WEBVTT - Ep34 "What is intelligence?" 0:00:04.600 --> 0:00:08.559 What's it like to have a much lower IQ than 0:00:08.600 --> 0:00:11.880 you currently have or to have a much higher IQ? 0:00:15.520 --> 0:00:18.400 Welcome to the inner Cosmos with me David Eagleman. I'm 0:00:18.400 --> 0:00:21.599 a neuroscientist and an author at Stanford and in these 0:00:21.720 --> 0:00:26.599 episodes we sail deeply into our three pound universe to 0:00:26.720 --> 0:00:30.920 understand why and how our lives look the way they do. 0:00:37.520 --> 0:00:43.160 Today's episode is about intelligence. What is it What would 0:00:43.240 --> 0:00:46.960 it be like to have the intelligence of a mosquito, 0:00:47.640 --> 0:00:51.400 or a horse or a squirrel. What would it be 0:00:51.560 --> 0:00:56.640 like to presumably understand only very basic things right around you, 0:00:57.400 --> 0:01:01.760 not doing sophisticated simulation of the future like we do 0:01:01.880 --> 0:01:06.040 as humans. And what can we say about the present 0:01:06.200 --> 0:01:12.520 and future of intelligence that is artificial? Okay, so let's 0:01:12.520 --> 0:01:15.319 start with this question of what is it like to 0:01:15.440 --> 0:01:20.520 have a different level of intelligence? I see people post 0:01:20.600 --> 0:01:24.880 this question sometimes online on forums like Quora. Someone will write, 0:01:25.680 --> 0:01:29.240 I have an IQ of sixty eight, what is it 0:01:29.520 --> 0:01:34.000 like to have a higher IQ? Now? First of all, 0:01:34.040 --> 0:01:38.400 I think this is an amazing question because it acknowledges 0:01:38.480 --> 0:01:42.160 that not everyone is having the same experience on the inside, 0:01:42.520 --> 0:01:45.400 and so someone is taking the time to ask, what 0:01:45.440 --> 0:01:48.440 would it be like to have what is called a 0:01:48.640 --> 0:01:54.960 higher intelligence level. What's the experience of that? Now, the 0:01:55.040 --> 0:01:58.000 interesting thing in life is that we can't run a 0:01:58.120 --> 0:02:02.480 control experiment on our own experience of the world, and 0:02:02.520 --> 0:02:06.480 so whatever IQ you have, you sort of have just 0:02:06.560 --> 0:02:10.120 that one experience of reality. But to get at this, 0:02:10.560 --> 0:02:13.040 let's start by thinking about what it would be like 0:02:13.600 --> 0:02:17.400 to have a much lower IQ than you do now. 0:02:18.040 --> 0:02:19.880 One way to get at this is to ask the 0:02:19.960 --> 0:02:24.200 question of what would it be like to be a squirrel. 0:02:24.600 --> 0:02:27.080 I'm choosing a squirrel just because I was watching one 0:02:27.160 --> 0:02:30.800 in my backyard yesterday, and I'm watching him run along 0:02:30.840 --> 0:02:33.280 the top of the fence and climb up the tree 0:02:33.320 --> 0:02:35.959 trunk and find a little scrap of food and look 0:02:35.960 --> 0:02:41.800 around nervously. And a squirrel's cerebrum has about one hundred 0:02:41.880 --> 0:02:47.280 million neurons, while ours has about one hundred billion neurons, 0:02:47.480 --> 0:02:52.200 so a thousand times more. Now, size isn't everything, which 0:02:52.200 --> 0:02:55.960 we'll return to a little bit. Presumably the issue is 0:02:56.000 --> 0:03:01.040 the algorithm that's running. But we can watch the behavior 0:03:01.520 --> 0:03:04.079 of lots and lots of squirrels over lots of time, 0:03:04.720 --> 0:03:08.200 and it certainly doesn't seem like they're having the kind 0:03:08.240 --> 0:03:12.240 of capacity for thought that we are. So I was 0:03:12.320 --> 0:03:14.800 watching this squirrel, and I thought, what would it be 0:03:15.000 --> 0:03:18.800 like to be able to jump around from branch to branch, 0:03:18.919 --> 0:03:23.640 but have no hope, presumably of ever discovering that force 0:03:23.680 --> 0:03:28.280 equals masstimes acceleration, or for that matter, or not even 0:03:28.440 --> 0:03:31.920 ever being able to discover that e equals mc squared, 0:03:32.040 --> 0:03:35.320 or just basic things like how do you build a chair, 0:03:35.920 --> 0:03:39.000 or how do you think about the competition between Amazon 0:03:39.040 --> 0:03:43.640 and Netflix, or just the idea that the