Crossposted from the AI Alignment Forum. May contain more technical jargon than usual.
Humans seem to have much higher degrees of consciousness and agency than other animals, and this may have emerged from our capacities for language. Helen Keller (who was deaf and blind since infancy, and only started learning language when she was 6) gave an autobiographical account of how she was driven by blind impetuses until she learned the meanings of the words “I” and “me”
Possible nitpick depending on how you define consciousness: this excerpt sounds like Keller was conscious in the global workspace sense, but rather lacked something like a phenomenal self-model.
According to this SSC book review, "the secret of our success" is the ability to learn culture + the accumulation of said culture, which seems a bit broader than ability to learn language + language that you describe.
Indeed, I would call complex culture 'a thing that happens in large and dense enough human populations' rather than 'something humans do'. There is a case study in Australia - Australia and Tasmania were separated by water at the end of the last glaciation, and ten thousand years later the population in Tasmania was very very low and they had lost most of the sophisticated tools that the Aboriginal people of Australia had. It's a percolation problem - with enough people and dense enough interaction networks you get reliable transmission of culture down the generations, and new innovations stick. I would argue that this, not intrinsic differences in cognition, is probably why Neanderthal toolkits stayed simple longer, they were living in the cold wastelands of Europe and Asia and genetics indicates they went through a LOT of low-population bottlenecks compared to our straightforward single bottleneck and expansion.
That's one of the "unique intellectual superpowers" that I think language confers us:
On a species level, our mastery of language enables intricate insights to accumulate over generations with high fidelity. Our ability to stand on the shoulders of giants is unique among animals, which is why our culture is unrivaled in its richness in sophistication.
(I do think it helps to explicitly name our ability to learn culture as something that sets us apart, and wish I'd made that more front-and-center.)
I HAVE TO plug Suzana Herculano-houzel's book "the human advantage" and all the research she and her group have done since it was published.
Short version: as you scale up a generic vertebrate brain, it only has 4x as many neurons every time it increases in mass by a factor of 10. (A factor of 16 after 100, etc). There are two clades that break this relationship: primates and birds, both of which have a 1:1 relationship between brain size and neuron number. The primate density is about the density of a mouse brain, and bird brains are 6x as dense as this. A large primate brain is much more impressive than a large generic-mammal brain. You get that elephants have brains about as impressive as chimps, and big whales have brains as impressive as late homo erectus - both of which I think make sense. Humans show up as having 4x the neurons of chimps/elephants and ~2x that of the biggest whales.
Human brains also appear to just be scaled-up primate brains, with the size of every brain region falling RIGHT on the trendlines of every other primate. I am skeptical of our subspecies being significantly smarter in any general way than other hominids with similar brain sizes.
Interesting. That table lists the methods that were used to get the neuron number; the method I trust most is the isotropic fractionator, it was explicitly designed to get around issues that had plagued neuron counts for a very long time using other methods. Most of the large whale numbers come from 'optical fractionators' instead.
Note the 'false killer whale' cortical neuron number - it lists two numbers from two methods, and the number from the isotropic fractionator is one third that of the optical fractionator.
I remembered reading about this a while back and updating on it, but I'd forgotten about it. I definitely think this is relevant, so I'm glad you mentioned it -- thanks!
Nice post; I think I agree with most of it. Two points I want to make:
Or is this “qualitative difference” illusory, with the vast majority of human cognitive feats explainable as nothing more than a scaled-up version of the cognitive feats of lower animals?
This seems like a false dichotomy. We shouldn't think of scaling up as "free" from a complexity perspective - usually when scaling up, you need to make quite a few changes just to keep individual components working. This happens in software all the time: in general it's nontrivial to roll out the same service to 1000x users.
One possibility is that the first species that masters language, by virtue of being able to access intellectual superpowers inaccessible to other animals, has a high probability of becoming the dominant species extremely quickly.
I think this explanation makes sense, but it raises the further question of why we don't see other animal species with partial language competency. There may be an anthropic explanation here - i.e. that once one species gets a small amount of language ability, they always quickly master language and become the dominant species. But this seems unlikely: e.g. most birds have such severe brain size limitations that, while they could probably have 1% of human language, I doubt they could become dominant in anywhere near the same way we did.
