hedge against collapse on Earth.

I find this argument more worth taking seriously than most critics give it credit for. The underlying concern about existential risk is real. The logic that a species concentrated on one planet is more vulnerable than one distributed across two is coherent. But the argument is doing more work than it usually admits, and some of its hidden premises deserve more scrutiny.

The most obvious one is timing. The existential threats most likely to end civilization on Earth in the foreseeable future — climate change, engineered pandemics, nuclear conflict, biodiversity collapse — are immediate relative to any realistic projection of a self-sustaining Martian colony. A genuinely self-sustaining Mars city, by most serious estimates, is generations away. The threats we are failing to address are not. If the backup civilization argument is meant to be taken literally as a response to existential risk, it would seem to require securing the primary civilization first — not as an alternative to Mars ambitions, but the sequencing matters considerably more than the discourse tends to acknowledge.

The governance question matters here too. The Mars colonization effort as it currently stands is being driven largely by the decisions of a very small number of extraordinarily wealthy individuals and their companies, operating mostly outside democratic institutions, international treaty frameworks, or any serious mechanism of public deliberation. The Outer Space Treaty of 1967 prohibits national sovereignty claims over celestial bodies, but it was not designed to address private colonization by corporations operating under whatever regulatory minimums they can find. The choices being made now — when to go, at what pace, under what protocols — will shape the terms of Mars activity for a very long time. The fact that those choices are being made by a small group of people with specific and concentrated interests seems like something a more serious public conversation would address.

What an honest accounting would require

I want to resist the easy conclusion here — the “we should never go” position that treats any Mars ambition as inherently reckless or hubristic. There are real arguments for human Mars exploration. The science alone — the geology of ancient riverbeds, the evidence of a once-warmer world, the complex chemistry of the regolith — has produced discoveries with no parallel in the history of planetary science, and there are legitimate cases that humans on the surface could accelerate that science in ways robots fundamentally cannot. I find the impulse to go, the sheer ambition of it, genuinely compelling on some level I can’t entirely defend rationally.

But I think we owe it to the question — and possibly to whatever might be living on that planet — to stop treating the survival problem as a substitute for the ethical one. An honest accounting would start with the life question: invest seriously in determining whether Mars is biologically empty before a crewed mission departs, and treat a positive finding as a real constraint on what comes next rather than a footnote to manage. It would include meaningful international deliberation about who gets to make these decisions, and why the current answer to that question is “the people with the most rockets.” It would take the backup civilization argument seriously enough to notice what it actually implies about sequencing and urgency on Earth.

The conversation I had a few months ago was a good one. The engineer was genuinely thoughtful, and I learned things I didn’t know. But I’ve been bothered, in the time since, by how naturally we both moved through the technical questions and how completely we both skipped the other kind. The “can we?” problem is captivating in a way the “should we?” problem never quite is. It has cleaner edges. It has milestones. It announces itself as progress.

The harder question doesn’t do any of that. It just sits there, waiting for the conversation to slow down enough to make room for it.

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The face you walked into the room with this morning was being read, by every person who looked at you, in approximately one hundred milliseconds — about a tenth of a second, faster than any conscious thought. The reading was not primarily about the features that took your DNA twenty years to assemble. The bones of your face, the colour of your eyes, the shape of your jaw, the symmetry of your features — these all contributed to the judgement, but they were not, on the available evidence, the only ingredients of it. A substantial part of how attractive any individual stranger perceived you to be, in the brief moment before they had any other information about you, was almost certainly whether you appeared to be having a good time. A genuine smile, animated expression, and the visible signs of a person enjoying being where they are produce, in the moment of first impression, attractiveness boosts that can rival what carefully selected clothing, makeup, or grooming can plausibly achieve.

According to a 2014 paper by Jessika Golle, Fred Mast, and Janek Lobmaier published in Cognition and Emotion titled “Something to smile about: The interrelationship between attractiveness and emotional expression”, the social effect of smiling on stranger-rated attractiveness has been replicated across enough independent studies and across enough cultural contexts to be considered one of the more robust findings in social psychology. Smiling faces are rated more attractive than neutral faces of the same person, across both sexes, across multiple age ranges, and across essentially every population that has been examined. The neuroimaging literature has identified the underlying mechanism: when human observers see a smiling face, the medial orbitofrontal cortex — a region of the brain involved in reward processing and the assignment of positive value to stimuli — shows a substantially stronger response than when the same observer sees a neutral face. The smiling face is, in a literal sense, registering in the observer’s brain as more rewarding to look at.

What kind of smile actually works

The specific type of smile matters substantially. As reported by a peer-reviewed PMC review of smile research and the broader perception literature, the most extensively studied distinction in the smile literature is between what researchers call Duchenne smiles and non-Duchenne smiles. The Duchenne smile, named after the 19th-century French neurologist Guillaume Duchenne who first characterised it, activates two distinct sets of facial muscles: the zygomatic major, which pulls up the corners of the mouth, and the orbicularis oculi, which creates the small crinkles around the outer corners of the eyes. Both muscle activations occur involuntarily when a person is genuinely amused or pleased. The non-Duchenne smile activates only the mouth corners and is the kind of polite, social smile produced on demand for photographs or to acknowledge a casual greeting.

The two types of smile are perceived very differently by observers, even though most people cannot articulate exactly what the difference is when they see one. Duchenne smiles register as genuine, warm, trustworthy, and substantially more attractive. Non-Duchenne smiles register as polite at best, performative or insincere at worst, and produce far smaller boosts to attractiveness ratings. The discrimination is automatic and is operating in the observer’s brain at the level of unconscious pattern recognition rather than conscious analysis. This is the underlying reason why the standard advice to “smile more in photos” often produces mediocre results in practice: the smiles are non-Duchenne. The viewer’s brain registers the difference even when the viewer cannot consciously identify what is wrong with the expression.

Why the effect is so large

Per a 2023 study in Evolutionary Human Sciences examining how smiling expressions interact with facial features in attractiveness judgements, the magnitude of the smiling-on-attractiveness effect is large enough to substantially affect outcomes in real-world social contexts. Across studies, happy facial expressions consistently produce the highest attractiveness ratings of any expression tested; angry expressions produce the lowest. The effect appears in both sexes but is particularly pronounced for ratings of female faces, where smiling can shift attractiveness ratings by amounts comparable to the difference between an averagely-rated face and a substantially above-average face. Even male facial masculinity — which interacts in complex ways with attractiveness preferences — is moderated by smiling: smiling reduces the avoidance response some women show toward strongly masculinised male faces.

The evolutionary and social explanation for this effect is, in the relevant literature, fairly direct. A smile is one of the few human expressions that is broadly cross-cultural — recognised across nearly every population that has been tested — and that consistently signals friendliness, low threat, willingness to engage, and positive emotional state. For an observer making rapid social judgements about whether to approach a stranger, the smile is a substantial piece of information: it indicates that the encounter is likely to go well, that the person on the other side is in a positive frame of mind, and that initial overtures will probably be reciprocated. The attractiveness boost is, in this account, the observer’s brain doing what brains do — bundling the information about the smile into a single quick-summary judgement about whether this stranger is worth engaging with. The summary judgement, in shorthand, comes back as “attractive.”

What the framework does not claim

Intellectual honesty requires noting the limits of the smiling-as-attractiveness effect. The research does not show that smiling can substitute for every other physical or social factor in attractiveness ratings. As covered by a 2025 review at All About Psychology on the broader smile-attractiveness literature, static physical features — facial structure, body shape, height, age, grooming — still contribute substantially to first-impression attractiveness ratings, and the smile effect is best understood as a substantial modifier of these underlying factors rather than as a replacement for them. A smiling face is more attractive than the same face not smiling. A smiling person is generally more approachable than a neutral one. Whether the smiling person is, in absolute terms, more attractive than a non-smiling person with substantially different underlying physical features is a question the research does not consistently answer.

What the research does support is a more specific and more practically useful claim. For any given person, in any given moment, the version of that person who appears to be genuinely enjoying themselves is going to be perceived as more attractive than the same person looking flat, distracted, or unhappy. The variable that each individual has the most direct control over, in the seconds before a first impression forms, is not their face or their body — those are mostly fixed at the moment of the encounter. The variable that is actually within their control is their expression, their visible emotional state, the degree to which they appear genuinely engaged with what is happening around them. The research consistently suggests that this variable, despite being the one most readily modifiable, is one of the larger factors that the observer’s brain weights when assigning the first-impression attractiveness rating. Looking like a person who is glad to be where they are turns out to be, by every available measure, a substantial part of what other people are responding to when they form their first impression of you.

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The face you saw in the mirror this morning was not the face anyone else saw when they looked at you over breakfast. The two are related but not identical. Most human faces are slightly asymmetric — the eyes are at slightly different heights, the smile pulls more strongly on one side than the other, the hair parts on one side, freckles sit in specific positions that do not perfectly mirror across the vertical axis. When you look in a mirror, you see one version of your face, with left and right reversed relative to what other people see. When other people look at you, they see the opposite. You have, over the course of your life, become deeply familiar with one of these two versions. They have become familiar with the other. Neither version is wrong. Both are, however, surprisingly different from each other in ways that affect how each party perceives the same underlying face.

According to a 1977 paper by Theodore Mita, Marshall Dermer, and Jeffrey Knight published in the Journal of Personality and Social Psychology, the experimental setup that established this phenomenon was straightforward. The researchers took a frontal photograph of each of 37 women — undergraduate psychology students at the University of Wisconsin-Milwaukee — and printed each photograph twice: once as a true image (showing the face as a camera or another person would see it), and once as a mirror-flipped image (showing the face as the subject herself would see it in a bathroom mirror). The subjects were then shown the two versions side by side and asked which they preferred. The same pairs were shown to the subjects’ friends and lovers, who were asked the same question. The results, in both Study 1 and a subsequent Study 2, were striking and consistent. The subjects themselves preferred the mirror-flipped version of their own face. Their friends and lovers preferred the true version.

Why this happens

The mechanism underlying the effect is one of the better-established findings in social psychology: the mere-exposure effect, first proposed by the University of Michigan psychologist Robert Zajonc in 1968. As described in Gizmodo’s coverage of the mere-exposure mechanism behind the mirror preference, the mere-exposure effect is the phenomenon by which repeated exposure to a stimulus increases a person’s preference for that stimulus. The more often you encounter something, the more comfortable you become with it, and the more positively you evaluate it on subsequent encounters. The effect operates across an enormous range of contexts. People develop preferences for songs they have heard repeatedly, for faces they have seen frequently in public, for words that appear often in their reading, for foods they have eaten before. It does not require any explicit reasoning or evaluation; it works at the level of automatic familiarity processing.

The mirror-image preference is a particularly clean demonstration of the effect because the two stimuli being compared — the true image and the mirror image of the same person’s face — are objectively almost identical. The asymmetries are small. The lighting is the same. The expression is the same. The only difference is which side of the face is on which side of the photograph. The subject has, over the course of her life, spent many thousands of hours looking at one specific version. Her friends and lovers have spent many thousands of hours looking at the opposite version. When the two parties are then asked which version “looks more like” the person in question, or which version is more attractive, each party prefers the version they have been seeing all along. Neither is wrong. Each is simply applying the mere-exposure effect to the version of the face they have the most experience with.

What this implies about self-perception

Per the Mita et al. paper’s broader theoretical discussion, the finding has implications that extend well beyond the specific experimental setup. The general principle is that the version of yourself that you have internalised as canonical — the face you recognise as belonging to you, the face you adjust before going out, the face whose minor blemishes and asymmetries you have catalogued in detail — is a version that essentially nobody else has ever seen. Every photograph anyone else has ever taken of you. Every memory anyone else has formed of your face. Every impression you have made on a stranger across a room. All of these have been based on the opposite version of the face from the one you have been carrying around in your own head.

