WEBVTT - Ep5 "How is your brain like a team of rivals?" 0:00:05.559 --> 0:00:10.120 How is your brain like Abraham Lincoln's political cabinet? And 0:00:10.160 --> 0:00:12.880 why is it easier to do a drone strike on 0:00:12.920 --> 0:00:15.840 an enemy than to stab them with a bayonet? And 0:00:15.880 --> 0:00:17.959 what does any of this have to do with Mel 0:00:18.040 --> 0:00:22.000 Gibson or the Twilight Zone or mister Spock from Star Trek. 0:00:24.360 --> 0:00:29.040 Welcome to Inner Cosmos with me David Eagleman. I'm a 0:00:29.080 --> 0:00:33.720 neuroscientist and an author at Stanford University, and in these 0:00:33.760 --> 0:00:37.519 next three episodes, we're going to sail deeply into our 0:00:37.720 --> 0:00:41.720 three pound universe to understand why and how our lives 0:00:41.760 --> 0:00:51.320 look the way they do. So today we're going to 0:00:51.400 --> 0:00:55.040 discover that you're not one thing with a single drive, 0:00:55.200 --> 0:00:59.360 but instead your brain is a team of rivals. It's 0:00:59.360 --> 0:01:02.960 a machine that's built of conflicting parts. This is going 0:01:03.000 --> 0:01:06.120 to allow us to understand how we make decisions, which 0:01:06.160 --> 0:01:08.640 is what we'll focus on in this episode, and in 0:01:08.680 --> 0:01:13.160 the next episode we'll talk about economic decisions in particular, 0:01:13.360 --> 0:01:15.520 like how do you choose which ice cream to buy 0:01:15.640 --> 0:01:18.600 or which car to buy? And finally, we'll talk about 0:01:18.959 --> 0:01:22.680 how we can leverage this sort of knowledge to optimally 0:01:23.360 --> 0:01:27.399 navigate our behavior, to make our behavior consistent with our 0:01:27.480 --> 0:01:31.119 long term thinking rather than the temptations that sit right 0:01:31.160 --> 0:01:34.800 in front of us. So for now, let's begin with 0:01:35.000 --> 0:01:39.920 human behavior and why we are all so complicated. So 0:01:39.959 --> 0:01:42.160 I'm going to start today with a story that I 0:01:42.200 --> 0:01:45.199 told in my book Incognito, and the story is about 0:01:45.240 --> 0:01:49.440 that two thousand and six arrest of the actor Mel Gibson. 0:01:49.680 --> 0:01:52.200 So he was pulled over for speeding. He was going 0:01:52.320 --> 0:01:55.560 almost twice the posted speed limit on the Pacific Coast 0:01:55.640 --> 0:01:59.080 Highway in Malibu, and the police officer, James Me, gave 0:01:59.160 --> 0:02:02.200 him a breath liizer test, and what that showed is 0:02:02.200 --> 0:02:05.840 that Gibson's blood alcohol level was at zero point one 0:02:05.960 --> 0:02:09.400 two percent, which is very high, well over the legal 0:02:09.440 --> 0:02:12.000 limit of point eight. And there was also an open 0:02:12.040 --> 0:02:15.160 bottle of tequila on the seat next to Gibson. So 0:02:15.280 --> 0:02:19.680 the officer places Gibson under arrest and asks him to 0:02:19.760 --> 0:02:23.880 get into the squad car, and Gibson goes nuts, and 0:02:23.919 --> 0:02:27.799 he says Jews are responsible for all the wars in 0:02:27.840 --> 0:02:30.800 the world, and he asks the officer are you a 0:02:30.919 --> 0:02:34.920 Jew And the officer, James Me, was indeed Jewish. So 0:02:35.080 --> 0:02:37.800 Gibson refuses to get in the squad car and he 0:02:37.840 --> 0:02:41.600 has to be handcuffed. So within a day the website 0:02:41.639 --> 0:02:45.520 TMZ leaks a video of this interaction, and there's this 0:02:45.720 --> 0:02:49.160 vigorous response from the media and everything gets very heated. 0:02:49.760 --> 0:02:53.920 So eventually Gibson writes a note of apology, and it 0:02:54.000 --> 0:02:57.799 reads quote, after drinking alcohol on Thursday night, I did 0:02:57.840 --> 0:03:00.360 a number of things that were very wrong and for 0:03:00.440 --> 0:03:03.120 which I am ashamed. I acted like a person completely 0:03:03.120 --> 0:03:05.760 out of control when I was arrested and said things 0:03:06.040 --> 0:03:08.000 that I do not believe to be true and which 0:03:08.080 --> 0:03:11.600 are despicable. So he goes on to say he's ashamed 0:03:11.639 --> 0:03:15.280 and he disgraced himself, and that he's been battling alcoholism, 0:03:15.639 --> 0:03:21.200 and he apologizes for his quote unbecoming