There's some discussion of this point in Laland's book Darwin's Unfinished Symphony, which I recommend. He argues that the behaviour of deliberate teaching is uncommon amongst animals, and doesn't seem particularly correlated with intelligence - e.g. ants sometimes do it, whereas many apes don't. His explanation is that students from more intelligent species are easier to teach, but would also be more capable of picking up the behaviour by themselves without being taught. So there's not a monotonically increasing payoff to teaching as student intelligence increases - but humans are the exception (via a mechanism I can't remember; maybe due to prolonged infancy?), which is how language evolved. This solves the problem of trustworthiness in language evolution, since you could start off by only using language to teach kin.
A second argument he makes is that the returns from increasing fidelity of cultural transmission start off low, because the amount of degradation is exponential in the number of times a piece of information transmitted. Combined with the previous paragraph, this may explain why we don't see partial language in any other species, but I'm still fairly uncertain about this.
I think this explanation makes sense, but it raises the further question of why we don't see other animal species with partial language competency. There may be an anthropic explanation here - i.e. that once one species gets a small amount of language ability, they always quickly master language and become the dominant species. But this seems unlikely: e.g. most birds have such severe brain size limitations that, while they could probably have 1% of human language, I doubt they could become dominant in anywhere near the same way we did.
Can you elaborate more on what partial language competency would look like to you? (FWIW, my current best guess is on "once one species gets a small amount of language ability, they always quickly master language and become the dominant species", but I have a lot of uncertainty. I suppose this also depends a lot on what exactly what's meant by "language ability".)
A couple of intuitions:
"Once one species gets a small amount of language ability, they always quickly master language and become the dominant species" - this seems clearly false to me, because most species just don't have the potential to quickly become dominant. E.g. birds, small mammals, reptiles, short-lived species..
Koko the gorilla had partial language competency.
AFAICT this is highly disputed. Many people think that her handlers had an agenda, and that the purported examples of her combining words were her randomly spamming sign language to get treats. Raw data was never realeased, and no one was allowed to interact with or see them interact with Koko except her handlers.
It seems plausible that the purported examples are a case of selective reporting, wishful thinking, and the Clever Hans effect.
There are other apes, including Washoe and Kanzi, who have been observed to use language.
Admittedly, they weren't very good at it by human standards.
This seems like a false dichotomy. We shouldn't think of scaling up as "free" from a complexity perspective - usually when scaling up, you need to make quite a few changes just to keep individual components working. This happens in software all the time: in general it's nontrivial to roll out the same service to 1000x users.
I agree. But I also think there's an important sense in which this additional complexity is mundane -- if the only sorts of differences between a mouse brain and a human brain were the sorts of differences involved in scaling up a software service to 1000x users, I think it would be fair (although somewhat glib) to call a human brain a scaled-up mouse brain. I don't think this comparison would be fair if the sorts of differences were more like the sorts of differences involved in creating 1000 new software services.
I think whether the additional complexity is mundane or not depends on how you're producing the agent. Humans can scale up human-designed engineering products fairly easily, because we have a high-level understanding of how the components all fit together. But if you have a big neural net whose internal composition is mostly determined by the optimiser, then it's much less clear to me. There are some scaling operations which are conceptually very easy for humans, and also hard to do via gradient descent. As a simple example, in a big neural network where the left half is doing subcomputation X and the right half is doing subcomputation Y, it'd be very laborious for the optimiser to swap it so the left half is doing Y and the right half is doing X - since the optimiser can only change the network gradually, and after each gradient update the whole thing needs to still work. This may be true even if swapping X and Y is a crucial step towards scaling up the whole system, which will later allow much better performance.
In other words, we're biased towards thinking that scaling is "mundane" because human-designed systems scale easily (and to some extent, because evolution-designed systems also scale easily). It's not clear that AIs also have this property; there's a whole lot of retraining involved in going from a small network to a bigger network (and in fact usually the bigger network is trained from scratch rather than starting from a scaled-up version of the small one).
