Speaker 1: How is your brain like Abraham Lincoln's political cabinet? And
Speaker 1: why is it easier to do a drone strike on
Speaker 1: an enemy than to stab them with a bayonet? And
Speaker 1: what does any of this have to do with Mel
Speaker 1: Gibson or the Twilight Zone or mister Spock from Star Trek.
Speaker 1: Welcome to Inner Cosmos with me David Eagleman. I'm a
Speaker 1: neuroscientist and an author at Stanford University, and in these
Speaker 1: next three episodes, we're going to sail deeply into our
Speaker 1: three pound universe to understand why and how our lives
Speaker 1: look the way they do. So today we're going to
Speaker 1: discover that you're not one thing with a single drive,
Speaker 1: but instead your brain is a team of rivals. It's
Speaker 1: a machine that's built of conflicting parts. This is going
Speaker 1: to allow us to understand how we make decisions, which
Speaker 1: is what we'll focus on in this episode, and in
Speaker 1: the next episode we'll talk about economic decisions in particular,
Speaker 1: like how do you choose which ice cream to buy
Speaker 1: or which car to buy? And finally, we'll talk about
Speaker 1: how we can leverage this sort of knowledge to optimally
Speaker 1: navigate our behavior, to make our behavior consistent with our
Speaker 1: long term thinking rather than the temptations that sit right
Speaker 1: in front of us. So for now, let's begin with
Speaker 1: human behavior and why we are all so complicated. So
Speaker 1: I'm going to start today with a story that I
Speaker 1: told in my book Incognito, and the story is about
Speaker 1: that two thousand and six arrest of the actor Mel Gibson.
Speaker 1: So he was pulled over for speeding. He was going
Speaker 1: almost twice the posted speed limit on the Pacific Coast
Speaker 1: Highway in Malibu, and the police officer, James Me, gave
Speaker 1: him a breath liizer test, and what that showed is
Speaker 1: that Gibson's blood alcohol level was at zero point one
Speaker 1: two percent, which is very high, well over the legal
Speaker 1: limit of point eight. And there was also an open
Speaker 1: bottle of tequila on the seat next to Gibson. So
Speaker 1: the officer places Gibson under arrest and asks him to
Speaker 1: get into the squad car, and Gibson goes nuts, and
Speaker 1: he says Jews are responsible for all the wars in
Speaker 1: the world, and he asks the officer are you a
Speaker 1: Jew And the officer, James Me, was indeed Jewish. So
Speaker 1: Gibson refuses to get in the squad car and he
Speaker 1: has to be handcuffed. So within a day the website
Speaker 1: TMZ leaks a video of this interaction, and there's this
Speaker 1: vigorous response from the media and everything gets very heated.
Speaker 1: So eventually Gibson writes a note of apology, and it
Speaker 1: reads quote, after drinking alcohol on Thursday night, I did
Speaker 1: a number of things that were very wrong and for
Speaker 1: which I am ashamed. I acted like a person completely
Speaker 1: out of control when I was arrested and said things
Speaker 1: that I do not believe to be true and which
Speaker 1: are despicable. So he goes on to say he's ashamed
Speaker 1: and he disgraced himself, and that he's been battling alcoholism,
Speaker 1: and he apologizes for his quote unbecoming behavior. But this
Speaker 1: didn't really land that well because there was no reference
Speaker 1: at all to the anti Semitic slurs. So Gibson then
Speaker 1: writes a longer note of apology directed toward the Jewish community,
Speaker 1: and he says, quote, there is no excuse, nor should
Speaker 1: there be any tolerance for anyone who thinks or expresses
Speaker 1: any kind of antisemitic remark. I want to apologize, specifically
Speaker 1: to everyone in the Jewish community for the vitriolic and
Speaker 1: harmful words that I said to a law enforcement officer
Speaker 1: the night I was arrested on a dui charge. Every
Speaker 1: human being is God's child, and if I wish to
Speaker 1: honor my God, I have to honor his children. But please,
Speaker 1: I know from my heart that I am not an
Speaker 1: anti Semite. I'm not a bigot. Hatred of any kind
Speaker 1: goes against my faith. So Gibson offered to meet one
Speaker 1: on one with leaders of the Jewish community to quote
Speaker 1: discern the appropriate path for healing. So he seemed genuinely apologetic,
Speaker 1: and Jewish leaders accepted his apology. But here's the question.