behavior. But this 0:03:21.240 --> 0:03:24.520 didn't really land that well because there was no reference 0:03:24.560 --> 0:03:27.960 at all to the anti Semitic slurs. So Gibson then 0:03:28.000 --> 0:03:31.960 writes a longer note of apology directed toward the Jewish community, 0:03:31.960 --> 0:03:35.440 and he says, quote, there is no excuse, nor should 0:03:35.480 --> 0:03:38.960 there be any tolerance for anyone who thinks or expresses 0:03:39.080 --> 0:03:43.400 any kind of antisemitic remark. I want to apologize, specifically 0:03:43.440 --> 0:03:46.840 to everyone in the Jewish community for the vitriolic and 0:03:46.920 --> 0:03:50.360 harmful words that I said to a law enforcement officer 0:03:50.440 --> 0:03:53.440 the night I was arrested on a dui charge. Every 0:03:53.520 --> 0:03:56.320 human being is God's child, and if I wish to 0:03:56.400 --> 0:03:59.920 honor my God, I have to honor his children. But please, 0:04:00.000 --> 0:04:01.800 I know from my heart that I am not an 0:04:01.800 --> 0:04:05.360 anti Semite. I'm not a bigot. Hatred of any kind 0:04:05.480 --> 0:04:09.520 goes against my faith. So Gibson offered to meet one 0:04:09.520 --> 0:04:12.920 on one with leaders of the Jewish community to quote 0:04:13.080 --> 0:04:18.560 discern the appropriate path for healing. So he seemed genuinely apologetic, 0:04:18.720 --> 0:04:22.920 and Jewish leaders accepted his apology. But here's the question. 0:04:23.880 --> 0:04:28.280 Are Mel Gibson's true colors that of an anti Semite 0:04:28.600 --> 0:04:31.960 or are his true colors those he showed afterwards in 0:04:32.040 --> 0:04:36.919 his eloquent and apparently heartfelt apologies. Well this was a 0:04:37.000 --> 0:04:40.040 question that got a lot of people arguing. So one 0:04:40.120 --> 0:04:43.839 journalist wrote in the Washington Post an article that he 0:04:43.960 --> 0:04:48.440 titled Mel Gibson it wasn't just the tequila talking, and 0:04:48.520 --> 0:04:51.760 he wrote, quote, well, I'm sorry about his relapse, but 0:04:51.880 --> 0:04:55.279 I just don't buy the idea that a little tequila, 0:04:55.400 --> 0:04:58.640 or even a lot of tequila, can somehow turn an 0:04:58.839 --> 0:05:03.480 unbiased person into a raging anti semite, or a racist, 0:05:03.560 --> 0:05:05.800 or a homophobe, or a bigot of any kind for 0:05:05.880 --> 0:05:10.680 that matter. Alcohol removes inhibitions, allowing all kinds of opinions 0:05:10.720 --> 0:05:15.160 to escape uncensored. But you can't blame alcohol for forming 0:05:15.279 --> 0:05:18.560 and nurturing those opinions in the first place. Then, the 0:05:18.600 --> 0:05:22.880 producer of the TV show Scarborough County drank alcohol on 0:05:23.040 --> 0:05:26.560 the show until he raised his blood alcohol level two 0:05:26.640 --> 0:05:29.760 point one two percent, which was Gibson's level on that night, 0:05:30.320 --> 0:05:35.560 and he reported quote, not feeling antisemitic after drinking. So, 0:05:35.880 --> 0:05:38.400 like a lot of people, the reporter and the producer 0:05:39.040 --> 0:05:44.120 suspected that the alcohol had loosened Gibson's inhibitions and revealed 0:05:44.160 --> 0:05:47.880 his true self, and the nature of their suspicion has 0:05:47.920 --> 0:05:52.720 a long history. An ancient Greek poet had coined a 0:05:52.880 --> 0:05:57.680 popular phrase which translates to in wine, there is the truth, 0:05:58.279 --> 0:06:02.680 and this was repeated by the Roman as in Vino veritas. 0:06:03.080 --> 0:06:06.440 A passage in the Babylonian Talmud makes the same point 0:06:06.600 --> 0:06:11.080 quote in came wine out went a secret. The Roman 0:06:11.200 --> 0:06:17.000 historian Tacitus claimed that the Germanic people always drank alcohol 0:06:17.040 --> 0:06:22.200 while holding councils to prevent anyone from lying. Okay, But 0:06:22.240 --> 0:06:26.240 going back to Mel Gibson, not everyone agreed with the 0:06:26.320 --> 0:06:31.320 hypothesis that alcohol revealed who he really was. A writer 0:06:31.440 --> 0:06:34.960 in The National Review argued, quote, the guy was drunk. 