Humans seem to have much higher degrees of consciousness and agency than other animals, and this may have emerged from our capacities for language. Helen Keller (who was deaf and blind since infancy, and only started learning language when she was 6) gave an autobiographical account of how she was driven by blind impetuses until she learned the meanings of the words “I” and “me”
This is fascinating, but there's a bit of a potential confounder in that she was six years old. I'm anecdotally aware of several people who feel they weren't really conscious before a certain age.
Compare Helen Keller with Ildefonso who was deaf and mute, and didn't learn language until age 27:
" But the interesting thing that he said is that he can’t even think that way anymore. (Music.) He said he can't think the way he used to think and when I pushed him to ask about what it was like to be languageless, the closest he ever came to any kind of an answer was exactly that. I don't know, I don't remember. I think differently now. " - Radiolab episode on words
Hmm, I'm not sure I understand what point you think I was trying to make. The only case I was trying to make here was that much of our subjective experience which may appear uniquely human might stem from our langauge abilites, which seems consistent with Helen Keller undergoing a phase transition in her subjective experience upon learning a single abstract concept. I'm not getting what age has to do with this.
I just want to share another reason I find this n=1 anecdote so interesting -- I have a highly speculative inside view that the abstract concept of self provides a cognitive affordance for intertemporal coordination, resulting in a phase transition in agentiness only known to be accessible to humans.
+1. It feels like this argument is surprisingly prominent in the post given that it's a n=1 anecdote, with potential confounders as mentioned above.
I might be confused here, but it seems to me that it's easy to interpret the arguments in this post as evidence in the wrong direction.
I see the following three questions as relevant:
1. How much sets human brains apart from other brains?
2. How much does the thing that humans have and animals don't matter?
3. How much does better architecture matter for AI?
Questions #2 and #3 seem positively correlated – if the thing that humans have is important, it's evidence that architectural changes matter a lot. However, holding #2 constant, #1 and #3 seem negatively correlated – the less stuff there is that makes humans special, the smaller the improvements to architecture that are required to achieve greater performance.
Since this post is arguing primarily about #1, the way it affects #3 is potentially confusing.
Questions #2 and #3 seem positively correlated – if the thing that humans have is important, it's evidence that architectural changes matter a lot.
Not necessarily. For example, it may be that language ability is very important, but that most of the heavy lifting in our language ability comes from general learning abilities + having a culture that gives us good training data for learning language, rather than from architectural changes.
The most quintessentially human intellectual accomplishments (e.g. proving theorems, composing symphonies, going into space) were only made possible by culture post-agricultural revolution.
I'm guessing you mean the beginning of agriculture and not the Agricultural Revolution (18th century), which came much later than math and after Baroque music. But the wording is ambiguous.
It seems like "agricultural revolution" is used to mean both the beginning of agriculture ("First Agricultural Revolution") and the 18th century agricultural revolution ("Second Agricultural Revolution").
they also escape feral children, and might escape animals for mundane reasons, like their not having critical periods long enough to learn these aspects of language.
On the other hand, humans having learned language at late ages (e.g. Helen Keller having learned it at 6) suggests that learning language during the critical period isn't a necessary requirement. (the Wikipedia links claims that deaf people who learn language at a late age never master it completely, but assuming that it hasn't been edited by others, the quoted Keller excerpt gives a rather different impression).
Chimpanzees, crows, and dolphins are capable of impressive feats of higher intelligence, and I don’t think there’s any particular reason to think that Neanderthals are capable of doing anything qualitatively more impressive
This seems like a pretty cursory treatment of what seems like quite a complicated and contentious subject. A few possible counterexamples jump to mind. These are just things I remember coming across when browsing cognitive science sources over the years.
My nonexpert sense is that it is at least controversial both how each of this is connected with language, and the extent to which nonhumans are capable of them.
I think that the problem of the specialness of the human brain might be illuminated by information of its evolution. At what point did the ancestors of humans become cognitively superior to most other animals? And how much distance did Brain evolution cover after that point? From what I inferred from data of cranial size increase, it seems like there was a strong positive selection for increase in brain size. Is this right?
Interesting post.
