The Science and Story of Albert Einstein’s Brain

When Albert Einstein died on April 18, 1955, at Princeton Hospital from a ruptured abdominal aortic aneurysm, the pathologist on duty did something that would spark decades of scientific fascination and ethical debate: he removed Einstein’s brain. Within hours, pathologist Thomas Harvey had weighed it (1,230 grams, slightly below average for a man of Einstein’s age), photographed it from dozens of angles, and immersed it in formalin for preservation.¹ What followed was not a tidy chapter of neuroscience but a strange, sprawling story involving lost tissue, contested permission, a handful of genuinely intriguing anatomical findings, and a sharp ongoing debate about whether any of it tells us anything real about genius.

How the Brain Was Removed and Divided

Harvey did not act under clear institutional authority. Permission to preserve and study the brain was obtained from Einstein’s son, Hans Albert, and his executor, Otto Nathan, both of whom attended the post-mortem examination.¹ But Einstein himself had expressed a preference for cremation, and the decision to keep the brain has been questioned ever since. Whether Harvey overstepped or acted within the bounds of the family’s consent remains a point of disagreement among historians.

Harvey was meticulous in his documentation. Using a 35mm Exakta camera, he took black-and-white photographs of the whole brain and then of the partially dissected brain. He then partitioned the hemispheres into 240 blocks, which were embedded in celloidin (a type of resin used to prepare tissue for microscopy) and mapped to a “roadmap” of the whole brain so that each piece could be traced back to its original location.² Many of these blocks were eventually cut into microscope slides. Over the following years, Harvey sent slides and small tissue chunks to researchers who requested them, sometimes by mail, sometimes hand-delivered in a cider box in the trunk of his car. The image of one of the twentieth century’s most important brains riding around in Tupperware containers became a minor legend in its own right.

Where the Brain Is Now

For decades, the whereabouts of many pieces were uncertain. Harvey kept a substantial portion himself through multiple job changes and cross-country moves, and other pieces were distributed to a scattering of researchers. Today the largest known collection of the original celloidin-embedded brain blocks, 180 out of the original 240, is housed at the University Medical Centre at Princeton. The largest aggregation of microscope slides, numbering 567, is at the National Museum of Health and Medicine.¹ Other pieces remain in private hands or at institutions around the world, and some of the original 240 blocks have never been accounted for. Many of the gauze-wrapped chunks that Harvey did not embed are believed to still be floating in two glass jars of formalin, somewhere.²

What Researchers Found (and Claimed)

Studies of Einstein’s brain began trickling out in the 1980s and continued into the 2010s. Each focused on a different anatomical feature, and each claimed to have found something unusual. The findings are genuinely interesting, but as we will see, they are also genuinely contested.

More Glial Cells in a Key Region

The first widely publicized study came from neuroscientist Marian Diamond and colleagues in 1985. They compared the ratio of neurons to glial cells (the support cells that surround and nourish neurons) in four regions of Einstein’s cortex against samples from 11 other male brains. In three of the four regions, Einstein’s tissue looked unremarkable. But in one area, called left area 39, located in the inferior parietal lobule, Einstein had proportionally more glial cells relative to neurons than the control group.³ Area 39 is part of a region involved in associative thinking, spatial reasoning, and mathematical cognition, so the finding was seized upon as a possible neurological fingerprint of Einstein’s abilities.

An Unusual Prefrontal Cortex

In 2012, anthropologist Dean Falk and colleagues analyzed 14 recently rediscovered photographs of Einstein’s brain, most taken from unconventional angles that previous researchers had not studied. Their analysis of the external surface anatomy described an “extraordinary prefrontal cortex,” with complex folding patterns in areas associated with planning, working memory, and abstract thought.⁴ The researchers also noted unusual features in the parietal lobes, somatosensory cortex, and primary motor cortex, suggesting that Einstein’s brain surface had distinctive folding in several regions simultaneously.

A Thicker Corpus Callosum

A 2013 study examined the corpus callosum, the thick band of nerve fibers connecting the brain’s two hemispheres. Researchers compared Einstein’s corpus callosum thickness against two control groups: 15 elderly men and 52 young men. While the overall size was similar to the controls, Einstein’s corpus callosum was significantly thicker in certain subregions, particularly the genu, body, and rostral body.⁵ The authors interpreted this as evidence for enhanced communication between hemispheres, which could theoretically support the kind of integrative, multi-domain thinking Einstein was known for.

