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Because we are being domesticated. Domesticated animals are all dumber than their wild counterparts. Every wild animal that ends up being domesticated ends up w
by algebraically 5y ago
Because we are being domesticated. Domesticated animals are all dumber than their wild counterparts. Every wild animal that ends up being domesticated ends up with a smaller brain. I should rephrase and maybe say that this doesn't necessarily mean the animals get dumber but they definitely change in the process of domestication and a smaller brain is one of those adaptations. [1]
> The reduced amount of white matter suggests that domestic rabbits have a compromised information processing possibly explaining why they are more slow reacting and phlegmatic than their wild counterparts.
1: https://phys.org/news/2018-06-differences-brain-morphology-wild-domestic.html https://phys.org/news/2018-06-differences-brain-morphology-w...
- Asooka 5y agoHm, then shouldn't people who live in tribal societies as hunter gatherers have bigger brains still? Has anyone studied that?
- algebraically 5y agoI don't know. That's a good question but most modern humans are essentially clones so I don't think there is going to be much difference. [1][2] 1: https://www.nationalgeographic.org/media/genetic-bottleneck/ https://www.nationalgeographic.org/media/genetic-bottleneck/ 2: https://en.m.wikipedia.org/wiki/Toba_catastrophe_theory https://en.m.wikipedia.org/wiki/Toba_catastrophe_theory
- misja111 5y agoIf you read the article you will find that your question is answered in there.
- lumost 5y agoAlternately, big brains are recessive/selected against in all circumstances except those from 6mya to 70kya. We've generally removed most selective pressure at this point, if having big brains is due to a combination of recessive traits we'd expect brain size to start shrinking.
- snek_case 5y agoI was going to say: maybe it's because we're so successful? We dominate our environment so well that we've made the world a much less threatening place, and so it's not as difficult to survive in the world anymore. Less selective pressure means we end up with a less selected population. I don't want to turn this into a political commentary, but the modern age is an extreme example of this. You could be the kind of person who doesn't finish high school and can't keep a job, a deadbeat, but still manage to have multiple kids. Even if you don't take care of them, someone else will ensure that your kids survive. Long ago, not being able to are and provide for your kids probably meant that they died. IMO, as we keep making the world increasingly more safe and comfortable, we might have to resort to genetic engineering. Otherwise, it might be inevitable that more and more genetic disorders will arise, just because we're able to keep people alive with all kinds of illnesses that would have been fatal before. People can argue about the ethics all they want, but it seems inevitable.
- SamoyedFurFluff 5y agoWouldn’t being able to retain maximal genetic diversity actually be a good thing species wide though? Because it also means we have ever bigger achievers in ever more niche but valuable roles.
- snek_case 5y agoWe can probably keep 99% of the diversity and just filter out diseases that significantly decrease quality of life.
- im3w1l 5y agoScreening and abortion are already used to prevent serious disorders. For instance, a huge fraction of downies are aborted. But subtler things are more challenging.
- quaintdev 5y agoRelevant http://www.paulgraham.com/boss.html http://www.paulgraham.com/boss.html
- kkoncevicius 5y agoThis is discussed in the article as one of the possibilities.
- algebraically 5y agoMakes sense.
- amelius 5y agoYes, people give away their private data for small conveniences, much like how pets give away their natural lives in wilderness for a guaranteed meal and a warm house.
- iamstupidsimple 5y agoWhat a bizarre comparison. Any animal would make the same 'choice'.
- FormerBandmate 5y ago70,000 years ago people were running around in groups of 50-200 people killing mammoths. Private data has nothing to do with this, that’s only happened in the past 20 years and there isn’t a generation that has lived their whole lives with smartphones that are adults yet. We have no idea what effect they’ll have on evolution
- FormerBandmate 5y agoDomesticated by whom? How?
- deleted 5y ago[deleted]
- lovecg 5y agoBy ourselves and the structures we created. Agriculture, etc.