telephone lines 0:03:43.640 --> 0:03:47.120 they're running on top of are carrying megabytes of information 0:03:47.360 --> 0:03:50.720 flowing as zeros and ones as one member of our 0:03:50.760 --> 0:03:54.520 species communicates to another, or that more broadly, we have 0:03:54.880 --> 0:04:00.680 airwaves and fiber optics carrying a flow of zetabytes information 0:04:01.200 --> 0:04:05.760 in a massive ocean of data around us. For the squirrel, 0:04:06.240 --> 0:04:11.160 none of this exists. For the squirrel, none of this 0:04:11.960 --> 0:04:16.040 is comprehensible. It's thinking about its acorn and where it 0:04:16.400 --> 0:04:19.320 hid its last one, and it's thinking about safety and 0:04:19.360 --> 0:04:22.400 maybe about mating. As far as we know, or as 0:04:22.400 --> 0:04:25.400 far as we can tell, which of course has its limitations. 0:04:26.040 --> 0:04:30.480 The squirrel is not ruminating on a play it saw 0:04:30.560 --> 0:04:35.120 last night. By the squirrel equivalent of Shakespeare and what 0:04:35.160 --> 0:04:38.800 it means about the aspirations of a monarch and the 0:04:39.240 --> 0:04:44.360 cruelty inherent in the competition for power. It's not thinking 0:04:44.440 --> 0:04:47.440 about how to get to the moon or how to 0:04:47.480 --> 0:04:50.800 build the next vaccine. Now, it's not to say that 0:04:50.839 --> 0:04:55.159 there aren't specialized kinds of intelligence. Every move that the 0:04:55.200 --> 0:04:58.800 squirrel makes along the tree branch is very impressive. There 0:04:58.880 --> 0:05:01.440 is no way that I can could hope to stick 0:05:01.800 --> 0:05:04.520 landing after landing like that from the branch of one 0:05:04.600 --> 0:05:06.880 tree to the next to the next. But the squirrel 0:05:07.200 --> 0:05:11.560 is capable of doing that. But even though it performs 0:05:11.600 --> 0:05:15.760 this incredible ballet in the face of gravity, it's presumably 0:05:16.560 --> 0:05:18.880 never going to get to the point where it can 0:05:19.400 --> 0:05:24.159 characterize gravity in equation form to understand how it should 0:05:24.279 --> 0:05:26.960 move if it were on a different planet, or to 0:05:27.080 --> 0:05:31.400 conceptualize gravity as curvature in the fabric of space time. 0:05:32.279 --> 0:05:35.880 Although humans are capable of getting that in high school, 0:05:36.520 --> 0:05:41.880 presumably squirrels of any age would find the concept well 0:05:41.920 --> 0:05:45.400 beyond what their brains could even hope to have a 0:05:45.520 --> 0:05:49.160 flicker of. And when you look around the animal kingdom 0:05:49.200 --> 0:05:54.120 around us, we find lots of creatures presumably occupying very 0:05:54.160 --> 0:05:58.719 different levels of intelligence. So a bat has let's call it, 0:05:58.800 --> 0:06:01.680 ten million neurons, and again it's not the size but 0:06:01.720 --> 0:06:02.840 the structure that matters. 0:06:02.880 --> 0:06:07.520 But presumably they are not writing the equivalent of bat 0:06:07.600 --> 0:06:11.279 books or building a little bat Internet where they can 0:06:11.360 --> 0:06:15.960 capture for eternity everything that every generation of bats before 0:06:16.000 --> 0:06:17.280 them has learned. 0:06:18.240 --> 0:06:21.839 A fish has only about one hundred thousand neurons, a 0:06:21.839 --> 0:06:26.200 house cricket has fifty thousand neurons. A common fruitfly has 0:06:26.240 --> 0:06:30.440 only about two five hundred neurons in the equivalent to 0:06:30.560 --> 0:06:33.680 its brain. So if you were a fruit fly, you 0:06:34.000 --> 0:06:37.800 simply don't have the notion of seeing the moon in 0:06:37.839 --> 0:06:41.320 the sky and thinking, okay, that's an orbiting sphere, and 0:06:41.360 --> 0:06:44.640 I'm going to derive a plan with my fellow flies 0:06:44.760 --> 0:06:48.080 to get there by building new technologies that we can 0:06:48.160 --> 0:06:50.800 fit our little bodies inside of so that we can 0:06:50.880 --> 0:06:54.400 survive in low oxygen. And what if you're a mosquito, 0:06:54.480 --> 0:06:57.800 with your little mosquito brain, all you know is the 0:06:57.839 --> 0:07:02.000 mad attraction to certain odors which indicate a warm