Daniel and Kelly answer listener questions about how we measure and define intelligence, hypotheses for why it arises, and why flies are so dumb.
Why are some animals so much smarter than others? And in particular, what is it that makes humans so incredibly smart? Now? I love animals as much as anyone else, and yes, other animals do do things like use tools and communicate with each other, But humans are the only species we know of that uncomplicated research programs to try to understand at a deep level why some animal species are more intelligent than others and how would these differences come about. We humans ask questions like why is it that crows have learned how to fashion sticks into tools that they can use to grab tasty bugs out of the nooks and crannies of trees, But I can't get my dumb chickens to stop eating the paints on the side of the chicken coop? And what kind of conditions would you need to have on another planet in order to produce highly intelligent aliens? These kinds of questions keep me up and also seem to be keeping many of you up at night as well. Today, we're going to tackle three wonderful listener questions that we've received related to intelligence. Welcome to Daniel and Kelly's Extraordinary Universe.
I'm Daniel, I'm a particle physicist, and I hope that humans are not the smartest folks in the galaxy.
Hello, I'm Kelly Wiener Smith. I study parasites and space, and yeah, I guess I hope we're not the smartest. As long as they're nice and smart, that would be great.
I don't even really need to put that caveat on it, Like if they're mean and smart, like, I'll take a little bit of meanness for some secrets of the universe.
What if they think we're delicious and they're smart, I think that's a bad combo.
I think I don't think I'm certainly very tasty, so I'm not worried that I'd be going to be like high on the list of humans to be consumed.
What would make you less tasty than other humans?
This is getting personal now?
Is us this sprinkled with stinky sauce or something.
I actually kind of am marbled through with the ribbons of fats, So maybe I would be quite tasty. I don't know. I try to stay fit.
You know, Marbling is a delicacy.
I think we just set a record for how quickly we started talking about aliens and consumption of human flesh.
Glad to see if by the end of the episode we hit poop and then we'll have the trifecta. But we'll probably get there, all right.
So my question for you today, Kelly, is do you think that we will ever crack the barrier to communicating with our fellow intelligent earthlings, Like somehow as AI or future linguistics can help us understand the chirpings of prairie dogs and the whistling of whales.
Wow, all right, So I've recently read this really great book called Do Aliens Speak Physics?
Ed?
That is a great book.
It's a fantastic book, and it kind of convinced me that unless you can have two way communication, it's really hard to get on the same page regarding language. You can, like work with dolphins to try to figure stuff out. Maybe we could get some very preliminary like you know, I say hello to you, you say hello to me. We're on the same page there, But like I guess I'm not super optimistic. What kind of communication do you need? Like, so, my dog is really cute but about as smart as a ton of bricks, and so I can't communicate too many complicated ideas to her. But you know, there are some border colligues that are brilliant. So how much communication do you feel like you need?
I just kind of want to know what's going on in there. Like the whales are definitely talking to each other. What are they saying? The honeybees are wiggling to each other. This definitely in for me. I just want to translate that information somehow, to know what they think is interesting to talk about. And like you, I know that my dog understands a lot of stuff, Like he picks up on pretty subtle patterns, so he knows when he's getting a walk. You know, shoes on plus the leash means a walk, shoes on plus the backpack I means Daniel's going to work this kind of stuff. And he notices patterns through the day, like he's definitely paying attention to patterns and understanding stuff. But I wish we could talk. I wish we could commun in the game more. I wish I could tell him like, Hey, we're getting in the car and we're going to this thing, or we're not going to the vet. You know this information I wish we could share with him, Like my dog when we leave, he has no idea are we going on a three week trip? Are we going to be back in an hour? He's cool, and if I could talk to him, I could share that with him.
So, first of all, I think it's very nice that you're worried about how your dog's going to feel about how long you're gone. I think that's very sweet. So bees do this waggle dance, and you can tell by the way that they're dancing, sort of like the direction and the distance that they're telling their nest mats. We're the great source of pollen or nectar is and so we can decipher that. But you know, I don't think that I could like dress up in a bee suit and shake my butt the right way and tell them like, hey, I just planted some flowers in the southern corner of the property. I mean, I think we can decode a lot of what animals say, but we have not yet figured out how to communicate back with them.
Yeah. Well, part of that depends on what's going on inside those animals' minds and what intelligence really means and where it comes from. So let's dig into the episode today. I'm dying here what you had to tell us.
I'm super excited about today's episode. But now I've got myself wondering, like, could you make a little electronic bee that was like a bee size and like do the waggle dance and maybe get the bees to go to like your source of nectar. Anyway, surely there's got to be funding for that. That sounds awesome. I find questions about animal intelligence to be absolutely fascinating, and this is actually a topic that we get a lot of questions from y'all about, And if you want to send us your questions, you can send us questions at questions at danieland Kelly dot org. So today we're going to tackle three of the questions that we've gotten from listeners about animal intelligence and they sort of build on one another, and so we're gonna, you know, do a bit of an overview on animal intelligence today.
This is super cool. Second new kind of episode is like a listener questions themes episode, almost like these listeners are working together to send us questions that click together so nicely.
That's right, Yeah, and these three click together very nicely. You know, we could have done something similar with our consciousness episode, but I think we got twenty questions about consciousness before we were like, all right, we get it, We're going to get an expert. Hopefully we answered everyone's questions with that one. But today we are going to start with a question from Tom. So let's go ahead and hear Tom's question.
I'm reasonably confident that humans are the only Earth species that has ever built rockets and such. So why is this level of intelligence so rare? Life on Earth is incredibly diverse and the Earth has been teeming with it for billions of years? How does the species even develop rocket level intelligence? Is intelligence a biologically selectable property that improves the chances for a population to survive? Or is rocket level intelligence just dumb luck? After all, the fact that rocket level intelligence emerged on Earth has proved to be quite unlucky for many coexisting species and may yet still be unlucky for humans. Thanks.
