Crows have been shown to understand the concept of zero
quantamagazine.org
quantamagazine.org
They were training a younger parrot and trying to get the younger parrot to count to two by tapping twice.
Alex overheard the training and got impatient with the other bird. He yelled out “two” and then after two more taps “four” and then “six”.
The trainers were just expecting “two” each time.
It was this book: https://www.amazon.com/Are-Smart-Enough-Know-Animals/dp/0393...
The book is interesting and goes into how humans need to set up experiments properly to actually test non-human animals in ways that make sense (rather than just in some biased human way).
One quick example was testing tool use, the original experimenters left branches on the ground for the monkeys to use, but the monkeys can’t pick stuff up that’s flat on the ground since they’re normally in trees (their hands don’t have thumbs that move that way). When he redid the experiment with the tool raised they were able to grab and use it.
Same author also wrote Chimpanzee Politics and did this great video experiment: https://youtu.be/meiU6TxysCg
I’d recommend his other stories too if you like that one.
I’ve also got a bunch of links to other stories I’ve liked here too: https://zalberico.com/about/
When the number of taps approached the correct answer, his trainer became excited. Hans picked up on this and stopped right when the trainer's excitement reached its peak. The trainer had no idea this was happening. He was fooled by a horse.
Children will make similar classification errors when learning too.
None of this means that it’s not possible they can also learn counting, but just that scientists need to be clever about experimental design. The book goes into that.
The example and class of failure (even if it didn't actually occur in this specific case) is still the point I was trying to make. Those types of failures can happen - even if the specifics of the tank example are urban legend.
Not necessarily. It could be just ability observe scale not individual numbers. i.e. 3 bags look big enough amount of bags for a walk not that there are 3 bags. Would the dog not come when 4 bags are taken? What if 2 bigger bags are taken? It's kinda hard to deduce anything from this anecdote other than the dog seems to understand a pattern.
> The crows mixed up a blank screen more often with images of a single dot than they did with images of two, three or four dots. Recordings of the crows’ brain activity during these tasks revealed that neurons in a region of their brain called the pallium represent zero as a quantity alongside other numerosities, just as is found in the primate prefrontal cortex.
(I'm a little disgruntled about skimming a longish article to find this 2/3 of the way down.)
I don't know anymore if we should salute the efforts of the author to contextualize the news, to the detriment of the news itself, or I'd we should blame them for lengthening artificially the article...
Probably a bit of both, as always.
That being said, thanks for the summary of the article, great tl;dr; ;)
I always thought pet peeve meant a hobby, a specific point of interest, not something you dislike!
Sorry for the mistake, I'm glad I've fixed this though! :D
I always thought pet peeve meant a hobby, a specific point of interest, not something you dislike!
Sorry for the mistake, I'm glad I've fixed this though! :D
Blaming people is discouraging, and divides communities. Criticise the article, not the author, and thank the author for what they got right (a good topic for discussion) so they'll create more in future.
We can also increase trust in the community using links. Mentioning names in a good way is particularly helpful, like academic citations.
Thank you for finishing with the "great tl;dr", xcambar, you're asking the right questions :)
IIRC the dead fish result had more to do with software than hardware though. My understanding is that the best of the best labs are careful with the analysis techniques applied, and they wouldn't have even made the dead fish mistake back then.
The commonly used analysis tools are continually improved, so improvements may have propagated to the median fMRI group, but to be honest I still start out skeptical of most fMRI papers unless they're from a group I have prior reason to trust (or they include other data types besides just scans). Too many groups just apply the popular pipelines without an understanding of what they are doing, leading to misuse of tools.
I'm tangential to the fMRI field though, so take with a grain of salt.
Has there been any improvement in the baseline quality once you exclude the dubious groups?
From a neuroscience perspective I do think the good fMRI labs have improved their analyses over time. One thing increasing in popularity that has been helpful IMO is scanning the same participant across multiple days. It's a pain in the ass to get people to come back so it has generally been the norm to scan each participant in a study only once. But more powerful analysis techniques can be performed with these multi-scan datasets, as heterogeneity between and within individuals can be better accounted for.
