(Major edits added on 2024-11-29.)
Some of my own observations and considerations:
(The first three anecdotes were added 2024-11-29.)
(ADDED 2024-11-10[4]: Tbc, while this is more advanced than I'd a priory expected from animals, the absence of observations of even more clearly stunning techniques is some counterevidence of orcas being smarter than humans. Though I also don't quite point to an example of what I'd expect to see if orcas were actually 250 IQ but what I don't observe, but I also didn't think for long and maybe there would be sth.)
(Mild counterevidence added 2024-12-02:)
(EDIT: Perhaps just skip this orca language section. Relevant is that orca language is definitely learned and not innate. Otherwise not much is known, except that we can eyeball the complexity of their calls. You could take a look by listening[5] here.[6] I'd say it seems very slightly less complex than in humans (though could be more) and much more complex than what is observed in other land animals.)
(Warning: Low confidence. What I say might be wrong.)
I didn't look deep into research into orca language (not much more than watching this documentary), my impression is that we don't know much yet.
Some observations:
I'd count (2) as some weakish evidence against orcas having as sophisticated language as humans, however not very strongly. Some considerations:
The onlymain piece of evidence that makes me wonder whether orcas might actually be significantly smarter than humans is their extremely impressive brain. I think it's pretty strong though.
As mentioned, orcas have 2.05 times as many neurons in their neocortex as humans, and when I look through the wikipedia list (where I just trust measured[7] and not estimated values), it seems to be a decent proxy for how intelligent a species is.
There needs to be some selection pressure for why they have 160 times more neurons in their neocortex than e.g. brown bears (which weigh like 1/8th of an orca or so). Size alone is not nearly a sufficient explanation.
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. (I'm keen to learn.) It's possible that caused humans to be smart more strongly incentivized our brains to be able to do abstract reasoning, whereas for orcas it might've been useful for some particular skills that generalize less well for doing other stuff.
If I'd only ever seen hunter gatherer humans, even if I could understand their language, I'm not sure I'd expect that species to be able to do science on priors. But humans are able to do it. Somehow our intelligence generalized far outside the distribution we were optimized on. I don't think that doing science is similar to anything we've been optimized on, except that advanced language might be necessary.
On priors I wouldn't really see significant reasons why whatever selection pressures optimized orcas to have their astounding brains, would make their intelligence generalize less well to doing science, than whatever selection pressures produced our impressive human brains.
One thing that would update me significantly downwards on orcas being able to do science is if their prefrontal cortex doesn't contain that many neurons. (I didn't find that information quickly so please lmk if you find it.) Humans have a very large prefrontal cortex compared to other animals. My guess would be that orcas have too, and that they probably still have >1.5 times as many neurons in their prefrontal cortex than humans, and TBH I even wouldn't be totally shocked if it's >2.5 times. (EDIT: The cortex of the cetacean brain is organized differently than in most mammals and AFAIK we currently cannot map functionality very well.)
(Read my comments below to see more thoughts.)
You might need a VPN to canada to watch it.
Btw there is no recorded case of a human having been killed by an orca in the wild, including when they needed to swim when the vessel was sunk. (Even though orcas often eat other mammals.) (I think I even once heard it mention that it seemed like the orcas made sure that no humans died from their attacks, though I don't at all know how active the role of the orcas was there (my guess is not very).)
I'd consider it plausible that they were trying to signal us to please stop fishing that much, but I didn't look nearly deeply enough into it to judge.
Actually I don't remember exactly when I added this. I still think it's true but to a weaker extent than I originally thought.
Or downloading the files and looking at the spectrogram in e.g. audacity.
If you want to take a deeper look, here are more recordings.
Aka optical or isotropic fractionator in the method column.
Another thought:
In what animals would I on priors expect intelligence to evolve?
AFAIK, orcas are the largest animals that use collaborative hunting techniques.[1] That plausibly puts them second be...
An argument against orcas being more intelligent than humans runs thus: Orcas are much bigger than humans, so the fraction of the metabolic cost the brain consumes is smaller than in humans. Thus it took more selection pressure for humans to evolve having 21billion neurons than for orcas to have 43billion.[1] Thus humans might have other intelligence-increasing mutations that orcas didn't evolve yet.
So the question here is "how much does scale matter vs other adaptations". Luckily, we can get some evidence on that by looking at other species and ratin...
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 importa...
Douglas Adams answered this long ago of course:
For instance, on the planet Earth, man had always assumed that he was more intelligent than dolphins because he had achieved so much—the wheel, New York, wars and so on—whilst all the dolphins had ever done was muck about in the water having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man—for precisely the same reasons.
As I commented on Are big brains for processing sensory input? I predict that the brain regions of a whale or Orca responsible for spatiotemporal learning and memory are a big part of their encephalization.
In the wikipedia list, the estimated number of neurons in the neocortex of a blue whale is 5 billion (compared to 43 billion in orcas), even though blue whales are much larger. (Unfortunately the blue whale estimate is just an estimate and not grounded in optical or isotropic fractionation measurements.)