Wow. Okay, so that is a great question, but it's a very specific question. So why is a rocket level intelligence so rare? So we have an end of one. We know of one species that is able to build rockets, and with such a small sample size it can be really hard to know for sure. A bit of a spoiler here, we don't know. In general, science does not know exactly what it was that put humans on the trajectory that we went on to be able to build rockets and all the other amazing things that we can do. We will talk about some of the hypotheses today that we think were important, but first let's back up and ask the question why can't all species build rockets? Why is this kind of intelligence so rare?
I mean, ants and termites can build impressive stuff, right, they definitely work together, and we see other species doing cool stuff. So why aren't they building rockets and getting off planet? What does that really require?
So again, the rocket thing is very specific, and part of it is, you know, ants just might not have the right appendages to build a rocket. You know, maybe they've got rocket plans and if they just had hands, they'd be building rockets, but probably not.
That's the kind of thing we could learn if we learned to speak ant and be you know, maybe they're desperate to fly into space and frustrated about their limitations.
We should be bringing them with us just you know, they might.
Appreciate that, or we should just have them on the podcast and ask them directly.
Maybe in five or ten years. So if you ask yourself, why can't all species build rockets. You're essentially asking, well, why aren't all animals intelligent? What holds you back? And we think the answer has to do with how much energy it takes to be super smart. So our adult brains weigh about three pounds, so for a person who weighs one hundred and eighty pounds, that's about two percent of your body weight. But by measuring oxygen consumption rates in different parts of our body, we estimate that our brain uses about twenty percent of all of the energy that we burn every single day. So this very small organ is using an outsized amount of energy. So brains are just energetically expensive. So if you are a species that doesn't need a super big, smart brain, then there's probably not great selection pressure for you to be expending a bunch of energy on an energetically expensive organ that you are not using.
So you're saying that this thing is expensive, right, that it costs us something, and then so if it doesn't pay for itself, it's definitely not going to survive because I've hung around and used up a bunch of energy and didn't provide tangible benefits. Then folks with big brains would die more often during famines and cold winters and stuff like that. That's the idea.
Yeah, so this is more of a species level argument. But yeah, so species with big brains that didn't need them would have to spend more time foraging or get better, higher quality food because of their big brains. And if that's not happening, it's not worth having.
I guess you could also imagine a population, right of a single species with smaller brains and bigger brains, And if the bigger brains aren't providing a benefit and they are providing a cost, then those big brain folks among us are not going to survive. There is a population level argument there also, right.
Yeah, there's a population level argument. There's often more variables at play when you start thinking about a specific species. So, for example, when human brains, if they were to get too big, you would start to have trouble getting those giant heads through the birth canal. And so there's limits on how big brains can be. And in general, there's not a ton of variability between the sizes of brains of adults. And now we can get into this whole different debate about is it really about how big the brain is? So like blue whales have much bigger brains than we do, but they haven't created rockets to get them out of space. Maybe that's because it's just too expensive to send a giant blue whale to space. But yeah, so trying to figure out exactly what feature of the brain we should measure is difficult. But we know that brains are expensive energetically, right, And.
I was actually reading a study about the size of the human brain that suggested that if you packed in the neurons more densely, you would add more noise. So making the neurons smaller and denser wouldn't actually improve your cognition because you'd be ending up adding noise. And so like, human brains are sort of at this sweet spot for how much you can squeeze them down to get cognition.
I think maybe one of these days we should have a whole separate episode on exactly how you should measure brains to correlate it with intelligence, because I read a paper that was arguing that actually, the reason we're so great is because we have denser neurons, and that it's not brain size, it's neuron density that really unlocks intelligence. I think in general, the field has not figured out exactly what we need to be measuring.
That's such a nice way of saying that these folks don't know what they're doing. Well, you gotta start is immature, Yes, well.
Yes, brains are complicated man, Yes they are.
No, you're totally right in great respect to folks who are studying the brain, because obviously it's important. And just because we don't understand everything doesn't mean that early studies are not valuable. They're the ones that lay the foundation for future progress. Yes, absolutely, and so we shouldn't mock them. We're grateful for their pioneering work.
Yes, I studied a brain infecting parasite of fish and I started getting into neuroanatomy and neurochemistry and I was like, no, I'm sticking with parasitology. Brains are complicated, so anyway, but here we're jumping in anyway.
I think also Tom's question has this fascinating flavor to it, which is like, you can make the evolutionary argument, and I think you're going to get into this later for why intelligence might be beneficial, right, it might even overcome the expense of the brain. But it's hard to understand why evolution would give us a brain that's capable of doing things that you didn't need to survive on the savannah, Right, You didn't need to be able to think about eleven dimensional mathematics and build rockets and all sorts of other easy stuff in order to survive evolutionarily. So why is it that evolution provided this tool which has this crazy capability clearly outstripping our needs.
Yeah, well, you could ask a similar question like why do peacocks have such big, showy tales? And I think that you know, natural selection doesn't just select for things that help us run faster to catch our food or help us garden more efficiently. It also selects for traits that make us more attractive mates in one way or another. So sometimes it makes you know, you bigger and more muscly if that's what the females want. But you know, there's also variability in what females of a species want, And some of us want super smart partners, our partners with musical abilities. And I think humans are kind of weird in this respect, that we really are interested in intellectual characteristics in addition to just physical characteristics. And I don't know exactly how that played into our evolution and made us unique. But you know, if you can do nine dimensional math, there's got to be a group of people who are into that.
Since both of us are married to nerds, I think we may be an unrepresentative subset of humanity. But I totally agree with you. Big brains are hot.
Yes, it's super hot, way more hot than muscles and being in good shape, I think. But could be biased. Okay, So the question was essentially about how do we get humans in particular, and the answer is, we don't know about how you get humans in particular, but we can get some hints by looking at other kinds of animals and trying to figure out what things selected for intelligence in other animals, and that might give us some insights into like maybe you know, we maxed out a particular you know, trait, or there was a particularly strong selective pressure for us. So we're going to start this conversation by talking about how we define intelligence outside of the ability to build rockets, and then some difficulties with measuring it, and towards the end of the episode, when we're answering other questions from other listeners, we'll talk about some of the leading hypotheses. So we're going to get to.
