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150 results for “brainsik”
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When it comes to brains, size doesn’t matter much
Image credit: Ionut Stefan
It all started from a reasonable assumption: bigger brains pack more neurons, and more neurons make one smarter, ergo bigger brain = smarter cookie. But if there’s one thing brains love, it’s nonlinearities (to be read as “freaking messes!”). To understand what that means, we’ll talk about how brains of different sizes are structured, and if it’s not size, what features actually make them smart.
We can approach this discussion at two levels: between species and within species. At the first level, brain size varies dramatically (imagine mouse vs. elephant), giving us a coarse-grained understanding of why size alone doesn’t explain intelligence. At the second one, we’ll look at comparisons between people, where the differences in brain size are much smaller, but the data is richer, giving us a more fine-grained picture of what might be going on.
What is intelligence
In both cases, we need to define what “smart” means. Intelligence, like a lot of other higher-order cognitive concepts, suffers from definition fuzziness: there are a bunch of ways to define it, and if we don’t clarify this upfront, we risk talking past each other. For this article, we’ll focus on general intelligence, or mental ability.
Another point to consider is that we’ll be talking about both humans and other species.
For all of them, general intelligence includes the ability to solve problems and come up with novel solutions, the capacity to learn and change one’s behavior based on experience, and the ability to think abstractly.In humans, however, intelligence tests obviously rely heavily on verbal ability, and many studies use something called the g factor. This variable summarizes positive correlations between different cognitive tasks, and is used to reflect something we’ve observed empirically: that people who do well on one cognitive test usually do well on others too.
There have been attempts to use the g factor for quantifying intelligence in other animals, but as you can imagine, the lack of verbal ability makes standardized inter-species comparisons extremely challenging. Instead, researchers rely on a set of indirect tests. These let them measure things such as learning and problem-solving, memory capacity, or even the ability for self-recognition (using the mirror test).
The lack of standardization makes it difficult to say with certainty that, for example, a crow is more intelligent than a baboon. Yes, crows can do geometry and baboons apparently can’t, but is that all it takes to be smart? Still, imperfect as they are, these measures allow us to challenge the assumption that bigger brains are smarter: if a crow, with a much smaller brain than a baboon’s, can do geometry, clearly there’s more at play than sheer brain size.
The comparison between species
But let’s back up a bit. In the section above, it seemed reasonable to define “smart”, but what if I told you we also need a definition for “brain size”? It might seem a bit ridiculous, but there really is more than one interpretation for this term. We saw the first one in the crow-baboon example, where we introduced absolute brain size. The problem with this is that absolute brain size correlates strongly with body size: larger animals have larger brains. And we don’t even need to compare crows and baboons, we can compare ourselves to whales and elephants. Even though they’re quite intelligent animals, they’re still not exactly on our level. So absolute brain size is not a good indicator of intelligence.
Another way to define brain size would be relative to the body weight. Take humans and whales again: the brain of a human weighs about 1.5 kg, and that of a whale about 9 kg. In terms of absolute brain size, whales win hands down. But if we look at brain weight as a percentage of the body weight, we get about 2.5% in humans and a measly 0.02% in whales. We now have a data point indicating that a species with a higher relative brain size is also more intelligent. We can now expand this to as many species as possible and see if it still holds. It’s not a big surprise that it doesn’t, but I bet you won’t guess which animal breaks the pattern. It’s the Etruscan shrew (this little guy), with a brain weight of about 0.1 g and a body weight of only 2 g, giving us a 5% value, double that of humans!
Alright, that’s another simple explanation gone down the drain. Back to the drawing board it is. We said that larger bodies go hand in hand with larger brains. Now, if intelligence didn’t play any role at all, we could assume that the brain is simply increasing in size because it needs to manage a larger body. In that case, if we knew an animal’s body size, we could mathematically predict what its absolute brain size should be. If we saw any increase in size on top of that, we could only assume that’s due to the extra brain being used for intelligence. That’s the simplest explanation for what scientists termed the third way of defining brain size, the encephalization quotient (EQ). As you might already guess, that didn’t work out very well either. Humans came up pretty well on this metric, but chimpanzees, gorillas, and whales, animals which we know are fairly smart, scored quite low EQs. More attempts were made to improve the EQ calculation formula. These only succeeded in making it more complicated, so I won’t bore you with the details. Bottom line is, the idea that brain size is related to intelligence across species was examined from multiple angles and it always came up short.
