Why are our brains shrinking? • Hacker News Board

Re: Why are our brains shrinking?

#161

Post by SideburnsOfDoom » Fri, Oct 29, 2021, 10:13 AM UTC

j9461701 wrote: post #148

AlotOfReading wrote: post #117

Earlier quoted context omitted.

I knew a professor that loved getting freshmen classes because he could disabuse them their Yankee in king Arthur's court ideas about how easy it'd be to bring technology back to the past. He had a whole slew of experiments that would explore path dependence and the difficulties of creating technologies with the available resources. Nominally this was to help them not underestimate the intelligence of early humans, b…

I feel like the pendulum has swing too far in the other direction on this topic, actually. Yes people in the past weren't dumb, and shouldn't be under-estimated, but even a normal person could provide huge gains to any pre-modern society. Their understanding of mathematics, biology, evolution, medicine, astronomy, economics, reading+writing, organization, etc. are immeasurably valuable. I don't think people appreciat…

> Their understanding of mathematics, biology, evolution, medicine, astronomy, economics, reading+writing, organization, etc. are immeasurably valuable.

You could tell them that disease is caused by tiny animals, and that the earth is a sphere that orbits the sun, but getting them to believe you is a another thing. And making use of it yet another. You won't introduce quarantine just because of germ theory: book of Leviticus already has a version of quarantine, "the law of the plague" well before germ theory.

Re: Why are our brains shrinking?

#162

Post by Jensson » Fri, Oct 29, 2021, 10:14 AM UTC

Kye wrote: post #90

Factorium wrote: post #87

Earlier quoted context omitted.

This is already playing out at a global level: https://www.sciencedirect.com/science/article/abs/pii/S01602... "There were strong negative correlations found between national IQ and three national indicators of fertility." I think we should look on with worry that there are people with smaller brains that we are now giving unlimited resources to (food, technology, medicine), via aid and welfare programs. The dysgenic…

There are so many problems with this post. * Implying a connection between IQ and brain size * Implying IQ is a measure of a person's worth to society * Implying people below some magic IQ threshold that renders them unworthy are being "given" resources

> * Implying a connection between IQ and brain size

There is a connection between IQ and brain size. There are a lot of other factors for IQ, but brain size do matter.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7440690/

Re: Why are our brains shrinking?

#163

Post by Jensson » Fri, Oct 29, 2021, 10:16 AM UTC

Kye wrote: post #116

lostmsu wrote: post #110

Earlier quoted context omitted.

While the first one is probably really wrong, the other two are clearly fine. Imagine a unique cat with an IQ of human. Would you say it is more worth to society, than any other cat? Probably so. Is there a magic IQ threshold that renders other cats not as worthy as humans to not be given the same kind of resources? In a way yes, as you would draw a line. Intelligence is what makes humans humans.

IQ is a culturally-biased measure that, on its best day, is useful for comparing different cohorts and, if it's being used for a good purpose, bridging any gaps. It only measures individual intelligence by a very narrow view of intelligence. There are plenty of high IQ dupes and highly effective people who'd flub an IQ test.

> highly effective people who'd flub an IQ test.

Evidence for this? Effective at what?

Re: Why are our brains shrinking?

#164

Post by cryptica » Fri, Oct 29, 2021, 10:18 AM UTC

It's a well known fact that domestication of wild animals such as wolves causes the head and brain size to shrink over multiple generations.

It's probably the same thing happening in humans. It would be interesting to measure the brain volume of politicians and business leaders to see if they follow the same trend as the general population.

Re: Why are our brains shrinking?

#165

Post by matheusmoreira » Fri, Oct 29, 2021, 10:37 AM UTC

danwills wrote: post #152

matheusmoreira wrote: post #97

Earlier quoted context omitted.

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.

Is this perhaps too focused on the individual which might not lead to the optimum for the zoomed-out / group (population-level) case? This reminds me of a meta-system-transition where simplified versions of individual (previously independent) units can lead to a unified cooperative whole that works better at the meta-system level (similar to what led to eukaryotes or to multicellularity). It's like a sacrifice that t…

> Should humans resist the formation of human meta-systems? Human/robot meta-systems?

No. I'm saying humans should not lose abilities or features because of it. We should be able to live comfortable lives and still maintain peak physical and mental performance. Any changes in our nature should not go against that.

Re: Why are our brains shrinking?

#166

Post by matheusmoreira » Fri, Oct 29, 2021, 10:38 AM UTC

hawk_ wrote: post #120

matheusmoreira wrote: post #97

Earlier quoted context omitted.