- algebraically 5y agoIt's possible for an animal to domesticate itself. This is one of the theories for how wolves were domesticated. It's not that humans did anything special to domesticate them but that wolves started hanging around humans and eating the scraps that were left over at campfires and other human habitation sites. Eventually the less fearful and tame wolves became human companions. Once people realized they could hang out with wolves they started actively breeding more tamer variants. The same is true for humans. The process is obviously slightly more complicated because unlike wolves people have more influence on their environment but it's undeniable that humans are now domestic animals. No modern human can survive in the wilderness and this process is accelerating. We are now, for all intents and purposes, dependent on mechanical tools and technology for our continued existence. Feeding 8B people is impossible without industrial farming and agricultural techniques, e.g. Haber-Bosch. [1] 1: https://www.sciencedirect.com/topics/engineering/haber-bosch-process https://www.sciencedirect.com/topics/engineering/haber-bosch...
- tomjen3 5y agoI did some research into this a couple years ago. There is an interesting theory that we didn't domesticate wolves, but that wolves domesticated us. For one, wolves naturally are very intelligent and pack hunters, so they could have used humans as a hunting partner. For another point, we domesticated wolves way before anything else (atleast 20000 years ago) and that makes no sense since every other animal we domesticated (goat, horse, chicken, etc) will eat pretty much anything and is only of very limited threat to us, whereas wolves are carnivores (very expensive to maintain) and extremely dangerous. However, if wolves domesticated us as hunting partners, then this starts to make a lot more sense. We didn't need to first learn domestication on easier species, the danger was limited and our hunting would be so much more effective that it was worth the premium. It also explains why we have the concept of werewolf and why some people have been charged with turning into wolves to be successful in hunting, but never any other animal (there are no cases of ware eagles/falcons). There is something primeval deep inside us that associates wolves with successful hunters. I find the theory neat, I am not convinced it is true.
- cogman10 5y agoI think the only thing I really quibble a bit with is the description of "dumber". Our "domestication" has historically been more that we've gone from a generalist species to a specialist society. With that, things that were previously probably a boon for survival and reproduction become less so (For example, quick reaction times don't matter so much when you have a city wall to keep out predators and a backup hunting party). My assumption is that what we've lost is more our brain matter used to sleep in trees and wake up/run from predators at all hours of the night. Stuff that's less important when you have night watchman, fires, and shelter. It's similar to how dolphins have huge brains, but most of that is dedicated to sound processing. If dolphins learned how to make huts, farm fish, and fight off predators I'd imagine the part of their brain dedicated to processing sound would start to shrink as there isn't the evolutionary pressure to keep it around. Sort of like how humans might be evolving towards color blindness because being able to tell the difference between red and green doesn't necessarily increase our ability to have children. That might lead to weird changes in our eyes and brains that could shrink them but wouldn't necessarily mean those humans are any dumber than their predecessors.
- algebraically 5y agoGood point.
- matheusmoreira 5y agoSounds like we need to take control of this evolutionary process and start engineering it. Just because we are no longer required to use these abilities on a daily basis doesn't mean we don't want them. Evolution can go to hell with its "pressures", humanity is supposed to get better over time, not worse.
- bobthechef 5y agoSounds like eugenics. Heh, no thanks. Also "better" and "worse" only mean something relative to an end. I do not deny ends (I take human nature to be teleological, for example), but many "evolutionists" (i.e., those who accept a basically materialistic worldview) do deny the reality of ends (and are wholly incapable of accounting for them even if reduced to mental phenomena by virtue of having painted themselves into a metaphysical corner).
- lordnacho 5y agoWhy is there evolutionary pressure for the brain to shrink? We seem to have enough calories to feed our brains, and we're not beholden to some master species that needs to economize.
- rackjack 5y agoThe brain itself is the evolutionary pressure. It is often repeated that the brain takes ~20% of our body's energy despite being ~2% of our body's mass. If there is no need to have a brain so large (due to a lack of predators) it is beneficial to shrink it.
- dymk 5y agoIt's beneficial to lower the brain's calorie intake it if it results in higher reproductive fitness. But like GP said, we have plenty of calories, more than we've had compared to the entire history of humanity. So it doesn't naturally follow that lower calorie brains are higher fitness in 2021.