This review focuses on the default network, but it mentions how the discovery that the default network is actually multiple networks that were being blurred together was enabled by the multi-scan approach. It also gives a decent general gist of some of the things that have been reliably reported in fMRI research versus some things that are lacking, but mainly just from the perspective of questions about the default network: https://pubmed.ncbi.nlm.nih.gov/31492945/
I also like the following paper as a deep dive into the scans of a single person, because he splits apart some seemingly small things like having coffee/breakfast in the morning and shows the effect on scan results. I also think a multi-modal approach is really helpful, so I appreciate the other datatypes included. Plus it's kind of funny the PI wrote a paper entirely about himself: https://www.nature.com/articles/ncomms9885
So yeah I think there is some self reflection and progress being made in the field in a meta sense, it just unfortunately can be drowned out (especially for people in other fields or even subfields of neuro) by the sheer popularity of shitting out fMRI papers.
That said, I don't find the interpretation of the results very convincing. I'm going only on the Quanta article, perhaps the original research tells a more compelling story. But with the details provided so far I don't see how the physiology can rule out the idea that crows have a concept of "none" but don't consider "none" as a potential number like "two".
> Some researchers, for example, propose that while humans have a “true” understanding of numerical concepts, animals only appear to be discriminating between groups of objects based on quantity when they’re instead relying on less abstract characteristics, like size or color.
It's a cognitive bias. People have this because their model of the world is ego centric with themselves as hero and Number 1, and animals far below.
We are alongside all other animals, with some skills much worse than other animals, some much better. Nothing more than that.
Hopefully the original research addressed this, but it felt like the Quanta article was reporting the results in a way completely disconnected with the material it had just introduced.
If we know the animals arrange quantities like a number line, why is there no report on where the animals place an empty set in that experiment? If we know that some young children don't understand the empty set can be a number, then why aren't results from young children on these tasks compared?
There are some interesting results described, but I wasn't convinced at all by the argument about zero specifically, which they make a big deal of in the intro and discussion.
To be honest I think Quanta is a bit overrated on HN in general, but that's another issue.
Me too, the title felt a little click-baitey
I recently saw a video of a seagull that entered a grocery store through the automatic door, picked up a (non-transparent) bag of potato chips (or something similar), walked out again, opened the bag and ate the chips. Think about it for a moment, the bird has to understand (to a degree) how an automatic door works, and that there is food inside these shiny bags. When let that sink in, I was thoroughly impressed. I knew seagulls are very opportunistic eaters, but I did not know they were capable of this degree of intelligence and planning.
I wonder how much more there is discover, and how that might affect how we view and more importantly treat animals. We might have to rethink our relationship with them.
There is another one fancying cold sandwiches: https://www.youtube.com/watch?v=JZZ822Za-nE
[0] https://www.reddit.com/r/nextfuckinglevel/comments/i69mu1/no...
monkeys can team up to resolve non trivial coordinated tasks
(vaguely related: gorillas still have the zero lag face recognition)
beside not speaking, often when I look at animals, it feels that they got wiser than us.. they could do more smart things but they just coast.
Not only do crows learn to recognize PEOPLE by their FACES, they teach their offspring to avoid/mistrust those same people. Those offspring teach their offspring. So the "grandchild" of the original bird learns to avoid a specific person. *(Note the documentary I watched with this revelation didn't follow any further generations. We don't know how many generations are taught this lesson.)
Think about that for a minute. I don't recognize the people that live 2 houses away from me, these birds teach their young that SPECIFIC humans are dangerous.
This isn't the study I watched, but it's close. https://www.discovermagazine.com/planet-earth/grudge-holding...
That documentary was so interesting(in my opinion at least). I think it might be on Youtube, but I don't remember the name.
One goal I'm really excited about is to see if they can solve a puzzle that requires two crows to work together, because I've only seen videos of individual crows solving puzzles online. Can you tell me more about the teamwork that you're referring to? Are there videos or papers I can look at? I'm super curious!
Thanks!