Them, all right. I love when we start a hard conversation with let's define what we're talking about, because it makes me feel all philosophical and nerdy. But also it's really important. If somebody doesn't do that, then I feel like they're going to be sloppy with their arguments because they're not being precise with their words.
Well, and I should say that while I was researching this topic, I came across a lot of different definitions, and I decided to try to go with something a little bit more general that feels pretty good to all of us. So here's what I came up with. It's just the ability to solve lots of different kinds of problems, because that's what they all seemed to narrow down to. But what do you think how would you define intelligence?
I definitely think the ability to solve problems is a component of it. It feels to me like also there should be a learning aspect, right, discovering patterns generalizing from them, you know, in machine learning, that's a big factor. We want to develop networks that are not just capable of solving the problems we've taught them, but solving a general class of problems, including examples they haven't seen before, bringing together ideas, coming up with bigger picture solutions. So something about generalizing from the examples that you've learned feels to me like an important part of intelligence.
Yeah, and I think that having the ability to solve lots of different kinds of problems does, to some extent imply the ability to learn, Okay, yeah, or at least to experiment with your environment to try new things, which I think is like learning. So I think we're pretty much on the same page. What do you think.
I think that's a good working definition. Okay, So then how do we measure this? Are we like giving tests to cats and dogs to see can you do eleven dimensional string theory?
We're not asking them about eleven dimensional string theory. We will talk about some experiments that we do, but first I wanted to tell a couple of stories about how we've thought we were measuring something but it turns out we're measuring something different. Just to highlight how difficult it is.
Here comes wet Blanket Kelly.
Come on, of course, we were going to get to wet Blanka Kelly. Okay, So clever Hans is horse in Germany at the end of the nineteenth century, and this horse became super famous because you could ask him questions about addition, subtraction, multiplication, division, including questions that involved fractions wow, and he would stomp out answers, so he would like stomp and then when he was done answering the question, so for the right numbers, like if the answer was five, he'd stop five times and then he'd sort of do like a little circle thing with his hoof to be like okay, I'm done.
Wow.
And then you could also ask Clever Hans questions like what is that woman holding in her hand? And using an alphabet that was on a board, each letter was separated into columns and rows, he could clamp out what letters he wanted to say, you know, umbrella or hot dog or something like that.
That implies some ability to read, right, yeah.
Yeah, yeah right. Some experts came in and they were like, oh my gosh, we totally agree because we can do the trick with Clever Hans too. We can ask clever Hans the same question, it's not just his owner, and he can answer it. So they decided that Clever Hans had the intelligence that was equivalent to about a thirteen year old child. But then another set of experimenters came in and they started walling clever Hans off from the room where the questioner was asking.
Oh, yeah, that's right.
It turns out that clever Hans could only answer questions correctly if the experimenter knew the answer ahead of time, and if Hans could see the experimenter.
Oh, man, this is just like those experiments with the wiki boards, right, uh right.
Like something else is sort of happening behind the scenes that's unintended. So it turned out clever Hans isn't smart in terms of the ability to do like division, but clever Hans was very smart at reading human body language. So even if you put a new person in that clever Hans had never encountered before, Clever Hans could tell that they were like holding their breath until he got to like the right number of stomps, and that then something about their body would change and then he'd know, okay, that was it. And so clever Hans was actually just queuing it on body language.
Wow, So clever Hans could really read human emotion and like understand what humans wanted him to do and then would do it.
Yes, right. But this points out one of the first difficult things about studying animals is that sometimes it can be really hard to figure out what you're measuring or what it is that they're actually learning, and it's not always what you think that they're learning. So you have to be very careful about how you design experiments, and you need to keep in mind that animals sense the world in different ways. So you know, some animals echo locate, some can see polarized light, some explore their universe using electricity, and so you need to make sure that you're asking questions that make sense with their sensory systems.
And not just for animals, right, like humans. Also, it's very hard to measure intelligence among humans. A lot of these tests have cultural biases in them.
For example, yep, yeah, absolutely, this is just really hard stuff. And then how do you compare you know, intelligence and a pigeon where maybe the amazing thing is their ability to like orient and travel great distances in their great spatial memory. And then compare that to you know, like a really smart crow that can whittle ass stick so that it can get at bugs in a tree, or like, how do you compare intelligence between those two different organisms.
Right, it seems like it's obviously not a single number. It's a multi dimensional right, And anytime you try to boil something complex down to a single number, and you're going to lose a lot of nuance.
Yes you are. And I want to tell one more quick story about when we thought that we had taught animals something and we had taught them something else. So there's this thing called perceptual categories, where essentially you're trying to figure out if animals can categorize things in ways similar to how humans can. So people showed pigeons a bunch of different pictures of things, and they trained the pigeons to peck a key and get a reward whenever a person was in the image, and so they actually got pretty good at this. Over time. They would pay the images, even if it was an image they had never seen before, if there was a person in it. And eventually they were able to get these pigeons to pick out pictures with bodies of water, pictures with trees, pictures with fish. So it turns out they were actually really good at coming up with these categories if you trained them. And then we did it with capuchin monkeys and we trained them on a bunch of different photos of people, and they were doing pretty well. But the experimenters did something really clever. They looked at the mistakes the monkeys were making and tried to see if there was anything informative in those mistakes. And one mistake the monkeys made was they did not count as a picture of a human anything that was torso and higher. So like you know, you think of your school pictures from when you were a kid, and it's like your torso and higher. The monkeys did not think that was a person.
They're counting legs only or what.
They didn't know exactly what they were counting, but they hadn't generalized a person. There was like a very particular all has to be there, So they hadn't learned exactly the category we had in mind. And they counted as a person an image of a jackal that was carrying a dead flamingo. And the reason they ended up thinking that the monkeys were categorizing that as a person is because that image had read in it, and the only other images in the training set that had read were three of the pictures of people, and so maybe they hadn't actually learned what humans were, but they had learned something about the image set, and we have problems with this with AI training sets.