- rackjack 5y ago"Although our brains were getting bigger progressively, around 70,000 years ago they plateaued, and have been shrinking ever since." From the article. 2021 is very recent. The article also discusses energy usage a little under the section "Fuel".
- Fricken 5y agoThere are no guarantees civilization won't collapse. The traits that were essential for our survival in the stone age aren't things we want to abandon. I'm a big fan of redundancy.
- Robotbeat 5y agoBeneficial how? Reduction in calories? We tend to have diseases of excess calories in the developed world now. If anything, the greater brain metabolism may actually help by burning some of those excess calories off…
- scoofy 5y agoWhoa... whoa... let's unpack all the intense presuppositions you're packing in here: "Domestication" is just a word for a natural evolutionary processes in a symbiotic system. The concept that "domestication" is like, actually a thing apart from evolution is a vastly more difficult idea to parse than it appears on it's face. >Domesticated animals are all dumber than their wild counterparts. I mean... again... there are so many things to unpack here. What do we mean by "dumb" and which parts of the brain are being used, and how their size relates to their usefulness. I think it would be extremely difficult to argue any of these claims on their face beyond: small brain -> less brain function, which is extremely spurious. Homo neanderthalensis had notably larger brains than us, yet they did not survive. Hardly an argument for the idea of greater intelligence -> greater brain size. AFAIK, specific areas in the prefrontal cortex is the primary point of interest when it comes to intelligence, and it's a relatively small section of the brain compared, say, to the visual cortex. https://www.discovermagazine.com/planet-earth/neanderthal-brains-bigger-not-necessarily-better https://www.discovermagazine.com/planet-earth/neanderthal-br... Finally... the most absurd of all the ideas packed in here is that natural selection for smaller brain size would even be a thing. Human mating is openly available for study, I see little-to-no argument for this being plausible beyond some sort of idiocracy world (is this the domestication thesis you hold? I see in the article they are treated separately), which is genuinely problematic. Possibly that certain types of brain sizes are predisposed to certain behavioral patterns. However, the idea that there is even a single evolutionary pattern for billions of humans is pretty ridiculous. We don't have evolutionary islands like other animals do.
- akomtu 5y agoDomestic animals have safe, boring and predictable environment. It's expected that they'd simplify their brain - the organ that consumes so much energy. If domesticated animals started playing chess, that would be a different story, but they spend their life mindlessly walking between a food dispenser and a litter box, taking naps in between.
- scoofy 5y ago>they'd simplify their brain This is not how evolution works! They are not in control of their breeding. Evolution is not some intelligent agent with goals. It is like a river, responding to to the path of least resistance in reproduction. Intelligence and/or brain size not a dominant evolutionary factor unless they are specifically bread for intelligence and/or brain size. Domesticated animal's dominant evolutionary qualities have nothing to do with the animal preferences for mating, thus brain size in fairly arbitrary, and we should suspect it to be some sort of drift, rather than rationally getting smaller.
- deleted 5y ago[deleted]
- 29athrowaway 5y agoSome signs of domestication in mammals - Floppy or reduced ears - Smaller brain and teeth - Docility - Juvenile behavior - Depigmentation
- vlovich123 5y agoHow does your argument explain the Flynn effect?
- algebraically 5y agoThe Flynn effect is now going in the opposite direction and I don't think it was a good indicator of intelligence anyway because intelligence is more than just IQ. [1] 1: https://news.ycombinator.com/item?id=29033354 https://news.ycombinator.com/item?id=29033354
- vmception 5y agoThe article touches on that too. It is pretty comprehensive about a variety of going theories and doesn’t make the mistake of choosing any single one of them as the “because”.
- algebraically 5y agoI did not read the article because I'm an armchair expert on such matters.
- thro1 5y agoIs there some study about brain sizes of kindergarten and free-range kids?
- helge9210 5y agoI've read some articles about brain complexity of wolves depending on complexity of their habitat.