After I did this consistently for a while, the crow came every morning. So then I decided to hide the peanuts in a container. I had a retainer case that springs open when you press on a button; I taped it to the railing and left it open with a peanut in it. The crow was very suspicious of it at first, giving it a wide berth while examining it from all sides. It took about a week for it to work up the courage to steal the peanut from the open container, and then another week for it to get used to the idea that the container wasn't going to cause it harm. Then I closed the container.
The crow learned to peck the button to pop open the retainer case, and that's when I got hooked. The crow brought over its partner, and later in the spring as I was stuck at home in lockdown, its fledgling came along too, and they would show the fledgling how to get the peanuts. I started putting out a series of different containers, and then eventually got them a dog intelligence toy, which they aced. I think these crows aren't as smart as the New Caledonian crows in the videos; it takes them a few days or weeks of experimenting to figure out a puzzle. It got to the point where I had four or five crows basically chilling at my house on most days, playing with the toys and taking baths and discussing the puzzles. I have way too much webcam footage of all this, which I've been meaning to post but haven't had the time to sort through and edit.
I have since moved to a new house and had to say goodbye to those crows. :( I have new crow friends now, though! I toss them peanuts whenever I see them on my street, and now they will follow me for a couple blocks if I walk by. This time I've made them a nice platform to land on, and they're learning to open containers, and are starting to play with a dog intelligence toy now.
this TED talk https://www.ted.com/talks/joshua_klein_a_thought_experiment_...
with a peanut machine to attract them and regularly make the setup more intricate to see if they manage to find the metaphorical key to get more seeds. more like crowd strategy search ?
It goes both ways, in the past we had Clever Hans[1]. People believed Hans could perform simple math, when his cleverness was actually watching his owners expression for small changes. So any observed intelligence ends up under suspicion of them acting on information gained from a much simpler side channel.
Mammals are somewhat close to us, but we have diverged from birds over a hundred million years ago and we still struggle to understand how a tiny and smooth brain such as corvids have can produce such an observably intelligent behavior.
Corvids may have small brains in terms of volume, but not measured by the number of neurons in the areas that count[1].
Maybe animal intelligence is not so different to ours, but our measure is.
Surely BBC or NPR has a decent documentary on the topic.
https://nymag.com/intelligencer/2013/04/john-paulson-loses-1...
Being smart does not save you (and not me, either!) from being dumb. And there have been times in my life when I was able to substitute inventiveness with stubbornness.
So there are upper bounds to everyone's intelligence, human or animal[0], genius or idiot. Given the variety we can observe in our fellow humans, I think it's fair to assume birds have their "village idiots", too.
[0] Except for barnacles, of course, but they are very discreet about it.
All of these require planning and risk assessment abilities. Being able to take a bag of potato chips away from human-infested buildings and opening it is not really that far outside the scope of their adaptations.
Still, crafty little bastards they are indeed.
"Are Crows the Ultimate Problem Solvers?"
"Smart Crow uses cars to crack nuts in Akita, Japan near Senshu Park"
My parents had a dog that was very smart and pretty aggressive to our cat. He had a dog kennel in a small section of backyard enclosed with high fence. Near the fence there was a small cherry tree where our cat liked to climb.
Cat wouldn't climb the tree when the dog was outside of his part of backyard, so the dog not only learnt to open the gate to the rest of the backyard (lifting a wire loop over the fence and pulling it just right), but also to shut it slightly to fool the cat. He would lie there pretending the gate is still closed, not reacting to the cat. Cat would climb the tree and then the dog would stop pretending, open the gate, go under the tree and bark at the cat till we come and free him. If we weren't home that could take hours - neighbors weren't too pleased.
Other example is dogs burying and re-burying treats when they see each other watching them bury it. That requires at least rudimentary theory of mind.
As for crows - I've personally seen them doing this trick (on a parking lot not on a pedestrian crossing, but same thing - they understood where the traffic is just right to be used for nut-cracking).
They are also huge assholes to other animals, bullying them in very creative ways.
I don't doubt crows are smart, just don't think that experiment was that impressive.