But why? Why? Why?
Well, for a bunch of reasons. Let’s start with our first assumption: “bigger brains pack more neurons”. Remember that? Across species, that’s not always true. What’s more, which brain regions have more neurons is also very important. As an example, elephants have 3 times (!) more neurons than humans. But in elephants, a lot of these neurons are found in the cerebellum, not in the cortex (presumably to control the fine-grained movements of the trunk), the neurons themselves are larger, and their number per cubic millimeter is much lower (only 6.000-7.000 neurons/mm3, compared to 25.000-30.000 neurons/mm3 in humans).
In contrast, although crows have tiny brains compared both to humans and elephants, their neuronal density is nothing short of impressive: in the nidopallidum, a region used for executive tasks, it can reach about 130.000-160.000 neurons/mm3. With such numbers, it’s no wonder crows can rival and even outperform some primates on cognitive tasks.
However, as we’ll see more clearly in the next section, the number, density, or location of neurons aren’t the only factors that matter. How they are connected and how fast information can travel between them also play important roles.
The comparison within species
The comparisons above showed us that, across species, brain size isn’t a good predictor of intelligence. Brains don’t just scale up, but some of their properties, such as neuron density or size, also change between species. But within species, and more specifically between people, we don’t expect such significant differences. That’s why, before diving into more complex structural features, it’s worth asking again how the relation between brain size and intelligence holds up in humans.
It turns out that it works slightly better. There is a small, positive correlation between brain size and the g factor. The correlation coefficient r (which goes from -1 to 1, with 1 indicating perfectly correlated, 0 meaning no correlation, and -1 perfectly anticorrelated) sits in the range of 0.2-0.3. It’s not much, but it’s honest work. What’s more, separating the brain into gray and white matter and correlating their volumes with intelligence shows that gray matter is the driver of this effect. But even so, this only explains a small part of the picture. So… where is the rest coming from?
We’ve already hinted above that it has to do with connections and information speed. In more concrete terms, we know the brain is basically a network of neurons. And the information-processing capacity of this network is what translates into intelligence. Unfortunately, studying large networks like the brain and how their properties relate to constructs such as intelligence tends to be a bit…complicated. That’s why, even though gathering relevant data in humans is much easier compared to other species, the full picture is still quite murky.
What we know so far is that networks connected more efficiently appear to correlate with higher intelligence and that good myelination is important for cognitive processing speed. In terms of theories, perhaps the most well-established one is the parieto-frontal integration theory, which tells us that a network formed by lateral frontal and parietal areas is highly relevant for intelligence. However, newer studies suggest it’s not just these regions, but how the entire brain is structured, that determines intelligence.
To sum up
Brains are complicated. And although it seems easy to assume that larger brains with more neurons can do more, nature doesn’t agree. There still a lot of work needed to determine what makes a brain smart. But so far we’ve learned that where those neurons are situated and how efficiently information can flow between them trumps simple upscaling. Maybe something to keep in mind for other so-called “brain-like” systems.
What did you think about this post? Let us know in the comments below. And if you’d like to support our work, feel free to share it with your friends, buy us a coffee here, or even both.