Speaker 1: Are Mel Gibson's true colors that of an anti Semite
Speaker 1: or are his true colors those he showed afterwards in
Speaker 1: his eloquent and apparently heartfelt apologies. Well this was a
Speaker 1: question that got a lot of people arguing. So one
Speaker 1: journalist wrote in the Washington Post an article that he
Speaker 1: titled Mel Gibson it wasn't just the tequila talking, and
Speaker 1: he wrote, quote, well, I'm sorry about his relapse, but
Speaker 1: I just don't buy the idea that a little tequila,
Speaker 1: or even a lot of tequila, can somehow turn an
Speaker 1: unbiased person into a raging anti semite, or a racist,
Speaker 1: or a homophobe, or a bigot of any kind for
Speaker 1: that matter. Alcohol removes inhibitions, allowing all kinds of opinions
Speaker 1: to escape uncensored. But you can't blame alcohol for forming
Speaker 1: and nurturing those opinions in the first place. Then, the
Speaker 1: producer of the TV show Scarborough County drank alcohol on
Speaker 1: the show until he raised his blood alcohol level two
Speaker 1: point one two percent, which was Gibson's level on that night,
Speaker 1: and he reported quote, not feeling antisemitic after drinking. So,
Speaker 1: like a lot of people, the reporter and the producer
Speaker 1: suspected that the alcohol had loosened Gibson's inhibitions and revealed
Speaker 1: his true self, and the nature of their suspicion has
Speaker 1: a long history. An ancient Greek poet had coined a
Speaker 1: popular phrase which translates to in wine, there is the truth,
Speaker 1: and this was repeated by the Roman as in Vino veritas.
Speaker 1: A passage in the Babylonian Talmud makes the same point
Speaker 1: quote in came wine out went a secret. The Roman
Speaker 1: historian Tacitus claimed that the Germanic people always drank alcohol
Speaker 1: while holding councils to prevent anyone from lying. Okay, But
Speaker 1: going back to Mel Gibson, not everyone agreed with the
Speaker 1: hypothesis that alcohol revealed who he really was. A writer
Speaker 1: in The National Review argued, quote, the guy was drunk.
Speaker 1: For Heaven's sake. We all say and do dumb things
Speaker 1: when we're drunk. If I were to be judged on
Speaker 1: my drunken escapades and follies, I should be utterly excluded
Speaker 1: from polite society. And so would you, unless you're some
Speaker 1: kind of saint. The Jewish conservative activist David Horowitz commented
Speaker 1: on Fox News, quote, people deserve compassion when they're in
Speaker 1: this kind of trouble. I think it would be very
Speaker 1: ungracious for people to deny it to him. There is
Speaker 1: an addiction psychologist named Alan Marlott who wrote in USA
Speaker 1: Today alcohol is not a truth serum. It may or
Speaker 1: may not indicate his true feelings, and Gibson's social circle
Speaker 1: publicly vouched for him. Earlier in the day before the arrest,
Speaker 1: Gibson had spent time at the house of his friend
Speaker 1: Dean Devlin, who was quoted saying, if Mel is an
Speaker 1: anti Semite, he spends a lot of time with us,
Speaker 1: which makes no sense. Devlin and his wife are both Jewish.
Speaker 1: For Devlin, that was proof enough against the arguments of
Speaker 1: anti Semitism. So which are Gibson's true colors? Those in
Speaker 1: which he shouts anti Semitic comments or those in which
Speaker 1: he feels remorse and shame and publicly says I am
Speaker 1: reaching out to the Jewish community for its help. Now,
Speaker 1: many people prefer a view of human nature that includes
Speaker 1: a true side and a false side. Words, we think
Speaker 1: that people have a genuine aim and the rest is
Speaker 1: decoration or evasion or cover up. Now that's intuitive, but
Speaker 1: it's incomplete. A study of the brain necessitates a more
Speaker 1: nuanced view of human nature. And as we're going to
Speaker 1: see in this episode, we are made of many drives
Speaker 1: under the hood, many different networks of neurons that sometimes
Speaker 1: have their own opinions. As the poet Walt Whitman put it,
Speaker 1: I am large, I contain multitudes. So Gibson's detractors are
Speaker 1: going to continue to insist that he is truly an
Speaker 1: anti Semite, and his defenders will continue to insist that
Speaker 1: he is not. But both may be defending an incomplete story.