Why Skeptics Are Unconvinced

Each of these findings sounds compelling in isolation. Taken together, they paint a portrait of a brain with more support cells in key regions, richer surface folding in the prefrontal and parietal areas, and thicker wiring between hemispheres. The trouble is that the methods behind these studies have serious limitations, and a thorough critical review published in 2014 found the entire body of Einstein brain research wanting. The review concluded that the results do not, in fact, provide support for the claim that the structure of Einstein’s brain reflects his intellectual abilities.⁶

The problems are structural, not just technical quibbles. Consider the sample sizes: Diamond compared one brain to eleven. The corpus callosum study compared one brain to fifteen elderly men and fifty-two young men. When your sample of interest is literally one individual, any unusual measurement might just be normal variation. Roughly half of all people are above average on any given metric, so finding that one person’s brain is above average in some area is not especially surprising unless you know in advance which area to look at and why.

And that leads to the second concern: none of these studies had pre-registered hypotheses. Researchers examined Einstein’s brain, found something that looked different, and then proposed a theory for why that difference might relate to his genius. This is the equivalent of shooting an arrow and painting the target around wherever it lands. If his prefrontal cortex had been unremarkable but his cerebellum had been unusual, there would likely have been a paper explaining why Einstein’s cerebellum was the key to relativity. The interpretive flexibility is essentially unlimited when you are working backward from the conclusion that this person was brilliant.

There are also concerns about the tissue itself. Einstein was 76 when he died. Aging changes the brain in ways that make it difficult to compare to younger controls, and formalin preservation introduces its own distortions. Postmortem changes begin within minutes: fluid shifts cause cell volume alterations, cell membranes deform, and the longer the delay between death and fixation, the greater the structural degradation.⁷ Harvey did preserve the brain fairly promptly, but decades of storage in formalin introduce further artifacts. When Diamond counted glial cells and neurons, she was counting in tissue that had been sitting in fixative for thirty years. Whether the ratios she measured reflected Einstein’s living brain or the effects of prolonged chemical preservation is genuinely unclear.

What Modern Neuroimaging Says About Mathematical Brains

Setting aside the specific claims about Einstein’s tissue, there is a separate and more rigorous body of research asking a related question: do the brains of people who are exceptionally good at mathematics look or function differently from those of others? This research uses brain scans of living people, with proper control groups, and the findings do overlap in interesting ways with some of what was reported about Einstein’s brain.

Studies of mathematically gifted adolescents performing complex reasoning tasks have found that they activate the fronto-parietal network more extensively and more bilaterally than controls. The biggest differences appear in the right inferior parietal lobule and frontal areas, supporting the idea that stronger visuospatial processing and logical reasoning recruit these regions more heavily.⁸ Structural studies echo this. Professional mathematicians have been found to have higher gray matter density in the right superior parietal lobule compared to non-mathematicians.⁹ Another study found increased gray matter density in the bilateral inferior parietal lobules and left inferior frontal gyrus of mathematicians, with the parietal increase strongly correlated with the number of years they had worked as academics.¹⁰

The parietal regions flagged in these modern studies are broadly the same areas where Diamond found an unusual glial-to-neuron ratio and where Falk described unusual surface folding. That convergence is suggestive but not conclusive. The modern studies compare groups of living mathematicians against control groups, with large enough samples to draw statistical inferences. The Einstein studies compared one deceased physicist’s preserved tissue against a handful of controls using century-old histological methods. The modern work lends plausibility to the idea that Einstein’s parietal regions could have been different; it does not validate the specific measurements made on his preserved brain.

It is also worth noting a chicken-and-egg problem. The correlation between years of mathematical practice and parietal gray matter density found in the neuroimaging study raises the possibility that Einstein’s brain looked the way it did partly because he spent decades doing physics, not solely because he was born with unusual anatomy. Brains change with sustained practice, and the line between innate structure and experience-driven remodeling is impossible to draw from a single post-mortem snapshot.

