7 ms·

There are some studies that suggest human brain sizes have been shrinking over the last 20,000 years. The theory is that as civilization developed the demand fo

There are some studies that suggest human brain sizes have been shrinking over the last 20,000 years. The theory is that as civilization developed the demand for individual humans to be independently intelligent has weakened because we developed a "collective brain" and also self-domesticated to be more cooperative.

veidelis 3mo ago
Honestly there might be truth to it, I don't get the downvotes - why?
- Someone 3mo ago
  The correlation between brain volume and intelligence is fairly weak. Neanderthals had larger brains than humans, for example. Looking outside the hominids, we have fairly smart corvids with relatively tiny brains. That means the chain of thought “brains volume decreased, so individuals must have gotten less intelligent. Yet, societies grew smarter, so there must be herd intelligence” breaks at “so individuals must have gotten less intelligent”. I think/guess that argument may have merit when replacing brain volume by number of neurons (https://en.wikipedia.org/wiki/List_of_animals_by_number_of_neurons https://en.wikipedia.org/wiki/List_of_animals_by_number_of_n...)
  - _aavaa_ 3mo ago
    Even if we grant your argument that brain volume between species isn’t good proxy for intelligence, It doesn’t immediately hold for comparisons within a specie.
    - Someone 3mo ago
      No, but correlations there aren’t large, either, if they exist. Einstein’s brain reportedly was below average size. That’s a n = 1 example, but there also is a 50/50 example: man vs women. on average, the brains of males are about 10% larger than those of women (https://en.wikipedia.org/wiki/Neuroscience_of_sex_differences#Volume https://en.wikipedia.org/wiki/Neuroscience_of_sex_difference...). That doesn’t show up in intelligence differences (https://en.wikipedia.org/wiki/Sex_differences_in_intelligence https://en.wikipedia.org/wiki/Sex_differences_in_intelligenc...) Even only looking at males or females, I don’t think larger (fe)males tend to be more intelligent.

veidelis 3mo ago

Honestly there might be truth to it, I don't get the downvotes - why?

Someone 3mo ago
The correlation between brain volume and intelligence is fairly weak. Neanderthals had larger brains than humans, for example. Looking outside the hominids, we have fairly smart corvids with relatively tiny brains. That means the chain of thought “brains volume decreased, so individuals must have gotten less intelligent. Yet, societies grew smarter, so there must be herd intelligence” breaks at “so individuals must have gotten less intelligent”. I think/guess that argument may have merit when replacing brain volume by number of neurons (https://en.wikipedia.org/wiki/List_of_animals_by_number_of_neurons https://en.wikipedia.org/wiki/List_of_animals_by_number_of_n...)
- _aavaa_ 3mo ago
  Even if we grant your argument that brain volume between species isn’t good proxy for intelligence, It doesn’t immediately hold for comparisons within a specie.
  - Someone 3mo ago
    No, but correlations there aren’t large, either, if they exist. Einstein’s brain reportedly was below average size. That’s a n = 1 example, but there also is a 50/50 example: man vs women. on average, the brains of males are about 10% larger than those of women (https://en.wikipedia.org/wiki/Neuroscience_of_sex_differences#Volume https://en.wikipedia.org/wiki/Neuroscience_of_sex_difference...). That doesn’t show up in intelligence differences (https://en.wikipedia.org/wiki/Sex_differences_in_intelligence https://en.wikipedia.org/wiki/Sex_differences_in_intelligenc...) Even only looking at males or females, I don’t think larger (fe)males tend to be more intelligent.