Speaker 1: So let's begin in the nineteen sixties, when the pioneers
Speaker 1: of artificial intelligence, we're struggling to build simple robotic programs
Speaker 1: that could manipulate small blocks of wood. So the idea
Speaker 1: was to identify the blocks and then to grip them,
Speaker 1: and then to stack them up in simple patterns. And
Speaker 1: this was one of those apparently simple problems that turns
Speaker 1: out to be incredibly hard, because for a robot, finding
Speaker 1: a block of wood requires figuring out which camera pixels
Speaker 1: correspond to the block and which ones don't, and then
Speaker 1: you have to recognize the block shape regardless of the
Speaker 1: angle and the distance of the block. And then you
Speaker 1: have to grab it, which requires visual guidance of graspers
Speaker 1: that have to squeeze in at the right moment from
Speaker 1: the right direction with the right force, and stacking requires
Speaker 1: an analysis of the rest of the blocks and adjusting
Speaker 1: to those details. And all these programs need to be
Speaker 1: coordinated so they happen at the right times in the
Speaker 1: right sequence. And so what these AI pioneers discovered is
Speaker 1: that tasks that seem simple are often masking enormous computational complexity.
Speaker 1: So some decades ago, the computer scientist Marvin Minsky and
Speaker 1: his colleagues started thinking about this problem and they came
Speaker 1: up with a really progressive idea. Maybe the robot could
Speaker 1: solve the problem by distributing the labor among specialized subagents.
Speaker 1: So imagine small computer programs that could each bite off
Speaker 1: a small piece of the problem. So one computer program
Speaker 1: is in charge of the job find, another could solve
Speaker 1: the Fetch problem. Another takes care of the stack block.
Speaker 1: And these subagents can be connected in a hierarchy just
Speaker 1: like a company, and they can report to one another
Speaker 1: and to their bosses. And because of this hierarchy, stack
Speaker 1: block would not try to start its job until Find
Speaker 1: and Fetch had finished their jobs. So they is that
Speaker 1: these subagents are totally mindless. But when these sub agents
Speaker 1: come together, the whole system starts to look pretty smart.
Speaker 1: So this idea of subagents didn't solve the problem entirely,
Speaker 1: but it helped a lot, and most importantly, it brought
Speaker 1: into focus a new idea about the working of biological brains.
Speaker 1: Marvin Minsky suggested that human minds perhaps were collections of
Speaker 1: enormous numbers of machine like mindless subagents that collaborate. So
Speaker 1: the key idea is that a bunch of small specialized
Speaker 1: workers can give rise to something like a society with
Speaker 1: all kinds of rich properties that no subagent has by itself.
Speaker 1: Each little guy is just doing some simple thing, but together,
Speaker 1: when they're connected in the right way, you get something
Speaker 1: that looks like intelligence. So the suggestion was that and
Speaker 1: thousands of little minds are better than one large one.
Speaker 1: And if this sounds weird, just think about how factories work.
Speaker 1: Each person on the assembly line is specialized. They do
Speaker 1: one simple job. No one there knows how to do everything,
Speaker 1: and yet complex products get built out of this. And
Speaker 1: this is also how government ministries operate. Each bureaucrat has
Speaker 1: one task or a few very specific tasks, and the
Speaker 1: government succeeds on its ability to distribute the work appropriately
Speaker 1: and on larger scales. This is how civilizations operate. They
Speaker 1: reach the next level of sophistication when they learn to
Speaker 1: divide labor. They commit some people to specialize in agriculture,
Speaker 1: and some to art, and some to warfare and so on.
Speaker 1: This division of labor allows specialization and a deeper level
Speaker 1: of expertise, so even though no one knows how other
Speaker 1: jobs work, as an emergent result, you get civilization. So
Speaker 1: this idea of dividing up problems into smaller subroutines that
Speaker 1: ignited the young field of artificial intelligence back in the
Speaker 1: nineteen seventies. Instead of trying to develop a single all
Speaker 1: purpose program, the scientists changed their goal. Now it was
Speaker 1: to build a system out of smaller, local expert networks
Speaker 1: which know how to do one single thing. And in
Speaker 1: this framework, the larger system only has to switch which
Speaker 1: of the experts has control at any given moment. The
Speaker 1: learning challenge now involves not so much how to do
Speaker 1: each little task, but instead how to distribute who's doing
Speaker 1: what when. So, as Minsky suggested in his book The
Speaker 1: Society of Mind, perhaps that's all the human brain has
Speaker 1: to do as well, and he noted that if brains
Speaker 1: really do work this way as collections of subagents, we
Speaker 1: wouldn't have any reason to be aware of the specialized processes.
Speaker 1: He said, quote thousands and perhaps millions of little processes
Speaker 1: must be involved in how we anticipate, imagine, plan, predicts,
Speaker 1: and prevent, and yet all this proceeds so automatically that
Speaker 1: we regard it as ordinary common sense. At first, it
Speaker 1: may seem incredible that our minds could use such intricate
Speaker 1: machinery and yet be unaware of it. When scientists began
Speaker 1: to look into the brains of animals, Minsky's society of
Speaker 1: mind idea open up a new way of looking at things.