blood 0:07:02.040 --> 0:07:06.560 and animal, and the pleasure of slipping your proboscis in 0:07:06.680 --> 0:07:10.440 and satisfying your thirst with the warm liquid. You presumably 0:07:10.720 --> 0:07:13.840 don't even have the concept of blood, that it has 0:07:13.920 --> 0:07:18.040 plasma and cells that are specialized for grabbing oxygen, and 0:07:18.080 --> 0:07:21.240 all kinds of useful machinery for defending the host animal, 0:07:21.240 --> 0:07:23.680 and so on and so on. So I've thought about 0:07:23.720 --> 0:07:26.680 these issues for years, and I think there's a way 0:07:26.720 --> 0:07:29.800 to understand what it is like to be so limited. 0:07:30.280 --> 0:07:32.840 The way that the mosquito might look at the human, 0:07:33.240 --> 0:07:35.080 if it could even have a concept of a human, 0:07:35.520 --> 0:07:38.400 how might look at the human and think, oh, my gosh, 0:07:38.440 --> 0:07:41.520 I can't believe they understand all that stuff, and they 0:07:41.520 --> 0:07:44.640 do it all at once. And the reason we can 0:07:44.720 --> 0:07:48.560 understand what it's like to be limited is because we 0:07:48.600 --> 0:07:52.560 are up against problems all the time that we're just 0:07:52.680 --> 0:07:57.200 smart enough to recognize, but not yet smart enough to solve. 0:07:58.000 --> 0:08:02.440 Take the origin of life, this is a massively difficult problem. 0:08:02.760 --> 0:08:06.040 I worked with brilliant scientists like Sidney Brenner and Francis 0:08:06.120 --> 0:08:09.280 Krik at the Salt Innstitute, who worked on theories of 0:08:09.320 --> 0:08:12.280 the origin of life. And these were among the smartest 0:08:12.320 --> 0:08:16.360 biologists of the twentieth century. And even they were like 0:08:16.440 --> 0:08:20.800 little fruit flies when trying to tackle that problem. They 0:08:20.960 --> 0:08:25.120 constantly were aware of the enormous gaps in whatever story 0:08:25.160 --> 0:08:28.480 they were hoping to put together, because we just don't 0:08:28.520 --> 0:08:32.640 have much of any lasting data from the past three 0:08:32.679 --> 0:08:36.559 point eight billion years, and we're talking about how trillions 0:08:36.559 --> 0:08:39.040 of atoms might come together in just the right way 0:08:39.080 --> 0:08:43.240 over time to form things that can self replicate. It's 0:08:43.720 --> 0:08:46.440 the kind of problem that when you really start to 0:08:46.520 --> 0:08:49.760 reach your arms down into it, you realize that even 0:08:49.960 --> 0:08:53.720 very smart human brains just aren't equipped for a problem 0:08:53.760 --> 0:08:57.280 of that size. Or just take something like thinking about 0:08:57.320 --> 0:09:02.480 the cosmos with one hundred billion galaxies in it and 0:09:03.000 --> 0:09:07.840 one hundred billion stars inside each of those galaxies, and 0:09:08.000 --> 0:09:12.240 uncountable numbers of planets rotating around those stars, and then 0:09:12.679 --> 0:09:16.800 trying to picture or answer whether there is life elsewhere 0:09:16.800 --> 0:09:19.840 in the galaxy and what it would look like. It's 0:09:19.920 --> 0:09:23.640 clear that our human brains aren't so good at grocking 0:09:23.760 --> 0:09:26.960 numbers like that. Even though we can estimate the numbers 0:09:26.960 --> 0:09:29.960 and we can use words to talk about them, we're 0:09:29.960 --> 0:09:34.839 not really capable of understanding them. And it's the same 0:09:34.840 --> 0:09:37.640 thing when we study neuroscience. Of course, we've got in 0:09:37.679 --> 0:09:41.400 the ballpark of eighty six billion neurons and each one 0:09:41.440 --> 0:09:44.040 of those is connected to so many of its neighbors, 0:09:44.080 --> 0:09:47.840 about ten thousand, that if you took a cubic millimeter 0:09:48.000 --> 0:09:51.679 of brain tissue, there are more connections in there than 0:09:51.760 --> 0:09:54.880 there are stars in the Milky Way galaxy. This thing 0:09:54.960 --> 0:09:58.400 that we're facing on a daily basis this thing the 0:09:58.440 --> 0:10:02.640 brain that tens of thousands of people on the planet's study, 0:10:02.679 --> 0:10:06.320 this three pound organ that we have completely cornered. It 0:10:06.400 --> 