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by Ftuuky 1521 days ago
A classic post by Peter Watts: https://www.rifters.com/crawl/?p=6116

"What scared me was the fact that this virtually brain-free patient had an IQ of 126."

6 comments

I think given that humans evolved to make trade-offs in order to have large brains is a sign that humans generally having large brains is useful, but the usual idea that a large brain is strictly necessary for human intelligence doesn't necessarily follow from that. It could be that what we think of as human intelligence doesn't need all that much brain matter to exist inside of, but having more brain matter increases redundancy and the chance of survival if you starve or get some brain damage, adds potential capacity that isn't always necessary, or it increases the chance of usual human thought processes developing somewhere within the brain to begin with. Maybe having more brain matter is more important as a very young child in order to help the brain bootstrap itself, but then after that most brain matter is redundant.
Wild theory: most of the human brain is there to harness untrammelled intelligence to the organism's best interests.

There is so much, because intelligence needs a complex cage - without the cage becoming sentient itself. A bit like a finite state automaton containing a Turing machine. People can still escape, but it's hard. Disorders like autism represent failure of the cage.

Couldn't add anything to that case myself:

https://www.gwern.net/Hydrocephalus

Yep everyone in this thread should read the whole page. I'll dump the last paragraph:

>Conclusion: No Evidence

>So to sum up: people have claimed that hydrocephalus destroys most of the brain yet having only a fraction of the brain is consistent with normal or above-average intelligence, and may even increase it. This is extremely implausible based on everything we know about intelligence and evolution and population distributions and is a bad description of what hydrocephalus does (conflating distribution & volume with brain matter). On average, hydrocephalus and similar things like hemispherectomy do (as expected) induce many deficits ranging from mild to severe, which can be accommodated to some degree by neural plasticity, individual differences, extensive environmental interventions, and freedom from natural selection . Claims to the contrary, aside from failing to deal with the many objections that this is implausible, turn out to be based on undocumented, fraudulent, or misleadingly described cases, and primarily pushed by cranks. Ultimately, hydrocephalus does not appear to present any particular challenge to the standard understanding of intelligence as being caused by a material brain whose efficiency at cognitive tasks is driven by neuron count, wiring patterns, neural integrity, and general health: not only is the evidence extraordinarily inadequate to justify the extraordinary claims made by some authors, it is unclear how much, if any, evidence there at all.

A few of these case studies have been used to argue the extraordinary claim that brain volume has little or nothing to do with intelligence; authors have argued that hydrocephalus suggests enormous untapped cognitive potential which are tapped into rarely for repairs and can boost intelligence on net, or that intelligence/ consciousness are non-material or tapping into ESP.

The thing about this "counter-argument" is it's conflating a basic point - some people, maybe only a few, are able to exhibit normal human intelligence with a much reduced brain size - with a host of apparently idiotic position people have taken in response to this situation. But of course dismissing the basic on this basis is fallacious.

The image of the brainless skull looks more like one of this man with an IQ of 75: https://www.reuters.com/article/us-brain-tiny-idUSN193051002...
He’s scared because of a third-hand anecdote about a score on an unknown test decades ago with no reproduction?

I’ve always been concerned about the lack of critical thinking skills in people who post about IQ scores.

Have you seen the picture of that brain? Quibbling about the measure of intelligence used was the last thing on my mind because I was amazed the person was alive at all. That said,

> He had a first-class honors degree in mathematics. He presented normally along all social and cognitive axes. He didn’t even realize there was anything wrong with him until he went to the doctor for some unrelated malady, only to be referred to a specialist because his head seemed a bit too large.

does the very next paragraph assuage your concerns?

I agree it’s impressive, but it’s a funny thing to lead with the number. If they were still around and wanted to contribute to science, an fMRI would be interesting for curiosity’s sake; maybe “stress makes their brain work harder” also means it ages differently too?

Or counting their neurons, but presumably they have to not be around anymore for that one.

The lower lizard brain is enough yo keep you alive
I think this is a nice example of why the folded surface of our brain matters so much.
I wonder if it’s the brain’s neurons offloading some functionality to other types of cells.