Einstein’s Brain: What Scientists Found When They Studied It
When Albert Einstein died on April 18, 1955, at Princeton Hospital, the pathologist on duty, Thomas Harvey, removed his brain during the autopsy — without prior authorization from Einstein or explicit consent from his family, a decision that would trigger a decades-long, ethically fraught saga involving a wandering pathologist, a brain kept in mason jars in a cider box, and, eventually, a genuinely interesting body of neuroanatomical research into what, if anything, was structurally unusual about the brain behind the twentieth century’s most famous scientific mind.
The Ethically Complicated Origin Story
Harvey photographed the brain, dissected it into approximately 240 blocks, and had it sectioned into thousands of microscope slides, distributing samples to various researchers over subsequent decades — all while working without institutional oversight and, for a significant period, without the Einstein family’s knowledge or approval. Einstein’s son Hans Albert eventually gave retroactive, reluctant permission for scientific study on the specific condition that any resulting research be published only in respected scientific journals and not used for sensationalized purposes — a condition not entirely honored, given how much of the subsequent coverage of Einstein’s brain has, inevitably, leaned toward the sensational. Harvey lost his medical license some years later for reasons unrelated to the brain’s removal, and continued to possess and periodically distribute pieces of the brain for research for the remainder of his life. This origin story is worth including honestly rather than glossing over, because it’s a legitimate and frequently raised ethical case study in the history of neuroscience research, and because it directly shapes how cautiously the resulting scientific findings ought to be interpreted — samples that traveled through such an irregular chain of custody, studied decades after death, invite more caution than a well-controlled, consented, contemporaneously studied case would.
The Diamond Study: More Glial Cells
The first major published scientific study of Einstein’s brain tissue, led by neuroscientist Marian Diamond and colleagues at UC Berkeley in 1985, examined samples from four brain regions, comparing them to samples from eleven deceased control brains matched for approximate age. The study reported that Einstein’s brain showed a significantly higher ratio of glial cells to neurons in one specific region studied — the left inferior parietal area (Brodmann area 39), a region associated with mathematical cognition, language, and visuospatial processing.
Glial cells serve a range of critical supportive functions for neurons, including providing metabolic support, forming myelin, and, per some more modern research, playing an active role in modulating neuronal signaling rather than serving purely as passive structural support as was once assumed. Diamond’s interpretation was that an elevated glia-to-neuron ratio in this specific region might indicate that Einstein’s neurons in that area had unusually high metabolic and functional demands placed on them. This study, however, has faced substantial methodological criticism over the decades since its publication — the sample size was extremely small, or in the case of the comparison group, drawn from a broader age range than ideal, the specific brain region examined was selected after the fact rather than specified in advance based on a pre-registered hypothesis (a practice now recognized as a significant source of potential false-positive findings, sometimes called “p-hacking” in modern methodological discussions), and a single small study of this kind, however intriguing, would not meet the bar for a robust, independently confirmed scientific finding by contemporary standards.
The Witelson Study: The Missing Sylvian Fissure
A more extensively cited and, in the view of several subsequent researchers, more methodologically careful study was published in 1999 by neuroscientist Sandra Witelson and colleagues, who had gained access to photographs of the whole brain taken by Harvey before dissection, along with some measurements, allowing analysis of overall brain structure rather than only small tissue samples. Witelson’s team compared Einstein’s brain photographs and measurements to a reference sample of 91 other brains from individuals of documented normal intelligence.
The most widely discussed finding from this study concerned Einstein’s parietal lobes, which were found to be about 15% wider than in the comparison sample, and which showed an unusual pattern in a structure called the Sylvian fissure — in most brains, this deep groove runs a considerable length through the parietal and temporal regions, but in Einstein’s brain, Witelson’s team reported that a specific posterior portion of this fissure was absent, or at least not present as a distinct anatomical landmark in the same way seen in typical brains. Witelson’s proposed interpretation was that this unusual anatomical configuration might have allowed neurons in the parietal region — an area heavily implicated in mathematical, spatial, and visuospatial reasoning by a substantial independent body of neuroimaging research — to be more densely packed and more extensively interconnected than would be possible with a typical, more clearly demarcated fissure structure physically separating the relevant subregions.
