Live data from Hacker News

Why are our brains shrinking?

usfblogs.usfca.edu

71–80 of 199 posts

Re: Why are our brains shrinking?

#71
What's the underlying measurement here? Raw brain size, or ratio of brain to body?

> We see an erosion of grey matter, not white matter.

Given the lack of an actual brain, I assume this is some sort of assumption based on which part of the brain has changed size?

Re: Why are our brains shrinking?

#72

Earlier quoted context omitted.

I don't think I have it backwards. I don't remember anything or know much about the world in general terms. I just know and remember enough key phrases for google to give me the answers when I need them which requires very little cognitive effort on my part. [1] 1: https://www.psychologytoday.com/intl/blog/the-athletes-way/2...

Computers are less than 100 years old, the idea that their existence has lead to brains shrinking is preposterous.

That wasn't the argument. You seem to be saying that the increasing volume of digital information will require new cognitive adaptations and I'm saying that's not the case because I don't need to be as smart to appear smart on a digital medium, I can just rely on external cognitive aids like google.

Re: Why are our brains shrinking?

#73

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…

Some signs of domestication in mammals

- Floppy or reduced ears

- Smaller brain and teeth

- Docility

- Juvenile behavior

- Depigmentation

Re: Why are our brains shrinking?

#74
It seems like the majority of the comments are not taking into account that this trend began approximately 70,000 years ago - slightly before the various things people here are blaming such as TikTok, Google, writing, Javascript and Twitter.

Cutting-edge (heh) technology 70,000 years ago was the stone blade as well as the earliest known primitive art.

An interesting guide whenever you're trying to put this kind of thing into context: https://en.wikipedia.org/wiki/Timeline_of_prehistory

Re: Why are our brains shrinking?

#75

Earlier quoted context omitted.

I definitely have evidence that wolves are smarter than dogs. [1][2] You're welcome to nitpick but it's obvious that wolves are smarter than dogs. 1: https://www.youtube.com/watch?v=soe-mONHGMc 2: https://www.studyfinds.org/wolves-smarter-dogs-logic/

That doesn't mean that humans are dumber now, though, nor does it mean that dogs were bred to be dumb, nor does it mean that dumb animals are easier to control. Humans with intellectual disability can in fact be extremely hard to control in my understanding!

That wasn't the claim. The claim was about the effects of domestication on cognition and at least for dogs it is very obvious they are less intelligent than their non-domesticated counterparts. Same is true for rabbits. So, at the very least, in at least 2 cases it is clear that domestication has lead to a decline in cognitive abilities. It doesn't take much to infer the same is true for people, domestication has reduced selective pressures on cognitive abilities.

If you know of cases and studies where the opposite is true then I'd like to see the research.

Re: Why are our brains shrinking?

#76

Earlier quoted context omitted.

I 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 huntin…

Sounds 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.

You're making a value judgement like "better" and "worse" as if there was a clear global optimum that you can reach. Why do you assume that's the case?

Let's assume there even is a global optimum. Why do we think this global optimum would be invariant on environment? We have clear examples of species that fail to adapt to their changing environment quickly enough dying off. If you took the survivors of a change and then changed things back, those survivors might die again. That means you are fit to the environment you find yourself in. As the environment changes, you're not "better" or "worse" than someone who's more fit to a different environment.

Humanity is not getting strictly better on all stats. It's like a video game. We might tweak improve some stats and have to give up others. We are a bit more unique in that we largely optimize for the environment we create for ourselves, but that doesn't mean humans are constantly "getting better" over time. You could maybe try arguing that the human condition has improved over time due to technology, medicine, etc, but even that's an imperfect analysis because our historical record is so inaccurate.

Re: Why are our brains shrinking?

#77

Earlier quoted context omitted.

Sounds 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.

Sounds 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…

Do you have a real concern with eugenics or is it just because your culture demonizes it?

We already have little bits of eugenics baked into law and culture. Why not a little bit more? It doesn't have to involve death camps.

Re: Why are our brains shrinking?

#78

It seems like the majority of the comments are not taking into account that this trend began approximately 70,000 years ago - slightly before the various things people here are blaming such as TikTok, Google, writing, Javascript and Twitter. Cutting-edge (heh) technology 70,000 years ago was the stone blade as well as the earliest known primitive art. An interesting guide whenever you're trying to put this kind of th…

I wish I could upvote this more. I would be willing to bet a number of such comments did not even read the article and responding based on impulse with their gripe about modern society du-jour.

Re: Why are our brains shrinking?

#79
post #47
post #45

Earlier quoted context omitted.

Domestic 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.

>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…

I think you're conflating biological evolution with evolution as a whole. Technology and culture also evolve. Just differently. Evolution is a much wider aspect of existence than mammalian genetic evolution, or even sexual evolution. I absolutely can simplify my brain consciously, by choosing to remember useful, compact things and by choosing to forget useless, complex ones. And then pass that knowledge through our cultural transfer mechanisms.

Re: Why are our brains shrinking?

#80

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…

How does your argument explain the Flynn effect?
Post reply on HN