Speaker 1: In the early nineteen seventies, researchers realized that a frog
Speaker 1: has at least two separate ways of seeing motion. One
Speaker 1: system is looking for small darting objects like a fly,
Speaker 1: and it directs the tongue, and the other system is
Speaker 1: looking for large looming objects like a person, and it
Speaker 1: tells the lef legs to jump. And presumably neither of
Speaker 1: these systems is conscious. Instead, they're just simple automated programs
Speaker 1: that are burned down in the circuitry. So the society
Speaker 1: of mind framework was an important step forward. But despite
Speaker 1: the initial excitement about it, a collection of experts with
Speaker 1: divided labor has never proven sufficient to yield the properties
Speaker 1: of the human brain. It's still the case that our
Speaker 1: smartest robots are less intelligent than a three year old child.
Speaker 1: So what went wrong? I suggested in my book Incognito
Speaker 1: that a critical factor was missing from the division of
Speaker 1: labor models, and we turn to that now. The missing
Speaker 1: factor in Minski's theory was competition among the experts who
Speaker 1: all believe they know the right way to solve the problem.
Speaker 1: Just like a good drama, the human brain runs on conflict.
Speaker 1: In an assembly line a government ministry, each worker is
Speaker 1: an expert in a small task. But in contrast, parties
Speaker 1: in a democracy hold different opinions about the same issues,
Speaker 1: and the important part of the process is the battle
Speaker 1: for steering the ship of state. Brains are like democracies.
Speaker 1: They're built of multiple overlapping experts who weigh in and
Speaker 1: compete over different choices. As the poet while Whitman correctly surmised,
Speaker 1: we are large, and we harbor multitudes within us, and
Speaker 1: those multitudes are locked in chronic battle. There's an ongoing
Speaker 1: conversation among the different factions in your brain. They compete
Speaker 1: to control the single output channel of your behavior. So
Speaker 1: as a result, you can accomplish the strange feats of
Speaker 1: arguing with yourself, or cussing yourself, or cajoling yourself. These
Speaker 1: are things that computers simply don't do. So when the
Speaker 1: hostess at a party offers you chocolate cake, you can
Speaker 1: find yourself on the horns of a dilemma. Some parts
Speaker 1: of your brain have evolved to crave the rich energy
Speaker 1: source of sugar. Other parts of your brain care about
Speaker 1: the negative consequences, like the health of your heart or
Speaker 1: the bulge of your love handles. Part of you wants
Speaker 1: the cake, and part of you tries to gather the
Speaker 1: strength to pass on it. And the final vote of
Speaker 1: the parliament determines which party controls what you ultimately do.
Speaker 1: In other words, whether you put your hand up or
Speaker 1: you put your hand out. In the end, you either
Speaker 1: eat the chocolate cake or you don't, but you can't
Speaker 1: do both. Because of these internal multitudes, biological creatures can
Speaker 1: be conflicted. Now, the term conflicted can't be sensibly applied
Speaker 1: to an entity that has a single program. Your car
Speaker 1: can't conflicted about which way to turn. It has one
Speaker 1: steering wheel commanded by one driver, and it follows directions
Speaker 1: without complaint. But brains can be of two minds, and
Speaker 1: often many more than that. We don't know whether to
Speaker 1: turn toward the cake or away from it, because there
Speaker 1: are several little sets of hands on the steering wheel
Speaker 1: of our behavior. Consider this simple experiment that's been done
Speaker 1: with laboratory rats. If you put some cheese at the
Speaker 1: end of a little corridor, the rat will go towards
Speaker 1: the cheese, and you can hook up a little harness
Speaker 1: to feel how strongly he's pulling towards that. Now, let's
Speaker 1: say instead of the cheese, you put an electrical shock.
Speaker 1: Now the rat moves away from the electrical shock, and
Speaker 1: with the harness you can measure the force. Okay, Now
Speaker 1: you put both cheese and the electrical shock at the
Speaker 1: end of the hallway. And what the rat does is
Speaker 1: he begins to approach, but with draws, and he finds
Speaker 1: the courage to approach again. And what happens is he
Speaker 1: oscillates conflicted, and it's exactly at the distance where the
Speaker 1: two forces cancel out. In other words, he's going towards
Speaker 1: a thing, and he's pulling away from the thing, and
Speaker 1: both programs are running at once. The pull matches the push.