Also, Yeah, there's a famous example of trying to teach an AI to tell the difference between wolves and dogs, and it was doing really, really well, and then they discovered that the pictures of wolves have snow in the background, pictures of dogs don't. As it was like learning to tell the difference between grass and snow, which is not that hard.
Right, right, And this was an experiment that was designed by humans who apparently had tried to think this stuff through. It's just really hard. So now that we have a sense of how difficult it is to ask these kinds of questions, let's take a break and when we come back, we'll move on to the next question, which will bring us to some of the hypotheses for what selects for intelligence.
Okay, we're back, and we are tackling some very difficult but fascinating questions from listeners today about the nature of intelligence and YBS have not yet gone off planet, and we started with a really fun question from Tom about how you end up with rocket level intelligence, and Kelly shed some light on how hard it is to even define and measure intelligence and through a wet blanket. I'm basically the whole history of that field my day, and so slightly unusually, we're not going to give a complete and definite answer to Tom's question right now. We're going to keep digging into this by answering more questions from listeners and then hope at the end to come back and give you our best answer to all of your queries.
All right, So let's go ahead then and jump into question two from.
Mark, Hi, Daniel, and Kelly. My question has to do with evolution and predation. Do you think it's possible for complex intelligent life to evolve without predation? Or do we think that predation is necessary for beings with human level intelligence or higher intelligence to exist? If there are aliens capable of interstellar travel that have never known predation, I imagine they would find Earth to be a nightmare with billions of organisms being murdered and consumed by other organisms every day. Interested to know your thoughts.
Thanks, okay, wow, all right? So when I first listened to this question, I was confused because I hadn't heard this hypothesis that predation is important for producing intelligent life. Had you heard this idea before Daniel.
I hadn't thought about in terms of predation. I thought about in terms of like society and culture, that maybe an important component of intelligence is having a complex interaction between the individuals in the species more than just like solitary folks. So I'm not sure how that connects to predation or being preyed on, or preying on people, like how taking down a mammoth requires like ten to fifteen people. Is that the same sort of thing.
So that's the social intelligence hypothesis, which we're going to get to next. But so the idea behind this predation hypothesis is that you end up with an arms race between predators in prey. So what happens here, So you've got a predator that needs to be able to see the prey so that it can find it in a tree or something. You know, if it's hiding in a tree, it kind of blends in, and so that selects for them to have better vision or a better memory for the kinds of behaviors that their prey typically engages in. So, for example, if a certain kind of prey that's extra super delicious is only active at dusk and dawn, then maybe you focus your predation efforts at dusk and dawn, because you've remembered that that's when the prey that's super tasty is active. And on the other hand, the prey might remember that when I smell cat urine, that means that there's a cat in the area, and so anywhere I smell cat urine, I'm just not going to hang out anymore. And so you end up with this competition for sensory systems and the ability to sort of like think through risks and benefits that over time results in smarter and smarter brains.
So is the argument just that smarter predators are more successful and smarter prey and more successful that it's one element of success in this sort of predator versus prey environment.
Yep, exactly.
But there's lots of predator prey situations and a lot of times one or both of them are kind of dumb deer not that smart, for example, though they've been highly selected for because people like wolves been gobbling up deer for many years. Is this just one possible way evolution can go or is the argument that prey and predation always leads to intelligence.
Yeah. So, first I'll note that it wouldn't surprise me to find out that deer have gotten more stupid over time because there's not tons of hunters out there and we've killed most of their predators on this continent, so they are perhaps a little bit relieved from the pressure of this arms race, and maybe that explains their intelligence. But yeah, so I think to me, that's one of the issues with this hypothesis is that it's not as far as I can tell, really clearer about which sets of predators in prey or which kinds of predators should end up, you know, maxing out being super smart and which prey should end up being super smart. But it's sort of more of a like, well, this is why you end up with complex thought at all, and then it just sort of depends on how much complex thought you need, depending on what kinds of races you find yourself in and with what kinds of organisms.
Because it's not hard to think of other examples, you know, like spiders and flies, right, flies are very good evading spiders, but they're not using intelligence. They're just like have a crazy hair trigger and you can jump out of the way in a bil I.
Mean that's pretty impressive as well, Like you know, those crazy hair triggers could be because you know, you've had selection for hairs that are particularly sensitive to you know, spider webs, or maybe their visual systems are particularly good at seeing the way light reflects off of a spider web with some dew on it. But yes, I don't think of flies as being particularly brilliant, although they outsmart me when I try to smack them, so maybe they're smarter than I give them credit for.
They're definitely amazing biological engineering. I don't know if it counts as intelligence, but now we're back into that morass of what is smart anyway. But I wouldn't put flies near the top of the list.
I haven't read a lot of papers where flies were like solving complex problems. Although I do think that they keep track of their social structures because they fight with each other, and I think who they fight with depends on you know, who they fought with in the past. So maybe there's a lot going on there that we can't see.
All right, But you must have some fun examples of predator and prey who have developed some clever intelligence.
I am particularly excited about chimps and New Caledonian crows who have managed to like pull stems off of trees and in some cases even like remove leaves and stuff to make particularly good tools for going inside of like trees, so that you can get bugs that are inside.
That's tool use. That's clever. Yeah.
Yeah.
And you'll find stories about crows who will sometimes like if they have a metal implement, they'll bend it so that they can sort of hook something out. There have been stories of crows that are able to like drop rocks into containers of water so that the water can come up high enough so that they can drink it. Oh wow, Like they do some pretty incredible things. Thinking about prey, there are octopus that do things like use halves of coconut shells and instead of using them like in Monty Python to make the sound of a horse galloping. No, I know, I don't understand, they pick up the coconuts shells, clean them out, get inside of them, and then carry them with them from place to place so that they've got a shelter to hide from anything that might want to harass or try to eat them. Okay, so there are some amazing examples of animals that show a lot of intelligence to either avoid being eaten or get their food.