0:06:35.080 --> 0:06:38.000 For Heaven's sake. We all say and do dumb things 0:06:38.000 --> 0:06:40.560 when we're drunk. If I were to be judged on 0:06:40.640 --> 0:06:44.600 my drunken escapades and follies, I should be utterly excluded 0:06:44.640 --> 0:06:47.960 from polite society. And so would you, unless you're some 0:06:48.120 --> 0:06:53.000 kind of saint. The Jewish conservative activist David Horowitz commented 0:06:53.040 --> 0:06:57.400 on Fox News, quote, people deserve compassion when they're in 0:06:57.440 --> 0:06:59.480 this kind of trouble. I think it would be very 0:06:59.600 --> 0:07:02.800 ungracious for people to deny it to him. There is 0:07:02.839 --> 0:07:06.440 an addiction psychologist named Alan Marlott who wrote in USA 0:07:06.520 --> 0:07:10.560 Today alcohol is not a truth serum. It may or 0:07:10.560 --> 0:07:15.080 may not indicate his true feelings, and Gibson's social circle 0:07:15.200 --> 0:07:19.400 publicly vouched for him. Earlier in the day before the arrest, 0:07:19.480 --> 0:07:22.600 Gibson had spent time at the house of his friend 0:07:22.840 --> 0:07:26.880 Dean Devlin, who was quoted saying, if Mel is an 0:07:26.920 --> 0:07:29.920 anti Semite, he spends a lot of time with us, 0:07:29.960 --> 0:07:33.560 which makes no sense. Devlin and his wife are both Jewish. 0:07:34.080 --> 0:07:37.440 For Devlin, that was proof enough against the arguments of 0:07:37.480 --> 0:07:43.840 anti Semitism. So which are Gibson's true colors? Those in 0:07:43.880 --> 0:07:47.000 which he shouts anti Semitic comments or those in which 0:07:47.000 --> 0:07:50.240 he feels remorse and shame and publicly says I am 0:07:50.320 --> 0:07:53.480 reaching out to the Jewish community for its help. Now, 0:07:53.560 --> 0:07:57.160 many people prefer a view of human nature that includes 0:07:57.360 --> 0:08:01.080 a true side and a false side. Words, we think 0:08:01.120 --> 0:08:05.440 that people have a genuine aim and the rest is 0:08:05.680 --> 0:08:09.520 decoration or evasion or cover up. Now that's intuitive, but 0:08:09.600 --> 0:08:13.800 it's incomplete. A study of the brain necessitates a more 0:08:13.960 --> 0:08:17.080 nuanced view of human nature. And as we're going to 0:08:17.120 --> 0:08:20.680 see in this episode, we are made of many drives 0:08:20.840 --> 0:08:24.800 under the hood, many different networks of neurons that sometimes 0:08:24.840 --> 0:08:28.400 have their own opinions. As the poet Walt Whitman put it, 0:08:29.000 --> 0:08:34.959 I am large, I contain multitudes. So Gibson's detractors are 0:08:35.000 --> 0:08:37.400 going to continue to insist that he is truly an 0:08:37.400 --> 0:08:41.000 anti Semite, and his defenders will continue to insist that 0:08:41.040 --> 0:08:45.480 he is not. But both may be defending an incomplete story. 0:08:46.800 --> 0:08:50.400 So let's begin in the nineteen sixties, when the pioneers 0:08:50.440 --> 0:08:55.640 of artificial intelligence, we're struggling to build simple robotic programs 0:08:55.679 --> 0:08:59.840 that could manipulate small blocks of wood. So the idea 0:08:59.880 --> 0:09:03.680 was to identify the blocks and then to grip them, 0:09:04.160 --> 0:09:07.080 and then to stack them up in simple patterns. And 0:09:07.120 --> 0:09:10.400 this was one of those apparently simple problems that turns 0:09:10.440 --> 0:09:15.600 out to be incredibly hard, because for a robot, finding 0:09:15.640 --> 0:09:20.360 a block of wood requires figuring out which camera pixels 0:09:20.440 --> 0:09:23.280 correspond to the block and which ones don't, and then 0:09:23.320 --> 0:09:26.800 you have to recognize the block shape regardless of the 0:09:27.080 --> 0:09:29.800 angle and the distance of the block. And then you 0:09:29.840 --> 0:09:33.880 have to grab it, which requires visual guidance of graspers 0:09:33.880 --> 0:09:36.800 that have to squeeze in at the right moment from 0:09:36.840 --> 0:09:41.000 the right direction with the right force, and stacking requires 0:09:41.480 --> 0:09:44.479 an analysis of the rest of the blocks and adjusting 0:09:44.520 --> 0:09:47.840 to those details. And all these programs need to be 0:09:48.000 --> 0:09:51.120 coordinated so they happen at the right times in the 0:09:51.200 --> 0:09:55.960 right sequence. And so what these AI pioneers discovered is 0:09:56.000 --> 0:10:05.040 that tasks that seem simple are often masking enormous computational complexity. 