0:10:10.920 is so vastly complex that there is no way for 0:10:11.040 --> 0:10:16.560 a human brain to understand itself. And in neuroscience we 0:10:16.640 --> 0:10:21.520 have foundational problems that we can't answer, like why something 0:10:21.880 --> 0:10:26.920 feels good? Take an orgasm? Why does an orgasm feel good? 0:10:27.200 --> 0:10:30.080 We can, of course tell the evolutionary story, which is 0:10:30.120 --> 0:10:33.680 that it benefits the species to reproduce, so it is 0:10:33.840 --> 0:10:37.360 advantageous for it to feel good. But the question from 0:10:37.400 --> 0:10:40.439 a neurobiology point of view is how do you build 0:10:40.480 --> 0:10:46.520 a network that feels anything. Take a big, impressive artificial 0:10:46.600 --> 0:10:50.479 neural network like GPT four. It can do incredibly impressive 0:10:50.559 --> 0:10:54.040 work by taking some prompt and written language and generating 0:10:54.120 --> 0:10:57.320 words that would statistically go with that prompt and so on. 0:10:57.400 --> 0:11:01.080 It's mind blowing how well it appears to do. But 0:11:01.160 --> 0:11:07.240 GPT four presumably can't feel pain or pleasure. There's nothing 0:11:07.280 --> 0:11:10.760 about one of its sentences that it generates that it 0:11:10.880 --> 0:11:15.760 appreciates as hilarious or tear jerking. It doesn't have any 0:11:16.120 --> 0:11:21.520 capacity to feel concerned about its survival or demise. When 0:11:21.520 --> 0:11:25.679 the programmers turn the computer off. It's just running numbers 0:11:26.200 --> 0:11:30.240 down a long, complex algorithmic network, and that's it. So 0:11:30.320 --> 0:11:34.840 how do we ever come to feel something? This is 0:11:34.880 --> 0:11:39.920 perhaps the central unsolved question in neuroscience. It's usually summarized 0:11:39.920 --> 0:11:45.840 as consciousness, and specifically the hard problem of consciousness, which 0:11:45.880 --> 0:11:49.720 is to say, why does all this signaling moving through 0:11:49.760 --> 0:11:54.240 networks of cells feel like something? How could you ever 0:11:54.360 --> 0:11:58.439 program a computer to feel pain or detect some wavelength 0:11:58.480 --> 0:12:03.320 of electromagnetic radiation and as purple, or to detect some 0:12:03.440 --> 0:12:10.560 wavelength of electromagnetic radiation and experience it as purpleness, or 0:12:10.600 --> 0:12:14.640 to enjoy the beauty of a sunset. These are totally 0:12:14.720 --> 0:12:19.720 unsolved questions in neuroscience, and presumably there are whole classes 0:12:19.840 --> 0:12:23.360 of problems that we are not even smart enough to 0:12:23.480 --> 0:12:28.800 realize our questions that we could be asking. So, despite 0:12:28.840 --> 0:12:34.480 the incredible pride filling progress of our species. Our ignorance 0:12:34.880 --> 0:12:40.120 vastly outstrips our knowledge, and that affords us just a 0:12:40.240 --> 0:12:44.960 little bit of insight into the limitations of our brains, 0:12:45.000 --> 0:12:48.400 the glass walls of our fish bowl, and lets us 0:12:48.679 --> 0:12:53.000 even very roughly imagine what it would be like to 0:12:53.160 --> 0:12:56.560 have the intelligence of a squirrel. And these are the 0:12:56.600 --> 0:12:58.679 things that I was thinking about when I wrote a 0:12:58.800 --> 0:13:02.840 fictional short story called Descentive Species in my book Some 0:13:03.520 --> 0:13:05.280 and so I'm going to read it here, and then 0:13:05.280 --> 0:13:10.400 I'll come back to the question of intelligence. In the afterlife, 0:13:10.960 --> 0:13:14.960 you are treated to a generous opportunity. You can choose 0:13:15.000 --> 0:13:16.960 whatever you would like to be in the next life. 0:13:17.320 --> 0:13:19.840 Would you like to be a member of the opposite sex, 0:13:20.400 --> 0:13:26.240 born into royalty, a philosopher with bottomless profundity, a soldier 0:13:26.400 --> 0:13:31.480 facing triumphant battles. But perhaps you've just returned here from 0:13:31.520 --> 0:13:36.199 a hard life. Perhaps you were tortured by the enormity 0:13:36.240 --> 0:13:40.640 of the decisions and responsibilities that surrounded you. And now 0:13:40.640 --> 0:13:45.680 there's only one thing you yearn for, simplicity that's permissible. 