Those are both definitely smarter than flies.
Well, but again, you know you're biased by what sounds important to you and what you can understand. Well, but yeah, I'll give you that. I hate flies. Diptorids are the worst. My daughter knows I hate diptorans.
What are diptorids?
They're like flies? And mosquitoes.
Oh god, mosquitos absolutely the worst. If I could delete mosquitos from the universe, I totally would do it. I mostly love living creatures, and I appreciate that everything contributes to the web of life. But mosquitoes, man, just delete those.
I know you are telling us in another episode recently that you guys got some Chinese mosquitos that are now all over the place and that you really hate them, and I feel for you.
Nothing against the Chinese, nothing, no, no, of.
Course, of course, yep, nope. Didn't mean to apply that. But so another part of Mark's question was would aliens find our planet appalling because of all of the killings. So, if predation is important for intelligence, and predation is like all over the place, could you end up with an intelligent alien species where there wasn't any predation? Is there some other selection pressure that produces intelligent aliens and what would aliens think of all of the killing? And you know, I don't know, it might be appalling. There's an interesting book called The Sparrow by Mary Doria Russell, and I do not recommend this book to children. Maybe read the Wikipedia summary before you read it. It covers some intense topics, but it's an interesting look at how humans feel when they go to an alien civilization and see how they deal with their predator prey relationships. But would you tell us about Eric Kirschenbaum's book.
Yeah. He's a biologist at Cambridge and he wrote this book called The Zoologist Guide to the Galaxy. What Animals on Earth reveal about aliens and ourselves. And I'll be honest, when I first saw this book, I thought, oh no, he scooped me because I was at the same time working on a book about what we can learn about aliens from examples here on Earth. But I was more focused on the side of it. And his book is really fascinating. It's essentially looking at examples of evolution on Earth and trying to draw conclusions about what might be universal and what might be local and unique to Earth. It's, of course impossible to know for sure, but you know, when you see things pop up over and over again, you can argue that they might be more common. And when you see something that only happened once on Earth, you can argue that maybe it's rare and therefore might not be everywhere in the universe. And something he talked a lot about was predation.
And you provided me with a quote where he even says no ecosystem can exist for long without someone trying to take a bite out of somebody else.
Yeah, exactly. He thinks it's essentially inevitable because you'll develop mobility, and then you'll start to consume, and then you'll start to consume other folks, and then other folks will try to get away from you. And so when you get big, you get noisy, and people develop ears and then they use those to hunt, and so he thinks predation is totally inevitable. Directly like, do you think aliens eat each other?
And he was like, oh, yeah, absolutely, okay, So at least that argues that if aliens visit Earth, they shouldn't find us too apart, although maybe they'd be shocked that we eat lobsters because gross.
Lobsters are like just huge ocean conchroaches. I don't get it, Like they look really gross to me.
Oh yeah, I'll pass. Sorry, I'm not into it. So to be honest, when I was researching hypotheses for why intelligence pops up from time to time, I didn't come across this predation hypothesis often. The hypothesis that I came across the most often is what's called the social intelligence hypothesis. This is what Daniel was talking about earlier, which is that group living selects for intelligence, and you need group living to do things like track members of a group. So remember, like, you know, when I was cooperating with Beth, you know, I pulled some ticks off her back, and the next day she pulled some ticks off my back. So that's great, I'll keep working with her. But I pulled some ticks off Frank's back, and that jerk never returned to the favor. So I'm not going to work again with Frank. And so it helps you like keep track of individuals in your group and how you should react with each of them differently.
Essentially, politics is complicated and it takes real intelligence, and in a society, politics are important for survival. You have to build coalitions, you have to worry about your enemies, you have to worry about being betrayed by your allies. It's complicated stuff.
Well, and you need to communicate with each other so that if you're you know, a bee, for example, you can waggle and tell everyone where the good food source is. Or you need to if your wolves coordinate so you can take down the moose so that you can feed everyone. So social behavior requires a lot of intelligence to work out.
Have you ever read the books about the Wolves of Yellowstone?
Oh? Have you?
Yeah, there's a fascinating series of books written by a guy who spent like forty years getting up at like three in the morning and just watching the wolves and each of a number, and he just got to know them all and wrote these books about their politics. And it's like a soap opera. You know, betrayals and arguments and you know, love affairs and all sorts of crazy stuff and wolve's going off to start their own packs and then coming back and fighting their parents and like it's dramatic stuff, and it leaves you with this sense of like, wow, this is a society. You know, these are intelligent creatures and they have all the same kind of politics that we do. It really is a soap opera. It's fascinating reading.
Robert Sipolski wrote a book about baboons called a Primates Memoir, which is sort of the same. It's really becomes clear how they're a society that has a lot of similarities to how humans work. And also he's a fantastic writer. I really enjoyed that memoir.
So I really recommend these books there by Rick McIntyre, one of them has called, for example, the Rise of Wolf eight. They're fantastic books. Really couldn't recommend them higher anyway, Go ahead, tell us about other intelligent critters.
Yeah. So in the nineteen nineties it was observed that there was this positive correlation between neo coortec side. So this is like the outer part of our brain that's close to our skull, and it's thought to be sort of like a more recent mammalian thing. And so monkeys and apes that had bigger neo cortexes were also thought to be smarter. And this part of the brain is used for things like language and sensory perception.
Can I stop you right there and be a little skeptical. Anytimes somebody says something like that like this part of the brain is used for XYZ, I'm like, we don't understand the brain. Isn't this some like correlational study using fMRI And it's like, well, there's more blood flow here when we show them this picture of a baboon and so therefore, right, it's all pretty fuzzy. I feel like this should be a huge asterisk anytime somebody says this part of the brain does.