0:10:05.080 --> 0:10:09.320 So some decades ago, the computer scientist Marvin Minsky and 0:10:09.360 --> 0:10:13.080 his colleagues started thinking about this problem and they came 0:10:13.160 --> 0:10:17.400 up with a really progressive idea. Maybe the robot could 0:10:17.480 --> 0:10:23.640 solve the problem by distributing the labor among specialized subagents. 0:10:24.160 --> 0:10:28.920 So imagine small computer programs that could each bite off 0:10:29.040 --> 0:10:32.400 a small piece of the problem. So one computer program 0:10:32.480 --> 0:10:36.040 is in charge of the job find, another could solve 0:10:36.080 --> 0:10:40.320 the Fetch problem. Another takes care of the stack block. 0:10:40.600 --> 0:10:44.840 And these subagents can be connected in a hierarchy just 0:10:44.880 --> 0:10:47.520 like a company, and they can report to one another 0:10:47.679 --> 0:10:51.840 and to their bosses. And because of this hierarchy, stack 0:10:51.880 --> 0:10:56.319 block would not try to start its job until Find 0:10:56.720 --> 0:11:00.640 and Fetch had finished their jobs. So they is that 0:11:00.679 --> 0:11:05.360 these subagents are totally mindless. But when these sub agents 0:11:05.400 --> 0:11:08.920 come together, the whole system starts to look pretty smart. 0:11:09.800 --> 0:11:13.960 So this idea of subagents didn't solve the problem entirely, 0:11:14.040 --> 0:11:17.160 but it helped a lot, and most importantly, it brought 0:11:17.160 --> 0:11:22.720 into focus a new idea about the working of biological brains. 0:11:23.400 --> 0:11:28.440 Marvin Minsky suggested that human minds perhaps were collections of 0:11:29.240 --> 0:11:35.640 enormous numbers of machine like mindless subagents that collaborate. So 0:11:35.760 --> 0:11:38.960 the key idea is that a bunch of small specialized 0:11:39.000 --> 0:11:43.200 workers can give rise to something like a society with 0:11:43.280 --> 0:11:48.199 all kinds of rich properties that no subagent has by itself. 0:11:48.600 --> 0:11:52.120 Each little guy is just doing some simple thing, but together, 0:11:52.240 --> 0:11:55.600 when they're connected in the right way, you get something 0:11:55.640 --> 0:12:00.040 that looks like intelligence. So the suggestion was that and 0:12:00.240 --> 0:12:03.920 thousands of little minds are better than one large one. 0:12:04.360 --> 0:12:08.120 And if this sounds weird, just think about how factories work. 0:12:08.360 --> 0:12:11.840 Each person on the assembly line is specialized. They do 0:12:11.960 --> 0:12:16.079 one simple job. No one there knows how to do everything, 0:12:16.640 --> 0:12:20.640 and yet complex products get built out of this. And 0:12:20.679 --> 0:12:24.880 this is also how government ministries operate. Each bureaucrat has 0:12:25.040 --> 0:12:28.199 one task or a few very specific tasks, and the 0:12:28.240 --> 0:12:32.880 government succeeds on its ability to distribute the work appropriately 0:12:33.320 --> 0:12:37.439 and on larger scales. This is how civilizations operate. They 0:12:37.520 --> 0:12:41.240 reach the next level of sophistication when they learn to 0:12:41.360 --> 0:12:46.040 divide labor. They commit some people to specialize in agriculture, 0:12:46.080 --> 0:12:48.800 and some to art, and some to warfare and so on. 0:12:49.400 --> 0:12:54.439 This division of labor allows specialization and a deeper level 0:12:54.440 --> 0:12:58.440 of expertise, so even though no one knows how other 0:12:58.600 --> 0:13:03.679 jobs work, as an emergent result, you get civilization. So 0:13:04.080 --> 0:13:08.839 this idea of dividing up problems into smaller subroutines that 0:13:09.040 --> 0:13:12.360 ignited the young field of artificial intelligence back in the 0:13:12.440 --> 0:13:16.240 nineteen seventies. Instead of trying to develop a single all 0:13:16.280 --> 0:13:21.360 purpose program, the scientists changed their goal. Now it was 0:13:21.440 --> 0:13:26.280 to build a system out of smaller, local expert networks 0:13:26.320 --> 0:13:29.200 which know how to do one single thing. And in 0:13:29.240 --> 0:13:33.160 this framework, the larger system only has to switch which 0:13:33.200 --> 0:13:36.720 of the experts has control at any given moment. The 0:13:36.800 --> 0:13:39.920 learning challenge now involves not so much how to do 0:13:40.040 --> 0:13:44.240 each little task, but instead how to distribute who's doing 0:13:44.280 --> 0:13:48.160 what when. So, as Minsky suggested in his book The 0:13:48.200 --> 0:13:52.679 Society of Mind, perhaps that's all the human brain has 0:13:52.720 --> 0:13:55.680 to do as well, and he noted that if brains 0:13:55.880 --> 0:14:00.160 really do work this way as collections of subagents, we 0:14:00.200 --> 0:14:04.679 wouldn't have any reason to be aware of the specialized processes. 