0:13:46.200 --> 0:13:49.920 So for the next round, you choose to be a horse. 0:13:50.920 --> 0:13:55.360 You covet the bliss of that simple life. Afternoons of 0:13:55.480 --> 0:13:59.920 grazing and grassy fields, the handsome angles of your skeleton 0:14:00.520 --> 0:14:04.000 and the prominence of your muscles. The peace of the 0:14:04.120 --> 0:14:09.320 slow flicking tail, or the steam rifling through your nostrils. 0:14:09.400 --> 0:14:15.280 As you lope across snow blanketed planes, you announce your decision. 0:14:16.280 --> 0:14:20.360 Incantations are muttered, a wand is waved, and your body 0:14:20.400 --> 0:14:26.840 begins to metamorphose into a horse. Your muscles start to bulge, 0:14:27.360 --> 0:14:30.600 A mat of strong hair erupts to cover you like 0:14:30.640 --> 0:14:35.320 a comfortable blanket in winter. The thickening and lengthening of 0:14:35.360 --> 0:14:39.160 your neck immediately feels normal as it comes about. Your 0:14:39.200 --> 0:14:44.280 carotid arteries grow in diameter, your fingers blend hoofward, your 0:14:44.360 --> 0:14:50.040 knees stiffen, your hips strengthen. And meanwhile, as your skull 0:14:50.320 --> 0:14:55.000 lengthens into its new shape, your brain races in its changes. 0:14:55.600 --> 0:15:00.680 Your cortex retreats as your cerebellum grows. The homuncular smelts 0:15:00.880 --> 0:15:07.120 man to horse neurons, redirect synapses, unplug and replug on 0:15:07.200 --> 0:15:12.800 their way to equestrian patterns, and your dream of understanding 0:15:12.880 --> 0:15:15.800 what it is like to be a horse gallops toward 0:15:15.880 --> 0:15:20.760 you from the distance. Your concern about human affairs begins 0:15:20.800 --> 0:15:25.480 to slip away, Your cynicism about human behavior melts, and 0:15:25.560 --> 0:15:29.160 even your human way of thinking begins to drift away 0:15:29.200 --> 0:15:34.280 from you. Suddenly, for just a moment, you are aware 0:15:34.520 --> 0:15:39.000 of the problem you overlooked. The more you become a horse, 0:15:39.720 --> 0:15:44.080 the more you forget the original wish. You forget what 0:15:44.160 --> 0:15:47.360 it was like to be a human, wondering what it 0:15:47.440 --> 0:15:51.520 was like to be a horse. This moment of lucidity 0:15:52.040 --> 0:15:56.200 does not last long, but it serves as the punishment 0:15:56.320 --> 0:16:02.840 for your sins. A Promethean entrails hecking moment, crouching half horse, 0:16:03.320 --> 0:16:07.520 half man with the knowledge that you cannot appreciate the 0:16:07.600 --> 0:16:12.840 destination without knowing the starting point. You cannot revel in 0:16:12.920 --> 0:16:18.400 the simplicity unless you remember the alternatives. And that's not 0:16:18.480 --> 0:16:21.960 the worst of your revelation. You realize that the next 0:16:22.000 --> 0:16:26.160 time you return here with your thick horse brain, you 0:16:26.200 --> 0:16:31.240 won't have the capacity to ask to become a human again. 0:16:31.920 --> 0:16:37.440 You won't understand what a human is. Your choice to 0:16:37.680 --> 0:16:43.080 slide down the intelligent sladder is irreversible, and just before 0:16:43.160 --> 0:16:49.080 you lose your final human faculties, you painfully ponder what 0:16:49.760 --> 0:16:55.600 magnificent extraterrestrial creature enthralled with the idea of finding a 0:16:55.720 --> 0:17:00.320 simpler life, chose in the last round to be come 0:17:01.040 --> 0:17:06.880 a human. So in the story, I try to give 0:17:06.920 --> 0:17:10.920 a way to think about the possibility that something could 0:17:11.000 --> 0:17:13.720 be much smarter than us, that we are not at 0:17:13.760 --> 0:17:16.480 the top of the latter but maybe somewhere in the middle, 0:17:16.880 --> 0:17:20.239 and that to some other creatures in the universe, we 0:17:20.320 --> 0:17:23.359 would appear to be like the squirrels are to us. 0:17:24.080 --> 0:17:27.640 It certainly could be that in this vast cosmos there 0:17:27.680 --> 0:17:31.560 are intelligences that are so much higher than ours that 0:17:31.600 --> 0:17:36.160 we lack even a good imagination or vocabulary to paint 0:17:36.200 --> 0:17:40.280 