One possibility is that the first species that masters language, by virtue of being able to access intellectual superpowers inaccessible to other animals, has a high probability of becoming the dominant species extremely quickly. (Humans underwent the agricultural revolution within 50,000 years of behavioral modernity—a blink of an eye on evolutionary timescales—after which their dominance as a species became unquestionable.) Since we shouldn’t expect to see more than one dominant species at a time, this would imply a simple anthropic argument for our unique capacities for language: we shouldn’t expect to see more than one species at a time with mastery of language, and we just happen to be the species that made it there first.
I agree with the first two sentences of that passage, but I'm not sure I see the logic behind the third sentence. Depending on how we define a "dominant species", perhaps we necessarily can only see one at a time, or should expect to only see one at a time. But the prior sentences were about how the first species to master language will become dominant. If another species now mastered language, we'd have a very strong lead on them in terms of cultural institutions and technology, so it seems exceedingly unlikely that they'd become dominant. So on that front, it seems like we could see another species master language, without anthropic issues arising.
The other question is whether we'd allow another species to master language. I've never considered this question before, but my guess is that we would. From examples so far where individual animals have appeared to get a handle on aspects of language, people seem fascinated and delighted, rather than afraid that we'll be overthrown. And species that are able to at least imitate human communication, like parrots, seem to often be kept as pets specifically for that ability, because some humans enjoy it.
So I'd guess that if we discovered that another species was mastering language, we'd become fascinated and/or delighted, and study them a lot, and make extra efforts to preserve them if necessary (e.g., if they were endangered). I think we'd quite reasonably not be afraid, because that species abilities, culture, power, etc. be so far behind ours. I think if that species started becoming especially capable, we might limit their advancements or even wipe them out, but that would likely happen years to millennia after mastery of language, not immediately.
This means that it seems to me totally plausible that a dominant species could witness another species coming to gradually master language, without any anthropic issues arising, because neither species is necessarily wiped out in the process. If this is the case, then it seems like the fact we're the only species that has mastered language remains as strong evidence as it seemed at first of the "difficulty" of mastering language (though I'm not sure how strong it is as evidence for that).
Is there a way I'm misinterpreting you or missing something?
The other question is whether we'd allow another species to master language. I've never considered this question before, but my guess is that we would.
At this point, we'd encourage it. (See people trying to communicate with dolphins, or dogs, or gorillas, or parrots, or...)
But the relevant time period was probably when there were multiple species in the homo genus; as most similar to humans, they were probably also the fewest steps away from language and also the most likely to be a competitor for the same ecological niche. There's much more reward to anatomically modern humans for driving neanderthals to extinction than driving parrots to extinction, and so we don't see our near competitors in the race to language anymore.
It's not that we'd wipe out another species which started to demonstrate language. Rather, since the period during which humans have had language is so short, it'd be an unlikely coincidence for another species to undergo the process of mastering language during the period in which we already had language.
(I may be misunderstanding you or the OP. Also, I'm writing this when sleepy.)
I think that that's true. But I don't think that that's an anthropic explanation for why we got there first, or an anthropic explanation for why there's no other species with language. Instead, that argument seems itself premised on language being hard and unlikely in any given timestep. Given that, it's unlikely that two species will develop language within a few tens of thousands of years of each other. But it seems like that'd be the "regular explanation", in a sense, and seems to support that language is hard or unlikely.
It seemed like the OP was trying to make some other anthropic argument that somewhat "explains away" the apparent difficulty of language. (The OP also said "Since we shouldn’t expect to see more than one dominant species at a time", which in that context seems to imply that a second species developing language would topple us or be squashed by us and that that was important to the argument.)
This is why I said:
If this is the case, then it seems like the fact we're the only species that has mastered language remains as strong evidence as it seemed at first of the "difficulty" of mastering language (though I'm not sure how strong it is as evidence for that). (emphasis added)
Perhaps the idea is something like "Some species had to get there first. That species will be the 'first observer', in some meaningful sense. Whenever that happened, and whatever species became that first observer, there'd likely be a while in which no other species had language, and that species wondered why that was so."
But again, this doesn't seem to me to increase or decrease the strength (whatever it happens to have been) of the evidence that "the gap we've observed with no second species developing language" provides for the hypothesis "language is hard or computationally expensive or whatever to develop".
