Another thought:

In what animals would I on priors expect intelligence to evolve?

1. Animals which use collaborative hunting techniques.
2. Large animals. (So the neurons make up a smaller share of the overall metabolic cost.)
3. Animals that can use tools so they benefit more from higher intelligence.
4. (perhaps some other stuff like cultural knowledge being useful, or having enough slack for intelligence increase from social dynamics being possible.)

AFAIK, orcas are the largest animals that use collaborative hunting techniques.^[1] That plausibly puts them second behind humans for where I would expect intelligence to evolve. So it doesn't take that much evidence for me to be like "ok looks like orcas also fell into some kind of intelligence attractor".

1. ^{^}

   Though I heard sperm whales might sometimes collaborate too, but not nearly that sophisticated I guess. But I also wouldn't be shocked if sperm whales are very smart. They have the biggest animal brains, but I don't whether the cortical neuron count is known.

Main pieces I remember were: Orcas already dominating the planet (like humans do), large sea creatures going extinct due to orcas (similar to how humans drove several species extinct, (Megalodon? Probably extinct for different reasons, weak evidence against? Most other large whales are still around)).

To clarify for other readers: I do not necessarily endorse this is what we would expect if orcas were smart.

(Also I read somewhere that apparently chimpanzees sometimes/rarely can experience menopause in captivity.)

If the species is already dominating the environment then the pressure from the first component compared to the second decreases. 

I agree with this. However I don't think humans had nearly sufficient slack for most of history. I don't think they dominated the environment up until 20000years ^[1]ago or so, and I think most improvements in intelligence come from earlier.

That's why I'm attributing the level of human intelligence in large part to runaway sexual selection. Without it, as soon as interspecies competition became the most important for reproductive success, natural selection would not push for even grater intelligence in humans, even though it could improve our ability to dominate the environment even more.

I'm definitely not saying that group selection lead to intelligence in humans (only that group selection would've removed it over long timescales if it wasn't useful). However I think that there were (through basically all of human history) significant individual fitness benefits from being smarter that did not come from outwitting each other, e.g. being better able to master hunting techniques and thereby gaining higher status in the tribe.

1. ^{^}

   Or could also be 100k years, idk

I'm not sure how it's relevant.

I thought if humans were vastly more intelligent than they needed to be they would already learn all the relevant knowledge quickly enough so they reach their peak in the 20s.

And if the trait, the runaway sexual selection is propagating, is itself helpful in competition with other species, which is obviously true for intelligence, there is just no reason for such straightening over a long timescale.

I mean for an expensive trait like intelligence I'd say the benefits need to at least almost be worth the costs, and then I feel like rather attributing the selection for intelligence to "because it was useful" rather than "because it was a runaway selection".

(For reference I think Tsvi and GeneSmith have much more relevant knowledge for evaluating the chance of superbabies being feasible and I updated my guess to like 78%.)

(As it happens I also became more optimistic about the orca plan (especially in terms of how much it would cost and how long it would take, but also a bit in how likely I think it is that orcas would actually study science) (see footnote 4 in post). For <=30y timelines I think the orca plan is a bit more promising, though overall the superbabies plan is more promising/important. I'm now seriously considering pivoting to the orca plan though.) (EDIT: tbc I'm considering pivoting from alignment research, not superbaby research.)

(haha cool. perhaps you could even PM Abram if he doesn't PM you. I think it would be pretty useful to speed up his agenda through this.)

Thanks!

I agree that sexual selection is a thing - that it's the reason for e.g. women sometimes having unnecessarily large breasts.

But I think it gets straightened out over long timescales - and faster the more expensive the trait is. And intelligence seems ridiculously expensive in terms of metabolic energy our brain uses (or childbirth motality).

A main piece that updated me was reading anecdotes in Scott Alexander's Book review of "The Secret of our success" where I now think that humans did need their intelligence for survival. (E.g. 30 year old hunter gatherers perform better at hunting etc than hunter gatherers in their early 20s, even though the latter are more physically fit.)

A few more thoughts:

It's plausible that for both humans and orcas the relevant selection pressure mostly came from social dynamics, and it's plausible that there were different environmental pressures.

Actually my guess would be that it's because intelligence was environmentally adaptive, because my intuitive guess would be that group selection^[1] is significant enough over long timescales which would disincentivize intelligence if it's not already (almost) useful enough to warrant the metabolic cost, unless the species has a lot of slack.

So an important question is: How adaptive is high intelligence?

In general I would expect that selection pressure for intelligence was significantly stronger in humans, but maybe for orcas it was happening over a lot longer time window, so the result for orcas could still be more impressive.

From what I observed about orca behavior I'd perhaps say a lower bound of their intelligence might roughly be like human 15 year olds or so. So up to that level of intelligence there seem to be benefits that allow orcas to use more sophisticated hunting techniques.

But would it be useful for orcas to be significantly smarter than humans? My prior intuition would've been that probably not very much.

But I think observing the impressive orca brains mostly screens this off: I wouldn't have expected orcas to evolve to be that smart, and I similarly strongly wouldn't have expected them to have that impressive brains, and seeing their brains updates me that there had to be some selection pressure to produce that.

But the selection pressure for intelligence wouldn't have needed to be that strong compared to humans for making the added intelligence worth the metabolic cost, because orcas are large and their neurons make up a much smaller share of their overall metabolic consumption. (EDIT: Actually (during some (long?) period of orca history) selection pressure for intelligence also would've needed to be stronger than selection pressure for other traits (e.g. making muscles more efficient or whatever).)

And that there is selection pressure is not totally implausible in hindsight:

• Orcas hunt very collaboratively, and maybe there are added benefits from coordinating their attacks better. (Btw, orcas live in matrilines, and I'd guess that from an evolutionary perspective the key thing to look at is how well a matriline performs, not individuals, but not sure. So there would be high selection for within-matriline cooperation (and perhaps communication!).)
• Some/(many?) Orca sub-species prey on other smart animals like dolphins or whales, and maybe orcas needed to be significantly smarter to be able to outwit the defensive mechanisms they learn to adapt.

But overall I know way too little about orca hunting techniques to be able to evaluate those.

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   I mean group selection that could potentially be on a level of species where species go extinct. Please lmk if that's actually called differently.

thanks. Can you say more about why?

I mean runaway sexual selection is basically H1, which I updated to being less plausible. See my answer here. (You could comment there why you think my update might be wrong or so.)