X OMG, yes, yeah, no, I totally agree with you, and so we'll move this point up a little bit. One of the issues with this field is that to try to support the hypothesis, they'll do things like look at relative brain size and correlate that with things that are related to social things like if you are a species that tends to live in groups of five rather than you know, by yourself, they'll look to see, do you have a bigger brain if you live in groups of five, or if you're a species that lives in a group of just one. Does that make sense? And so there's a lot of these correlations, but there's a lot of argument about what you should be measuring in a brain to begin with, like, what is the relevant part of the brain you should be measuring. Is it the whole brain, is it the neocortex? Is it actually the density of neurons and a very particular part of the brain that matters. And additionally, you know, there are animals that can do similarly smart tasks that have very different kinds of brains. You know, how do you compare, for example, a primate brain and a bird brain. And so one of the big critiques in this field is that they do rely a lot on different measures of brains that have not necessarily been locked in as the correct thing to be measuring when you're interested in intelligence.
Right, And we mentioned these as critiques of the field not because we think these folks don't know what they're doing. Yeah, they're following a glorious tradition in science, which is like tackling and possibly hard question by doing the only things they know how to do. And often this leads to breakthroughs you didn't expect. It's better than just sitting on the couch and saying, well, it's impossible, let's not do it. But another glorious tradition in science is being open about the critiques of what we really do know and what we don't know, and being careful about drawing too broad a conclusion.
Yeah, exactly. There have been a lot of correlations where they have found that complicated social behaviors in insects and birds and mammals are correlated with either bigger brains or bigger brain parts. And that's at least suggestive. And again, it's really hard to compare between two different species. What is the right measurement for how intelligent they are? How do you rank them? You know, as you're sort of stumbling around in a dark room with no light on, you've got to start somewhere. And I feel like they have made some exciting progress and they're having these conversations about what is the right thing to be measuring, and you know, where do we go from here? And we found something tantalizing here, how do we follow up and get like a better answer based on this sort of tantalizing initial result. That's pretty much where we are right now. There's this interesting correlation, but we're still trying to figure out what to measure and how to measure it.
So when you say correlation, you're saying there's a correlation between brain size and like social activity, and that suggests that bigger brains are smarter and social activities connected to being smarter.
Yeah, that if you've got a bigger brain, you are more able to, for example, live in a bigger social group where you presumably have more you know, sort of peers or conspecifics that you need to keep track of so that you can remember their prior behaviors and you can tell the difference between them. And so more complicated social systems tend to be correlated with bigger brains relative to body size or bigger brain parts. Sometimes this falls apart. For example, little owls, which is Athena noctua. It's a species of owl that is super cute. They are not social like at all, but they got real big four brains, and so it's kind of surprise that they're like, not super social, but they got big old breaks. Why we don't know.
Maybe they're sitting there thinking about eleven dimensional string theory and maybe they know the answer.
Oh my god, we have to learn to talk to the little owls.
Tell me, little owl what is the nature of the universe?
Oh?
That should be a poem like that sounds like the kind of poem you sing to a kid when they're going to bed.
All right, let's write that children's book.
All right. Okay, So now we're going to take a break, and when we get back, we're going to talk about one of the other hypotheses for the evolution of intelligence as we answer our third listener question.
Okay, we are back, and we're talking about smartness across the animal and alien kingdom? Is intelligence inevitable? What can we learn from life on Earth and the patterns of intelligence or deer and fly like dumbness on Earth? Is there something we can tell about why humans ended up so dang smart?
We as humans have long looked to the stars with wonder and all trying to figure out exactly what the universe is, what is it made of, what is our place in it? And ultimately, I guess to try to answer the age old question are we alone in the universe? So if one of our Mars rovers or Europa Clipper found even microbial signs of life out there, it would of course be a game changer, a seismic event, to be sure. And while it would be scientifically exciting, I think it could also be somewhat disappointing because when most of us look to the stars in hopes of finding signs of life, I think we envision not just a bacterial colony, but an actual, functioning civilization. So my question to you is this, as you look at life here on Earth, is there any indication at all that intelligence is inevitable? I mean, given enough time for evolution to do its thing, do you believe sentient beings would be the ultimate result? And to put a finer point on that, imagine if the asteroids that wiped out the dinosaurs had narrowly missed the Earth and that extinction event never occurred. Let's say mammals remained as nothing more than small, furry, little rodent like creatures and did not lead to the rise of the human species. Under those circumstances, do you have any reason to believe that there might be an intelligent civilization developed by reptilian creatures instead of warm blooded things like us. Do you think dinosaurs could be running the show these days?
Anyway?
Thank you for your consideration in answering this, and I look forward to hearing what you say. Love the show, Keep up the good work.
So Howard wanted to know if intelligence is inevitable and man I don't know the answer, and it probably depends on what the bar is for intelligence. But if you're asking about like human level intelligence, there's over two million described species on the planet, but only one human, and so apparently you can have a lot of organisms without getting us, you know, rocket level smart species. You only get that once out of two million. So what do you think Daniel would t Rex have been coming up with Shakespearean style pros if that asteroid mister Earth?
Well, first, I want to quibble with your claim that there's only one intelligent species. Okay, right, I think that's a little bit definitional. Like we think, probably fifty thousand years ago, there were multiple intelligent species. We just like killed, raped, or ate the other ones, right, And so in some sense, and you get smart enough, you're likely, I think, to just kill off all the other intelligent competition un till it becomes part of your in group. So you might inevitably just get to one. But it seems like the evidence suggests that there were multiple strands at least of human life intelligence on Earth. Weren't there?
So usually when a listener asked the question, they mean, like humans like as smart as us, you know, creating rockets nine dimensional math. I don't know that even our ancestors were that smart, you know, one hundred thousand years ago, and so I'm not quite sure that there was you know, songs were being sung by other species of humans. We might never know, but you're right, they probably were very smart relatively relative to other organisms on the planet.
Yeah, you're right that we don't know biologically. Do they really have the same capacity and Neanderthals, for example, or other variations. It's hard to know. And maybe they had a different kind of smartness, right, maybe they would be like, hey, eleven dimension string theory, that's the wrong way to go, man, you should be doing loop quantum gravity.