these creatures in the same way that presumably the squirrels 0:17:40.520 --> 0:17:44.120 would be unable to give a reasonable description of us 0:17:44.160 --> 0:17:48.720 and what we're up to. Maybe these extraterrestrials can understand 0:17:48.760 --> 0:17:51.679 the entirety of cosmic evolution by the time they're in 0:17:51.720 --> 0:17:55.280 second grade, and they can keep in mind the trillions 0:17:55.320 --> 0:17:59.600 of animal species on this planet and all the other planets, 0:17:59.840 --> 0:18:03.880 and keep track of all the interactions and therefore understand 0:18:04.040 --> 0:18:08.800 the biological history and future of a planet at depth. 0:18:09.640 --> 0:18:13.440 While we mostly just use the word evolution to capture 0:18:13.560 --> 0:18:18.760 something that we can't comprehend at a deep level. Now, 0:18:18.880 --> 0:18:21.879 let me put on the table that I'm completely uncompelled 0:18:21.960 --> 0:18:25.480 by the claims that there are UFOs, or nowadays they're 0:18:25.520 --> 0:18:29.480 called UAPs. But I have a very smart friend named 0:18:29.560 --> 0:18:32.040 Kevin who told me the other day that he has 0:18:32.119 --> 0:18:35.400 no problem believing that that's true. Now, I'm not defending 0:18:35.400 --> 0:18:38.720 his position, but his stance was simply that if you 0:18:38.880 --> 0:18:43.760 imagine the aliens are much smarter than we are, then 0:18:43.800 --> 0:18:48.040 the particulars of what we're looking for, some Morse code 0:18:48.080 --> 0:18:51.840 signal or some take me to your leader's sign, that's 0:18:51.880 --> 0:18:54.240 actually the wrong thing for us to be looking for. 0:18:54.760 --> 0:18:59.720 Because if we imagine some civilization that is, say, totally 0:18:59.760 --> 0:19:03.360 differ from us and three million years ahead of us, 0:19:03.960 --> 0:19:07.399 and they are to us as we are to the squirrels, 0:19:08.200 --> 0:19:12.399 it's certainly not difficult to imagine the possibility that we 0:19:12.520 --> 0:19:16.800 are simply not smart enough to construct a good model 0:19:16.800 --> 0:19:21.760 of them and therefore even recognize them. Now, you might 0:19:21.800 --> 0:19:24.720 assume that if they're much smarter than us, then they 0:19:24.720 --> 0:19:28.440 could dumb themselves down to communicate with us the way 0:19:28.480 --> 0:19:30.639 that we sort of know how to talk with a 0:19:30.760 --> 0:19:35.480 child at a child's level. But our ability to model 0:19:35.720 --> 0:19:39.600 lesser intelligences is still pretty terrible. I mean, you still 0:19:39.600 --> 0:19:41.800 have no idea how to go out in your yard 0:19:41.960 --> 0:19:46.560 and communicate with squirrels. Just try having a meaningful conversation. 0:19:46.920 --> 0:19:50.359 Good luck. We're so much smarter than a squirrel, but 0:19:50.400 --> 0:19:54.119 we have no idea how to plug into their neural networks. 0:19:54.720 --> 0:19:56.560 Or just go to a zoo and try to have 0:19:56.600 --> 0:20:01.080 a conversation with a panda bear and commune unicate to him. 0:20:01.520 --> 0:20:03.840 Take me to your leader, or do that with a 0:20:03.880 --> 0:20:06.000 camel or a dolphin. You get the point, which is 0:20:06.000 --> 0:20:10.520 that just because you are smarter doesn't necessitate that you 0:20:10.640 --> 0:20:14.080 know how to talk to these other animals. And this 0:20:14.160 --> 0:20:18.000 is the situation that we could hypothetically be in with 0:20:18.160 --> 0:20:22.920 extraterrestrial civilizations. That we are here even though we don't 0:20:23.000 --> 0:20:26.640 recognize that they are there, because we don't even have 0:20:26.720 --> 0:20:31.320 the capacity to imagine them, and they have no meaningful 0:20:31.359 --> 0:20:34.840 way to communicate with us, because our needs and desires 0:20:34.880 --> 0:20:38.960 are so different from what they can even understand. Now, 0:20:39.080 --> 0:20:43.760 this lack of communication across species or across planets is 0:20:43.800 --> 0:20:48.040 really brought into relief when we consider that intelligence is 0:20:48.080 --> 0:20:51.680 not one thing, but there are many different behaviors that 0:20:51.720 --> 0:20:56.800 we might put under the umbrella of intelligence. To this point. 