0:14:04.720 --> 0:14:09.520 He said, quote thousands and perhaps millions of little processes 0:14:09.640 --> 0:14:14.959 must be involved in how we anticipate, imagine, plan, predicts, 0:14:15.000 --> 0:14:19.600 and prevent, and yet all this proceeds so automatically that 0:14:19.640 --> 0:14:23.960 we regard it as ordinary common sense. At first, it 0:14:23.960 --> 0:14:27.200 may seem incredible that our minds could use such intricate 0:14:27.320 --> 0:14:31.600 machinery and yet be unaware of it. When scientists began 0:14:31.680 --> 0:14:36.080 to look into the brains of animals, Minsky's society of 0:14:36.240 --> 0:14:39.560 mind idea open up a new way of looking at things. 0:14:40.240 --> 0:14:44.600 In the early nineteen seventies, researchers realized that a frog 0:14:45.200 --> 0:14:49.320 has at least two separate ways of seeing motion. One 0:14:49.400 --> 0:14:52.720 system is looking for small darting objects like a fly, 0:14:52.960 --> 0:14:55.800 and it directs the tongue, and the other system is 0:14:55.840 --> 0:14:59.440 looking for large looming objects like a person, and it 0:14:59.480 --> 0:15:02.600 tells the lef legs to jump. And presumably neither of 0:15:02.640 --> 0:15:07.760 these systems is conscious. Instead, they're just simple automated programs 0:15:08.120 --> 0:15:11.800 that are burned down in the circuitry. So the society 0:15:12.000 --> 0:15:16.400 of mind framework was an important step forward. But despite 0:15:16.440 --> 0:15:20.600 the initial excitement about it, a collection of experts with 0:15:20.680 --> 0:15:26.000 divided labor has never proven sufficient to yield the properties 0:15:26.040 --> 0:15:28.680 of the human brain. It's still the case that our 0:15:28.960 --> 0:15:32.680 smartest robots are less intelligent than a three year old child. 0:15:33.080 --> 0:15:36.920 So what went wrong? I suggested in my book Incognito 0:15:37.400 --> 0:15:41.480 that a critical factor was missing from the division of 0:15:41.560 --> 0:15:45.480 labor models, and we turn to that now. The missing 0:15:45.560 --> 0:15:50.880 factor in Minski's theory was competition among the experts who 0:15:50.880 --> 0:15:53.440 all believe they know the right way to solve the problem. 0:15:53.960 --> 0:15:58.280 Just like a good drama, the human brain runs on conflict. 0:15:59.000 --> 0:16:03.120 In an assembly line a government ministry, each worker is 0:16:03.160 --> 0:16:07.800 an expert in a small task. But in contrast, parties 0:16:07.840 --> 0:16:12.280 in a democracy hold different opinions about the same issues, 0:16:12.680 --> 0:16:16.400 and the important part of the process is the battle 0:16:16.600 --> 0:16:22.080 for steering the ship of state. Brains are like democracies. 0:16:22.120 --> 0:16:27.280 They're built of multiple overlapping experts who weigh in and 0:16:27.320 --> 0:16:33.000 compete over different choices. As the poet while Whitman correctly surmised, 0:16:33.080 --> 0:16:37.160 we are large, and we harbor multitudes within us, and 0:16:37.200 --> 0:16:42.360 those multitudes are locked in chronic battle. There's an ongoing 0:16:42.480 --> 0:16:47.400 conversation among the different factions in your brain. They compete 0:16:47.680 --> 0:16:51.360 to control the single output channel of your behavior. So 0:16:51.480 --> 0:16:55.160 as a result, you can accomplish the strange feats of 0:16:55.880 --> 0:17:01.040 arguing with yourself, or cussing yourself, or cajoling yourself. These 0:17:01.040 --> 0:17:04.480 are things that computers simply don't do. So when the 0:17:04.480 --> 0:17:08.320 hostess at a party offers you chocolate cake, you can 0:17:08.320 --> 0:17:11.480 find