That's right, that's right.
But yeah, the really deep question is like, is intelligence inevitable in some creature? Are you likely to have it no matter what happens? If the afteroid hadn't hit or something else has gone different? On Earth, would you have superintelligent spiders or whales dominating the planet, or reptiles or something? And boy, I wish I knew the answer that, because that would tell us a lot about the nature of intelligence out there in the universe. Right, whether it's likely when we land on alien planets to just find a bunch of fun. Guy or something's going to be smart on those planets. And I think the answer that we really need a better understanding of how intelligence arose on Earth. And as you could tell from this whole episode, we don't know the answer to that either.
That's true. And you mentioned super intelligent spiders. Have you read the Children of Time series?
Of course I have, Yes, I love that book. Yeah, fantastic. We had Adrian Tchaikowsky on the Daniel and Jorge podcast, really fun conversations. You guys should check that out.
Awesome. So, as you've pointed out, the other theories are not exactly ironclad that we've talked about yet. There is one additional hypothesis for why you get intelligence that we haven't talked about yet that I saved for now because it's possibly the one that's most relevant to space. It's a bit of a stretch, but you know, I try to have an answer for every question, no matter how confused I am, So all right, here's my best shot. So this hypothesis is called the cognitive buffer hypothesis, and the idea is that how variable your environment is determines whether or not you need to be intelligent to survive in it. So maybe more variable planets would be more likely to produce intelligent aliens. But so let's dig in for a second and revisit that idea at the end. So one of the ideas is that seasonality is important. So if you live in an area where sometimes it's really hot and sometimes it's really cold, maybe you need to be smart to survive that transition between temperatures. So, for example, migratory birds have two pretty smart solutions to this problem. Some of them migrate and have amazing long term spatial memory relative to non migratory ones, so they essentially figure out how to leave when it gets bad and then how to come back later, and that requires some incredible brain abilities. And then there are other birds that don't leave, but they have amazing memories for where they've cached food, so even when food is rare, they've hidden it when times are good, and they remember where they can go to find it when times are bad. And so the idea here is that living in a super variable environment requires you to become intelligen so that you can survive. There was a study looking at twelve hundred bird species that found that you get bigger brains and birds that live in environments that are more variable, So suggesting that if things change more, you got to be smarter to make it. What do you think, Daniel, Do you buy it?
It makes some sense. It connects to the idea we were talking about earlier that intelligence is about generalization, like being able to solve new problems you hadn't seen before. So if your environment is changing around you, ice ages are ending, climate is changing something, you can't just rely on the techniques handed down to you by ancestors. You have to come up with new ideas to solve new problems, and that requires intelligence. So it makes sense to me that a climate with a lot of variation, or an environment with a lot of variability to it would require more intelligence in order to survive. On the other hand, I don't know that. I consider like geese that's smart. I mean, yes, they can do something amazing, which is like navigate the planet with their magnetic sense in their eyeballs. It's incredible. I couldn't do that. But I don't know if that makes them smart. They seem like hyper optimized to this one situation, like if for example, the planet change the magnetic field flipped or where they need to migrate to changed. Do you think geese would be able to adapt to that situation?
So, the last time I was reading about birds and their ability to sense the magnetic fields, my understanding is that we don't actually understand that very well, and that a lot of animals that we suspect rely on magnetic fields also have other memory cues that they rely on to get to where they're going.
Did you read that study about how whales might be looking at the stars and navigating by the stars. Oh amazing, Oh my god.
Okay, we should talk about that in a future show because that's amazing. I'd love to read that.
Yeah.
Yeah, I guess that goes back to the question how do you measure intelligence? And how do you make sure that you're not measuring intelligence in a too human centric way? Or maybe it doesn't matter because maybe if you're specifically interested in how did you get human intelligence? Then maybe focusing on human intelligence is fine. But I get lost, like going to the grocery store sometimes, Like I use my GPS in the town that I've been living in for half a decade all the time.
And so GPS your goose positioning system.
So I'm impressed in these long distance migrants no matter how they do it, because I would get lost. I'd be in a lake.
Again the same way, like flies are impressive. They're very responsive. They're faster off the starting block than I am, or probably seen bolt is. But I don't know that. I call it smart and so, but maybe you're right, maybe I'm being too humanistic there. I'm looking for the kind of intelligence that I know the same way like I see in my dog, a lot of the kind of intelligence I see in people. And that's what impresses me. Sea patterns and respond to them and understand the world around him and adapt to it.
Yeah, and appear to be able to read like the emotions of people around them. Yeah, agreed. You've got this seasonality components, which is about like you know, escaping extreme temperatures and stuff. Another component of this idea is resource availability. So, for example, if you are a monkey species that eats fruits, fruits kind of ripen at different times, so they're available sometimes not at other times. You need to remember where the fruit trees are. And so there's some evidence that monkeys that rely on fruit are smarter than monkeys that can eat leaves because leaves are just always available, they're easy to find, they're just much more reliable. So the idea is that if seasons are changing your environment, or resources that you need, or sort of popping in and out of existence, either of those things are important for intelligence. But you know, when you read about any of these hypotheses, like the recent papers that I was reading, everybody's got like their favorite hypothesis, point out limitations of the other hypothesis, and at the end of the day, it could be some combination of things. You know, it could be if you're in a hyper variable environment and you've got a big social group, that's when you get the super smart individuals. Or maybe it's you know, the three things we've talked about today, those are all important, plus a fourth thing that nobody's thought about yet, and so at the end of the day, we don't really have the answer.
So what I like to think about sometimes is like fantasy data, Like if you had infinite resources and you've asked me these kind of questions before you could go all the way around the galaxy, whatever, is there a way we could answer this question someone definitively with infinite scientific powers you know, do you think actually seeing aliens and surveying intelligence across the galaxy would answer this question or or did just make it murky again?
