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Why are our brains shrinking?

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Re: Why are our brains shrinking?

#121

Post by SamoyedFurFluff »

exporectomy wrote: post #77
bobthechef wrote: post #57

Earlier quoted context omitted.

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.

Eugenics involved horrific deprivations of human dignity for arbitrary decisions of what seemed at the time to be “self evidently good” traits that are much less self evidently good now… if the traits were even retained.

Re: Why are our brains shrinking?

#122

Post by SamoyedFurFluff »

matheusmoreira wrote: post #97
vlovich123 wrote: post #76

Earlier quoted context omitted.

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 t…

Surely having sharper and more intelligent humans is an objectively better uncontroversial outcome. If there's even a chance that our environment is somehow downregulating important features such as intelligence, we must find a way to reverse that process.

But do you have any evidence of that? With our supposedly down regulated intelligence we’re achieving ever more and faster.

Re: Why are our brains shrinking?

#123

Post by SamoyedFurFluff »

snek_case wrote: post #98
lumost wrote: post #81

Earlier quoted context omitted.

Alternately, 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.

I 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 pe…

Wouldn’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.

Re: Why are our brains shrinking?

#124

Post by hawk_ »

bobthechef wrote: post #55
cogman10 wrote: post #21

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…

I agree that smaller brain does not mean dumber. This is a very simplistic idea of what brains are for. Whales have huge brains, but I would guess that has more to do with their size. I don't understand what you mean by "generalist" vs "specialist". I think intelligence is related to why, for example, human beings lack armor, fur, and all sorts of specialized features, functions, and excellences that other species ha…

> This is a very simplistic idea of what brains are for.

Or it could be that my small brain is incapable of seeing how small brain can mean dumber

Re: Why are our brains shrinking?

#125

Post by aranchelk »

> we developed elaborate speech. We also have advanced culture

I’m surprised there was no speculation involving memes in the article (“meme” as in the original meaning coined by Dawkins).

We’re running a complicated and evolved software suite now. The idea that we have less raw computing to do than our bare-brained ancestors might be worth exploring.

Re: Why are our brains shrinking?

#126

Post by algebraically »

iratewizard wrote: post #118
renewiltord wrote: post #91

Earlier quoted context omitted.

A thing on HN you will see frequently is that someone will be told that X happened and they’ll explain confidently post hoc why. Occasionally, they will misunderstand this as Y happening and they’ll explain that. In the best universe, they will misunderstand X having happened as Y having happened and explain it even though Y did not happen. The existence of this last characteristic makes me trust post hoc explanation…

The point system here is meant to help people find insightful comments. There was even a time on this site when it was used like that. But now it's used to show support for opinions you agree with and to find the confident idiots with grand theories of how the world can be modeled.

Oh the irony.

Re: Why are our brains shrinking?

#128

Post by herval »

catmanjan wrote: post #109
herval wrote: post #100

Earlier quoted context omitted.

That was very much guided evolution though - elephants without tusks get spared, the others get killed for the tusks. There’s nothing like that happening with humans at a population scale, outside the realm of conspiracy theories

Are you more, or less likely to breed the more social media you consume?

If 90% of the people that use social media were culled every 2 years, and only the remaining survived enough to reproduce, we'd (maybe) see some accelerated evolution/correlation in a generation or two, right? (extremely improbable as you're not eliminating a specific physical trait, like in the elephant's case)

Re: Why are our brains shrinking?

#129

Post by shlurpy »

I didn't see in the article any evidence for this shrinkage correlating with intelligence. It seems plausible that the initial adaptation is just raw, inefficient fast growth (ie, evolution solving intelligence the simplest possible way through raw unorganized volume), and the subsequent shrinkage is accompanied by internal structural improvements and optimization. In other words, like we often do in engineering, first we just throw more more hardware at it to fulfill demands, and then as we optimize algorithmic efficiency the extra hardware becomes unnecessary again.

Re: Why are our brains shrinking?

#130

Post by kataklasm »

guerrilla wrote: post #101
tamaharbor wrote: post #89

Earlier quoted context omitted.

Kind of like warming since the end of the last glacial period 10,000 years ago.

You're not trying to imply that that is the cause of the current global warming, are you?

relevant xkcd: https://xkcd.com/1732/
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