yourself on the horns of a dilemma. Some parts 0:17:11.520 --> 0:17:14.760 of your brain have evolved to crave the rich energy 0:17:14.800 --> 0:17:18.000 source of sugar. Other parts of your brain care about 0:17:18.000 --> 0:17:21.080 the negative consequences, like the health of your heart or 0:17:21.119 --> 0:17:24.679 the bulge of your love handles. Part of you wants 0:17:24.720 --> 0:17:27.199 the cake, and part of you tries to gather the 0:17:27.280 --> 0:17:30.679 strength to pass on it. And the final vote of 0:17:30.760 --> 0:17:35.480 the parliament determines which party controls what you ultimately do. 0:17:36.119 --> 0:17:37.879 In other words, whether you put your hand up or 0:17:37.880 --> 0:17:41.359 you put your hand out. In the end, you either 0:17:41.400 --> 0:17:44.000 eat the chocolate cake or you don't, but you can't 0:17:44.040 --> 0:17:50.640 do both. Because of these internal multitudes, biological creatures can 0:17:50.680 --> 0:17:55.960 be conflicted. Now, the term conflicted can't be sensibly applied 0:17:56.080 --> 0:17:59.639 to an entity that has a single program. Your car 0:17:59.680 --> 0:18:02.520 can't conflicted about which way to turn. It has one 0:18:02.560 --> 0:18:06.880 steering wheel commanded by one driver, and it follows directions 0:18:06.880 --> 0:18:11.520 without complaint. But brains can be of two minds, and 0:18:11.600 --> 0:18:14.439 often many more than that. We don't know whether to 0:18:14.520 --> 0:18:17.880 turn toward the cake or away from it, because there 0:18:17.880 --> 0:18:21.359 are several little sets of hands on the steering wheel 0:18:21.480 --> 0:18:25.200 of our behavior. Consider this simple experiment that's been done 0:18:25.200 --> 0:18:28.679 with laboratory rats. If you put some cheese at the 0:18:28.800 --> 0:18:31.600 end of a little corridor, the rat will go towards 0:18:31.640 --> 0:18:33.960 the cheese, and you can hook up a little harness 0:18:34.119 --> 0:18:38.320 to feel how strongly he's pulling towards that. Now, let's 0:18:38.320 --> 0:18:40.840 say instead of the cheese, you put an electrical shock. 0:18:40.960 --> 0:18:44.560 Now the rat moves away from the electrical shock, and 0:18:44.600 --> 0:18:48.160 with the harness you can measure the force. Okay, Now 0:18:48.520 --> 0:18:51.919 you put both cheese and the electrical shock at the 0:18:52.040 --> 0:18:54.679 end of the hallway. And what the rat does is 0:18:54.720 --> 0:19:00.359 he begins to approach, but with draws, and he finds 0:19:00.400 --> 0:19:02.520 the courage to approach again. And what happens is he 0:19:02.720 --> 0:19:07.560 oscillates conflicted, and it's exactly at the distance where the 0:19:07.600 --> 0:19:11.560 two forces cancel out. In other words, he's going towards 0:19:11.560 --> 0:19:13.879 a thing, and he's pulling away from the thing, and 0:19:14.040 --> 0:19:18.840 both programs are running at once. The pull matches the push. 0:19:19.160 --> 0:19:22.880 The poor rat has two pairs of paws on its 0:19:22.920 --> 0:19:27.399 steering wheel, each pulling in opposite directions, and as a result, 0:19:27.440 --> 0:19:31.560 he can't get anywhere. So brains, whether rat or human, 0:19:32.000 --> 0:19:36.960 are machines made of conflicting parts. If building a contraption 0:19:37.119 --> 0:19:41.760 with internal division seems strange, just consider that we already 0:19:41.800 --> 0:19:45.879 build social machines like this. Think of a jury of 0:19:46.080 --> 0:19:50.320 peers in a courtroom trial. You have twelve strangers with 0:19:50.480 --> 0:19:54.320 different opinions, and they're tasked with this single mission of 0:19:54.359 --> 0:19:59.200 coming to a consensus. So the jurors argue and cox 0:19:59.280 --> 0:20:03.160 and the influence, and eventually the group coheres to a 0:20:03.240 --> 0:20:08.639 single decision, having differing opinions. It's not a drawback to 0:20:08.720 --> 0:20:12.119 the jury system. It is the central feature. When the 0:20:12.160 --> 0:20:16.560 President Abraham Lincoln was putting together his presidential cabinet, he 0:20:16.720 --> 0:20:21.760 chose to put in adversaries. The historian Doris Kern's Goodwin 0:20:22.119 --> 0:20:26.639 described his cabinet as a team of rivals, and we 0:20:26.720 --> 0:20:28.840 see this kind of team of rivals all the time. 0:20:29.359 --> 0:20:33.560 In Zimbabwe some years ago, the president Robert Mugabe agreed 0:20:33.600 --> 0:20:36.640 to share power with a rival that he had earlier 0:20:37.000 --> 0:20:40.360 tried to assassinate. And in China in two thousand and nine, 0:20:40.440 --> 0:20:45.439 the President Hu Jintao named two opposing faction leaders to 0:20:45.520 --> 0:20:51.199 help him craft China's future. I proposed in incognito that 0:20:51.280 --> 0:20:55.639 the brain is best understood as a team of rivals, 0:20:56.119 --> 0:20:58.160 and the rest of this episode and the next two 0:20:58.640 --> 0:21:02.320 are going to explore that framework. Who the parties are, 0:21:02.720 --> 0:21:06.359 how they compete, how the union is held together, what 0:21:06.520 --> 0:21:10.119 happens when things fall apart. How this framework allows us 0:21:10.160 --> 0:21:13.920 to understand what products we buy and how we can 0:21:14.119 --> 0:21:17.919 use this understanding of the team of rivals to better 0:21:18.040 --> 0:21:23.040 navigate our own behavior into the future. As we move along, 0:21:23.160 --> 0:21:28.240 remember that different political parties typically have the same goal, 0:21:28.560 --> 0:21:31.639 which is success for their country, but they just have 0:21:31.760 --> 0:21:35.760 different ways of going about it. So, as Lincoln put it, 0:21:36.400 --> 0:21:40.119 rivals should be turned into allies quote for the sake 0:21:40.160 --> 0:21:43.119 of the greater good and for networks. In your brain 0:21:44.119 --> 0:21:50.359 neural subpopulations, the common interest is the thriving and survival 0:21:50.560 --> 0:21:54.399 of you the organism. In the same way that liberals 0:21:54.520 --> 0:21:58.240 and conservatives both love their country but can have different 0:21:58.280 --> 0:22:01.639 strategies for steering it. It's the same way in the 0:22:01.680 --> 0:22:04.919 brain you have competing factions that all believe they know 0:22:05.640 --> 0:22:25.400 the right way to solve problems. When trying to understand 0:22:25.440 --> 0:22:31.200 the strange details of human behavior, psychologists or economists sometimes 0:22:31.240 --> 0:22:36.160 refer to a dual process account, and you'll know this, 0:22:36.200 --> 0:22:40.520 for example, if you've read Daniel Kahneman's book Thinking Fast 0:22:40.560 --> 0:22:44.520 and Slow. In that framework, the brain has two separate systems. 0:22:44.600 --> 0:22:48.119 One is fast and automatic and below the surface of 0:22:48.200 --> 0:22:53.640 conscious awareness, and the other system is slow and cognitive 0:22:53.960 --> 0:22:59.119 and conscious, and these two systems are always battling it out. Now, 0:22:59.440 --> 0:23:01.720 this is a very good start to thinking about it, 0:23:01.760 --> 0:23:04.640 but there's no real reason to assume that there are 0:23:04.680 --> 0:23:07.600 only two systems. In fact, as we're going to see, 0:23:07.640 --> 0:23:11.640 there are many systems, and there are also different ways 0:23:11.680 --> 0:23:15.359 to think about how to divide things up. So in 0:23:15.440 --> 0:23:20.280 nineteen twenty, Sigmund Freud suggested three competing parts in his 0:23:20.440 --> 0:23:23.760 model of the psyche. There was the id, the ego, 0:23:23.920 --> 0:23:28.080 and the superego. The id was all about instinct, the 0:23:28.240 --> 0:23:33.080 ego was realistic and organized, and the super ego was 0:23:33.240 --> 0:23:38.120 critical and moralizing. In the nineteen fifties, the neuroscientist Paul 0:23:38.200 --> 0:23:42.440 MacLean suggested that the brain is made of three layers 0:23:42.920 --> 0:23:50.080 that represent successive stages of evolutionary development. There's the reptilian brain, 0:23:50.560 --> 0:23:55.200 which is involved in survival behaviors, and the limbic system, 0:23:55.240 --> 0:23:59.240 which underlies the emotions. And in higher animals, there's the 0:23:59.640 --> 0:24:04.280 neo core text, which is used in higher order thinking. Now, 0:24:04.680 --> 0:24:08.440 the details of both Freud's model and Maclean's model have 0:24:08.600 --> 0:24:11.760 largely fallen out of favor, but the heart of the 0:24:11.880 --> 0:24:17.760 idea survives, which is that brains are made of competing subsystems. 