(EDIT: Hm interesting, the linked reddit post mentions 15billion for blue whales. Not sure what is correct.)
I imagine that part of the difference is because Orcas are hunters, and need much more sophisticated sensors + controls.
I gigantic jellyfish wouldn't have the same number of neurons as a similarly sized whale, so it's not just about size, but how you use that size.
I had a discussion with @Towards_Keeperhood what we would expect in the world where orcas either are or aren't more intellectually capable than humans if trained. 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)). I argued that @Towards_Keeperhood was also underestimating the intricacies that hunter-gatherers are capable of, and gave the book review for the secret of our success as an example. I think @Towards_Keeperhood did update in that direction after reading that post. I also reread that post and funnily enough stumbled over some evidence that orcas might have fallen into a similar "culture attractor" for intelligence, like humans:
Learn from old people. Humans are almost unique in having menopause; most animals keep reproducing until they die in late middle-age. Why does evolution want humans to stick around without reproducing?
Because old people have already learned the local culture and can teach it to others. Heinrich asks us to throw out any personal experience we have of elders; we live in a rapidly-changing world where an old person is probably “behind the times”. But for most of history, change happened glacially slowly, and old people would have spent their entire lives accumulating relevant knowledge. Imagine a world where when a Silicon Valley programmer can’t figure out how to make his code run, he calls up his grandfather, who spent fifty years coding apps for Google and knows every programming language inside and out.
Quick google search revealed Orcas have menopause too! While chimpanzees don't! I would not have predicted that.
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.)
I'd put a reasonably high probability (5%) on orcas and several other species having all the necessary raw mental capacity to be "uplifted" in just a few (<20) generations with technology (in the wider sense) that has been available for a long time. Being uplifted means here the ability to intellectually engage with us on a near-equal or even equal footing, to create culture, to actively shape their destiny. Humans have been training, selecting, shaping other animals since before the dawn of history. Whenever we did so, it was with the goal of improving their use as tools or resources. Never, to my knowledge, has there been a sustained effort to put these abilities to use for the sole purpose of the mental and cultural flourishing of another species. It is my belief that many other universal learning machines beside the human brain have been produced by evolution, but just lack or lacked the right training environment for the kind of run-away development the homo genus went through, for various reasons.
Could "uplifted" orcas outperform humans on hard scientific problems? Would they care to? I don't know, but I'd love to find out.
Indeed, I would have very much preferred to see other animal minds elevated before we turned to the creation of artificial ones. To explore a wider space of minds and values, to learn more about what an intelligent species can be, before we believed ourselves ready to "build" intelligence from scratch. But it seems at least half a century too late for this now.
(Btw everything I write here about orcas also applies to a slightly lesser extent to pilot whales (especially long finned ones)[1].)
(I'm very very far from an orca expert - basically everything I know about them I learned today.)
I always thought that bigger animals might have bigger brains than humans but not actually more neurons in their neocortex (like elephants) and that number of neurons in the neocortex or prefrontal cortex might be a good inter-species indicator of intelligence for mammalian brains.[2] Yesterday I discovered that orcas actually have 2.05 times as many neurons in their neocortex[3] than humans from this wikipedia list. Interestingly though, given my pretty bad model of how intelligent some species are, the "number of neurons in neocortex" still seems like a proxy that doesn't perform too badly on the wikipedia list.
Orca brains are not just larger but also more strongly folded.
Orcas are generally regarded as one of the smartest animal species, sometimes as the smartest, but I'm wondering whether they might actually be smarter than humans -- in the sense that they could be superhuman at abstract problem solving if given comparable amounts of training as humans.
Another phrasing to clarify what I mean by "could trained to be smarter": Average orcas significantly (possibly vastly) outperforming average (or even all) humans at solving scientific problems, if we enabled them to use computers through BCI and educated them from childhood like (gifted?) human children.[4]
I would explain the evidence and considerations here in more detail but luckily someone else already wrote the post I wanted to write on reddit, only a lot better than I could've. I highly recommend checking this out (5min read): https://www.reddit.com/r/biology/comments/16y81ct/the_case_for_whales_actually_matching_or_even/
One more thing that feels worth adding:
I'd be interested in more thoughts and evidence, so please feel free to write an answer even if you don't have an answer but only one more interesting piece of evidence or consideration to contribute.
Also possible there are more animals/dolphins/whales for which this applies. We often don't have good estimates on how many neurons are in a neocortex of some animal.
It could be that animals with larger bodies need more neurons to be similarly intelligent as smaller animals (e.g. for body control), but I think this effect is relatively slight.
I didn't quickly find something on what share of the orca brain is prefrontal cortex.
Btw I could imagine that even if they were able to do so they might not be motivated for it because maybe evolution had longer time to more precisely align them to do what's reproductively useful in their natural environment or sth.
Btw here's a reddit comment (from a different thread than the main one I linked) linking to 3 references that seem relevant, though I didn't check them: https://www.reddit.com/r/orcas/comments/18yu41m/comment/lriv011/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button
e.g. https://en.wikipedia.org/wiki/Machiavellian_intelligence_hypothesis