Some hypothesizes and argues that our ancestors extinguished every other species that showed intelligence by eating them, which I think is a bit too wild of a theory. But maybe the fact that it’s often small birds that shows intelligence is also interesting. They’re among hardest to hunt.
> The attitude that animals are basically humans seems much healthier than the converse.
From his book https://www.prickly-paradigm.com/titles/the-western-illusion...
Are you referring to hunter gatherers doing a mystical bear or eagle dance? Reincarnation as an ant? in those cases, it is belief in a non-corporeal spirit-being that underpins the other belief. Do you believe in non-corporeal spirit-beings, and if you do, aren't you more mystified by people who don't believe in them; or vice versa?
Otherwise, I'm skeptical and would love citations?
https://philosophynow.org/issues/108/Descartes_versus_Cudwor...
Well, riddle me this. In this thread people are marveling at animals doing things like using automatic doors and opening bags of chips. Who would be impressed if a human did these things? I don't exactly find myself persuaded by these examples that actually animal intelligence is just like human intelligence.
An example of something that might surprise many people: animals can use medicine.
Here is a fascinating podcast that discuss the subject with researchers and experts.
Podcast description:
> Listener Andrew Chen got in touch to ask whether animals use any kind of medicine themselves. After all, our own drugs largely come from the plants and minerals found in wild habitats. So perhaps animals themselves are using medicines they find in nature.
> We think of medicine as a human invention - but it turns out that we’ve learnt a lot of what we know from copying the birds, bugs and beasts.
This podcast is highly recommended - I guarantee you'll come away amazed and humbled by the intelligence of animals.
Do animals use medicine?: https://www.bbc.co.uk/programmes/w3cszv77
Earlier BBC documentaries show animals (birds and fish) seek the "service" of certain types of fish to clean them from parasites.
So the idea of animals using medicine is kind of presenting itself. It's not totally in your face, but it's no more out there than prehistoric humans discovering the medicinal properties of certain plants.
I'm not sure I see that, that is, the "understanding" part. I mean, this is not some new kind of behavior, even if everyone here reacts with surprise. Anyone with a pet dog or cat knows the various mischief they can get into. Many of us have been at the beach and watched seagulls do all sorts of interesting stuff. Animals aren't "dumb" and I don't know anyone who would say that they are. What people do object to is the unwarranted inference that because they display what looks like clever behavior then this must entail capacity for abstract thought with concepts. I don't see how abstraction is necessary in these examples at all. Language in the fullest sense demonstrates the existence of abstract thought. Non-human language does not appear to show any sign of descriptive and argumentative function, only signalling and expression (in the Popperian sense).
It’s not hard for me to see how our language faculty convinced past humans we were somehow masters of reality beyond other creatures.
Past humans did pass on a lot of dumb ideas.
One of the justifications used for this reasoning is "You don't go to the market and buy 0 fish". But all that tells us is: There's no reason to record buying 0 fish or owning 0 acres of land. Another justification given is the difficulty children experience with 0 - but we don't teach children to start counting with 0, so it makes sense that they would get tripped up there.
I guess the argument sometimes seems to be that we didn't have a symbol for 0, and that this was somehow more confusing to adopt than other symbols? But if that's the case, then isn't claiming any culture "invented" zero the same as claiming a culture "invented" any concept they came up with a word for?
I'd love to hear all the reasons I am wrong and stupid.
Even today, when you ask someone "how many kids to you have," and they don't have any, they say "I don't have any," not "zero." In other words, they respond with a phrase, often one with a negation (not), instead of a number.
Please err on the side of me understanding your question well.
I agree its not clear, though I might lean the other way. Who knows.
Many believe that animals do not have an "I" the self reflective "I", that they are not aware of themselves etc etc. This runs contrary to my beliefs, I have had several conversations/arguments on HN along those lines, but lets not dwell on mere beliefs.
What I find interesting is what test/experiment can one perform that can demonstrate that a human, who is not allowed to communicate linguistically, has the attributes mentioned above. If we cannot design such a compelling experiment that shows are inability to detect those attributes in animal even if those attributes maybe present.