0:20:56.880 --> 0:21:00.800 In nineteen seventy four, the philosopher Thomas Nagel wrote an 0:21:00.920 --> 0:21:05.000 essay called what is it Like to Be a Bat? 0:21:05.800 --> 0:21:09.399 Because fundamentally, being a bat is a pretty different experience 0:21:09.440 --> 0:21:12.200 than being a different human. If you are a blind 0:21:12.320 --> 0:21:15.919 echo locating bat, you emit chirps in the dark, and 0:21:15.960 --> 0:21:20.000 you receive back echoes of your chirps, and you translate 0:21:20.200 --> 0:21:24.119 those air compression waves into a three dimensional picture of 0:21:24.160 --> 0:21:26.680 what is in front of you. You make a mental 0:21:27.119 --> 0:21:30.760 map of your surroundings this way. So Nagel asked this 0:21:30.880 --> 0:21:33.280 question of what it's like to be a bat in 0:21:33.359 --> 0:21:37.080 the context of consciousness, as in, given that we have 0:21:37.200 --> 0:21:40.879 such a different sensory world, is there any way that 0:21:40.920 --> 0:21:44.159 we could understand what it would be like to be 0:21:44.240 --> 0:21:47.600 in such a different way of detecting and sensing the world. 0:21:48.000 --> 0:21:50.240 But this same question could be applied to what we're 0:21:50.280 --> 0:21:54.640 thinking about here, which is intelligence. Intelligence in the context 0:21:54.680 --> 0:21:58.080 of a bat allows the bat to navigate around and 0:21:58.200 --> 0:22:01.639 find food, and talk with other and adapt when the 0:22:01.680 --> 0:22:05.800 conditions change. But it's hard to directly compare it to 0:22:05.880 --> 0:22:10.760 human intelligence because they have traits and adaptations that are 0:22:10.880 --> 0:22:15.120 very sophisticated in their own way. Like I said, with echolocation, 0:22:15.200 --> 0:22:18.200 they're creating this three D map in their space. They're 0:22:18.280 --> 0:22:22.640 using auditory information in real time, and they can have 0:22:22.760 --> 0:22:26.280 such precision that they can detect an object as thin 0:22:26.359 --> 0:22:30.359 as a hair and fly around, that they can figure 0:22:30.359 --> 0:22:33.560 out the size and shape and speed of objects like 0:22:33.600 --> 0:22:36.439 a little moth flying around, so they can zoom in 0:22:36.520 --> 0:22:39.720 on it and grab it. And they also have sophisticated 0:22:39.880 --> 0:22:44.840 social behavior, but presumably about different social things than what 0:22:44.880 --> 0:22:47.400 we care about. And we know that they do all 0:22:47.520 --> 0:22:50.120 kinds of problem solving, but it strikes me that it's 0:22:50.160 --> 0:22:54.480 really difficult to know what sorts of problems they solve, 0:22:55.000 --> 0:22:57.880 because some of the problems are so foreign to us 0:22:58.280 --> 0:23:01.439 that we don't even know how to think about them. 0:23:01.960 --> 0:23:04.560 So all this leads us back around to the main 0:23:04.680 --> 0:23:08.679 question for today, which is what is intelligence? How do 0:23:08.720 --> 0:23:10.080 we define it? 0:23:10.880 --> 0:23:11.080 Well? 0:23:11.080 --> 0:23:13.359 As it turns out, this has not been an easy 0:23:13.440 --> 0:23:16.520 question for scientists, and it has come with lots of debate. 0:23:17.119 --> 0:23:18.960 And this is one of those things where we all 0:23:18.960 --> 0:23:22.080 have an intuition about what we mean by the word. 0:23:22.800 --> 0:23:25.840 But the trick from a neuroscience perspective is how do 0:23:25.880 --> 0:23:28.919 you rigorously define it and therefore, how do you study it? 0:23:29.880 --> 0:23:32.919 When we talk about intelligence, let's say just human intelligence, 0:23:32.960 --> 0:23:35.439 what are we even talking about. We all have a 0:23:35.920 --> 0:23:39.439 sense of what an intelligent person is, but what is 0:23:39.520 --> 0:23:43.160 happening in their brain that is different from someone else 0:23:43.160 --> 0:23:45.760 who you might think is not so intelligent. How do 0:23:46.000 --> 0:23:52.639 giant networks of individual neurons, billions of them manipulate information 0:23:52.720 --> 0:23:56.199 that you've taken in before and simulate possible futures and 0:23:56.280 --> 0:24:00.359 evaluate those and throw out all the information that doesn't matter. 