This is the underlying psychological mechanism behind the common experience of looking at a photograph of yourself and finding it subtly wrong. The face in the photograph is the true image — the version other people have been seeing all along — but it does not match the mirror image you have spent your life looking at. The mismatch produces the small but real sense of discomfort that most people experience when seeing themselves in photographs, particularly photographs they did not pose for and in which they had no opportunity to adjust their expression before the shutter clicked. The photographs are not unflattering. The photographs are accurate. Your face is mirroring back at you, several centimetres off from where you expected it to be.

The selfie problem

The modern environment has complicated the picture in ways that the Mita team could not have anticipated in 1977. As covered by Goody Feed’s analysis of how mirror-image preferences apply to selfie photography, most smartphone cameras now display selfies in the front-facing camera as a mirror image of the user — because that is what the user is accustomed to seeing — and then save the resulting photograph in one of two ways, depending on the phone model and the specific app being used. Some phones save the mirror-flipped version (the version the user saw in the viewfinder). Others save the true version (the version other people would see). The user is, accordingly, receiving inconsistent feedback about which version of their face is “really” them. A selfie that looked fine in the camera viewfinder may appear subtly wrong when reviewed afterwards, because the photo has been flipped to the true orientation. The same selfie viewed by a friend may look slightly strange to the user but entirely normal to the friend, who has been seeing that orientation of the face all along.

The broader implication, beyond the specific case of selfies, is that nearly every modern human is now navigating a world in which both versions of their own face are routinely available — the mirror version every morning in the bathroom, the true version in every photograph, video, and reflective non-mirror surface. The two versions are different enough that the brain registers the discrepancy. The version each person has learned to recognise as their own is, by all available evidence, the one that other people have not seen, except in the rare case of looking at the person directly while standing on the opposite side of a mirror. Everyone else has been seeing the other one. Your face, the one in your head, is essentially the reverse of the one the world has been looking at for as long as you have had it.

The post The face you see in the mirror every morning is not the face other people see — when researchers show people two photos of themselves, most prefer the mirror-flipped version, while their friends and partners shown the same pair consistently pick the unflipped one, meaning the face you have grown to recognize as your own is essentially the reverse of the one the world has been seeing all along appeared first on Space Daily.

Casey Harrell can now talk for twelve hours at a stretch. Two years ago, he could not talk at all. The ALS he was diagnosed with several years earlier had progressively destroyed the motor neurons controlling the muscles of his face and throat, leaving him with the symptoms doctors call dysarthria and, eventually, anarthria — the inability to speak intelligibly even with substantial effort. Harrell still knew what he wanted to say. The neural commands his brain was sending toward the muscles of his lips, tongue, jaw, and larynx were intact. The muscles themselves no longer responded. What the BrainGate clinical trial team at UC Davis did, in a July 2023 surgery that took several hours, was implant four small arrays of microelectrodes into the left precentral gyrus of Harrell’s brain — the region of the speech motor cortex that ordinarily sends those commands to those muscles. The arrays contain 256 electrodes between them. The electrodes record the firing patterns of individual neurons in real time. Machine-learning software running on a nearby computer translates the patterns into the words that Harrell, despite no longer being able to produce them with his mouth, is still trying to say.

According to UC Davis Health’s June 2026 announcement of the latest results, the system now operates at approximately 99 percent accuracy across a working vocabulary of 125,000 words — essentially every word an English-speaking adult would ordinarily need. Harrell’s average speaking rate via the device is approximately 56 words per minute, comparable to slow natural conversation. He has used the system at home, without researchers present, for more than 3,800 hours over a 400-day continuous-use period — averaging roughly five hours of daily use, with maximum single sessions of approximately twelve hours. He has produced more than 183,000 sentences and approximately two million words. His synthesised voice is modelled on recordings of his own pre-ALS voice. When he first heard it during the early trial phase, his own comment was: “It feels a lot like me.”

What changed between 2024 and 2026

The BrainGate team’s first publication on Harrell’s case, in the New England Journal of Medicine in August 2024, established that the basic approach worked — that brain activity recorded from the speech motor cortex could be decoded into fluent speech with high accuracy, in a setting with researchers present and a constrained working session. The June 2026 paper documents something fundamentally different: the same patient continuing to use the same system, but now in an independent home setting, operated by his own care team rather than by researchers, for thousands of hours over multiple years. As reported by ScienceAlert’s coverage of the latest results, this transition — from a proof-of-concept demonstration in a research lab to a sustained, independent communication tool used as part of daily life — is the genuinely novel achievement that the BrainGate team is reporting.

David Brandman, the UC Davis neurosurgeon who implanted the device and co-led the research, framed the shift directly: “For years, BCIs have been proof-of-concept devices that lived in highly controlled research labs. This work shows that we may have crossed a threshold, by empowering a person with paralysis to speak on his own terms.” The practical difference is substantial. A device that requires researchers to be physically present every time it is used can demonstrate scientific feasibility but cannot become part of a person’s actual life. A device that the patient’s regular home care team can connect every morning and disconnect every evening, with no specialist intervention required, can. Harrell has been doing the latter for two years.

What the system actually does

The fundamental insight underlying the BrainGate speech BCI is that the brain continues to send speech commands even after the muscles can no longer execute them. When Harrell attempts to speak, the neurons in his speech motor cortex fire in patterns that are essentially identical to the patterns they would have produced if he could still move his speech muscles normally. The implanted microelectrodes record those firing patterns from approximately 256 individual neurons. The decoding software, trained on Harrell’s specific neural signatures during initial calibration sessions, identifies which phonemes he is trying to produce and assembles them into words. Per The Next Web’s analysis of the BRAND platform that powers the decoding, the system uses a custom machine-learning architecture optimised for real-time speech reconstruction, with continuous adaptation to changes in the neural signal over time.

One of the more remarkable aspects of the system is its inclusion of a deliberate “privacy mode,” in which Harrell can disable data recording when he does not want his neural activity captured or used to train future versions of the decoder. The feature exists because the technology raises real concerns about the boundary between intended speech and unspoken thought. Brain-computer interfaces, by their nature, record neural activity that the user may not have chosen to externalise. The BrainGate team has been careful to design the system so that the user controls what gets recorded and what does not.

What this means for the broader field

The Harrell case is part of a broader convergence in the BCI field that has been gathering pace over the past several years. As covered by a Clinical Trials Arena analysis of the BCI clinical trial landscape, the BrainGate consortium — which has been running clinical trials of brain-computer interfaces since the early 2000s, and now spans Brown University, Massachusetts General Hospital, the VA, and UC Davis — is one of several parallel efforts working on the same general problem. Elon Musk’s Neuralink, Synchron, Paradromics, and the UCSF and Stanford BCI groups have all produced demonstrations of varying scope and ambition. The BrainGate Harrell case is, at present, the most extensively documented sustained-use BCI result in the published literature, but it sits within a broader trajectory in which the basic technology is moving from research curiosity to clinical reality.

For the approximately 30,000 Americans currently living with ALS, the practical implications of the Harrell case are limited in the short term. The technology remains experimental, requires invasive surgery, and is not yet commercially available outside the clinical trial setting. Scaling the approach to a second patient, a tenth patient, a hundredth patient will require substantial work on hardware durability, surgical standardisation, software adaptation across individual neural signatures, regulatory approval, and the long list of practical and economic questions that any new medical device must answer before becoming generally available. None of these are insurmountable. None of them are immediate. Harrell himself is now able to communicate, work, and participate in family and social life in ways that were not available to him two years ago. The question of how soon the same becomes true for other ALS patients, for stroke survivors with severe communication impairment, for people with locked-in syndrome, and for the broader population of patients with severe paralysis is now a question of engineering, manufacturing, and policy rather than of fundamental scientific possibility. The threshold the BrainGate team is now claiming to have crossed, in Brandman’s framing, is the one between proof-of-concept and tool. Whether the rest of the field follows, and how quickly, will define the next decade of BCI research.

The post A brain-computer interface has, for the first time, restored fluent everyday speech to a person who had lost it — a man with ALS who had not spoken aloud in years until a small implant from the BrainGate clinical trial began translating his attempts to speak directly into computer-synthesised words, in a result researchers reported in June 2026 appeared first on Space Daily.

Red Granite Pictures, a small Los Angeles production company co-founded by Riza Aziz, the stepson of then-Malaysian Prime Minister Najib Razak, wrote the checks that put Leonardo DiCaprio on a yacht in Martin Scorsese’s The Wolf of Wall Street. The film, released in December 2013, cost roughly $100 million to make and grossed almost $400 million worldwide. U.S. Department of Justice civil forfeiture filings later alleged that a large share of that production budget came from money looted out of 1Malaysia Development Berhad, the sovereign wealth fund known as 1MDB.

A movie about a stockbroker who defrauds investors was paid for, prosecutors say, with the proceeds of one of the largest financial frauds in history.

The irony is the kind screenwriters usually have to invent.

The fund that was supposed to build Malaysia

1MDB was set up in 2009, the year Najib Razak became prime minister. The pitch was straightforward: a state investment vehicle that would borrow on the strength of Malaysia’s sovereign credit and pour the money into power plants, real estate, and infrastructure that would lift the country into the upper tier of developed economies.

Within a few years, the fund had raised billions through bond issues arranged by Goldman Sachs. Where the money actually went became the subject of investigations on four continents.

U.S. prosecutors allege that at least $4.5 billion was siphoned out of 1MDB between 2009 and 2015, routed through shell companies and offshore accounts, then spent on penthouses in Manhattan, a Bombardier jet, a 300-foot superyacht called the Equanimity, Van Gogh and Monet paintings, jewelry for Australian model Miranda Kerr, and a slate of Hollywood films.

Red Granite and the Scorsese pitch

Riza Aziz founded Red Granite Pictures in 2010 with an American partner, Joey McFarland, a former event promoter from Kentucky. Neither had produced a major studio film. Within two years they had outbid Warner Bros. for the rights to The Wolf of Wall Street, the memoir by convicted penny-stock fraudster Jordan Belfort that Scorsese and DiCaprio had been trying to get made for years.

Red Granite covered the entire production budget. They threw a launch party in Cannes in 2011 with Kanye West performing. The young executives told the trade press they had backing from wealthy Middle Eastern investors.

The real source, according to the Justice Department’s 2016 and 2017 civil forfeiture complaints, was Low Taek Jho, better known as Jho Low, a Malaysian financier in his early thirties who had become close to the Najib family and who allegedly orchestrated the looting of 1MDB from the inside.

How the money moved

The U.S. complaints trace a specific path. In 2012, prosecutors alleged, hundreds of millions of dollars traceable to diverted 1MDB bond proceeds moved into accounts linked to Red Granite and were used to fund film production.

From there, prosecutors say, money tied to the diverted bond proceeds helped finance The Wolf of Wall Street specifically. DOJ remarks at the time put the figure at more than $100 million involved in the theft from 1MDB used to finance the film.

The film opened on Christmas Day 2013. DiCaprio was nominated for an Academy Award. He thanked Riza Aziz and Joey McFarland at the Golden Globes when he won Best Actor in a Musical or Comedy.

The yacht, the paintings, the Oscar statuette

The asset list U.S. authorities tried to recover reads like a parody of what a 1990s screenwriter would imagine a corrupt billionaire owns. The Equanimity, valued at around $250 million, was seized off Bali in 2018 and later sold to a Malaysian gaming company for $126 million.

Malaysian authorities have since recovered and displayed Picasso and Joan Miró works that prosecutors say were bought with stolen funds, unveiling the paintings publicly as part of the asset-recovery effort.

Jho Low also allegedly bought Marlon Brando’s Oscar statuette for On the Waterfront as a birthday gift for DiCaprio. DiCaprio handed it back to investigators in 2017, along with a Picasso he had been given and a Basquiat collage.

Settlements, pleas, and a fugitive

Red Granite Pictures settled with the U.S. Department of Justice in March 2018, agreeing to pay $60 million without admitting wrongdoing. The settlement covered claims that production money for The Wolf of Wall Street, Dumb and Dumber To, and Daddy’s Home had come from tainted sources.