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References
Barbey, A. K., Karama, S., & Haier, R. J. (Eds.). (2021). The Cambridge Handbook of Intelligence and Cognitive Neuroscience. Cambridge: Cambridge University Press. https://doi.org/10.1017/9781108635462Coyle, T. R. (2021). Defining and Measuring Intelligence. The Cambridge Handbook of Intelligence and Cognitive Neuroscience, 3–25. https://doi.org/10.1017/9781108635462.003
Dicke, U., & Roth, G. (2016). Neuronal factors determining high intelligence. Philosophical Transactions of the Royal Society B: Biological Sciences, 371(1685), 20150180. https://doi.org/10.1098/rstb.2015.0180
Herculano-Houzel, S., Avelino-de-Souza, K., Neves, K., PorfÃrio, J., Messeder, D., Mattos Feijó, L., Maldonado, J., & Manger, P. R. (2014). The elephant brain in numbers. Frontiers in Neuroanatomy, 8. https://doi.org/10.3389/fnana.2014.00046
Sablé-Meyer, M., Fagot, J., Caparos, S., van Kerkoerle, T., Amalric, M., & Dehaene, S. (2020). Sensitivity to geometric shape regularity in humans and baboons: A putative signature of human singularity. https://doi.org/10.31234/osf.io/hj3m6
Schmidbauer, P., Hahn, M., & Nieder, A. (2025). Crows recognize geometric regularity. Science Advances, 11(15). https://doi.org/10.1126/sciadv.adt3718
Ströckens, F., Neves, K., Kirchem, S., Schwab, C., Herculano‐Houzel, S., & Güntürkün, O. (2022). High associative neuron numbers could drive cognitive performance in corvid species. Journal of Comparative Neurology, 530(10), 1588–1605. Portico. https://doi.org/10.1002/cne.25298
van den Heuvel, M. P., Stam, C. J., Kahn, R. S., & Hulshoff Pol, H. E. (2009). Efficiency of Functional Brain Networks and Intellectual Performance. Journal of Neuroscience, 29(23), 7619–7624. https://doi.org/10.1523/jneurosci.1443-09.2009
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External fermentation of food may be the key to the evolution of increased brain size.
It wasn't fire (cooked food has more bioavailable energy than raw) because brain size started increasing a million years before fire was tamed and used.
Interesting new study and brief summary article — see:
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Bird-brained? Climate change may affect intelligence in birds - Raw Story - Celebrating 19 Years of Independent Journalism
#Birds
#Intelligence
#ClimateChange
#BrainSize
#Brain
https://www.rawstory.com/bird-brained-climate-change-may-affect-intelligence-in-birds-2659695394/ -
Organoids hint at origins of enlarged brains in autistic people
https://www.spectrumnews.org/news/organoids-hint-at-origins-of-enlarged-brains-in-autistic-people/
#brainsize #organoids #stemcells #autism #cortex #News -
Growth charts map brain changes across lifespan
https://www.spectrumnews.org/news/growth-charts-map-brain-changes-across-lifespan/
#brainimaging #brainsize #autism #cortex #News #MRI -
Cerebellum size shows tenuous genetic link to autism
https://www.spectrumnews.org/news/cerebellum-size-shows-tenuous-genetic-link-to-autism/
#brainimaging #cerebellum #brainsize #autism #News -
A clip of @siracusa asking why things can’t be both beautiful and accessible and defining success as creating an accessible tool that most people enjoy using.
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Inspired by the Debian 14 announcement, I’ve finally made my json-store #Python package create reproducible builds.
This was super easy thanks to all the work done by the hatch build system.
https://hatch.pypa.io/1.16/config/build/#reproducible-builds
You should too. 😁
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It's true; I sometimes get mistaken for the #ZodiacKiller... | #BrainLikeABulletTrain
#IT's #True... #StillTrue™️
🧙:Polymaths:🤖:wolfparty:🤖:Polymaths:🧙 | :fediverse:🦹:PirateBadge:🦄:PirateBadge:🦹:fediverse:
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It's true; I sometimes get mistaken for the #ZodiacKiller... | #BrainLikeABulletTrain
🧙:fediverse:🤖:wolfparty:🤖:fediverse:🧙 | :PirateBadge:🚅🦹🦄🦹🚅:PirateBadge:
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Long, but great read from #HAProxy on the state of #TLS libraries. Includes some scathing remarks about the #OpenSSL project.
“The development team has degraded their project’s quality, failed to address ongoing issues, and consistently dismissed widespread community requests for even minor improvements.”
“This unfortunate situation considerably hurts QUIC protocol adoption. It even makes it difficult to develop or build test tools to monitor a QUIC server.”
“When some of the project members considered a 32% performance regression ‘pretty near’ the original performance, it signaled to our development team that any meaningful improvement was unlikely.”