Speaker 1: The poor rat has two pairs of paws on its
Speaker 1: steering wheel, each pulling in opposite directions, and as a result,
Speaker 1: he can't get anywhere. So brains, whether rat or human,
Speaker 1: are machines made of conflicting parts. If building a contraption
Speaker 1: with internal division seems strange, just consider that we already
Speaker 1: build social machines like this. Think of a jury of
Speaker 1: peers in a courtroom trial. You have twelve strangers with
Speaker 1: different opinions, and they're tasked with this single mission of
Speaker 1: coming to a consensus. So the jurors argue and cox
Speaker 1: and the influence, and eventually the group coheres to a
Speaker 1: single decision, having differing opinions. It's not a drawback to
Speaker 1: the jury system. It is the central feature. When the
Speaker 1: President Abraham Lincoln was putting together his presidential cabinet, he
Speaker 1: chose to put in adversaries. The historian Doris Kern's Goodwin
Speaker 1: described his cabinet as a team of rivals, and we
Speaker 1: see this kind of team of rivals all the time.
Speaker 1: In Zimbabwe some years ago, the president Robert Mugabe agreed
Speaker 1: to share power with a rival that he had earlier
Speaker 1: tried to assassinate. And in China in two thousand and nine,
Speaker 1: the President Hu Jintao named two opposing faction leaders to
Speaker 1: help him craft China's future. I proposed in incognito that
Speaker 1: the brain is best understood as a team of rivals,
Speaker 1: and the rest of this episode and the next two
Speaker 1: are going to explore that framework. Who the parties are,
Speaker 1: how they compete, how the union is held together, what
Speaker 1: happens when things fall apart. How this framework allows us
Speaker 1: to understand what products we buy and how we can
Speaker 1: use this understanding of the team of rivals to better
Speaker 1: navigate our own behavior into the future. As we move along,
Speaker 1: remember that different political parties typically have the same goal,
Speaker 1: which is success for their country, but they just have
Speaker 1: different ways of going about it. So, as Lincoln put it,
Speaker 1: rivals should be turned into allies quote for the sake
Speaker 1: of the greater good and for networks. In your brain
Speaker 1: neural subpopulations, the common interest is the thriving and survival
Speaker 1: of you the organism. In the same way that liberals
Speaker 1: and conservatives both love their country but can have different
Speaker 1: strategies for steering it. It's the same way in the
Speaker 1: brain you have competing factions that all believe they know
Speaker 1: the right way to solve problems. When trying to understand
Speaker 1: the strange details of human behavior, psychologists or economists sometimes
Speaker 1: refer to a dual process account, and you'll know this,
Speaker 1: for example, if you've read Daniel Kahneman's book Thinking Fast
Speaker 1: and Slow. In that framework, the brain has two separate systems.
Speaker 1: One is fast and automatic and below the surface of
Speaker 1: conscious awareness, and the other system is slow and cognitive
Speaker 1: and conscious, and these two systems are always battling it out. Now,
Speaker 1: this is a very good start to thinking about it,
Speaker 1: but there's no real reason to assume that there are
Speaker 1: only two systems. In fact, as we're going to see,
Speaker 1: there are many systems, and there are also different ways
Speaker 1: to think about how to divide things up. So in
Speaker 1: nineteen twenty, Sigmund Freud suggested three competing parts in his
Speaker 1: model of the psyche. There was the id, the ego,
Speaker 1: and the superego. The id was all about instinct, the
Speaker 1: ego was realistic and organized, and the super ego was
Speaker 1: critical and moralizing. In the nineteen fifties, the neuroscientist Paul
Speaker 1: MacLean suggested that the brain is made of three layers
Speaker 1: that represent successive stages of evolutionary development. There's the reptilian brain,
Speaker 1: which is involved in survival behaviors, and the limbic system,
Speaker 1: which underlies the emotions. And in higher animals, there's the
Speaker 1: neo core text, which is used in higher order thinking. Now,
Speaker 1: the details of both Freud's model and Maclean's model have
Speaker 1: largely fallen out of favor, but the heart of the
Speaker 1: idea survives, which is that brains are made of competing subsystems.
Speaker 1: I'll start with a simple model of competition as a
Speaker 1: starting point because it captures one way to see this picture,
Speaker 1: but by the next episode we'll see that it's even
Speaker 1: more sophisticated than that. So we'll start with a general
Speaker 1: statement about the brain's anatomy, which is that some areas
Speaker 1: of your brain are involved in higher order operations regarding
Speaker 1: events in the outside world. For the cognitionandy, this area
Speaker 1: is like the dorsilateral prefrontal core text, which is on
Speaker 1: the surface of your brain, just inside your temples, so
Speaker 1: those are monitoring and assessing the outside world, while other
Speaker 1: areas are involved with monitoring your internal state, like your
Speaker 1: level of hunger, or your sense of motivation, or whether
Speaker 1: something is rewarding to you. And this includes areas like
Speaker 1: the region just behind your forehead called the medial prefrontal cortex,
Speaker 1: in several areas deep below the surface, so these monitor
Speaker 1: what's going on on the inside. Now, again, the real
Speaker 1: situation is even more complex than this rough division would imply,
Speaker 1: because brains do a lot more than just monitor the
Speaker 1: outside and the inside. Your brain also simulates future states
Speaker 1: and reminisces about the past and figures out where to
Speaker 1: find things not immediately present, and so on. We'll get
Speaker 1: into that, but for the moment, this division into systems
Speaker 1: that monitor the outside and the inside will serve as
Speaker 1: a rough guide, and we can refine this picture later.