The Falk Study: Unusual Cortical Folding Patterns
A further analysis published in 2013 by anthropologist Dean Falk and colleagues, using the same set of photographs Witelson’s team had worked from, conducted a more detailed examination of the overall pattern of gyri and sulci — the folds and grooves across the entire cortical surface — across all four lobes of the brain, comparing Einstein’s folding pattern to that of a broader comparison group. Falk’s team reported several additional unusual features beyond the parietal region Witelson had focused on, including an unusual prefrontal cortex folding pattern that the researchers speculated might be associated with enhanced planning and abstract reasoning capacity, and additional unusual features in the somatosensory and motor cortex regions corresponding to the face, a finding the researchers connected, speculatively, to some of Einstein’s own written descriptions of his thought process involving vivid internal visualization rather than purely verbal or symbolic reasoning.
The Corpus Callosum Finding
A separate 2013 study, led by Weiwei Men and colleagues, examined the thickness of Einstein’s corpus callosum — the major fiber bundle connecting the brain’s left and right hemispheres, discussed elsewhere in this series’ article on white matter and brain connectivity — using specialized measurement techniques applied to the preserved photographs. This study found that Einstein’s corpus callosum was thicker in several specific subregions compared to both a group of older adult controls and, notably, a separate group of younger adult controls closer to Einstein’s age at the time several of his most celebrated theoretical breakthroughs occurred. A thicker, presumably better-developed corpus callosum would be consistent with the broader connectivity-focused account of exceptional cognitive ability discussed in this series’ white matter article — enhanced communication between the two hemispheres potentially allowing more effective integration of the verbal-analytical processing typically associated with the left hemisphere and the more spatial, visual processing typically associated with the right, a combination that would align intriguingly with Einstein’s own frequently quoted descriptions of his physics-related thinking as substantially non-verbal and image-based, involving what he called “combinatory play” with visual and even muscular or kinesthetic mental imagery rather than words or mathematical symbols, which he reportedly translated into formal language only as a secondary, subsequent step.
The Necessary Scientific Caveats
Before drawing any strong conclusions from this genuinely fascinating research program, several serious limitations deserve explicit emphasis, because the popular treatment of “what scientists found in Einstein’s brain” frequently omits them. This is, in the most basic and unavoidable methodological sense, a sample size of one — no matter how many distinct anatomical features researchers identify as unusual, a single case cannot establish which, if any, of those features were actually causally related to Einstein’s specific cognitive achievements, as opposed to being unrelated anatomical variations that any individual brain, examined in this much painstaking, multi-decade detail by multiple independent research teams, might well be found to possess somewhere. Related to this, researchers studying the brain knew in advance whose brain they were examining, creating an unavoidable and difficult-to-fully-control risk of confirmation bias in both the selection of which measurements to report and the interpretation of ambiguous findings. The brain was also examined years to decades after death, using photographs and preserved tissue rather than the kind of live, functional neuroimaging discussed in this series’ brain-scan article — meaning none of this research can speak directly to how Einstein’s brain actually functioned during the years of his most important theoretical work, only to its static structural anatomy as later preserved and photographed. And Einstein died at 76, meaning some observed anatomical features could reflect age-related changes, general health factors, or simple normal individual variation entirely unrelated to his earlier scientific achievements decades before his death.
What the Research Reasonably Supports
Taken together with appropriate caution, the multi-decade research program on Einstein’s preserved brain has identified a genuinely consistent cluster of anatomical peculiarities, concentrated substantially in the parietal lobes and the interhemispheric connective tissue of the corpus callosum — regions and structures that independently, through the large body of population-level neuroimaging research discussed elsewhere in this series, are already well-established as relevant to mathematical reasoning, spatial cognition, and cross-hemispheric integration in the general population. This convergence between one carefully studied individual case and a much larger body of independent population research is more scientifically suggestive than any single anatomical finding would be in isolation. But “suggestive” remains the operative and appropriately modest word — this research offers an intriguing, partially corroborating data point that fits comfortably within the broader connectivity-and-integration account of exceptional cognitive ability this series has developed across multiple articles, rather than a definitive, standalone explanation for what made one particular twentieth-century physicist’s mind capable of the specific theoretical breakthroughs that made him famous.