Najib Razak lost the 2018 Malaysian general election to a coalition led by his former mentor Mahathir Mohamad. He was arrested weeks later. In July 2020 he was convicted on seven charges of abuse of power, criminal breach of trust, and money laundering tied to a smaller 1MDB-linked entity called SRC International, and sentenced to 12 years in prison. His sentence was later halved to six years. His path from prime minister to prison inmate took barely two years.

Riza Aziz was charged in Malaysia in 2019 with laundering $248 million of 1MDB funds. Those charges were dropped in 2020 under a settlement requiring him to return assets, a decision that prompted public anger in Kuala Lumpur.

Goldman Sachs paid more than $2.9 billion in penalties to U.S., Malaysian, and other regulators in 2020 for its role in arranging the 1MDB bond issues. Its Malaysian subsidiary pleaded guilty.

Jho Low remains at large. Interpol has issued a red notice. He is believed to be in China.

The Switzerland trial

The case keeps generating new courtrooms. In April 2024, two men accused of embezzling $1.8 billion from the fund went on trial in Switzerland, another set of hearings stemming from the multibillion-dollar scandal that has touched banks, royals, and Hollywood studios across half a dozen jurisdictions.

Swiss prosecutors have been pursuing the case since 2015, when the country’s attorney general announced criminal proceedings over what he described as serious indications that funds had been misappropriated from Malaysian state companies.

What the film became

The Wolf of Wall Street made Scorsese’s longest theatrical cut, at three hours and two minutes, and the film’s reputation has only grown. It is taught in business ethics courses. Belfort himself tours the world giving motivational speeches.

Whether films about financial crime glamorize the behavior they depict, or warn against it, is a live question in academic research on media representation and public perception of crime. Outlets shape understanding by selecting which incidents to report and how to frame them, and the 1MDB case is a near-perfect study in that framing problem.

The film about Belfort’s quaaludes and stolen millions was paid for, prosecutors allege, with quaaludes-and-stolen-millions money. The closing scene shows Belfort, freshly out of prison, running a sales seminar in Auckland. The audience leans forward. They want to learn how he did it.

Why people do this

The psychology of large-scale financial fraud is its own field. One useful clue is the gap between how people see their own ethics and how they judge everyone else’s. A Psychology Today discussion of researchers’ self-ratings points to bounded ethicality and motivated reasoning, the ordinary mental machinery that can let people preserve a moral self-image while making decisions they might condemn from the outside.

Jho Low, in the few public statements his lawyers have made, has consistently denied wrongdoing. Najib has maintained that he believed the funds in his personal accounts, a now-famous transfer of roughly $681 million, were a gift from the Saudi royal family.

Malaysian voters did not buy that explanation. According to reports, Najib defended distributing money to win votes, a practice that critics said epitomized his administration’s approach to governance.

A footnote in the credits

The opening credits of The Wolf of Wall Street still carry the Red Granite Pictures logo. Streaming services have not edited it out. The film plays on Paramount+, on airline seatback screens, on television at 1 a.m. on a Tuesday.

The closing scene with Belfort in Auckland was shot in late 2012. By then, according to U.S. prosecutors, the wire transfers into Red Granite-linked accounts had already cleared. The film was, in a sense, already inside the crime it was about to depict.

Of the roughly $4.5 billion U.S. authorities allege was stolen from 1MDB, the Malaysian government has so far recovered a little over half. Jho Low’s whereabouts are unknown. The Equanimity sails under a new name. And somewhere in a federal evidence locker, a Picasso and an Oscar statuette wait to be sent home.

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The American population pyramid is changing shape in real time, and the rate of change is accelerating. The country has always been, demographically, a relatively young society — substantially younger than most of Europe, dramatically younger than Japan, and shaped throughout its history by waves of younger immigrants and high birth rates that kept the population pyramid wide at the bottom. That configuration is now ending. The 78 million baby boomers, born between 1946 and 1964, are aging through the older brackets of the population in a single demographic wave that will not be replaced by an equivalent generation of children behind them. The youngest boomers will reach 65 in 2029. By 2030, every member of the boomer generation will be 65 or older. By 2034, on the most recent Census Bureau projections, the population of Americans aged 65 and older will, for the first time in the nation’s history, exceed the population of Americans under 18.

According to the U.S. Census Bureau’s official announcement of the 2017 National Population Projections, Jonathan Vespa, the Census Bureau demographer who led the projection work, characterised the milestone directly: “The aging of baby boomers means that within just a couple decades, older people are projected to outnumber children for the first time in U.S. history. By 2034, there will be 77.0 million people 65 years and older compared to 76.5 million under the age of 18.” The Bureau’s updated estimates have refined the crossover year slightly — earlier projections had placed it in 2035, while the current best estimate places it in 2034 — but the basic milestone is the same. Within approximately the next decade, the United States will become, in a measurable demographic sense, an old country.

The arithmetic of the crossover

Per the Census Bureau’s June 2025 release of the Vintage 2024 Population Estimates, the gap between the two populations is now closing faster than at any previous point in American demographic history. In 2020, the 65-and-older population numbered approximately 55.8 million, while the under-18 population was approximately 73.1 million — a gap of just over 20 million favouring children. By 2024, the gap had narrowed to under 12 million. The 65-and-older population had risen to 61.2 million, growing at 3.1 percent in a single year, while the under-18 population had declined by 0.2 percent to 73.1 million. The pattern is now well-established: over the four-year period from 2020 to 2024, the 65-and-older population grew by 13.0 percent, while the under-18 population declined by 1.7 percent. Working-age adults grew by just 1.4 percent over the same period.

The two trends are not symmetric. The 65-and-older population is being driven upward by two compounding forces: the boomer cohort moving sequentially into older age brackets, and the continued slow extension of life expectancy at older ages. Both forces are likely to continue operating through at least the early 2040s, with the 85-and-older population projected to grow approximately 200 percent by 2060 — from approximately 6 million today to approximately 19 million. The under-18 population is being held down by sustained sub-replacement fertility rates (currently 1.6 children per woman in the U.S., below the 2.1 needed for population replacement), combined with declining birth cohorts year over year. Without a substantial increase in either fertility or immigration, the gap between the two populations will continue closing through 2034 and then reverse.

What “older country” actually looks like

The United States is not the first developed country to experience this transition. Japan crossed the equivalent demographic threshold in the 1990s and now has approximately 28 percent of its population aged 65 or older — substantially older than the U.S. at 18 percent. Italy is at 23 percent. Germany is at 22 percent. The U.S. is now beginning the same transition that these countries have been navigating for the past two to three decades, with the corresponding challenges to social security systems, healthcare infrastructure, labour markets, and intergenerational political dynamics. The current median age of an American is approximately 39 years; the current median age of a Japanese resident is approximately 49.5 years — the oldest of any major country. The U.S. is unlikely to reach Japan’s current median age within the next two decades, but the trajectory is in that direction. Under the Census Bureau’s projections, the U.S. median age will reach approximately 44 by 2060 — older than the U.S. has ever been, though still substantially younger than Japan is today.

As documented in the Census Bureau’s 2020 Demographic Turning Points for the United States publication, the structural implications of the transition are substantial. The ratio of working-age adults to those aged 65 and older will shift from approximately 3.5 working-age adults per retiree in 2020 to approximately 2.5 by 2060. The implications for Social Security and Medicare funding, which depend on payroll taxes from current workers to fund benefits for current retirees, are direct. The U.S. will also become, beginning approximately in 2030, a country in which net international migration overtakes natural increase (births minus deaths) as the primary driver of population growth — another demographic first for the United States, and one that will substantially shape the politics of immigration policy for the rest of the century.

What has already happened

Per Population Education’s analysis of the 2020 Census results, the largest single demographic change in the United States between 2010 and 2020 was the 27 percent expansion of the population aged 55 and older — a rate of growth dramatically faster than any other age group. The under-18 population, by contrast, actually declined by 1.4 percent over the same decade. This is the configuration that produces an old country: not a single dramatic event, but a slow, accumulating divergence between the growth rates of the older and younger populations that, over decades, produces a population pyramid radically different from the one the country has always had. As of 2024, eleven U.S. states — Maine, Vermont, New Hampshire, Florida, West Virginia, and several others — already have more adults over 65 than children under 18. Nearly half of all U.S. counties (approximately 1,500 of 3,100) have already crossed the same threshold. The national milestone in 2034 will be, in effect, the moment when the rest of the country catches up to where these states and counties already are.

The transition itself is not bad or good. It is a structural fact that will reshape essentially every institution designed for a younger demographic configuration — schools, family policy, pension systems, healthcare infrastructure, the housing market, the political coalitions that have organised around generational interests, the labour markets that depend on younger workers, and the cultural assumptions of a country that has, until now, always thought of itself as relatively young. The crossover year of 2034 is not the destination but the marker. The destination is a configuration of American life in which the median citizen is substantially older than the median citizen has ever been, in a country whose institutional design was built around a demographic configuration that, by every available indication, is now ending.

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Viktor Frankl returned to Vienna after liberation from the Nazi camps, having lost his wife, mother, father, and brother, and he dictated the manuscript that would become Man’s Search for Meaning in a compressed period of intense work. He had been a prisoner at concentration camps including Theresienstadt and Auschwitz. The book has sold millions of copies in dozens of languages, and its central claim — that meaning is found in serving something beyond yourself, not in pursuing your own happiness — has outlasted nearly every popular psychology trend of the last eighty years.

Frankl initially considered publishing the book anonymously. His friends convinced him to add his name to the cover. He later said he was certain the book would fail.

A manuscript carried in memory

The writing pace was not literary affectation. Frankl had been carrying the manuscript in his head for years. An earlier manuscript had been confiscated when he arrived at Auschwitz. He spent the rest of his imprisonment reconstructing it mentally and on scraps of paper, rehearsing the arguments during forced labor.

When he got back to Vienna, the words came out fast because they had been written, erased, and rewritten in his memory for nearly three years. According to accounts of the manuscript’s creation, he worked through intense sessions of dictation to produce the book rapidly.

The first edition came out in German in the mid-1940s. The English translation arrived under the title From Death-Camp to Existentialism, then was later retitled Man’s Search for Meaning. The Library of Congress named it one of the most influential books in America.

The thing he saw in the camps

Frankl was a trained neurologist and psychiatrist before the war. He had developed an approach he called logotherapy — after Freud’s psychoanalysis and Adler’s individual psychology. Drawing from the Greek word for meaning, he believed that the deepest human drive was not pleasure or power but the search for significance.

The camps gave him a laboratory he never wanted. He watched, clinically, who survived and who did not. Physical strength was not the predictor. Education was not the predictor. The prisoners who endured, he observed, were those who had something outside themselves to live for — a manuscript to finish, a child waiting in another country, a piece of work only they could do. The ones who lost that thread tended to die quickly. He described prisoners who simply lay down in their bunks one morning and refused to get up.

From this he built his core argument: meaning is not something you find by looking inward. It is something you find by looking outward — at a task, a person, a cause, a piece of suffering you have been asked to bear with dignity.

Why happiness can’t be the goal

Frankl was sharp on this point. He thought the pursuit of happiness as an end in itself was self-defeating. The more you chase it, he argued, the more it recedes. Happiness has to ensue from something else — from devotion to a cause, love for another person, or the way you carry an unavoidable burden. Chase it directly and you end up empty.

His logotherapy framework identified three routes to meaning: creating a work or doing a deed, experiencing something or encountering someone (love being the highest form), and the attitude one takes toward unavoidable suffering. The third was the one the camps had taught him. You cannot always choose what happens to you. You can always choose your response.

He often quoted Nietzsche: “He who has a why to live for can bear with almost any how.” In the camp barracks at night, he said, that sentence had kept men alive.

What the research has done with the idea

Decades on, the empirical literature has caught up with Frankl in ways that would have surprised him. Building on concepts of eudaimonic well-being — the deep satisfaction of living for something larger than yourself — versus hedonic well-being focused on pleasure, research on well-being suggests that purpose and meaning are not luxuries layered on top of survival but central to it.

Work from the Greater Good Science Center at Berkeley has documented that people who orient their lives toward service report higher meaning scores and lower rates of depression than those who orient toward self-improvement or pleasure.