Perhaps the argument is something like that many species may be on separate pathways that will get to language, and humans just happened to get there first, and what this anthropic argument "explains away" (to some extent) is the idea that the very specific architecture of the human brain was very especially equipped for language?
Perhaps the idea is something like "Some species had to get there first. That species will be the 'first observer', in some meaningful sense. Whenever that happened, and whatever species became that first observer, there'd likely be a while in which no other species had language, and that species wondered why that was so."
I think this is the idea. You're right that it doesn't change our estimate of how difficult language is from the non-existence of a second species with language; the thing that it does is point out that "even if you observe 1 element of a rare set, you shouldn't think the set is common instead of rare, because you were conditioning on observing at least one element of that set." [That is, we're not seeing any of the planets that have life but no language, or directly observing any of the 50 kiloyear time periods when Earth was one of those.]
(Not sure the following makes sense - I think I find anthropics hard to think about.)
Interesting. This sounds to me like a reason why the anthropic principle suggests language may been harder to evolve than one might think, because we think we've got a data point of it evolving (which we do) and that this suggests it was likely to evolve by now and on Eath, but in fact it's just that we wouldn't be thinking about the question until/unless it evolved. So it could be that in the majority of cases it wouldn't have evolved (or not yet?), but we don't "observe" those.
But I thought the OP was using anthropics in the other direction, since that paragraph follows:
If language isn’t a particularly difficult cognitive capacity to acquire, why don’t we see more animal species with language? (emphasis added)
Basically, I interpreted the argument as something like "This is why the fact no other species has evolved language may be strong evidence that language is difficult." And it sounds like you're providing an interesting argument like "This is why the fact that we evolved language may not provide strong evidence that language is (relatively) easy."
Perhaps the OP was indeed doing similar, though; perhaps the idea was "Actually, it's not the case that language isn't a particularly difficult cognitive capacity to acquire."
But this all still seems disjointed from "Since we shouldn’t expect to see more than one dominant species at a time", which is true, but in context seems to imply that the argument involves the idea that we shouldn't see a second species to evolve language while we have it. Which seems like a separate matter.
One could say that ants have a global population, need mainly only consider other ants and have way more other species adapt too them rather than them adapting to others. The kind of arguments that would "disqualify" a weird kind of species can be used to make checks whether a conception of domination past muster.
For example the earth is not 100% covered in cities (human nests). In that way one could say that humans are only in very small localised areas. Domesticating cows or dogs is somewhat tame compared to how ants harvest resources from other species.
Because of reproductive compatiblity other human species were more of a subspecies. Domination via direct competition is useful for comparin species that share ecological niches. If a species is going to further speciate they are in such direct comparability. But for species that occupy different niches it might not make sense to call one of them dominant even if one of them was way more complex than the other.
Humans do have outgroup hate behaviours which can lead to stuff like burning a competing village. But humans do not have a sense that they should try to drive bears or lions into extinction.
Culture also doesn't need to monospecial. We have role for dogs and parrots to live in. We even have jobs for dogs and have given war medals and such. A big limitor on why animals are outside of culture is that they are not brought into upbringing or education programms. Humans raised by wolfes are not especially impressive but we let wolves rise wolfcubs. Chantek was a orangutan which was selected in a an experiment to be brough up as a human. He managed to atleast get to a point where he would clean up for money and use it in a fast food restaurant for treats. The limit to the development was community acceptance as city folks didn't feel safe or didn't want to have a monkey walking freely about so at assault/sexual misbehaviour drama he was sentenced to life in prison ie taken out of the human society. The limit probably isn't neurological there. As he was a working sign language conversational partner one gets insight how that felt. When asked about his conspecies living mates in zoo "Who are they?" he answered "dogs" as used to interacting with humans which he probably saw himself as a person and the usually brought up organisms as non-persons.
I think what the author meant was that the anthropic principle removes the lower bound on how likely it is for any particular species to evolve language; similar to how the anthropic principle removes the lower bound on how likely it is for life to arise on any particular planet.
So our language capability constitutes zero evidence for "evolving language is easy" (and thus dissolving any need to explain why language arose; it could just be a freak 1 in 10^50 accident); similar to our existence constituting zero evidence for "life is abundant in the universe" (and thus dissolving the Fermi paradox).