We need the restriction of no-linguistic-communication so that animals and humans are on the same playing field. Hellen Keller, when she did not have language she would have been on the same playing field.
My position is that if I cant even prove/demonstrate to others that you are sentient in the senses described above, how can we even claim that animals aren't sentient. We have no way of demonstrating it even if they were.
This seems fairly trivially true just based on how common it is for someone to have 100% full understanding of a concept and then be completely incapable of remembering the word describing it, or even a phrase that conveys a decent approximation.
Indeed some of the ancient Greeks were of the opinion that 1 was not a number (since numbers were for counting a plurality of things).
It's quite the realisation that you can use the usual rules of arithmetic for 1 and 0, and not have anything go wrong. (Except of course division does go wrong!)
What you said about it not being in the numeric system is definitely part of it (ex: roman numerals not having it) but also all the problems that come up with zero have to be dealt with (e.g allowing dividing by it allows you to prove anything, and there's a great proof that winston churchill is a carrot in the book showing as such), and there's some overlap with religions in fearing "nothing" and what that might mean
On the one hand, it means there's none of a thing in there. Most animals understand this. There is zero food here. There are zero predators on that island. Pretty sure crows have this one down pat.
Taking it one step further, you have zero as a number. Zero which is on equal footing as numbers like one or seven-- it is a number that you can perform arithmetic on or with. You can multiple by zero, you can add by zero, you can divide by -- wait, you can't divide by zero! The Greeks understood this. But lots of people say the Greek's "didn't have/didn't invent zero" because they used the word "nothing" instead of its own word. But Aristotle did say "nothing and nothing, added together, make nothing" and "there is no ratio of nothing to a number".
Crows probably don't understand that you cannot divide by zero. Maybe you could teach a crow that if two crows got ten total nuts, each crow would get five nuts, and so on. If you told that crow to split ten nuts between no crows, and ask the crow how many nuts each crow would get, the crow might tell you ten nuts, but it's not going to tell you that that operation is undefined.
Then there's the use of zero as a digit in a place-value system, like the one we use, as opposed to Roman numerals or Chinese numerals or so forth. Before there was a symbol for zero, you couldn't write one hundred and four as 104, it would just be 14 which was ambiguous. So when the Indians "invented zero" in the 7th century or whatever, it wasn't zero that they were inventing, it was the place-value system we use today to conduct our daily lives with, which is a shitload better than Roman numerals or trying to do arithmetic with a straightedge and compass or whatever.
There are a lot of people who claim that, for instance, the Maya were more mathematically advanced than the ancient Greeks, because the Maya had a symbol for zero (which looks sorta like a French baguette and an American football had a baby) and the Greeks didn't. While the Mayan way of writing down a number was much better than the Greek method, we don't have any evidence that the Mayans had much in the way of math beyond counting and extrapolating. The Mayans primary method of calculating is by drawing out tables: they knew the cycle of Venus is (roughly) 585 days, they knew the cycle of Mercury was 117 days, so you'd get a table with thousands of entries counting up the cycles. The Dresden codex has a table with 2340 entries, with 585 entries for Venus repeated 4 times and 117 entries for Mercury repeated 20 times. With a place-value system that used zeroes for zero digits. Which... ok, the place-value system was more advanced than the Greeks, but the Greeks would have done that same 'calculation' with a lot less tedium.
Then you have zero as in the additive identity, which opens whole new worlds of mathematics to you. Now you can start talking about things like rings, fields, and groups, and can have all sorts of fun. Pretty sure crows haven't sat down and discusses abelian vs non-abelian groups, but I wouldn't put it past them.
So anyway, any time someone starts talking about inventing or understanding the concept of zero but do not, themselves, display an understanding the concept of zero, (by explaining what it means in that context) it's generally a good time to stop listening.
One of the cats left when he had them all, while other cats kept waiting ( or begging ). Sometimes they needed to be shown there were none left.
But that one cat, no matter how many people were at the table, always seemed to know when he had them all.
Clearly she has clear the negative concept of "not enough".