The medical field has begun to fold this in. A 2026 paper covered by EurekAlert called on lifestyle medicine practitioners to treat meaning, purpose, and spirituality as foundational components of patient care rather than optional extras, citing their measurable effect on adherence to treatment and long-term health outcomes.

The statue of responsibility

Frankl had a proposal he repeated for the rest of his life. He thought the Statue of Liberty on the east coast of the United States should be matched by a Statue of Responsibility on the west coast. Freedom, he argued, was only half of the human story. Freedom without responsibility for something or someone else was just license, and license was not the same as meaning.

He lived this out. After the war he returned to clinical practice and lecturing. He remained active into old age.

What the intensive writing period produced

The book itself is short, with the camp memoir occupying roughly the first half and a primer on logotherapy filling the second. The prose is plain. There is almost no rhetorical flourish. Frankl describes the smell of the barracks, the way frozen feet feel inside cardboard-stuffed boots, the small economies of bread, the moment a guard’s casual cruelty could decide whether a man ate that day. And then, without warning, a sentence like: “Everything can be taken from a man but one thing: the last of the human freedoms — to choose one’s attitude in any given set of circumstances, to choose one’s own way.”

That sentence has been quoted on graduation programs, in twelve-step rooms, in hospice wards, in military training manuals, and on the walls of palliative-care clinics. It came out of a man who had watched his family murdered and had days to put what he learned into words before the grief swallowed him.

The argument that refuses to age

Self-help publishing has cycled through optimism training, mindfulness, manifestation, dopamine fasting, hustle culture, and a dozen variants of personal-happiness engineering since Frankl’s death. None of them have displaced the book. It continues to sell widely. College syllabi still assign it. Hospice workers still hand it to dying patients.

Part of the durability is the credential. Frankl was not theorizing from a comfortable office. He had run the experiment on himself in the worst laboratory ever built, and he came out the other side with a finding he was willing to stake his career on: the people who survive — and the people who live well after surviving — are the ones who have something or someone to live for outside themselves.

The book ends with Frankl’s conclusion that nothing would so effectively help one survive even the worst conditions as the knowledge that there is meaning in one’s life — a conclusion he drew from observing who survived the camps and who did not. He wrote it down in a Vienna apartment in the late summer of 1945, with the windows open and the city still in ruins, and it has not gone out of print since.

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In the early 1970s, a Hungarian psychologist named Mihaly Csikszentmihalyi sat in a Chicago studio watching painters work. They had been at it for hours. Lunch came and went. The painters did not notice. One artist, asked later why he had skipped meals and let his coffee go cold, could not really explain it — he had simply been inside the canvas. Csikszentmihalyi wrote down the phrase his subjects kept reaching for: it felt like being carried by a current. In his book Beyond Boredom and Anxiety, he gave the state a name. He called it flow.

Half a century later, the finding has been diluted into a productivity slogan. That dilution obscures what Csikszentmihalyi actually discovered, and why it matters now more than ever: flow is not a kind of focus you can summon. It is what happens when attention points so completely outward that the self goes quiet — and the device in your pocket is engineered to make exactly that impossible.

The argument of this piece is narrow. The neuroscience that has emerged in the last decade does not extend Csikszentmihalyi’s theory so much as confirm its strangest claim: that the vanishing of self-monitoring is not a feeling, but a measurable redistribution of brain activity. And the conditions that produce that redistribution are precisely the ones the modern attention economy is built to prevent.

The man with the rock

Csikszentmihalyi’s interest in absorbed states began long before the Chicago studios. As a child in wartime Europe, he watched adults around him struggle to find meaning after catastrophe, and noticed that the ones who coped best tended to lose themselves in something — chess, music, mountain climbing. He carried that observation into his graduate work at the University of Chicago.

One of his early subjects was a rock climber. Another was a chess master. Another was his own older brother, a mineralogist who could spend an entire afternoon studying a single stone. As Psychology Today recounted, the brother’s quiet absorption in a piece of quartz was one of the seeds of the entire theory.

The common thread across climbers, chess players, surgeons and painters was not the activity. It was the structure of attention.

What the painters told him

Csikszentmihalyi’s method was unglamorous. He handed people pagers, later replaced by digital devices, and beeped them at random moments during the day. When the pager went off, the subject filled out a short form: What are you doing? How hard is it? How skilled do you feel? How absorbed are you?

The data, gathered across thousands of subjects over decades, kept producing the same shape. Flow appeared when three conditions lined up at once: a clear goal, immediate feedback, and a challenge that sat right at the edge of the person’s skill — hard enough to demand full attention, not so hard that it tipped into panic. Below that edge, people reported boredom. Above it, anxiety. Inside the narrow band, the self went quiet.

The surgeons he interviewed said they forgot they had bodies. The composers said the music seemed to write itself. The climbers said the mountain seemed to move them rather than the other way around. None of them could enter the state on command. They could only set up the conditions and let it arrive.

Why the brain seems to cooperate

The behavioural finding sat unexplained for decades. Csikszentmihalyi could describe what subjects reported, but he could not say what was actually happening inside their skulls. The neuroscience of the last fifteen years has begun to fill that gap, and the pattern it has found maps closely onto what the painters told him.

The default mode network — a set of midline brain regions associated with self-referential thinking, mind-wandering and autobiographical rehearsal — was first characterised by Raichle and colleagues in 2001. It is the circuitry that hums when you are worrying about a conversation or imagining yourself from outside. A growing body of imaging work, reviewed in Frontiers in Psychology, finds that this network quiets down during tasks meeting Csikszentmihalyi’s flow conditions, while sensorimotor regions become tightly coupled to the work at hand.

The mechanics of how blood flow tracks neural activity, captured by techniques described in neurovascular coupling research, allow researchers to watch this redistribution happen in real time. In jazz pianists improvising, in expert climbers visualising routes, in writers composing fluently, the self-monitoring circuits dim and the task-relevant circuits dominate. The behavioural strangeness — the vanishing self — has a neural signature.

Recent work has gone further. A 2024 study from Washington University traced a mechanical link between body motion and fluid movement in the brain through a network of veins, suggesting that the physical engagement characteristic of flow states — climbing, playing, surgery — may shape neural conditions in ways that pure cognition cannot.

The conditions the phone destroys

One of the most-cited findings from Csikszentmihalyi’s pager studies was that flow is not tied to any particular kind of work. Factory workers entered it on assembly lines. Mothers entered it reading to children. Accountants entered it in spreadsheets. The activity did not matter. The structure did.

What separated people who experienced flow often from those who rarely did was not their job description. It was whether they had organised their attention so that something — anything — could demand all of it.

This is where the modern problem comes into focus. People who spent their evenings flicking between apps reported the lowest flow frequencies. People who played an instrument, gardened, climbed, cooked complex meals, or wrote in journals reported the highest. The phone, with its endless drip of low-stakes novelty, sits exactly in the wrong zone: enough stimulation to keep attention from settling, not enough challenge to absorb it. It is, in effect, an anti-flow device — engineered to keep the default mode network humming, to keep the self always slightly aware of itself.

As National Geographic reported, climbers like Steph Davis describe entering a state on big walls where fear, plans, and self-talk drop away and only the next handhold exists. Free soloists in particular — climbers without ropes — describe the state as not optional but necessary. Any intrusion of self-consciousness at 600 metres above the ground is dangerous. They are, in a sense, the last group for whom the conditions are non-negotiable.

Why it cannot be forced

The paradox at the centre of the theory is that flow rewards attention pointed away from itself. The harder a person tries to be in flow, the further it retreats. Trying to be in flow is, by definition, attention pointed at the self.

Csikszentmihalyi’s advice, repeated across his books and lectures, was indirect. Set up the conditions. Choose a task with a clear goal. Match the difficulty to your current skill. Remove interruptions. Then forget about the state and do the work.

What the painters were really doing

Looking back at the studio interviews that started everything, the detail that still stands out is how mundane the painters’ answers were. They were not chasing transcendence. They were trying to solve a problem on the canvas. The colour was wrong. The composition needed something in the lower left. The hand had to move in a particular way.

The state Csikszentmihalyi named arose as a byproduct of that ordinary attention — attention so completely committed to the object in front of them that there was no spare capacity left to think about themselves. That is the part of the finding that has resisted fifty years of dilution into self-help. Flow is not a productivity hack. It is not a brand of focus that can be summoned with the right playlist. It is what happens to a mind when something outside it becomes, briefly, more interesting than the mind itself.

Csikszentmihalyi died in 2021. The painters he interviewed in Chicago are mostly gone too. The pagers have been replaced by phones, and the phones, on the whole, have made the state harder to reach. But the structure he identified has not changed, and the neuroscience has only sharpened it. A clear goal. Immediate feedback. A task at the edge of one’s skill. And then the quiet, when the self steps out of the way and the work fills the room.

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The objection Darwin knew would be hardest to answer was not about bones or fossils. It was about conscience. As long as the moral sense could be held apart from animal life, the distance between human beings and other creatures remained intact. Rev. Leonard Jenyns made exactly this argument in a letter to Darwin in January 1860, writing that he could not bring himself to accept that “man’s reasoning faculties and above all his moral sense could ever have been obtained from irrational progenitors, by mere natural selection.” Take the moral sense out of nature and you preserve, as Jenyns put it, “the Divine Image that forms the insurmountable distinction between man and brutes.”

Darwin’s response, worked out across Chapters 3 and 5 of The Descent of Man (1871), was not to deny that the moral sense was special. It was to explain where it came from without appealing to anything outside the natural world. The argument is more specific, and stranger, than it is usually remembered.

The hypothesis Darwin actually made

Darwin’s central claim was a conjecture he stated plainly near the opening of Chapter 4: “any animal whatever, endowed with well-marked social instincts, the parental and filial affections being here included, would inevitably acquire a moral sense or conscience, as soon as its intellectual powers had become as well, or nearly as well developed, as in man.”

This is worth reading carefully. Darwin was not saying that morality evolved because it was useful to individuals. He was not saying that conscience is simply clever self-interest. He was saying that if you take social instincts, which already exist in many species, and combine them with sufficient intelligence, memory, and language, something like a conscience is the outcome. Not a chosen outcome. An inevitable one.

The social instincts Darwin had in mind were real biological tendencies: propensities to take pleasure in the company of others, to feel something like sympathy with them, and to perform services for them. These tendencies, he argued, are persistent. They do not disappear when they are overridden. Other impulses, hunger, desire, self-preservation, can suppress social instincts in a given moment, but the social instincts persist as a background disposition, always present, always able to reassert themselves once the pressing impulse has passed.

Where memory enters the argument

The mechanism Darwin proposed for the emergence of conscience depends on memory. An animal with strong social instincts but no memory of its past actions cannot experience the conflict between what it did and what its social nature would have preferred. It acts, it satisfies an appetite, and it moves on. The social instinct, frustrated but not forgotten, leaves no trace.

Add memory, and the calculation changes entirely. After an act that violated social instinct, that persistent social feeling reasserts itself in memory and produces a disagreeable feeling that Darwin described with precision: “He will then feel remorse, repentance, regret, or shame.” This is conscience, in his account. Not a divine faculty. Not a special human endowment. It is the collision, remembered, between what was done and what the social nature would have preferred. “Conscience looks backwards,” he wrote, “and serves as a guide for the future.”

Memory alone is not enough. Darwin added language as the mechanism by which communities build explicit shared norms, what he called “public opinion” as to how members should act for the common benefit. These norms are conventional, not instinctive. Their content varies across cultures and times. But their binding force, Darwin argued, depends on something that is instinctive: sympathy. “Our regard for the approbation and disapprobation of our fellows depends on sympathy, which forms an essential part of the social instinct, and is indeed its foundation-stone.”

The consequence of how we understand civilisation

If this argument is substantially right, a particular way of thinking about manners, conscience, and moral restraint becomes harder to hold. The traditional view treats these things as the victory of something higher over something lower: reason over appetite, culture over nature, the civilised over the animal. Darwin’s account does not work that way. Manners are not the suppression of instinct. They are one set of instincts, the social ones, as they have been elaborated and made explicit through memory, language, and the accumulated judgments of people living together.