I think that makes sense. This seems similar to Vaniver's interpretation (if I'm interpreting the interpretation correctly). But as I mention in my reply to that comment, that looks to me like a different argument to the OP's one, and seems disjointed from "Since we shouldn’t expect to see more than one dominant species at a time".
A source you may find interesting or useful for this topic is the Open Philanthropy Project's 2017 Report on Consciousness and Moral Patienthood. Obviously the primary topic of that is different, but it contains some discussion of the general discussion/sophistication of nonhuman animals compared to humans, including specifically in relation to language (e.g., in this section). Although you may have already encountered the most relevant sources drawn on in that report.
Humans are capable of feats of cognition that appear qualitatively more sophisticated than those of any other animals. Is this appearance of a qualitative difference indicative of human brains being essentially more complex than the brains of any other animal? Or is this “qualitative difference” illusory, with the vast majority of human cognitive feats explainable as nothing more than a scaled-up version of the cognitive feats of lower animals?
“How special are human brains among animal brains?” is one of the background variables in my framework for AGI timelines. My aim for this post is not to present a complete argument for some view on this variable, so much as it is to:
Does mastery of language make humans unique?
Human conscious experience may have emerged from language
Humans seem to have much higher degrees of consciousness and agency than other animals, and this may have emerged from our capacities for language. Helen Keller (who was deaf and blind since infancy, and only started learning language when she was 6) gave an autobiographical account of how she was driven by blind impetuses until she learned the meanings of the words “I” and “me”:
Mastery of language may have conferred unique intellectual superpowers
I think humans underwent a phase transition in their intellectual abilities when they came to master language, at which point their intellectual abilities jumped far beyond those of other animals on both an individual level and a species level.
On an individual level, our capacity for language enables us to entertain and express arbitrarily complex thoughts, which appears to be an ability unique to humans. In theoretical linguistics, this is referred to as “digital infinity”, or “the infinite use of finite means”.
On a species level, our mastery of language enables intricate insights to accumulate over generations with high fidelity. Our ability to stand on the shoulders of giants is unique among animals, which is why our culture is unrivaled in its richness in sophistication.
Language aside, how unique are humans?
Humans ≈ Neanderthals + language?
The most quintessentially human intellectual accomplishments (e.g. proving theorems, composing symphonies, going into space) were only made possible by culture post-agricultural revolution. So, when evaluating humans’ innate intellectual capacities, a better reference point than modern humans like ourselves would be our hunter-gatherer ancestors.
We can reduce the question of how complex our hunter-gatherer ancestors’ brains are into two sub-questions: how complex is our capacity for mastering language, and how complex are brains that are similar to ours, but don’t have the capacity for mastering language?
Neanderthal brains seem like plausible proxies for the latter. Neanderthals are similar enough to modern humans that they’ve interbred, and the currently available evidence suggests that they may not have mastered language in the same way that behaviorally modern humans have. (I don’t think this evidence is very strong, but this doesn’t matter for my purposes—I’m just using Neanderthals as a handy stand-in to gesture at what a human-like intelligence might look like if it didn’t have the capacity for language.)
Higher intelligence in animals
Chimpanzees, crows, and dolphins are capable of impressive feats of higher intelligence, and I don’t think there’s any particular reason to think that Neanderthals are capable of doing anything qualitatively more impressive. I’ll share some examples of these animals’ intellectual feats that I found particularly illustrative.
Chimpanzees have been observed to lie to each other under experimental conditions. From Wikipedia:
In Aesop’s fable of the crow and the pitcher, a thirsty crow figures out that it can drop pebbles into a pitcher, so that the water rises to a high enough level for it to drink from. This behavior has been experimentally replicated, indicating that crows have a “sophisticated, but incomplete, understanding of the causal properties of displacement, rivalling that of 5–7 year old children”.