The Tradition of Preserving Famous Brains

Einstein’s brain was not preserved in a vacuum. The practice of removing and studying the brains of notable people stretches back centuries. For much of that time, brain collections were assembled by individual researchers and stored in jars of alcohol or formalin, serving purposes that ranged from genuine neuroanatomy to phrenological pseudoscience to outright political propaganda.¹¹

One of the most famous predecessors to the Einstein project was the study of Vladimir Lenin’s brain. After Lenin died in 1924 from progressive cerebrovascular disease, the Soviet government commissioned the eminent German neuroscientist Oskar Vogt to examine it. An entire Institute for Brain Research was founded in Moscow for the purpose. Tens of thousands of serial sections were cut, and in his 1929 report, Vogt concluded that the pyramidal neurons in certain layers of Lenin’s cortex were exceptionally large and numerous.¹² The political motivation behind that conclusion is hard to miss: a government seeking biological proof that its founder was a singular genius funded a study that, unsurprisingly, found exactly that.

The broader history of brain archiving tracks the evolution of preservation technology itself, from early experiments storing tissue in spirits of alcohol through increasingly refined chemical fixation to modern cryogenic methods that freeze tissue rapidly enough to preserve molecular-level detail.¹³ By the 1960s, the first modern brain banks began actively collecting and strategically preserving both diseased and healthy brains for distribution to the broader scientific community, moving away from the idiosyncratic personal collections that characterized earlier eras.¹¹ Einstein’s brain sits awkwardly at the transition between these two eras: it was collected in the old style, by one pathologist acting largely on his own initiative, but it has been studied intermittently with increasingly modern tools.

The Deeper Problem With Studying Genius Post-Mortem

Even if every measurement made on Einstein’s brain were technically flawless, there would still be a fundamental conceptual problem with the enterprise. Neuroscience has no reliable way to work backward from a preserved brain to a living mind. You can describe the grooves, count the cells, and measure the fiber bundles, but you cannot replay the neural activity, trace the thought patterns, or reconstruct the cognitive processes that produced the theory of special relativity. Brain structure is a scaffold, and a remarkable amount of what makes cognition exceptional happens in the dynamics of how neurons fire, how networks synchronize, and how patterns of activity shift in real time. None of that survives death.

This is not just a practical limitation; it is a logical one. Intelligence, creativity, and scientific insight are not single traits localized in single regions. They emerge from the interplay of memory, attention, motivation, education, cultural context, and sheer chance. Attributing Einstein’s contributions to a thicker corpus callosum or a peculiar prefrontal fold is a bit like attributing a great novel to the writer’s unusually large hands. The physical substrate matters, but the relationship between structure and outcome is vastly more complex than the Einstein brain studies can capture.

The skeptical review published in 2014 made this point forcefully, arguing that the entire tradition of Einstein brain research amounts to a form of neuromythology: scientifically flavored storytelling that satisfies our desire to locate genius in the body but that does not hold up under rigorous scrutiny.⁶ That does not mean the studies were worthless. They generated hypotheses, drew attention to parietal lobe function, and prompted better-designed research on mathematical cognition. But the conclusions they drew about Einstein specifically remain, at best, educated speculation.

What Einstein Himself Wanted

There is an uncomfortable irony running through the whole saga. Einstein valued his mind, obviously, but he was wary of the cult of personality that surrounded him. He requested cremation. He did not want to become a relic. The story of his brain, passed around in jars and Tupperware, studied in fragments by researchers looking for the biological spark of genius, has an element of the very idolatry he tried to resist.

Harvey, for his part, seemed to genuinely believe he was serving science. He spent decades trying to get researchers interested in the tissue, mailing slides to anyone with credible credentials, and ultimately returned the bulk of the collection to Princeton before his death in 2007. Whether the science that resulted justified the removal is a question that different people will answer differently, depending on how much weight they give to the consent of the dead, the ambitions of the living, and the modest yield of the research itself.

What the Einstein brain story illustrates most clearly is not a fact about Einstein’s cognition but a fact about ours: we are drawn to the idea that extraordinary minds must have extraordinary hardware, and we are willing to read that conclusion into ambiguous evidence. The parietal findings are suggestive enough to keep the question alive, and the modern neuroimaging work on mathematical expertise gives them a plausible context. But the honest summary, after six decades and more than a dozen published studies, is that we still cannot point to Einstein’s preserved brain tissue and say with confidence, “This is why he was Einstein.”