0:24:01.000 --> 0:24:04.720 And do people who are intelligent store knowledge in a 0:24:04.760 --> 0:24:08.679 different way, Maybe not categorically different, but just perhaps in 0:24:08.680 --> 0:24:12.080 a way that's more distilled or more easily retrievable. So 0:24:12.119 --> 0:24:14.800 these are the kind of questions we're facing now. The 0:24:14.840 --> 0:24:18.439 first thing to appreciate about intelligence in the brain is 0:24:18.440 --> 0:24:23.360 that size does not seem to matter. Andre the giant 0:24:23.680 --> 0:24:26.880 had a brain volume that might have been eight times 0:24:26.920 --> 0:24:30.520 the size of yours, but he was probably not eight 0:24:30.600 --> 0:24:34.760 times smarter than you. In fact, what is so remarkable 0:24:35.080 --> 0:24:39.520 is that brains that are enormous, like in elephants, and 0:24:39.720 --> 0:24:43.080 brains that are very tiny, like a little mouse brain 0:24:43.960 --> 0:24:48.320 can both tackle very complex problems like foraging for food 0:24:48.359 --> 0:24:52.040 and setting up a home and mating and defending itself 0:24:52.080 --> 0:24:58.400 against predators. The Spanish neuroscientist Santiago Romoni Cajol, like many 0:24:58.440 --> 0:25:02.000 neuroscientists before and after him, was really struck by this thought, 0:25:02.359 --> 0:25:06.200 and he had this beautiful comparison of large and small 0:25:06.240 --> 0:25:11.480 brains to large and small clocks like big ben and 0:25:11.840 --> 0:25:17.359 a wristwatch both tell the time with equal accuracy despite 0:25:17.440 --> 0:25:20.320 the size difference. So all this is to say that 0:25:20.400 --> 0:25:24.159 when we stare at brains, this secret of intelligence is 0:25:24.200 --> 0:25:46.720 not immediately obvious just from looking at the brain. Now, 0:25:46.920 --> 0:25:50.000 when we look across species, we can see what we 0:25:50.119 --> 0:25:54.600 might mean by intelligence. For example, good problem solving skills. 0:25:55.359 --> 0:25:59.320 Some primates are really good at using tools, like orangutans, 0:25:59.680 --> 0:26:02.760 while well other primates like bonobo's are really good at 0:26:02.880 --> 0:26:07.280 social intelligence. If you look at purposes, you find that 0:26:07.320 --> 0:26:11.160 they are better problem solvers and do much more than 0:26:11.200 --> 0:26:15.480 say other swimmers like catfish. And when we examine humans 0:26:15.840 --> 0:26:19.160 we see that somebody can be a genius in one 0:26:19.280 --> 0:26:23.280 domain but quite bad at another. Rinaldo is a genius 0:26:23.280 --> 0:26:25.600 at soccer, but he might not be so great at 0:26:25.640 --> 0:26:29.080 differential equations. I recently saw a video of a kid 0:26:29.119 --> 0:26:32.119 who can do a Rubik's cuban about three seconds, but 0:26:32.200 --> 0:26:36.280 he's autistic and therefore is not particularly good at anything 0:26:36.359 --> 0:26:40.800 involving social interaction. So how can we put a measure 0:26:40.880 --> 0:26:44.439 to what we are talking about here? About a century 0:26:44.440 --> 0:26:46.960 and a half ago people started working on the question 0:26:47.480 --> 0:26:52.160 of how you could quantify this. The British scientists Sir 0:26:52.240 --> 0:26:54.560 Francis Galton was one of the first that I know 0:26:54.600 --> 0:26:58.880 of who said we should be able to measure intelligence. 0:26:59.400 --> 0:27:02.840 So is that you could quantify it by measuring things 0:27:02.920 --> 0:27:06.719 like the strength of someone's eyesight and hearing, or the 0:27:06.760 --> 0:27:10.240 strength of their grip. So that approach didn't last long, 0:27:10.720 --> 0:27:14.480 but by nineteen oh five, two scientists, Alfred Binet and 0:27:14.520 --> 0:27:19.080 Theodore Simon built the Simon Benay test as a way 0:27:19.119 --> 0:27:24.080 of quantifying some number for intelligence. And then in nineteen 0:27:24.160 --> 0:27:27.640 sixteen here at Stanford University there was an educator named 0:27:27.680 --> 0:27:30.880 Lewis Turman who developed the test more and he renamed 0:27:30.880 --> 0:27:33.720