Speaker 1: Now to pick two labels that'll be familiar to everyone.
Speaker 1: We can call these the rational and the emotional systems.
Speaker 1: Are a little underspecified and imperfect, but they carry this
Speaker 1: starting point about rivalries in the brain. The rational system
Speaker 1: is the one that cares about analysis of things in
Speaker 1: the outside world, while the emotional system monitors the internal
Speaker 1: state and worries whether things will be good or bad.
Speaker 1: In other words, as a rough guide, rational cognition involves
Speaker 1: external events, while emotion involves your internal state. So you
Speaker 1: can do a math problem without consulting your internal state,
Speaker 1: but you have to consult your internal state to order
Speaker 1: a dessert off the menu, or to prioritize what you
Speaker 1: feel like doing next. The emotional networks are absolutely required
Speaker 1: to rank your possible next actions in the world. If
Speaker 1: you were an emotionless robot who rolled into a room,
Speaker 1: you might be able to analyze this stuff around you,
Speaker 1: but you would be frozen with indecision about what to
Speaker 1: do next. Choices about the priority of actions are determined
Speaker 1: by our internal states. When you get home, will you
Speaker 1: head straight to your refrigerator or the bathroom or the bedroom.
Speaker 1: That doesn't depend on the external stimuli in your home
Speaker 1: because those haven't changed, but instead on your body's internal states.
Speaker 1: So the battle between the rational and the emotional systems
Speaker 1: can be brought to light by what philosophers call the
Speaker 1: trolley dilemma. Here's the scenario. A trolley is barreling down
Speaker 1: the train tracks. It's going out of control, and five
Speaker 1: workers are making repairs way down the track, and you,
Speaker 1: a bystander, realize that they're all going to get killed
Speaker 1: by this trolley. But you also notice that there's a
Speaker 1: lever nearby that you can throw, and that will divert
Speaker 1: the trolley down a different track where there's a single
Speaker 1: worker who will be killed. So what do you do?
Speaker 1: Do you throw the lever or not? If you're like
Speaker 1: most people, you have no hesitation about throwing the lever
Speaker 1: because it's far better than only one person gets killed
Speaker 1: than five people. Right, Okay, so that's a good choice.
Speaker 1: But there's a second version. Of the trolley problem that
Speaker 1: presents an interesting twist. Imagine that the same trolley is
Speaker 1: barreling down the tracks. The same five workers are gonna
Speaker 1: get killed, but this time you're a bystander on a
Speaker 1: footbridge that goes over the tracks, and you notice that
Speaker 1: there's an obese man standing on the footbridge, and you
Speaker 1: realize that if you push him off the bridge, his
Speaker 1: bulk will be sufficient to stop the train and save
Speaker 1: the five workers. Do you push the man off? If
Speaker 1: you're like most people, you bristle at this suggestion of
Speaker 1: murdering an innocent person. But here's the thing. What differentiates
Speaker 1: this from your previous choice. Aren't you trading one life
Speaker 1: for five lives? In both versions of the dilemma? Doesn't
Speaker 1: the math work out the same way? So what is
Speaker 1: the difference in these two cases. Philosophers propose that the
Speaker 1: difference lies in how people are being used. In the
Speaker 1: first scenario, you're simply reducing a bad situation, the death
Speaker 1: of five people, to a less bad situation, the death
Speaker 1: of one person. In the case of the man on
Speaker 1: the bridge, he is being exploited as a means to
Speaker 1: an end. So that's a popular explanation in the philosophy literature,
Speaker 1: but there's also a more brain based approach to understanding
Speaker 1: this reversal in your choice. Neuroscientists Joshua Green and Jonathan
Speaker 1: Cohen did brain imaging while people consider these two scenarios,
Speaker 1: and what they found was that the difference pivots on
Speaker 1: the emotional component of actually touching someone that is interacting
Speaker 1: with them at a close distance. So if the problem
Speaker 1: is constructed so that the man on the footbridge can
Speaker 1: be dropped with the flip of a switch through a trapdoor,
Speaker 1: many people will vote to let him drop. But there's
Speaker 1: something about interacting with the person up close that stops
Speaker 1: most people from pushing the man to his death. Why
Speaker 1: it's because that sort of personal interaction activates these emotional networks.
