(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:
Orcas are very social animals.[5] It’s plausible to me that what caused humans to become this intelligent were social dynamics selecting for intelligence[6], and that orcas might’ve fallen into a similar attractor, and while humans took off technologically once they were smart enough to invent writing, agriculture, money and science, orcas were stuck without hands in water and just continued being selected for higher intelligence without taking off technologically.
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
- ^
(Major edits added on 2024-11-29.)
Some of my own observations and considerations:
Anecdotal evidence for orca intelligence
(The first three anecdotes were added 2024-11-29.)
Orcas leading orca researcher on boat 15miles home through the fog. (See the 80s clip starting from 8:10 in this youtube video.)
Orcas can use bait.
An orca family hunting a seal can pretend to give up and retreat and when the seal comes out thinking it’s safe then BAM one orca stayed behind to catch it. (Told by Lance Barrett-Lennard somewhere in this documentary.[1])
Intimate cooperation between native australian
hunter gathererswhale hunters and orcas for whale hunting around 1900: https://en.wikipedia.org/wiki/Killer_whales_of_Eden,_New_South_WalesOrcas being skillful at turning boats around and even sinking a few vessels[2][3]: https://en.wikipedia.org/wiki/Iberian_orca_attacks
Orcas have a wide variety of cool hunting strategies. (e.g. see videos (1, 2)). I don’t know how this compares to human hunter gatherers. (EDIT: Ok I just read Scott Alexander’s Book review of “The Secret of our success” and some anecdotes on hunter gatherers there seem much more impressive. (But also plausible to me that other orca hunting techniques are also more sophisticated than the examples but in ways it might not be legible to us.))
(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:)
Btw it’s worth noting that orcas do sometimes get tangled up in fishing gear or strand (and die of that), though apparently less frequently than other cetaceans, though didn’t check precisely whether it’s really less per individual.
Worth noting that there are only 50000-100000 orcas in the world, which is less than for many other cetacean species, though not sure whether it’s less in terms of biomass.
Orca language
(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:
Orcas language seems to be learned, not innate. Different regions have different languages and dialects. Scientists seem to analogize it to how humans speak different languages in different countries.
For some orca groups that were studied, scientists were able to cluster their calls into 23 or 24 different calls clusters, but still with significant variation of calls within a call cluster.
(I do not know how tightly calls are clustered, or whether there often are outliers.)
Orcas communicate a lot. (This might be wrong but I think they spend a significant fraction of their time socializing where they exchange multiple calls per minute.)
(Orcas emit clicks and whistles. The clicks are believed to be for spacial navigation (especially in the dark), the whistles for communication.) (EDIT: Actually also pulsed calls, which I initially lumped in with whistles but are emitted in pulses. Those are probably the main medium of communication.)
I’d count (2) as some weakish evidence against orcas having as sophisticated language as humans, however not very strongly. Some considerations:
Sentences don’t necessarily need to be formed through having temporal sequences of words, but words could also be some different frequency signals or so which are then simultanously overlayed.
(The different 24 call types could be all sorts of things. E.g. conveying what we convey through body language, facial expressions, and tone. Or e.g. different sentence structures. Idk.)
Their language might be very alien. I only have shitty considerations here but e.g.:
Orca language doesn’t need to have at all similar grammar. E.g. could be something as far from our language as logic programming is, though in the end still not nearly that simple.
Orcas might often describe situations in ways we wouldn’t describe them. E.g. rather about what movements they and their prey executed or sth.
Orcas might describe more precisely where in 3D water particular orcas and animals were located, and they might have a much more efficient encoding for that than if we tried to communicate this.
More 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?
Animals which use collaborative hunting techniques.
Large animals. (So the neurons make up a smaller share of the overall metabolic cost.)
Animals that can use tools so they benefit more from higher intelligence.
(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”.
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.
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 rating how intelligent they are and correlating that with (1) number of cortical neurons and (2) fraction of metabolic cost the brain uses, to see how strong of an indicator each is for intelligence.