0:24:18.160 --> 0:24:21.240 I'll start with a simple model of competition as a 0:24:21.280 --> 0:24:25.200 starting point because it captures one way to see this picture, 0:24:25.680 --> 0:24:28.040 but by the next episode we'll see that it's even 0:24:28.080 --> 0:24:32.080 more sophisticated than that. So we'll start with a general 0:24:32.160 --> 0:24:35.840 statement about the brain's anatomy, which is that some areas 0:24:35.840 --> 0:24:40.040 of your brain are involved in higher order operations regarding 0:24:40.240 --> 0:24:44.080 events in the outside world. For the cognitionandy, this area 0:24:44.160 --> 0:24:47.000 is like the dorsilateral prefrontal core text, which is on 0:24:47.080 --> 0:24:50.399 the surface of your brain, just inside your temples, so 0:24:50.880 --> 0:24:54.960 those are monitoring and assessing the outside world, while other 0:24:55.160 --> 0:24:59.719 areas are involved with monitoring your internal state, like your 0:24:59.800 --> 0:25:03.399 level of hunger, or your sense of motivation, or whether 0:25:03.440 --> 0:25:06.679 something is rewarding to you. And this includes areas like 0:25:06.720 --> 0:25:10.800 the region just behind your forehead called the medial prefrontal cortex, 0:25:10.840 --> 0:25:14.960 in several areas deep below the surface, so these monitor 0:25:14.960 --> 0:25:18.480 what's going on on the inside. Now, again, the real 0:25:18.520 --> 0:25:22.600 situation is even more complex than this rough division would imply, 0:25:23.440 --> 0:25:26.840 because brains do a lot more than just monitor the 0:25:26.880 --> 0:25:31.960 outside and the inside. Your brain also simulates future states 0:25:31.960 --> 0:25:35.080 and reminisces about the past and figures out where to 0:25:35.119 --> 0:25:37.960 find things not immediately present, and so on. We'll get 0:25:38.000 --> 0:25:42.800 into that, but for the moment, this division into systems 0:25:42.800 --> 0:25:47.480 that monitor the outside and the inside will serve as 0:25:47.480 --> 0:25:50.399 a rough guide, and we can refine this picture later. 0:25:50.840 --> 0:25:53.840 Now to pick two labels that'll be familiar to everyone. 0:25:54.240 --> 0:25:58.840 We can call these the rational and the emotional systems. 0:26:00.240 --> 0:26:04.080 Are a little underspecified and imperfect, but they carry this 0:26:04.400 --> 0:26:09.160 starting point about rivalries in the brain. The rational system 0:26:09.280 --> 0:26:12.439 is the one that cares about analysis of things in 0:26:12.440 --> 0:26:17.840 the outside world, while the emotional system monitors the internal 0:26:17.880 --> 0:26:20.560 state and worries whether things will be good or bad. 0:26:21.040 --> 0:26:25.760 In other words, as a rough guide, rational cognition involves 0:26:25.800 --> 0:26:30.919 external events, while emotion involves your internal state. So you 0:26:31.000 --> 0:26:34.800 can do a math problem without consulting your internal state, 0:26:35.119 --> 0:26:38.280 but you have to consult your internal state to order 0:26:38.400 --> 0:26:41.879 a dessert off the menu, or to prioritize what you 0:26:41.880 --> 0:26:47.040 feel like doing next. The emotional networks are absolutely required 0:26:47.560 --> 0:26:51.880 to rank your possible next actions in the world. If 0:26:51.920 --> 0:26:56.080 you were an emotionless robot who rolled into a room, 0:26:56.600 --> 0:26:59.920 you might be able to analyze this stuff around you, 0:26:59.640 --> 0:27:03.000 but you would be frozen with indecision about what to 0:27:03.160 --> 0:27:08.520 do next. Choices about the priority of actions are determined 0:27:08.520 --> 0:27:12.320 by our internal states. When you get home, will you 0:27:12.680 --> 0:27:16.320 head straight to your refrigerator or the bathroom or the bedroom. 0:27:16.720 --> 0:27:19.920 That doesn't depend on the external stimuli in your home 0:27:19.960 --> 0:27:24.640 because those haven't changed, but instead on your body's internal states. 0:27:25.200 --> 0:27:28.840 So the battle between the rational and the emotional systems 0:27:29.200 --> 0:27:32.560 can be brought to light by what philosophers call the 0:27:32.960 --> 0:27:38.640