“In blunt terms: running OpenSSL 3.0.2 as shipped with Ubuntu 22.04 results in 1/100 of #WolfSSL’s performance on identical hardware! To put this into perspective, you would have to deploy 100 times the number of machines to handle the same traffic, solely because of the underlying SSL library.”
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Các nhà khoa học vừa tạo ra chip nano lỏng với khả năng ghi nhớ như não bộ! Chip MOF này điều khiển dòng proton phi tuyến tính, hoạt động như một memristor ion. Phát hiện này mở ra hướng đi mới cho công nghệ iontronics và máy tính mô phỏng sinh học.
#KhoaHoc #CongNghe #Memristor #NanoFluidics #BrainLikeComputing #Science #Technology #IonTrònics
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Các nhà khoa học vừa tạo ra chip nano lỏng với khả năng ghi nhớ như não bộ! Chip MOF này điều khiển dòng proton phi tuyến tính, hoạt động như một memristor ion. Phát hiện này mở ra hướng đi mới cho công nghệ iontronics và máy tính mô phỏng sinh học.
#KhoaHoc #CongNghe #Memristor #NanoFluidics #BrainLikeComputing #Science #Technology #IonTrònics
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Các nhà khoa học vừa tạo ra chip nano lỏng với khả năng ghi nhớ như não bộ! Chip MOF này điều khiển dòng proton phi tuyến tính, hoạt động như một memristor ion. Phát hiện này mở ra hướng đi mới cho công nghệ iontronics và máy tính mô phỏng sinh học.
#KhoaHoc #CongNghe #Memristor #NanoFluidics #BrainLikeComputing #Science #Technology #IonTrònics
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Các nhà khoa học vừa tạo ra chip nano lỏng với khả năng ghi nhớ như não bộ! Chip MOF này điều khiển dòng proton phi tuyến tính, hoạt động như một memristor ion. Phát hiện này mở ra hướng đi mới cho công nghệ iontronics và máy tính mô phỏng sinh học.
#KhoaHoc #CongNghe #Memristor #NanoFluidics #BrainLikeComputing #Science #Technology #IonTrònics
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Umm, hell yeah. I had no idea this was a thing!
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9News | The motley crew of billionaires tagging along on Trump's China visit by 9News
AI generated summary, Read the full article for complete information.
Donald Trump arrived in Beijing atop Air Force One accompanied by a heavyweight delegation of U.S. business leaders and billionaires whose combined net worth exceeds a trillion dollars, including Elon Musk, Tim Cook (referred to as “Tim Apple”), Jensen Huang of NVIDIA, leaders from Apple, Boeing, Meta, Mastercard, Visa, Goldman Sachs, Micron and others, as well as filmmaker Brett Ratner. Trump announced that his first request of President Xi will be to “open up” China for these companies to make deals, hoping to revive U.S.‑China trade after recent tariffs that have slashed Chinese purchases of American goods. The entourage also sparked controversy, with Musk facing potential legal trouble for traveling abroad despite a court order, and Trump defending the inclusion of Huang after a media report claimed he had been snubbed. The trip underscores Trump’s pattern of surrounding himself with corporate titans to pursue economic and diplomatic goals in China.
#DonaldTrump #ElonMusk #TimCook #GoldmanSachs #JensenHuang #LarryFink #StephenSchwarzman #KellyOrtberg #BrianSikes #JaneFraser #larryculp #DavidSolomon #SanjayMehrotra #CristianoAmon #BrettRatner
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PBS NewsHour - The Latest | Who was on Trump's plane to China? Elon Musk, Nvidia CEO and more by Michelle Chapman, Associated Press
AI generated summary, Read the full article for complete information.