I have two friends who are looking into this for a few hours on the side (where one tries to find cortical neurons and metabolic cost data, and the other looks at animal behavior to rate intelligence (without knowing about neuron count or so)). It’ll be rather a crappy estimate but hopefully we at least have some evidence from this in a week.
Of course metabolic cost doesn’t necessarily need to be linear in the number of cortical neurons, but it’d be my default guess, and in any case I don’t think it matters for gathering evidence across other species as long as we can directly get data on the fraction of the metabolic cost the brain uses (rather than estimating it through neuron count).
EDIT: I was a bit hasty and phrased this wrong, I didn’t mean to suggest roundtrip is quadratic in length. The max roundtrip time is twice the diameter.
The density of neurons matters a lot. A larger brain means it takes longer for signals to propagate
. If the brain is 2x larger, it takes 4x longer for a two way communication.This is a large constraint in both biological brains and GPU design.Actually out of curiosity, why 4x? (And what exactly do you mean by “2x larger”?) (And is this for a naive algorithm which can be improved upon or a tight constraint?)
I highly recommend the following sources for a deep dive into these topics and more:
Jacob Cannells’ brain efficiency post https://www.lesswrong.com/posts/xwBuoE9p8GE7RAuhd/brain-efficiency-much-more-than-you-wanted-to-know [thought take the Landauer story with a grain of salt]
and the extraordinary Principles of Neural Design by Sterling & Laughlin https://mitpress.mit.edu/9780262534680/principles-of-neural-design/
Could you explain or directly link to something about the 4x claim? Seems wrong. Communication speed scales with distance not area.
I thought the consensus on that post was that it was mostly bullshit?
Sorry i phrased this wrong. You are right. I meant roundtrip time which is twice the length but scales linearly not quadratically.
I actually ran the debate contest to get to the bottom of Jake Cannells arguments. Some of the argument, especially around the landauer argument dont hold up but i think it s important not to throw out the baby with bathwater. I think most of the analysis holds up.
https://www.lesswrong.com/posts/fm88c8SvXvemk3BhW/brain-efficiency-cannell-prize-contest-award-ceremony
Yeah I read that prize contest post, that was much of where I got my impression of the “consensus”. It didn’t really describe which parts you still considered valuable. I’d be curious to know which they are? My understanding was that most of the conclusions made in that post were downstream of the Landauer limit argument.
Thanks for pointing that out! I will tell my friends to make sure they actually get good data for the metabolic cost and not just use cortical neuron count as proxy if they cannot find something good.
(Or is there also another point you wanted to make?)And yeah it’s actually also an argument for why orcas might be less intelligent (if they sorta use their neurons less often). Thanks.My guess is that there probably aren’t a lot of simple mutations which just increase intelligence without increasing cortical neuron count. (Though probably simple mutations can shift the balance between different sub-dimensions of intelligence as constrained through cortical neuron count.) (Also of course any particular species has a lot of deleterious mutations going around and getting rid of those may often just increase intelligence, but I’m talking about intelligence-increasing changes to the base genome.)
But there could be complex adaptations that are very important for abstract reasoning. Metacognition and language are the main ones that come to mind.
So even if the experiment my friends to will show that the number of cortical neurons is a strong indicator, it could still be that humans were just one of the rare cases which evolved a relevant complex adaptation. But it would be significant evidence for orcas being smarter.
A few more thoughts:
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.
ADDED 2024-11-29:
To my current (not at all very confident) knowledge, orcas split of from other still alive dolphin species 5-10million years ago (so sorta similar to humans—maybe slightly longer for orcas). So selection pressure must’ve been relatively strong I guess.
Btw, bottlenose dolphins (which have iirc 12.5 billion cortical neurons) are to orcas sorta like chimps are to humans. One could look how smart bottlenose dolphins are compared to chimps.
(There are other dolphin species (like pilot whales) which are probably smarter than bottlenose dolphins, but those aren’t studied more than orcas, whereas bottlenose dolphins are.)
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.