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.

> Surely having sharper and more intelligent humans is an objectively better uncontroversial outcome What if there's a level of intelligence above which humans decide not to reproduce?

I question the intelligence of a human species that does not reproduce.

Re: Why are our brains shrinking?

#167

Post by misja111 » Fri, Oct 29, 2021, 10:44 AM UTC

Asooka wrote: post #42

algebraically wrote: post #5

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…

Hm, then shouldn't people who live in tribal societies as hunter gatherers have bigger brains still? Has anyone studied that?

If you read the article you will find that your question is answered in there.

Re: Why are our brains shrinking?

#168

Post by T-A » Fri, Oct 29, 2021, 10:48 AM UTC

DeathArrow wrote: post #133

It seems that now we use around 10% of the brain power. Maybe we were optimizing for energy consumption? Until the second half of the last century it was hard for the majority of people to find enough food. I would expect that our brain will start to grow slowly if food won't be a problem for a long period. The same way our bodies started to grow once we had enough food.

> It seems that now we use around 10% of the brain power

https://en.wikipedia.org/wiki/Ten_percent_of_the_brain_myth

Re: Why are our brains shrinking?

#169

Post by j9461701 » Fri, Oct 29, 2021, 11:17 AM UTC

SideburnsOfDoom wrote: post #161

j9461701 wrote: post #148

Earlier quoted context omitted.

I feel like the pendulum has swing too far in the other direction on this topic, actually. Yes people in the past weren't dumb, and shouldn't be under-estimated, but even a normal person could provide huge gains to any pre-modern society. Their understanding of mathematics, biology, evolution, medicine, astronomy, economics, reading+writing, organization, etc. are immeasurably valuable. I don't think people appreciat…

> Their understanding of mathematics, biology, evolution, medicine, astronomy, economics, reading+writing, organization, etc. are immeasurably valuable. You could tell them that disease is caused by tiny animals, and that the earth is a sphere that orbits the sun, but getting them to believe you is a another thing. And making use of it yet another. You won't introduce quarantine just because of germ theory: book of L…

> You could tell them that disease is caused by tiny animals, and that the earth is a sphere that orbits the sun, but getting them to believe you is a another thing.

I can find a cholera outbreak, and tell whoever will listen to stop drinking water from the local wells and eating from the local markets. Go to another part of the city for water and food. Those who listen, even if only one, will be my proof. I can also do a cool science experiment with seaweed agar, silver and bacterial growth but that's not as dramatic.

The earth being a sphere that orbits the sun can't be proved without a telescope, but I can propose a vastly simpler and just as accurate approach using kepler's laws. If I was paying attention in high school physics, I can even do cool stuff with Newton's laws of gravitation to show that "As above, so below" (the planets obey the same law of gravity that we earthlings do).

Yes people might still not believe you, as we can be a stubborn and prideful species, but you know the 'why' of many things and so can keep making correct predictions based on that.

> You won't introduce quarantine just because of germ theory: book of Leviticus already has a version of quarantine, "the law of the plague" well before germ theory.

The bible simply lists procedures, it doesn't explain why you do these things or allow you to extrapolate to other situations and scenarios. By contrast, simply by knowing the "why" of infectious diseases, a smart person or government could isolate the cause of - for example - the black death fairly rapidly (rats w/ fleas) and begin taking steps to solve the issue.

A modern person has a head full of correct answers for questions people 2,3,4000 years ago have yet to even ask. That's powerful stuff, and once they've proved their credentials in some way the books they write will advance humanity by millenia.

Re: Why are our brains shrinking?

#170

Post by owenversteeg » Fri, Oct 29, 2021, 11:22 AM UTC

SideburnsOfDoom wrote: post #160

owenversteeg wrote: post #103

Earlier quoted context omitted.

If an intelligent modern person with some knowledge of history was sent back to 70,000 years ago (70 kya) we'd probably be able to bring significant help to the group - assuming we were accepted into the group and not immediately killed by our ancestors in peak physical condition. Personally, I'd attempt to introduce: - art and culture from the far future (flutes, 42 kya; figurative art, 40 kya) - Simple ovens (29 ky…

> - "Water bottles": animal skins sealed with pitch Where would you get pitch? Isn't it only found in a very few locations?

You can make pitch by burning certain woods like pine and collecting the stuff that drips from the fire. Also, maybe I’ve been particularly lucky, but I’ve found bituminous deposits in the wild before that would probably be usable. Barring that, tree sap or beeswax would also be very useful for sealing.