Restraint is not the opposite of instinct. It is what instinct looks like after it has been complicated by the awareness that others are watching and will remember.

This is unsettling in a specific way. It means that the moral progress of a society cannot be understood as a movement away from biology toward something purely rational or conventional. It means that the social instincts, those old biological tendencies toward sympathy and mutual regard, are doing continuous work underneath the surface of any functioning moral culture. When those instincts weaken, when the conditions that maintain sympathy erode, there is no backup system of pure reason to fill the gap.

What Darwin acknowledged the argument could not do

Darwin was a careful enough thinker to register the difficulty his own account ran into. He wanted to say that the social instincts, including sympathy, were themselves products of natural selection. But natural selection works on individuals, and sympathy is a propensity that benefits others, sometimes at the individual’s expense. He gestures toward what would later be called group selection, the idea that tribes with more cooperative members outcompete those without, and toward something close to kin selection. He did not resolve it. The mechanisms that actually account for the evolution of altruistic behaviour were worked out in the twentieth century by W. D. Hamilton and Robert Trivers, building on foundations Darwin laid.

There is a further limitation worth naming. Darwin’s account of conscience as social-instinct-plus-memory is a psychological and evolutionary account. It describes how the moral sense likely arose and what it is composed of. It does not, by itself, tell us what we ought to do. Darwin was explicit about this. He was more cautious than Herbert Spencer and others who tried to derive ethical prescriptions directly from evolutionary facts. What evolution explains is the origin of our moral faculties, including their biases, their reach, their limitations. It is not a replacement for moral reasoning.

The reading that travels farthest

What we keep coming back to in Darwin’s account is how little of it requires the human animal to be exceptional in the ways that traditional moral philosophy assumed. The components he identifies, social instinct, memory, language, the sensitivity to others’ approval and disapproval, are not inventions unique to our species. They are elaborations, remarkable ones, of tendencies that appear in recognisable forms across many social animals.

This does not diminish the moral achievements of human cultures. It relocates them. What seems to belong to a separate, higher domain turns out to be built from materials that were already present, already working, long before anything we would call civilisation. The notebooks Darwin kept in 1838, more than thirty years before The Descent of Man was published, already contain the essential idea, written in his characteristic shorthand: “Society could not go on except for the moral sense, any more as a hive of Bees without their instincts.”

The comparison to bees was not meant as a reduction. It was meant as an observation about what holds any social life together. The moral sense, in Darwin’s reading, is not a ceiling above our animal nature. It is something that grew from within it, shaped by the fact that we live together, remember our actions, care what others think of us, and inherit the social tendencies of creatures far older than ourselves.

The post Charles Darwin argued that the roots of human morality were not separate from animal life, and the surprise is what that does to civilization — manners, conscience, and restraint become not the opposite of instinct, but instinct complicated by memory, language, and the judgment of others appeared first on Space Daily.

The World Health Statistics 2026 report, published by the World Health Organization on 13 May, carries a paradox on almost every page. The gains it documents are genuine. A 40 percent reduction in new HIV infections between 2010 and 2024. A 36 percent drop in the number of people requiring interventions for neglected tropical diseases over the same period. The WHO’s African Region achieved faster reductions in new HIV infections than the global average — down 70 percent since 2010 compared with 40 percent globally — and also outpaced the global rate on tuberculosis. These are not small movements. They represent millions of lives in different conditions than they would otherwise have been.

The report also states that the world is “off track to achieve any of the health-related Sustainable Development Goals by 2030,” that progress in many areas has slowed, and that in some it has reversed. The HIV and NTD figures are cited as among the bright points. But the infrastructure that produced them, the funding systems, the programmes, and the health systems they flow through, is now under significant and specific pressure.

What the HIV figure represents

A 40 percent reduction in new infections across fourteen years is a result of sustained investment in prevention, testing, antiretroviral treatment access, and targeted behavioural programmes. No single intervention produced it. The figure reflects the cumulative effect of programmes that operated at scale, consistently, over a long period.

The United States has historically been the largest single contributor to international HIV funding, providing around 73 percent of all donor funding for HIV programmes in low- and middle-income countries in 2023, primarily through the President’s Emergency Plan for AIDS Relief, known as PEPFAR. Early in 2025, USAID grant holders were instructed to stop work. Testing counsellors and clinic staff were laid off in the same period. Studies from Mozambique and South Africa documented immediate drops in HIV testing and new treatment initiations in the first quarter of 2025. Modelling work published by UNAIDS in 2025 projected that if US-supported programmes were halted without equivalent replacement, there could be more than 6 million additional new HIV infections by 2030 — potentially returning infection levels to those not seen since the early 2000s.

Neglected tropical diseases and what the 36% figure includes

Neglected tropical diseases, or NTDs, are a group of conditions, including lymphatic filariasis, trachoma, schistosomiasis, and several others, that predominantly affect people living in poverty in tropical and subtropical regions. The 36 percent reduction in the number of people requiring interventions between 2010 and 2024 reflects a combination of mass drug administration programmes, improved sanitation, and sustained public health campaigns that, like the HIV work, required consistent funding and logistical infrastructure over many years.

The gains in this area are concentrated in specific regions and specific diseases. They are not uniformly distributed. And because NTD programmes depend on donated medicines, coordinated delivery, and community health infrastructure that is itself dependent on external funding, they are vulnerable to the same financing pressures that now affect HIV programmes.

Where the broader picture is worse

The HIV and NTD improvements are among the few areas where the World Health Statistics 2026 report can present an unambiguously positive trajectory. Much of the rest of the data is more difficult.

Progress toward universal health coverage has slowed sharply. The WHO’s service coverage index rose only from 68 to 71 between 2015 and 2023. One quarter of the global population faced financial hardship from health costs. Around 1.6 billion people were living in or pushed into poverty from out-of-pocket health spending in 2022. Malaria incidence increased by 8.5 percent since 2015. Anaemia affects 30.7 percent of women of reproductive age, with no improvement over the past decade. Childhood vaccination coverage remains below target.

The COVID-19 pandemic’s shadow runs through the report. Between 2020 and 2023, it is linked to an estimated 22.1 million excess deaths, including indirect deaths. That figure is more than three times the number of officially reported COVID-19 deaths. The WHO states that this reversed a decade of gains in life expectancy, and that recovery remains incomplete and uneven.

The data gap underneath all of this

There is a further problem the report names directly. As of the end of 2025, only 18 percent of countries were reporting mortality data to WHO within one year. Nearly one third have never reported cause-of-death data. Of the estimated 61 million deaths globally in 2023, only around one third were reported with cause-of-death information, and roughly one fifth had usable coded data.

This matters for how to read all the figures above, including the gains. The 40 percent reduction in HIV infections and the 36 percent drop in NTD burden are derived from the best available data. Where data collection is poor, those estimates carry more uncertainty. The WHO notes this not to undercut its own figures but because the data gap affects the ability to monitor whether progress is holding, slipping, or reversing in real time. Progress built on incomplete reporting is harder to protect.

What the WHO is asking for

Dr Tedros Adhanom Ghebreyesus, the WHO Director-General, said in the report’s accompanying statement that “investing in stronger, more equitable health systems, including resilient health data systems is essential to target action, close gaps and ensure accountability.” Dr Yukiko Nakatani, the WHO Assistant Director-General for Health Systems, named “a worsening health financing crisis” as one of the conditions requiring urgent response, alongside rising environmental risks and ongoing health emergencies.

The language is institutional and measured. The situation it describes is not. A decade of measurable progress in two of the most intractable areas of global health is now contingent on decisions about funding that are being made in contexts entirely external to the public health systems that produced the gains. The WHO’s report is, among other things, a record of what was built and a description of how fragile the conditions for maintaining it have become.

The post New HIV infections fell by 40 percent between 2010 and 2024 and the number of people requiring treatment for neglected tropical diseases dropped by 36 percent in the same period, according to the World Health Statistics 2026 report — gains now at risk as the funding that built them comes under pressure appeared first on Space Daily.

The popular framing of emotional pain treats it as something metaphorical. The broken heart of unrequited love, the sting of rejection, the ache of grief, the cutting remark, the wound that will not heal: the language of physical injury used to describe emotional injury is so widespread across cultures and languages that it has been treated, until quite recently, as a poetic convention rather than a scientific claim. People who use the language to describe their suffering are usually understood to be reaching for a metaphor that captures something about the intensity of what they feel.

The peer-reviewed neuroscience of the past two decades has substantially complicated this picture.

What the brain imaging evidence has shown, across multiple research teams, multiple methodologies, and multiple populations, is that emotional pain is not metaphorically similar to physical pain. The two states activate substantially overlapping neural systems, produce substantially similar behavioural and physiological responses, and respond to substantially the same pharmacological interventions. The language of broken hearts and stinging rejection is, on the strongest current reading of the evidence, more literally accurate than the popular framing has assumed.

The 2003 Cyberball study

The foundational peer-reviewed study of the neuroscience of social pain was published in October 2003 by Naomi Eisenberger, Matthew Lieberman, and Kipling Williams in the journal Science. The team designed an experiment to induce social rejection in a controlled laboratory setting while participants were inside a functional magnetic resonance imaging scanner. They used a computer game called Cyberball, in which the participant played a virtual ball-tossing game with what they believed were two other human players. After a brief inclusion phase in which all three players passed the ball to each other, the two other players began passing the ball only to each other, excluding the participant for the remainder of the game.

The two other players were not, in fact, human. They were computer-controlled. The exclusion was a designed feature of the experiment. From the participant’s subjective experience, however, they had just been deliberately excluded from a social activity by two people they had been interacting with moments earlier.

The brain activation pattern during the exclusion phase was the most significant finding of the study. The dorsal anterior cingulate cortex, a region of the brain that processes the affective component of physical pain, was significantly more active during exclusion than during inclusion. The level of activation correlated positively with the participant’s self-reported distress at being excluded. The same region of the brain that becomes active when a person is burned, cut, or struck became active when the same person was ignored in a virtual ball-tossing game.

The Eisenberger team’s interpretation, supported by the subsequent literature, was that the human brain treats social exclusion as a form of injury. The neural alarm system that evolved to alert humans to physical damage to their bodies is, on the available evidence, the same alarm system that alerts humans to damage to their social bonds.

The 2010 Tylenol study

The strongest follow-up evidence for the Eisenberger thesis came from a different direction. In 2010, a team led by Nathan DeWall at the University of Kentucky, with colleagues at Toronto, Florida, UCLA, Florida State, and Georgia College, published a study in Psychological Science that asked a simple question. If social pain and physical pain activate the same neural systems, then a pharmacological intervention that reduces physical pain should also reduce social pain. The team tested this prediction directly.

Participants in the first experiment took either 1,000 milligrams of acetaminophen, the active ingredient in Tylenol and Panadol, or a placebo, every day for three weeks. They reported their daily experience of social pain (feelings of rejection, exclusion, hurt feelings) on a standardised scale throughout the study period. The participants who took acetaminophen reported significantly lower social pain than those who took placebo, with the difference emerging gradually over the three weeks and becoming statistically significant by the end of the study.

The second experiment, also with three weeks of acetaminophen or placebo, used functional magnetic resonance imaging at the conclusion of the dosing period. Participants played the same Cyberball exclusion game while being scanned. The acetaminophen group showed significantly reduced neural activation in the dorsal anterior cingulate cortex and the anterior insula during the exclusion condition, compared with the placebo group. The pharmacological intervention designed to reduce physical pain had reduced both the felt experience and the brain activation associated with social pain.

The finding was substantial. Acetaminophen is one of the most widely used pain relievers in the world, taken by hundreds of millions of people for headaches, muscle aches, fever, and other physical conditions. Its mechanism of action involves central nervous system effects rather than purely peripheral pain blocking, which is the reason it can affect the brain regions that process social pain in addition to the brain regions that process physical pain. The DeWall team noted that this finding has implications for the treatment of social rejection, chronic loneliness, and the social aspects of grief, although they emphasised that acetaminophen is not a recommended long-term treatment for any of these conditions.