Many years ago there was a study involving crows, as I recall. N, starting at 2, researchers went into a blind, then N-1 came out. They had to get up to N = 13 before they fooled the birds into thinking the blind was actually empty.
https://neurosciencenews.com/neuron-counting-9898/
This article goes into it and mentions "numerical distance effect", which looks appropriate but not what I remember.
I did learn that people who play first person shooters can usually recognize more objects at once instantly; 6 or 7 instead of a more typical 4 or 5, if I recall correctly.
They used number of grapes in a hand to measure.
This is an odd claim —- based on the neural network experiment (which showed that gradient descent applied to object detection problems naturally results in the development of “counting” signals), it seems much more likely that for as long as beings have been interacting with their surroundings they’ve been able to count, and any modern slight differences in counting infrastructure are simply a divergence of the original counting machinery rather than the same thing being invented over and over by evolution in many different ways, but only recently (for some reason..?)
> The fact that those three species are from diverse taxonomic groups — primates, insects and birds — suggests that certain numerical abilities have evolved over and over again throughout the animal kingdom.
> Their last common ancestor “was [barely] able to perceive anything,” Avarguès-Weber said, much less count.
> Moreover, he added, “When you look at the history of mathematics, it turns out that [zero] is an extreme latecomer in our culture as well.” Historical research finds that human societies didn’t begin to use zero as a number in their mathematical calculations until around the seventh century.
When people make claims about "zero" they're essentially meaningless unless they specify which meaning of zero they're talking about.
I have to imagine that the multiplicative identity (1) and additive identity (0) were also known at that time. They really figured out everything else there is to integer-based math.
They failed at irrational numbers (like sqrt(2)). But their mastery of integers was outstanding. Perhaps 0 wasn't used on the number-representation yet, but the concept had to have been known.
(mods I promise I'm not here to shill this book but people keep wondering about the history and that's a great resource that I like XD)
> Hindu units of time are described in Hindu texts ranging from microseconds to trillions of years, including cycles of cosmic time that repeat general events in Hindu cosmology.
Source:
A popular science book
"The history of numbers or the history of a great discovery" (Georges Ifrah)
Contains some fun chapters like "How to count if you can't count". For example if natives in a stereotypical jungle want to count numbers to a holiday. They memorize a sequence of items, for example body parts: little finger of one hand, palm, wrist, forearm, arm, shoulder, neck.... then they measure once and conclude one needs to wait as many days as there are from the little finger on left hand to, say, navel.
Mom hen knows if a chick is missing. Can she count? Of course she can, how else would she know it. But show me a chicken that will abstract number 5. As 5 chicks, 5 pieces of grain, 5 drops of rain or 5 whatever, so that five becomes an object by itself. I thought it is common knowledge that our ability to abstract is what separates us from animals, but seeing people interested in horses and crows able to count I am starting to doubt it really is so. Animals (mammals at least) feel like us...love, anger, pleasure...they might not hate as us though. Animals can build...spiders, beavers and so on. They can think, communicate, count, have social structures, dream... It is ability of our intellects for abstraction that differs us from them.
Animals can not abstract numbers, they miss faculty for it, whatever that faculty is.
> The crows mixed up a blank screen more often with images of a single dot than they did with images of two, three or four dots.
This can very well happen even if there is no understanding of zero as a symbol. You're looking for nothing, and the screen with 1 dot is almost that - in terms of the existing symbol occupying the least space, closest to nothing. Not evidence of a mapping of nothing to a symbol at all.
I'm sure (animal intelligence) researchers would be getting more grants if they put more effort into capturing some of these feats on video.
Cheyennes divide birds into 3 groups: plain, great and sacred. They count magpie in the sacred ones :-). There's a magpie on my fence as I'm typing this.
They like magpies because they're smart, talkative, they announce guests, they live close to humans.
Australian "magpie" is not even a corvid.
Show me an animal that can describe and argue and you will have my attention. For now, I only see signalling and expression, but no language showing signs of description and argumentation.
You know nothing, Jon Snow.
No they didn't.