Speaker 1: It changes the problem from an abstract, impersonal math problem
Speaker 1: into a personal emotional decision. So when people consider the
Speaker 1: trolley problem, here's what the brain imaging reveals. In the
Speaker 1: footbridge scenario, where you actually have to push the guy,
Speaker 1: the brain areas involved in motor planning and emotion become active.
Speaker 1: But in pulling the lever scenario, the only brain errors
Speaker 1: involved are those involved in rational thinking. People register emotionally
Speaker 1: when they have to push someone. But if you only
Speaker 1: have to tip a lever, your brain behaves like mister Spock,
Speaker 1: who's the vulcan on Star Trek, who's all rationality and
Speaker 1: no emotion, who says emotions are alien to me. The
Speaker 1: battle between emotional and rational networks in the brain is
Speaker 1: nicely illustrated by an old episode of The Twilight Zone,
Speaker 1: which I saw years ago. Here's how it goes. A
Speaker 1: stranger in an overcoat shows up at a man's door
Speaker 1: and proposes a deal. He says, here is a box
Speaker 1: with a single button on it. All you have to
Speaker 1: do is press the button, and I will pay you
Speaker 1: one thousand dollars. The man says, what happens when I
Speaker 1: press the button? And the stranger says, when you press
Speaker 1: the button, someone far away, someone you don't even know,
Speaker 1: will die. So the man suffers over this moral dilemma
Speaker 1: through the night, and the button box rests on his
Speaker 1: kitchen table and he stares at it, and he paces
Speaker 1: around it, and sweat is on his brow, and he's
Speaker 1: thinking about his desperate financial situation, and finally he lunges
Speaker 1: to the box and he punches the button and nothing happens.
Speaker 1: It's quiet, anticlimactic. And suddenly there's a knock at the door,
Speaker 1: and the stranger in the overcoat is there, and he
Speaker 1: hands the man the money and he takes the box,
Speaker 1: and the man says, wait, what happens now, And the
Speaker 1: stranger says, now, I take the box and I give
Speaker 1: it to the next person, someone far away, someone you
Speaker 1: don't even know now. I loved this story because it
Speaker 1: highlights the ease of impersonally pressing a button. If the
Speaker 1: man had been asked to attack someone with his hands,
Speaker 1: he presumably would have declined the offer. In earlier times
Speaker 1: in our evolution, there wasn't really any way to interact
Speaker 1: with other people at any distance other than hands and
Speaker 1: feet are possibly a stick, and that distance of interaction
Speaker 1: was salient and consequential. And this is what our emotional
Speaker 1: reaction reflects. But interestingly, as we evolved, the situation began
Speaker 1: to change. Generals and even soldiers could very commonly find
Speaker 1: themselves very far removed from the people that they were killing.
Speaker 1: There's a great line in Shakespeare's Henry the Sixth where
Speaker 1: a man challenges a nobleman and mocks the fact that
Speaker 1: the nobleman has never known the danger of the battlefield.
Speaker 1: The man says, when struckest thou one blow in the field,
Speaker 1: and the nobleman responds, great men have reaching hands oft?
Speaker 1: Have I struck those that I never saw? And struck
Speaker 1: them dead? And this is what happens all the time.
Speaker 1: In modern warfare, we can launch Tomahawk surface to surface
Speaker 1: missiles from the deck of Navy ships with the touch
Speaker 1: of a button. The result of pushing that button is
Speaker 1: then watched by the missile operator live on CNN. Minutes
Speaker 1: later when buildings in the enemy's city disappear in plumes,
Speaker 1: so the proximity is lost, and so is the emotional influence.
Speaker 1: This impersonal nature of waging war makes it disconcertingly easy.
Speaker 1: I recently heard an argument between an old time fighter
Speaker 1: pilot who was lamenting how easy it is for drone
Speaker 1: pilots to do something, and he's right, But it should
Speaker 1: also be noted that it's easy when you're thousands of
Speaker 1: feet in the air. If you watch the footage of
Speaker 1: the bombing of Hiroshima and Nagasaki, which was dropping these
Speaker 1: ten thousand pound nuclear bombs onto civilian targets, you'll hear
Speaker 1: the total casualness of the pilot even though each bomb
Speaker 1: wiped out almost one hundred thousand people, and in fact,
Speaker 1: the pilot later said quote, I made up my mind
Speaker 1: then that the morality of dropping that bomb was not
Speaker 1: my business. I was instructed to perform a military mission
Speaker 1: to drop the bomb. Now, I'm not making a judgment
Speaker 1: about a military pilot's obligation in the middle of a
Speaker 1: world war. It was a complex issue that is difficult
Speaker 1: to be understood by a modern audience who hasn't just
Speaker 1: lived through years of war and is looking for a
Speaker 1: way to end it. That I am saying saying it's
Speaker 1: surprising to see how easy it appeared to press the
Speaker 1: button to open the bomb doors from thirty three thousand
Speaker 1: feet in the air, as opposed to if the pilot
Speaker 1: had been sent in to murder one hundred thousand civilians,
Speaker 1: including women and children, with a knife or with his hands.