The 2011 somatosensory finding

A third major piece of evidence came from a 2011 study by Ethan Kross, Marc Berman, Walter Mischel, Edward Smith, and Tor Wager, published in the Proceedings of the National Academy of Sciences. The Kross team designed the most powerful induction of social pain that had been attempted in a brain imaging study. They recruited 40 participants who had experienced an unwanted romantic break-up within the previous six months and who reported that thinking about their ex-partner still produced significant emotional distress. The participants were placed in an fMRI scanner and shown alternating photographs of their ex-partner and of a familiar but emotionally neutral acquaintance. In a separate task, the same participants experienced a moderate physical pain stimulus, applied as heat to the forearm.

The Kross team found that thinking about the rejecting ex-partner activated not only the affective regions of the brain associated with physical pain, as the Eisenberger team had shown, but also the somatosensory regions, including the secondary somatosensory cortex and the dorsal posterior insula. These are the brain regions that process the felt sensory quality of physical pain, not merely the emotional response to it. The activation pattern in these regions during the romantic rejection condition was 88 per cent predictive of physical pain when compared with a database of more than 500 published pain studies.

The finding moved the science forward in an important way. Until 2011, the strongest interpretation of the Eisenberger data was that social and physical pain shared the affective components but probably not the sensory components. The Kross data suggested that, at sufficient intensity, social pain activates the sensory components as well. The brain of a person looking at a photograph of an ex-partner who has recently rejected them is, on the available evidence, doing something substantially similar to the brain of a person who has been physically burned.

Our team came across an interesting short video that explains the psychology behind what happens when someone has been through too much in life. If this article resonates, it’s worth a watch – click here to view it. 

Why the brain works this way

The current best evolutionary explanation for these findings is that the social attachment system in the human brain piggybacked on the existing physical pain system rather than developing a separate alarm mechanism of its own. Mammalian young, including human infants, require an unusually long period of caregiving to survive. An infant separated from its caregivers will die. The evolutionary pressure to keep infants attached to caregivers, and caregivers attached to infants, has been one of the strongest selection pressures shaping the human brain over the past several hundred thousand years.

The existing physical pain system, which had evolved to register damage to body tissue and motivate behaviour that reduces such damage, was already capable of producing a sufficiently intense aversive signal. The most parsimonious evolutionary solution was to extend this signal to social loss, so that the threat of being separated from social bonds would feel as urgent and unbearable as the threat of physical injury. The result is that the human brain treats damage to relationships, exclusion from social groups, and the loss of attachment figures as variants of the same general category of threat that includes physical wounds.

This explanation, sometimes called the social attachment piggyback hypothesis, has been articulated in detail by Eisenberger in subsequent papers and is the standard evolutionary interpretation of the imaging findings. It is also consistent with the cross-cultural ubiquity of physical pain language in descriptions of social loss. Speakers of unrelated languages, in unrelated cultures, with no shared history of metaphor formation, describe rejection and grief in substantially the same terms. The convergence on physical pain vocabulary appears to be driven by the underlying neural reality rather than by any cultural transmission.

The honest limitations

The social-pain-physical-pain overlap thesis is not, despite the strength of the evidence above, fully settled in the peer-reviewed literature.

A 2014 study by Choong-Wan Woo, Tor Wager, and colleagues, published in Nature Communications, applied a more sophisticated form of brain imaging analysis called multivariate pattern analysis to data on both social rejection and physical pain. The Woo team found that while the same anatomical brain regions are activated by both kinds of pain, the precise neural patterns within those regions are distinct. The brain appears to be using the same general neighbourhood for both kinds of pain, but it is doing different things within that neighbourhood.

The Woo finding does not negate the Eisenberger and Kross results. It does mean that the strongest possible interpretation, in which social and physical pain are essentially the same experience differently triggered, is too strong. The current best reading is that the two kinds of pain share substantial neural infrastructure but are not identical. The overlap is genuine and substantial. The identity claim is too strong on the available evidence.

A separate methodological concern is that the laboratory inductions of social pain, including the Cyberball game and the ex-partner photograph paradigm, are short-duration acute experiences that may not perfectly model the chronic social pain of long-term loneliness, sustained grief, or persistent interpersonal trauma. The neural systems engaged by acute laboratory rejection may differ in important ways from those engaged by months or years of sustained social suffering. The peer-reviewed evidence on chronic social pain is thinner than the evidence on acute laboratory social pain, although the available work suggests broadly similar neural patterns.

What it means

Several things follow from the neuroscience of social pain that are worth saying clearly.

The first is that the popular framing in which emotional suffering is treated as fundamentally different from physical suffering, less real, less serious, less worthy of medical attention, is not supported by the available evidence. The brain treats damage to social bonds as a category of injury and produces a measurable distress signal that overlaps substantially with the distress signal produced by physical injury. The chronic loneliness that the World Health Organization now treats as a global public health concern, the grief that follows the death of a close attachment figure, and the social rejection that produces measurable mortality in long-term studies are all, on the available evidence, registering in the brain as forms of sustained low-grade pain.

The second is that the language people use to describe their emotional suffering is, on the strongest current reading, an accurate report of what is happening rather than a poetic exaggeration of it. A person who describes a breakup as feeling like being punched in the chest is not being dramatic. They are providing the most accurate available verbal description of a neural state that genuinely shares features with being punched in the chest.

The third is that the pharmacological evidence suggests interesting possibilities for the treatment of acute social pain, although the practical implications remain genuinely contested. The DeWall finding that acetaminophen reduces social pain has been replicated and extended in subsequent work, but the long-term implications for grief management, loneliness intervention, and the treatment of attachment-related disorders are not yet established.

The fourth, on the strongest current reading of approximately twenty years of peer-reviewed neuroscience, is that the human capacity for enduring pain extends to the capacity for enduring social pain, because the same neural systems are involved in both, and the same biological constraints determine what can be borne and for how long.

The popular framing has, in a sense, always known this.

The neuroscience is just confirming what every person who has ever lost someone has already been trying to say.

The post Research into the neuroscience of social rejection has shown that the brain regions that activate when a person is excluded, rejected, or grieving a lost relationship are the same regions that activate during physical injury, with the overlap being so substantial that a standard over-the-counter painkiller measurably reduces both kinds of pain, because the human brain has co-opted the physical pain system to register damage to social bonds appeared first on Space Daily.

There is a specific moment, usually in childhood or early adolescence, when most people first hear a recording of their own voice and discover, with mild horror, that it does not sound the way they expected. The voice on the recording is thinner. Higher. More nasal. Less authoritative. Less resonant. It does not seem to match the voice the person has been hearing inside their own head for their entire life. The instinctive reaction is that the recording must be defective somehow — that microphones distort, that playback equipment is poor, that something has gone wrong in the chain between vocal cords and loudspeaker. The recording, in nearly all cases, is fine. The misalignment is between two distinct ways of hearing the same sound, only one of which is available to the listener and only the other of which is available to everyone else who has ever listened to that voice. The recording is a reasonable approximation of the second one. The voice in the speaker’s head is, in important respects, an illusion produced by the speaker’s own skull.

According to a 2023 Mirage News explainer drawing on the underlying acoustics literature, the human auditory system actually has two distinct pathways by which sound reaches the inner ear. The first, called air conduction, is the pathway most people think of as “hearing”: sound waves travel through air, enter the ear canal, vibrate the eardrum, set off a chain of vibrations in the three small bones of the middle ear, and ultimately stimulate the cochlea — the fluid-filled, snail-shaped organ in the inner ear that converts mechanical vibration into the neural signals the brain interprets as sound. The second pathway, called bone conduction, bypasses the outer and middle ear entirely. Vibrations from a sound source travel directly through the bones of the skull — particularly the mastoid and temporal bones near the ear — and reach the cochlea by a structural route rather than an airborne one.

Why bone conduction makes the voice in your head deeper

When a person speaks, the vibration originates in the vocal cords, which sit deep inside the throat, surrounded by skull and jawbone. The sound produced travels outward into the air, where it can be heard by everyone else in the room via ordinary air conduction. But the sound also travels inward, through the bones surrounding the vocal cords, up through the skull, and into the speaker’s own inner ear via bone conduction. The speaker, accordingly, hears their own voice through both pathways simultaneously. Everyone else in the room hears it through only one.

The catch is that bone is not a neutral conductor of sound. As reported by Imperial College London’s coverage of Dr. Tobias Reichenbach’s 2014 research on the mechanics of bone conduction, the bones of the human skull are substantially more efficient at transmitting low-frequency vibrations than high-frequency ones. The bone-conducted version of a person’s voice is therefore weighted toward the lower end of the frequency spectrum — bassier, fuller, and more resonant than the air-conducted version. The voice the speaker hears in their own head is the sum of the air-conducted and bone-conducted versions, with the bone-conducted contribution adding low-frequency depth that no external listener has ever heard. Reichenbach summarised the implication directly in his 2014 paper: “Many of us cringe when we play back a recording of our own voice. This is because we perceive our voice differently to how others hear it. Interestingly, bone conduction plays a role in how we recognise our voice. This is because the process is more effective at transmitting lower-frequency sounds to the brain, which means that we perceive our voice as being deeper than what it is.”

What the recording actually captures

A microphone, sitting in air several feet from the speaker, picks up only the air-conducted version of the voice — the same version that reaches the ears of everyone else within hearing range. When that recording is played back, the listener hears their own voice as it actually sounds to others, without the low-frequency bone-conducted overlay that has, until that moment, been the only version of their voice they have ever known. The mismatch is real, well-characterised, and produces a specific psychological phenomenon that auditory researchers refer to as “voice confrontation” — the sense of cognitive dissonance that accompanies hearing one’s own recorded voice for the first time.

Per an explainer from ENT and Allergy Associates on the phenomenon, the voice-confrontation effect tends to be most pronounced in people who have rarely or never heard recordings of themselves. It also tends to diminish, somewhat, with repeated exposure — singers, podcasters, broadcasters, and others who routinely listen to their own recorded voices gradually adjust their internal voice-image to better match the external reality. But the underlying physical mismatch never goes away. As long as a person has a skull and intact bone conduction, they will hear their own voice with low-frequency emphasis that no one outside their body can detect. The mental image of one’s own voice, accumulated over a lifetime of speaking and listening simultaneously, is structurally different from the voice that anyone else has ever encountered.

The thing humans never heard until 1877

Per Today You Should Know’s overview of the air-conducted versus bone-conducted distinction, one of the historically interesting features of this whole phenomenon is that humans never actually heard the “external” version of their own voice until the late 19th century. Thomas Edison’s phonograph, invented in 1877, was the first technology that could capture sound and play it back — and was, accordingly, the first technology that could ever show a person what they actually sounded like to other people. For approximately 200,000 years before Edison, every member of the species had a mental image of their own voice that was systematically different from the voice that everyone they had ever spoken to had heard. The internal voice was the only voice anyone had ever experienced from inside their own head. The discrepancy was undetectable, and presumably did not exist as a recognisable phenomenon.

The first generation of phonograph users would, by all available historical accounts, have been the first humans in history to experience voice confrontation. The experience has since become a routine part of growing up in any technologically modern society — the moment when a child first hears themselves on a voicemail, or a recording from school, or a video clip, and registers, with confusion, that the voice on the playback does not match the voice they have been hearing inside their own head for as long as they have been speaking. The cognitive adjustment that follows is the small but real psychological work of integrating the external version of oneself into the internal model. For most people, the external version will always sound slightly off. The internal version — fuller, deeper, more resonant — is the version constructed by a brain that has spent its entire life listening to itself through the bones of its own head, with no one else ever in a position to compare notes.

The post Your own voice sounds different to other people than it sounds to you, because the version you hear is reaching your inner ear partly through the bones of your skull, which amplify lower frequencies that everyone else cannot hear — and the recorded version that strikes most people as alien when they first hear it is in fact the only version of their voice anyone else has ever known appeared first on Space Daily.