All human cultures I'm aware of have, at least, the concepts of none, one, two, three, and many. They all understand that none is exactly one less than one, and most of them (but not all!) understand that there's no natural limit to the counting numbers, and have a way of expressing some amount of those numbers.
But zero is a human invention. It comes from India (probably, might be China) and is probably related to the abacus: but the abacus came to the West without the zero, which followed it later.
Zero is both a symbol for null and a placeholder used for writing numbers modulus the radix. This is a conceptually powerful force multiplier, making all arithmetic operations dramatically easier.
It also lets us make up a "name" for any integer we want. We can just add more zeroes; when this gets awkward we can start counting the zeroes using exponential notation, and when that becomes inconvenient we can develop ↑ notation, which gets us further than we really need for any practical purpose.
It should be obvious that crows neither know about this nor care. It's interesting and cool that they understand none, but so did the Ancient Greeks, who had no idea about zero and could have gotten much further in mathematics if they did.
Moral of the story, after reading this article, I agree with you. This isnt as groundbreaking or interesting as it seems. I'm pretty sure they're finding patterns that dont exist and are over rationalizing. Of course an animal would have the concept of none, a little, a bit more and a lot, especially when applied to the idea of scavenging for food. Appling the idea of mathematical concepts to them, with little support just feels like a cheap attempt for grant money. Which, surprise surprise, was the same sham pulled with Koko.
That and some of these tests they talk about, either they're shit at describing them or even I would fail to prove I could count or do arithmetic.
...what do you think human children are doing for the first ~4 years of their life?
Also, different learning methods are used by the subject depending on their mood -- most importantly frustration -- and other context. Brute force learning tends to be the last stage before they're so frustrated they give up or become aggressive. It's also a common exploratory tactic.
Teaching human sign language over a variant organically developed by the subject and team would have what advantage, exactly? It may be nominally more interesting to know a gorilla could adopt a purely human communication system -- very interesting. But it's also such a corner case of studying communication and particularly interspecies communication that to call it out as a problem is nothing more useful than a nitpick.
We're coming from an age where all animals were by default assumed to be a sort of squishy -- sometimes tasty -- automaton. We have a long way to go in unlearning that particular arrogance. Assuming that intelligence can only be demonstrated in the purely human terms you seem to be looking for is just another vestige of that same arrogance.
I think you are grossly missing the point.
As it is, I feel lied to when folks say that it takes kids 4 or more years to get language.
That is, with how off the idea that 4 year old can't take language is, I didn't make it to the argument. And I am sympathetic to the idea that animals can pick up on language.
You're asking an animal to internalize a system of communication quite literally designed from the ground up for different hardware. It's like asking why does my Oculus headset take so long to communicate over ZigBee. What would be magical is that it did it at all. Lamenting how long it took to bend the Oculus hardware into some contorted SDR would be stupid.
Consider, my dog can fumble around trying to make me happy with really good emotional understanding of my reactions and basic mimicry. I wouldn't claim that is a usage of language, though. From the counters here, there is an argument that if my dog was dextrous with his arms and hands, he could pass off similar results.
The OP is right that Koko stumbled around a lot, even after the signs had supposedly been "mastered". This article presents one of the more bizarre results of that: https://slate.com/technology/2018/06/koko-the-ape-obituaries...
We probably are underrating animal intelligence, and whether Koko understood language is largely dependent on what one considers to qualify as "language" - there definitely were some impressive displays of intelligence at times. But through an unbiased lens I think it's also pretty clear the researchers were constantly making the most charitable possible interpretation of Koko's signs.
As far as the GP comment, it is well documented that zero as a mathematical concept was developed surprisingly late, while the concept of "nothing" existed prior to any formal notion of integers at all. The Quanta article is conflating "nothing" with "zero", although perhaps the original research makes the distinction more clear.
My quibble is conflating this with zero, which is a much more powerful and advanced concept. Greeks, Romans, early medieval Europeans, none of them had the concept of zero, and they suffered for it.
And what you've said about Koko the gorilla is true as far as I understand it. It was a media stunt, more Clever Hans than Mister Ed. It would be pretty cool if it wasn't, but I'd have to see some replication and I don't expect to.