Wouldn't surprise me that on a different planet there could be some different thing that selects for intelligence relative to what we find here on Earth. You'd think that if you could find enough alien civilizations that had enough like equivalents of New Caledonian crows and Homo sapiens, and you know, enough different kinds of intelligence and enough variability and intelligence, you'd be able to find some patterns. But in terms of what you could do here on Earth, I think we're doing what you can do here on Earth. Like I think we're doing the best we can right now.
No, I think the alien question is the fascinating one, and I think a lot of people feel like, of course you do. If we could visit those planets and see those then we would know, and you know, we'd get some answers, like if we saw there's alien life, we could be like, Okay, very clearly life is not as rare, but for intelligence, it's so much harder to define that unless we find alien life and it's intelligent and exactly the same way we are, which would tell us like, Okay, this kind of intelligence is weirdly inevitable. That instead we're going to find like a huge variety of different kinds of intelligences and we're going to get stuck in the same question, just now on a bigger scale. And it might be this question doesn't really have an answer.
Yeah, I mean it could be that there's no one answer. I do feel like if you had thirty planets that intelligence arose on all of them, you'd probably be able to say, like, Okay, in every case where there's seasons, you find some animals that are intelligent in this way. Maybe it's like they're better at remembering where the good food was or something. I imagine that we'd find some common threads. But would we ever answer all of our questions. No, probably not. Probably we'd get a lot more questions from those twenty or thirty planets, But that would be exciting too.
I mean, we can't even agree on this podcast about whether flies are intelligent. So I feel like what we're really asking is when we find aliens, are they going to have culture the way we have? Are they going to develop technology? Are they going to be scientific? Are they going to be exploring the universe? Are they going to be like us? So in the end, I think, really what these questions, deep down or asking is is our experience universe. So so I think it really is a human like thing. We could find aliens that are really super duper smart, but so different from us that we don't call it intelligence. We call it something else, schmid intelligence or something. I think, really this is probing about human intelligence.
Yeah, So first I want to reiterate that I do feel like you should be in charge of naming new things in just about any fields shima in front of it, and I think that's great. Actually my first blog was Fungilius schmundolous because I think schma is a great thing to end in front of other words. But you know, we didn't even talk about all of the hypotheses today. So you mentioned culture. There's a cultural intelligence hypothesis that focuses in particular on learning and like learning in a cultural context and how that might be really important for things like humans, And so I agree with what you said. There's even more hypotheses we didn't get a chance to talk about today. So let's take a step back and see if we've answered all of the questions that we were asked today. And so, you know, Tom wanted to know what makes rocket level intelligence and I threw up my arms and trucks, I don't know. But Tom wanted to know if there's things that select for intelligence. And we've talked about a couple things that we think maybe select for intelligence. Yeah, and he pointed out that intelligence might yet be unlucky for us, and you know, maybe we will all blow up because of our nuclear weapons. I hope not.
I don't know why I'm laughing at that.
Yeah, well, sometimes you laugh or you cry. Laughing is better. And then we addressed Mark's question about whether or not predation is necessary. Some people think it's important, but you know, we don't know if it's the only thing. Then we looked at Howard's question about whether or not intelligence is inevitable, and I yet again threw up my arms and shrugs. But you know, we had fun imagining it.
And I think that these are really fascinating questions. I love the folks ask them, even if we don't have answers. I think it's exciting to think about what efforts people are making and tackling these really big, really deep questions, because you know, those first steps are the hardest ones. Like when you look back what the Greeks did or what ancient civilizations have done to take the first steps towards science, they seem obvious in hindsight maybe, but it's difficult to take those first steps when you're up against the abyss of our ignorance about these deep questions.
Yeah, and at the end of the day, I think it's amazing that there is a species on our planet that's asking these questions and are trying to buddle through. And you know, I, when I looked at the neuroanatomy textbook, threw up my hands and said, I'm studying something else. Thank goodness. There are people who are like, I'm going to spend my whole life banging my head against this problem and make a little bit a headway and move us all ahead. And so I lately feel like there's a lot of reasons to be down on our species. But it is pretty cool that we do this kind of stuff, and I find the science that we do super inspirational.
Yes, although I think we can agree that the smartest people on the planet are the folks who listen to this podcast.
Right, agreed, and that is the perfect note to end on.
And so before we sign off, we were curious did we answer Tom and Mark and Howard's questions. We sent this to them and hear what they had to say.
Thanks Daniel and Kelly for answering this question. You know, one of the reasons I love your podcast so much is because no matter how complete your answers are, you always offer a more beautiful question at can't. And I guess one of the reasons I was focused on rockets is because aliens were more likely to kind of discover alien technology than we are. Aliens first, and I imagine that rockets are pretty important in getting off planet. I'm not aware of any other way to do that, but yeah, I mean, I very satisfied with your discussion, and I look forward to finding out what this field is discovering about intelligence and different kinds of intelligences and what we might expect to find out there in the universe.
Thank you, Hi, Daniel Cally. Yes, you answered my question. And while I was hoping the answer would be that there could be some world out there where all the creatures hold hands or tentacles or whatever and sing Kumbaya and are cool to each other. It sounds like the real answer is wherever there's life, whether it's intelligent or not, something is gone, sooner or later get the idea to eat something else. So thanks for taking my question and thanks for the book suggestion. I will definitely check it out, and of course thanks for the wonderful show.
Thank you Daniel and Kelly. This is Howard and I want to thank you for taking on my question. I know it can be challenging when the question has no definitive answer, but I kind of knew that going in. But what I really appreciated was listening to your thought processes, how you break it down, how you would approach it, what hilarities are there that might apply.
To it, And that was invigorating. Thank you so much. I appreciate it. A quick non science announcement. May tenth, twenty twenty five is the Stamp Out Hunger Drive, organized in tandem with the US Postal Service. It's very easy to help fill up your local food banks. Just leave non perishable food at your mailbox and your carrier will collect it for you. That's all you have to do. Leave non perishable foods by your mailbox on May tenth, twenty twenty five to help stamp out hunger.
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