The story begins in Taiwan in the early 1980s, where roughly 10 to 15 percent of school-age children were nearsighted. By the year 2000, the figure among older teens had risen to approximately 84 percent. No human population can shift its genetic profile by a factor of seven in less than two decades. Something else was happening to children’s eyes, and a generation of ophthalmologists has spent the intervening 25 years trying to figure out what. The current best understanding, drawn from systematic reviews of more than 145 studies involving over 2 million participants worldwide, is that the prevalence of myopia — the technical term for nearsightedness, in which the eyeball grows slightly too long during childhood and distant objects no longer focus properly on the retina — is rising at a rate that has no parallel in any other documented condition of vision or physical development. By 2050, on the available projections, slightly more than half of the entire human population will be affected.

According to the Brien Holden Vision Institute’s summary of its 2016 paper in Ophthalmology, the projected global myopia rate will rise from approximately 28 percent in 2010 to approximately 52 percent in 2050 — meaning nearly 5 billion myopic people by mid-century, with roughly 1 billion of them at significantly elevated risk of permanent blindness due to high myopia (defined in the Holden paper as -5 diopters or worse), a more severe form of the condition that increases lifetime risk of retinal detachment, glaucoma, macular degeneration, and cataracts. The findings have since been confirmed and extended by multiple subsequent systematic reviews, most recently a 2025 meta-analysis in the British Journal of Ophthalmology covering global prevalence trends in children and adolescents from 1990 to 2050.

What is actually happening inside the eye

Myopia is, fundamentally, a problem of axial length. The human eye works by focusing incoming light onto the retina at the back of the eyeball. If the eyeball is too long relative to the focusing power of the cornea and lens, the focal point falls in front of the retina rather than on it, and distant objects appear blurry. The condition is typically progressive during childhood and adolescence — the eyeball continues to elongate as the child grows, and the degree of myopia worsens — before stabilising sometime in early adulthood. Once the eye has elongated, the change is structural and effectively permanent. Glasses, contact lenses, and laser refractive surgery can compensate for the optical consequences, but the underlying eyeball remains longer than it would have been in an unaffected individual, with the lifelong elevation in retinal disease risk that comes with it.

The biological mechanism connecting environmental factors to eyeball elongation has been substantially worked out over the past two decades. As reported by Scientific American’s review of recent myopia research, exposure to natural daylight stimulates the release of dopamine in the retina, and retinal dopamine inhibits the axial elongation of the developing eye. Children who spend substantial time outdoors during the critical developmental years — roughly ages 6 to 12 — receive sufficient daylight exposure to maintain dopamine release and keep eyeball growth on a normal trajectory. Children who spend most of their waking hours indoors, in artificial lighting that is typically one to two orders of magnitude dimmer than natural daylight, receive insufficient stimulation of retinal dopamine, and the eye grows longer than it would otherwise.

The two-factor model

Per a peer-reviewed PMC review of the global myopia epidemic, the strongest predictors of myopia onset and progression in children are two specific environmental factors operating in tandem. The first is reduced outdoor time, which limits the dopamine-mediated protection against eyeball elongation. The second is increased near-focus work — reading, writing, screen-based learning, and recreational device use — which forces sustained accommodation of the eye at close distances and appears to contribute independently to axial elongation. The two factors are partly correlated (children who spend more time on near work typically spend less time outdoors) but operate through separable biological mechanisms. A 2018 Canadian study found that each additional hour per week of outdoor time reduces a child’s odds of developing myopia by approximately 14 percent. A separate Chinese cohort found that children with little daylight exposure have approximately 5 times the myopia risk of well-exposed peers, rising to 16 times the risk when low daylight exposure is combined with heavy near-work activity.

The genetic contribution to myopia is real but limited. Children with one or two myopic parents do have elevated risk, and several genetic variants associated with eyeball geometry have been identified. But the timescale of the global increase rules out genetics as the primary driver. The human gene pool has not changed in any meaningful way over the past 50 years. The myopia rate has, in many populations, tripled or quadrupled over the same period. The environmental contribution must therefore account for the great majority of the recent shift, with genetics modulating individual susceptibility rather than driving the population-level trend.

What the COVID years showed

The pandemic lockdowns of 2020-2021 functioned, inadvertently, as a large natural experiment in the link between indoor time and myopia development. As documented by a 2026 Optometry Times review of the global myopia trajectory, large-scale Chinese cohort studies during the lockdown period reported mean myopic shifts of up to -0.30 diopters within just a few months of confinement — substantially faster progression than the same children would have experienced under normal conditions. The effect was most pronounced in children aged 6 to 8, the age window during which the developing eye appears to be most sensitive to environmental input. The lockdown data essentially closed the remaining scientific debate about whether outdoor time and near work were causally related to myopia or merely correlated. The natural experiment produced exactly the prediction that the environmental hypothesis had been making for years.

What can be done

The interventions that have shown the most consistent effects in randomised trials and population-level programmes are also the simplest. Taiwan, which had the world’s most acute childhood myopia epidemic in the late 20th century, has since 2010 mandated that primary-school students spend at least two hours per day outdoors, with measurable effects on school-age myopia rates. Singapore has implemented similar programmes. Several jurisdictions are now prescribing low-dose atropine eye drops to children showing early myopic progression, which has been shown to slow axial elongation by approximately 50 percent over multi-year follow-up. Orthokeratology contact lenses and specialised multifocal lenses can also slow progression. The most effective single intervention, by every available measure, remains the simplest: getting children outdoors, in natural daylight, for at least an hour or two per day, during the years when their eyes are still forming. The biological logic is straightforward. The cultural logic — getting children to put down screens and spend time outside — has, in most modern environments, turned out to be substantially harder than the biology suggested it should be.

The post By 2050, more than half of the world’s population is projected to be myopic — needing glasses or contacts to see clearly at a distance — according to a series of international vision studies, in a shift driven not by genetics but by the amount of time children now spend indoors and the relative absence of time spent focusing on the horizon during the years when the eye is still forming appeared first on Space Daily.

A child born this year will, by the time they reach late middle age, almost certainly live in a world where the human population is no longer growing. By the time that same child reaches retirement, the population will, on the available projections, have begun to shrink. This is not a fringe demographic claim. It is the central finding of the most recent set of population projections published by the United Nations Department of Economic and Social Affairs, released on World Population Day in July 2024. The report, drawing on data from 1,910 censuses across 237 countries and territories, projects that the global population will peak at approximately 10.3 billion people in the mid-2080s, plateau briefly, and then decline to approximately 10.2 billion by the year 2100. The peak is now expected slightly earlier and slightly lower than the 2022 projections suggested, primarily because fertility rates in several large countries — China most prominently — have fallen substantially faster than demographers had anticipated.

According to the UN’s official World Population Prospects 2024 Summary of Results, the probability that the global population will peak within the current century is now estimated at approximately 80 percent — up substantially from the roughly 30 percent the UN was estimating in 2013. The shift reflects a steady accumulation of evidence over the past decade that fertility rates worldwide are declining faster than mid-twentieth-century demographers had expected. The global fertility rate now sits at approximately 2.25 children per woman, just above the replacement level of 2.1 needed to maintain a stable population. The global rate is projected to cross below replacement in approximately 2036 — within the next decade — at which point the only thing keeping the human population growing will be the demographic momentum of large existing cohorts of young adults still in their reproductive years.

What the country-level data show

The aggregate global figures conceal an extraordinary divergence across countries. Per Population Connection’s analysis of the 2024 UN projections, the populations of 63 countries had already peaked before 2024 — including China, Germany, Japan, Italy, and South Korea — and are now in active decline. An additional 48 countries are projected to peak between 2025 and 2054, covering approximately a tenth of the current world population. Among the lowest fertility rates currently recorded are South Korea at approximately 0.7 children per woman, Hong Kong at 0.8, Taiwan at 0.9, Singapore at 1.0, and China at 1.0 — figures so far below replacement that, absent immigration, these populations will halve every 35 to 50 years on current trajectories. Japan, Italy, and Spain sit at approximately 1.2. Most of Eastern Europe, Northeast Asia, and Southern Europe is now well below 1.5.

At the other end of the distribution, the countries with the highest current fertility rates are concentrated in sub-Saharan Africa. Niger has the world’s highest rate at approximately 6.6 children per woman, followed by Somalia (~6.0), Chad (~5.9), Mali (~5.7), the Democratic Republic of Congo (~5.4), and Nigeria (~5.0). Sub-Saharan Africa as a whole is projected to add approximately 1 billion people by 2054 — accounting for essentially all of the remaining global population growth through the century. The combination of rapid decline in most of the world and continued growth in Africa means that the demographic composition of the species is shifting substantially. By 2100, more than 40 percent of children under five globally will be African, compared to approximately 25 percent today.

Why the trajectory is hard to reverse

The features of the demographic transition that make it particularly difficult to undo were laid out in detail by the UN demographers in their 2024 report. As reported by the French National Institute of Demographic Studies (INED) in its summary of the UN findings, for the 24 countries already at ultra-low fertility with peaked populations, the probability of fertility rates returning to 2.1 or higher within the next 30 years is approximately 0.1 percent — essentially zero. The reason is structural rather than cultural. By the late 2030s, half of the women in those countries will be too old to have children by natural means. Even if pro-natalist policies somehow succeeded in raising the per-woman fertility rate substantially, the absolute number of women in their childbearing years will have contracted so much that total births would continue to fall. The demographic momentum runs in both directions: just as a large cohort of young adults can sustain population growth even at sub-replacement fertility, a small cohort of young adults will produce population decline even if individual fertility rates rise.

The countries that have implemented serious pro-natalist policies — South Korea, Hungary, Singapore, China, Japan — have, to date, produced essentially no measurable effect on fertility rates. Cash payments, parental leave extensions, childcare subsidies, fertility treatment coverage, and direct propaganda campaigns have all been tried, and the rates have continued to fall. The reasons are debated. Most demographers attribute the decline to some combination of education and labour-market participation by women, the rising direct and opportunity costs of raising children in high-income economies, urbanization, housing costs, the prevalence of contraception, changing cultural expectations about parenthood, and the broader transition of children from economic assets to economic costs that has characterised industrialised societies since the mid-twentieth century.

What the end of growth means

As discussed in Population Matters’ overview of the 2024 UN projections, the implications for the structure of human societies are substantial and not yet well-absorbed by most economic and political institutions. By 2080, people aged 65 and older will outnumber children under 18 globally. By the mid-2030s, people aged 80 and over will already outnumber infants worldwide. The age structure of the species is inverting in real time, with consequences for labour markets, pension systems, healthcare infrastructure, military demographics, real estate markets, and essentially every institution that was designed for an expanding population. Immigration will become the primary driver of population growth in approximately 52 countries through 2054 — including the United States, Canada, Australia, and the United Kingdom — meaning the political contests around immigration will, for most of the rest of the 21st century, become inseparable from the demographic survival of the receiving societies.

The Black Death, in the 14th century, was a brief and catastrophic event that killed an estimated 30 to 60 percent of the European population within a few years. The current demographic shift is the opposite kind of phenomenon — slow, voluntary, distributed across decades, and the product of billions of individual decisions about when and whether to have children. The Black Death population decline lasted approximately 150 years before growth resumed. The current decline, on the available projections, has no clear end date in view. Some recent research — notably by the demographer Dean Spears at the University of Texas — argues that the UN projections themselves still overestimate future fertility, and that the global peak may come as early as 2061 at approximately 9.5 billion, rather than the 10.3 billion the UN models project. Whether the peak arrives in 2061 or 2084, the basic direction of the trajectory is no longer in serious dispute among demographers. The era of sustained human population growth — which produced essentially all of the institutional infrastructure of modern civilisation — is ending. The next several centuries will be the first sustained test of how human societies function when the species is contracting rather than expanding.