President Donald Trump flew to Beijing on Air Force One accompanied by a high‑profile delegation of U.S. business leaders – among them Elon Musk, the Tesla and SpaceX CEO who previously headed Trump’s short‑lived Department of Government Efficiency; Tim Cook, Apple’s outgoing chief executive; Jensen Huang, founder and CEO of Nvidia; and Boeing’s CEO Kelly Ortberg – as well as top executives such as BlackRock chairman Larry Fink, Blackstone’s Stephen Schwarzman, Cargill’s Brian Sikes, Citi’s Jane Fraser, GE Aerospace chief H. Lawrence Culp, Goldman Sachs’s David Solomon, Illumina’s Jacob Thaysen, Mastercard’s Michael Miebach, Meta’s Dina Powell McCormick, Micron’s Sanjay Mehrotra, Qualcomm’s Cristiano Amon and Visa’s Ryan McInerney. The entourage underscores the trip’s focus on trade, artificial‑intelligence policy and broader economic issues as Trump meets President Xi Jinping.
Read more: https://www.pbs.org/newshour/world/who-was-on-trumps-plane-to-china-elon-musk-nvidia-ceo-and-more
#DonaldTrump #ElonMusk #TimCook #JensenHuang #KellyOrtberg #LarryFink #StephenSchwarzman #Nvidia #Apple #Boeing #China #donaldtrumpnews #techindustry #XiJinping #BrianSikes #JaneFraser #LawrenceCulp #DavidSolomon #JacobThaysen #MichaelMiebach #DinaPowellMcCormick #SanjayMehrotra #CristianoAmon #RyanMcInerney
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🫡 Today is a great day to learn about #FredKorematsu, Ernest Besig, Wayne M. Collins, and the work they did trying to unfuck the U.S. decision to incarcerate Japanese Americans during WWII. #FredKorematsuDay
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"Anchor Brewing was a cockroach."
A bittersweet stroll through all the near deaths #AnchorBrewing went through before finally succumbing to Sapporo's leadership. "The oldest operating craft #brewery in the United States is dead." ⚱️
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Rad, have you done much work in #mandelbulb3D ?
Loved working with it once upon a time, used for my profile banner. love to try a new tool and this sounds like a super fun project.
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#BTW: #IF (and #IT's a #BIG #IF) you're #Considering a #Career in #PatientAdvocacy; #One "needs" to be #Patient, which is #QuiteHard when you have a #BrainLikeABulletTrain...
#IT's a #Challenge; but, #DefinitelyWorthIT...
🧙⚔️🤖:wolfparty:🤖⚔️🧙 | :fediverse:🦹:loading:🦄:loading:🦹:fediverse:
#SnakeRiverConspiracy: How Soon Is Now?
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https://www.europesays.com/uk/85924/ Bigger Brains and Strong Immunity Linked to Longer Lifespans #Aging #BrainResearch #BrainSize #Genetics #ImmuneSystem #lifespan #Longevity #neurobiology #Neuroscience #Science #UK #UnitedKingdom #UniversityOfBath
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Inspired by the Debian 14 announcement, I’ve finally made my json-store #Python package create reproducible builds.
This was super easy thanks to all the work done by the hatch build system.
https://hatch.pypa.io/1.16/config/build/#reproducible-builds
You should too. 😁
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Here we go. The massively subsidized #AI plan pricing is continuing to break down. #Anthropic has been doing different sneaky things to slowly acclimate folks to a new (more expensive) reality. This latest move is classic #shrinkflation.
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Here we go. The massively subsidized #AI plan pricing is continuing to break down. #Anthropic has been doing different sneaky things to slowly acclimate folks to a new (more expensive) reality. This latest move is classic #shrinkflation.
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Here we go. The massively subsidized #AI plan pricing is continuing to break down. #Anthropic has been doing different sneaky things to slowly acclimate folks to a new (more expensive) reality. This latest move is classic #shrinkflation.
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Here we go. The massively subsidized #AI plan pricing is continuing to break down. #Anthropic has been doing different sneaky things to slowly acclimate folks to a new (more expensive) reality. This latest move is classic #shrinkflation.
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Can you upload a human mind into a computer? A neuroscientist ponders what’s possible
#AI #ChatGPT #MindUploading #DigitalImmortality #Neuroscience #MRI #FutureTech #Consciousness #BrainSimulation #Mind #Robotics #TransHumanism #ScienceExplained #Brain
https://the-14.com/can-you-upload-a-human-mind-into-a-computer-a-neuroscientist-ponders-whats-possible/