When Kelly the dolphin was given rewards of fish for picking up scraps of paper, “Kelly figured out that she received the same fish regardless of the size of the piece of trash she was delivering to her trainer. So she began hiding big pieces of trash under a rock. Kelly would then rip off small pieces from the trash and deliver them one at a time so that she could receive more fish.” Additionally, “when a bird landed in the pool, Kelly snatched it and delivered it to her trainers. She received a large amount of fish in return. Knowing this, she decided to start hiding fish each time she was fed. She would then use the fish to lure birds when none of her trainers were around. Kelly knew that by saving one or two fish now, she could get many more fish later by turning in a bird.“ (Also reported on The Guardian; I don’t know how reputable these sources are, so take this anecdote with a grain of salt.)
See these Wikipedia pages for some more interesting examples, and see here for a more thorough review of the evidence of higher intelligence in animals.
“Qualitatively” more advanced cognition may emerge from scale
Many aspects of human cognition that may appear qualitatively different from what other animals are capable of, such as long chains of abstract reasoning, also appear qualitatively different from what less intelligent humans are capable of. As a particularly extreme example, John von Neumann’s cognitive abilities were so advanced that a Nobel Laureate, Hans Bethe, once remarked that "[his] brain indicated a new species, an evolution beyond man".
At the same time, the genes that code for different humans’ brains are virtually identical from an evolutionary perspective. This suggests that the seemingly qualitative differences between humans’ and animals’ cognition might not be so different from the seemingly qualitative differences between John von Neumann’s cognition and mine—our brains might be doing essentially the same thing as theirs, except at a higher scale.
How hard is mastery of language?
Could language capacity fall out from general capacities?
Maybe it was extraordinarily difficult to evolve the cognitive mechanisms that allow us to learn language, above and beyond our cognitive machinery for learning other things. I think this is plausible, but I don’t think the case for this is very strong.
Animals (Washoe, Koko, and Alex the parrot) have demonstrated the ability to learn simple forms of symbolic communication, which they never evolved to do, indicating that their ability to learn things in general is good enough to learn very simple forms of language. It’s true that there are aspects of human language that escape animals, but they also escape feral children, and might escape animals for mundane reasons, like their not having critical periods long enough to learn these aspects of language.
Additionally, AI language models provide evidence that simple and general learning mechanisms can capture many of the intricacies of human language that other animals miss, further suggesting that there’s nothing intrinsically difficult about learning language. Here’s an excerpt from GPT-2, a relatively recent language model:
Why haven’t other species mastered language?
If language isn’t a particularly difficult cognitive capacity to acquire, why don’t we see more animal species with language?
One possibility is that the first species that masters language, by virtue of being able to access intellectual superpowers inaccessible to other animals, has a high probability of becoming the dominant species extremely quickly. (Humans underwent the agricultural revolution within 50,000 years of behavioral modernity—a blink of an eye on evolutionary timescales—after which their dominance as a species became unquestionable.) Since we shouldn’t expect to see more than one dominant species at a time, this would imply a simple anthropic argument for our unique capacities for language: we shouldn’t expect to see more than one species at a time with mastery of language, and we just happen to be the species that made it there first.
It may also turn out that language is hard to evolve not because it’s a particularly sophisticated cognitive mechanism, but because the environments that could have supported language and selected for it might have been very unique. For example, it may be that a threshold of general intelligence has to be crossed before it’s viable for a species to acquire language, and that humans are the only species to have crossed this threshold. (Humans do have the highest cortical information processing capacity among mammals.)
It might also turn out that the cultural contexts under which language could evolve require a mysteriously high degree of trust: “... language presupposes relatively high levels of mutual trust in order to become established over time as an evolutionarily stable strategy. This stability is born of a longstanding mutual trust and is what grants language its authority. A theory of the origins of language must therefore explain why humans could begin trusting cheap signals in ways that other animals apparently cannot (see signalling theory).”
My current take
As we came to master language, I think we underwent a phase transition in our intellectual abilities that set us apart from other animals. Besides language, I don't see much that sets us apart from other animals—in particular, most other cognitive differences seem explainable as consequences of either language or scale, and I don’t think the cognitive mechanisms that allow us to master language are particularly unique or difficult to acquire. Overall, I don’t see much reason to believe that human brains have significantly more innate complexity than the brains of other animals.
Thanks to Paul Kreiner and Stag Lynn for helpful commentary and feedback.