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The popular framing of human evolution, repeated across textbooks, museum exhibits, and most contemporary writing on the subject, is that the human brain has been getting larger across the entirety of our evolutionary history. The story typically begins with the early hominins of approximately 6 million years ago, whose brains were comparable in size to those of modern chimpanzees, and proceeds through a series of steady increases in cranial capacity that culminated in the modern human brain, which is approximately three to four times larger than that of our earliest hominin ancestors and proportionally larger than that of any other primate.

The story is broadly correct for the first 5.99 million years of human evolution. It is, on the strongest current reading of the peer-reviewed evidence, wrong for the most recent chapter.

The average modern human brain is approximately 8.5 per cent smaller than the average late Pleistocene human brain, the difference is real and has been documented repeatedly across nearly ninety years of independent peer-reviewed research, and no one in the relevant scientific disciplines has yet been able to establish either when exactly the reduction occurred or what caused it.

A ninety-year-old observation

The first peer-reviewed observations that modern human brains were smaller than the brains of late Pleistocene humans were published in the 1930s and 1940s by Gerhardt von Bonin (1934) and Franz Weidenreich (1946), both working with the limited cranial samples available at the time. The observation was not initially considered controversial. The data was thin, the methodology was crude by modern standards, and the finding sat quietly in the background of physical anthropology research for several decades.

The observation began to attract more sustained attention from the 1970s onward, as larger cranial datasets became available and as better statistical methods for analysing them were developed. Phillip Tobias published comparative measurements in 1971. Maciej Henneberg, an Australian biological anthropologist who has spent his career studying global cranial datasets, published a series of papers from 1988 onward documenting the reduction across multiple population samples on multiple continents. By the early 2000s, the basic empirical claim that the modern human brain is smaller than the late Pleistocene human brain had been documented in approximately nineteen independent peer-reviewed studies, spanning samples from Europe, Africa, East Asia, Australia, and the Americas.

The average reported reduction across these studies is approximately 8.5 per cent. The late Pleistocene average, on the largest available compilations, was approximately 1,458 cubic centimetres. The modern average sits closer to 1,300 to 1,350 cubic centimetres. The difference of approximately 150 cubic centimetres is roughly the volume of a tennis ball.

The reduction is, in evolutionary terms, surprisingly large. Average hominin brain size increased by approximately 70 cubic centimetres per 100,000 years across the long arc of the Pleistocene, between approximately 800,000 years ago and 30,000 years ago. The Holocene reduction has occurred at a rate that is, depending on how the timing is set, between thirty and one hundred times faster than the earlier increase. In evolutionary terms, the human brain has been shrinking with unusual rapidity by the standards of its own previous trajectory.

The 2021 DeSilva analysis

In October 2021, a team led by Jeremy DeSilva at Dartmouth College, with collaborators James Traniello at Boston University, Alexander Claxton at Oklahoma State University, and Luke Fannin at Dartmouth, published a study in Frontiers in Ecology and Evolution that attempted to identify the precise timing of the brain-size reduction. The team compiled a dataset of 985 cranial measurements from across the full hominin fossil and recent human record, ranging from approximately 9.8 million years ago to the present, and applied a statistical method called change-point analysis to identify the moments at which the rate of brain-size change shifted.

The analysis identified three significant change points in hominin brain evolution. Two were positive, corresponding to known periods of brain-size expansion approximately 2.1 million years ago (coinciding with the early evolution of the genus Homo) and approximately 1.5 million years ago (coinciding with the appearance of Homo erectus and the development of more sophisticated stone tool industries). The third change point was negative. The DeSilva team’s analysis dated it to approximately 3,000 years ago.

The proposed timing was a substantial departure from earlier estimates, which had placed the reduction anywhere from 35,000 to 10,000 years ago. The 3,000-year figure placed the brain reduction in a period of well-documented human history, after the development of agriculture, after the emergence of the earliest cities, and during the rapid expansion of literate societies in the Bronze Age. The DeSilva team’s interpretation, drawn from a comparative analysis of brain evolution in ant species with similar social structures, was that the reduction reflected the externalisation of cognitive load into social structures, the distribution of knowledge across literate groups, and the consequent reduction of selective pressure on individual brain size.

The hypothesis was provocative. It also, the team acknowledged in the paper, depended on the specific timing they had identified, which depended in turn on the specific statistical method they had applied to the specific dataset they had compiled.

The 2022 critique

In July 2022, Brian Villmoare at the University of Nevada Las Vegas and Mark Grabowski at Liverpool John Moores University published a peer-reviewed critique in the same journal. The Villmoare and Grabowski analysis reexamined the DeSilva dataset and identified what the authors considered substantial methodological problems with the original conclusion.

The first issue was sample distribution. The DeSilva dataset of 987 skulls was heavily weighted toward modern samples, with more than half of the specimens dating from the most recent 100 years of the 9.8-million-year time range. The 23 critical specimens from the period in which the brain reduction was supposed to have occurred were drawn from geographically heterogeneous locations, including England, China, Mali, and Algeria. Villmoare and Grabowski argued that this heterogeneity made the dataset unsuitable for detecting a fine-grained change point, because population-level variation between regions was being conflated with temporal variation across the species.

The second issue was the change-point methodology itself. Villmoare and Grabowski reanalysed portions of the same dataset using independent statistical methods and were unable to reproduce the 3,000-year change point. Their analysis found no statistically significant brain-size reduction during the time frame DeSilva had identified. The Villmoare and Grabowski conclusion was that the alleged reduction either did not occur, or that the available data was insufficient to demonstrate it.

The Villmoare and Grabowski critique did not reject the entire 90-year-old observation that modern brains are smaller than late Pleistocene brains. Their argument was specifically that the dramatic 3,000-year reduction the DeSilva team had proposed was not supported by the evidence, and that any actual reduction was likely to have occurred over a much longer time scale and through different mechanisms than the social-evolution hypothesis required.

The 2023 response

In 2023, the DeSilva team published a response to the Villmoare and Grabowski critique, also in Frontiers in Ecology and Evolution. The response acknowledged some of the methodological concerns raised in the 2022 paper and presented a revised dataset that addressed several of them. The revised dataset removed juvenile Neanderthal specimens that had been accidentally included in the original compilation, removed a duplicated entry, and dropped data from the historically problematic Morton collection. The revised dataset also added additional Pleistocene specimens to address the under-sampling concern.

The DeSilva team’s reanalysis with the revised dataset, they argued, still detected a statistically significant brain-size reduction in the recent Holocene. They acknowledged that the exact timing was uncertain and could reasonably be placed anywhere between approximately 5,000 and 3,000 years ago, but they maintained that the broader pattern of reduction was robust. The response also emphasised that the underlying observation, that modern human brains are smaller than late Pleistocene brains, was supported by approximately nineteen independent studies over nearly ninety years and could not reasonably be dismissed even if the specific 3,000-year timing was challenged.

The Villmoare and Grabowski position is that the brain may have reduced more gradually since the origin of Homo sapiens approximately 300,000 years ago, or may not have reduced at all in any statistically defensible sense. The DeSilva position is that a rapid Holocene reduction is real and recent. The dispute is genuinely ongoing in the peer-reviewed literature.

Why the brain might have shrunk

The peer-reviewed literature has produced at least six major hypotheses for why human brain size might have decreased in the Holocene, none of which has won scientific consensus.

The first is the social externalisation hypothesis advanced by DeSilva and colleagues. Cognitive load, on this view, has been progressively distributed across literate populations, writing systems, oral traditions, and social structures, reducing the selection pressure on individual brain size.

The second is the body-size hypothesis. Human body size has reduced measurably during the Holocene, possibly as a result of dietary changes following the agricultural transition, and brain size and body size are known to be correlated in mammals. On this view, the brain reduction is a passive consequence of overall body-size reduction. The Villmoare and Grabowski critique points out that body-size reduction can only account for a small fraction of the observed brain-size reduction, and that other factors must be involved.

The third is the agricultural diet hypothesis. The transition to grain-based diets, which began approximately 12,000 years ago in different regions, reduced overall nutritional quality compared with the hunter-gatherer diet that preceded it. Brain tissue is metabolically expensive to maintain, and reduced nutritional intake may have produced selection pressure for smaller brains.

The fourth is the self-domestication hypothesis. Multiple peer-reviewed analyses have argued that humans have undergone a process of self-domestication during the Holocene, with measurable reductions in aggression-related neural systems and corresponding changes in facial structure. Domesticated animals consistently show brain-size reductions of approximately 10 to 15 per cent compared with their wild ancestors, and the human brain reduction may reflect the same mechanism.

The fifth is the energetic efficiency hypothesis. Smaller brains may have been selected for because they require less metabolic energy to operate. The human brain consumes approximately 20 per cent of total body energy, and even modest reductions in brain size can produce substantial energy savings that may have been advantageous under conditions of dietary stress or population pressure.

The sixth is the cognitive efficiency hypothesis, distinct from but related to the social externalisation argument. On this view, the human brain has not become less capable but has become more efficient, with the same cognitive functions implemented in a smaller volume through changes in neural organisation, white-matter density, or synaptic efficiency.

The hypotheses are not mutually exclusive, and most researchers in the field accept that some combination of factors is probably responsible. The disagreement is about which factors matter most and how they interact.

The honest limitations

Several methodological caveats apply to the literature described above.

The first is that cranial capacity is an indirect proxy for brain size, not a direct measurement of it. The brain does not fill the entire cranial cavity, and the relationship between endocranial volume and actual brain mass varies between populations and individuals. The Holocene reductions identified in the literature are based on cranial measurements, not direct brain measurements, and the relationship between the two is not entirely settled.

The second is that the available fossil and recent human cranial samples are not evenly distributed across time, geography, or population. The Pleistocene samples come from a relatively small number of well-preserved individuals from specific regions. The Holocene samples come from much larger numbers of individuals from much wider geographic and population coverage. Comparing the two requires statistical adjustments that involve assumptions about how representative each sample is, and different researchers have made different assumptions.

The third is that the relationship between brain size and cognitive ability is not direct. Larger brains do not, on the contemporary evidence, reliably produce greater intelligence within or between populations. The Holocene reduction, even if real, does not necessarily indicate that modern humans are less intelligent than late Pleistocene humans. The relationship between brain volume and cognitive function is mediated by neural organisation, connectivity, and efficiency in ways that volume measurements cannot capture.

What it means

Several things follow from the brain-shrinkage evidence that are worth saying clearly.

The first is that the popular framing of human evolution as an ongoing march toward larger brains is not supported by the most recent peer-reviewed data. The available evidence, on the strongest current reading, indicates that the human brain has been shrinking, slowly, for somewhere between 3,000 and 300,000 years. The standard textbook narrative of ever-expanding cranial capacity ends approximately 30,000 years ago, in the late Pleistocene, when the maximum average human brain size was reached. Everything since has been a slow contraction.

The second is that the cause of the reduction is genuinely unknown. At least six major peer-reviewed hypotheses are currently in active scientific competition, and the dispute about which one is correct, and whether the reduction occurred 3,000 years ago or 30,000 years ago or across the whole Holocene, is one of the more interesting open questions in physical anthropology.

The third is that the finding sits uncomfortably with the broader cultural narrative about human progress. The 3,000-year time frame that DeSilva proposed, in particular, coincides with the rise of writing, the emergence of cities, the development of complex political institutions, and the cumulative cultural achievements that most accounts of human history treat as the defining markers of advancement. If the DeSilva interpretation is correct, the average human brain has been getting smaller throughout the entire period of recorded civilisation, and the cause may be the very social and technological developments that civilisation is usually understood to consist of.

The fourth, on the strongest current reading of nearly ninety years of peer-reviewed evidence, is that the human brain may be getting smaller because we no longer need it to do quite as much as it once had to.

The peer-reviewed scientific literature has not yet established whether this is true.

It is, however, on the strongest available evidence, not impossible.

The post The average human brain volume has decreased by approximately 150 cubic centimetres since the late Pleistocene, equivalent to roughly the volume of a tennis ball, in a finding documented across nearly ninety years of peer-reviewed physical anthropology research, with no agreed scientific explanation for why one of the most distinctive evolutionary trends of our species has reversed appeared first on Space Daily.