Speaker 1: I assume it would have been a very different experience
Speaker 1: for him. So, in thinking about these issues about how
Speaker 1: easy it is to wage war when it's impersonal, one
Speaker 1: political thinker in the nineteen sixties suggested that the button
Speaker 1: to launch a nuclear war should be implanted in the
Speaker 1: chest of the president's closest friend. That way, if the
Speaker 1: president wants to make the decision to annihilate millions of
Speaker 1: people on the other side of the globe, he'd first
Speaker 1: have to physically harm his friend. He'd have to rip
Speaker 1: open his chest to get at the button that would
Speaker 1: at least engage his emotional system in the decision making
Speaker 1: so as to guard against letting the choice be impersonal.
Speaker 1: Because both of these neural systems battle to control the
Speaker 1: single output channel of your behavior, emotions can tip the
Speaker 1: balance of decision making, and this ancient battle has turned
Speaker 1: into a directive of sorts from many people. If it
Speaker 1: feels bad, it is probably wrong. Now, there are lots
Speaker 1: of counter examples to this. For example, you can find
Speaker 1: yourself put off by a particular choice, but still conclude
Speaker 1: that it's not morally wrong, like putting your pet down
Speaker 1: when it gets too old and sick, even though it
Speaker 1: breaks your heart. Nonetheless, emotion serves as a generally useful
Speaker 1: steering mechanism for decision making. The emotional systems are evolutionarily
Speaker 1: quite old, and they're shared with many other species, while
Speaker 1: the development of the rational system is more recent. But
Speaker 1: the novelty of the rational system doesn't necessarily indicate that
Speaker 1: it's by itself superior. Societies would not be better off
Speaker 1: if everyone were like the vulcan mister Spock, all rationality
Speaker 1: and no emotion. Instead, a balance, a teaming up of
Speaker 1: the internal rivals is probably optimal for brains. And that's
Speaker 1: because the disgust that we feel at pushing the man
Speaker 1: off the footbridge is critical to social interaction. The impassivity
Speaker 1: that one feels at pressing a button to launch a
Speaker 1: Tomahawk missile is probably detrimental to civilization. Some balance of
Speaker 1: the emotional and rational systems is needed, and that balance
Speaker 1: may already be optimized by natural selection in human brains. Or,
Speaker 1: to put it in another way, a democracy that is split
Speaker 1: across the aisle maybe just what you want, because a
Speaker 1: takeover in either direction would almost certainly prove less optimal.
Speaker 1: The ancient Greeks had an interesting analogy for life that
Speaker 1: captured this wisdom. The idea was that life is as
Speaker 1: though you are a charioteer and your chariot is being
Speaker 1: pulled by two horses. One is the horse of reason
Speaker 1: and the other is the horse of passion. One horse
Speaker 1: is always trying to tug you off one side of
Speaker 1: the road, and the other is trying to pull you
Speaker 1: off the other side, and your job is to hold
Speaker 1: on to them tightly and keep them in check so
Speaker 1: that you can continue down the middle of the road.
Speaker 1: And that's what we try to do with the brain
Speaker 1: networks involved in rationality and emotion. So what we've introduced
Speaker 1: in today's episode is the way in which the brain
Speaker 1: is a machine built out of conflicting parts. In the
Speaker 1: next episode, we're going to explore how this team of
Speaker 1: rivals expresses itself in very particular ways, like how we
Speaker 1: choose what to buy or how much something should cost.
Speaker 1: This is the basis of a new type of economics
Speaker 1: called neuroeconomics, so tune into that to uncover the next
Speaker 1: juicy bits. That's all for this week. To find out
Speaker 1: more and to share your thoughts, head over to eagleman
Speaker 1: dot com, slash Podcasts, and you can also watch full
Speaker 1: episodes of Inner Cosmos on YouTube. Subscribe to my channel
Speaker 1: so you can follow along each week for new updates
Speaker 1: until next time. This is Inner Cosmos and I'm David Eagleman.