The Brain with Dr. David Eagleman (2015) s01e05 Episode Script
Why Do I Need You
What does a brain need to be healthy? Well, it needs nutrients from the food you eat, it needs oxygen from your blood, plenty of water but there's something else, something equally as important.
It needs other people.
Human beings are extremely social creatures.
We come together, we team up, we share moments of intense joy and disappointment.
We don't just seek out other people to have a good time.
Your brain function depends on the social web that you're in.
Your neurons require other people's neurons to thrive and survive.
I want to show you how our brains are fundamentally wired to work together How this social network that envelops us from birth is vital for our survival.
Yeah? Ok! Eagleman, voice-over: Understanding how brains deal with each other allows us to understand what bonds our species, driving us to help one another.
And what makes us hate What allows acts of human violence.
It helps us to make sense of our past and holds the key to our future.
There are 7 billion people living today 7 billion brains moving, choosing, acting, believing, and connecting with other brains.
Brains are traditionally studied in isolation.
But, in fact, much of circuitry of the brain has to do with other brains.
We're fundamentally social creatures.
And our society is a complex web of interaction.
On any normal day, we intersect with an enormous number of people.
Eagleman, voice-over: Our lives are built on these intersections, not just between us and our family and friends and work colleagues, but also between them and the people they meet.
Even the most basic encounter Like getting a cup of coffee Eagleman, voice-over: Relies on trust with a stranger.
Can I get a latte, please? Definitely.
Thanks.
Eagleman, voice-over: Everywhere we look, we see complex social interactions relationships forming and breaking, bonds of love and support, social networking.
We clump into large groups to share our knowledge.
We got all these random spots in your brain that get wired up into an associative neural network.
Eagleman, voice-over: We work to impress each other.
And we swap ideas.
I'll stick around for any questions that anyone has.
Thank you.
Eagleman, voice-over: Most research looks at one brain at a time, but that misses the fact that a great deal of our brain activity is dedicated to communicating with each other, interpreting each other.
Our social drive is deeply rooted in our neural circuitry.
Take a look at this film from the 1940s.
What do you see happening here? Is this just a simple animation of some shapes or something more? Do you see a chase? A fight? A love story? The big one seems to be pushing the little one around.
Seems like the two triangles are in a little bit of a squabble.
There are relationships re in terms of one is more dominant than the other.
Eagleman, voice-over: Back in the 1940s, psychologists Fritz heider and marianne simmel created this film as part of an experiment.
The ball doesn't seem to want to be in there.
It's freaking out.
It's scared.
It looks like a trap to me.
It looks like the small triangle is being shut out and, like, trying to peer in.
They are paired in a way that seems friendly.
Yeah! This is really fun.
It's fun, right? Ha ha! Eagleman, voice-over: What heider and simmel found, as I did, is how easy it is to look at moving shapes and to see meaning and motives and emotion all in the form of a social narrative.
I kind of get the sense that they're cats and dogs.
It seemed like the big one might have been, like his, uh, his dad or something.
Just call it more of, like, a mating ritual two competitors going for one possible mate.
These are just shapes on a screen, but we can't help but tell stories about them.
Why? It's because our brains are so primed for social interaction that we look for intention and relationships all around us.
One way we navigate the social world is by judging other people's intentions.
Is she trying to be helpful? Are we a trustworthy team? Our brains are good at making these sorts of judgments.
And we do it constantly.
But do we learn this skill from life experience, or are we born with it? To figure out which one it is, I've invited over some people who don't have much experience with the world.
I've invited them to a puppet show.
These babies are all under 12 months old.
They're just beginning to explore the world around them.
You could say they're all a little short on life experience.
We decided to run a simple experiment developed at Yale university.
Here's a duck struggling to open a box.
One bear helps the duck.
The other is mean to the duck.
Ok, bowie, here you go.
There are two puppets Eagleman, voice-over: When the show's over, I let the babies choose a bear to play with.
want to play with? Yeah? Ok, is that the one you want? All right.
Eagleman, voice-over: Almost every one of them chooses the bear that's been kind.
These babies can't walk or talk.
And yet they already have the tools to make judgments about others.
Yeah? Ok! It's often assumed that trust is something that we learn from our experience in the world.
But these experiments demonstrate that even as babies, we come equipped with social antennae for feeling our way through the world.
The brain comes with inborn instincts for figuring out who's trustworthy and who's not.
Eagleman, voice-over: As we grow, our social challenges become even more subtle and complex.
Understanding others is one of the most demanding operations that our brains perform.
They have to interpret words.
And, more than that, inflection, facial expressions, body language.
"Does she like me?" "Is he interested in what I'm saying?" "Do they want my help?" Society runs on our ability to read each other's social signals.
Take that ability away and the world becomes a very strange place.
Car enthusiast John robison has always struggled to read other people.
Robison, voice-over: When I was a little boy, I was bullied and rejected by other kids.
And that didn't happen with machines.
You know, I could stand, uh, by, uh, a tractor on my grandparents' farm.
And I could learn how to adjust it.
And it wouldn't tease me or do anything bad.
It wouldn't run away.
It would always be there.
And I could count on it.
And i i guess I learned to make friends with the machines before I learned how to make friends with other people.
Eagleman, voice-over: In time, John's affinity for technology took him to places his bullies could only dream of.
By 21, he was a roadie for the band kiss.
This was me back with, uh, kiss in the seventies.
Uh, I look older and fatter and stuff.
I don't look the same anymore.
Eagleman, voice-over: Surrounded by legendary rock and roll excess, his outlook remained different from other people's.
People would come up to me all the time.
And they would say, "what's this guy like," or, "what's that guy like?" I would say, "yeah, their stage setup, "they had sunn 2000s bass amps," or Or, "gene played sunn coliseums", and we had seven bass amps chained together.
"We had 2,200 watts in the bass system for that.
" But I maybe couldn't tell you the first thing about the musicians who sang through them.
Now I realize that shows that I did kind of live in a different world all those years a world of machines and equipment.
Eagleman, voice-over: When he was 40, John was diagnosed with asperger's a form of autism.
Many regions of the brain are engaged during social interaction.
But in autism that brain activity isn't seen as strongly.
And that's paralleled by diminished social skills.
I didn't really understand that there were complex messages in faces until I was well into adulthood and learned about autism.
I knew that people could, uh, display signs of crazed anger.
But if you, um, asked about more subtle expressions you know, "I think you're sweet", "and I wonder what you're hiding," or, "I'd really like to do that," or, "I wish you'd do this" Or that.
II had no idea about things like that.
Eagleman, voice-over: But then came a transforming moment in John's life.
In 2008, he was invited to Harvard medical school to take part in an experiment on his brain overseen by Dr.
Alvaro pascual-Leone.
It was an attempt to try to understand how activity in one area affects activity in an area In another area and how that affects behavior.
Eagleman, voice-over: The experiment was only meant to help the scientists gain greater knowledge about the autistic brain, but then something unexpected happened.
John was given transcranial magnetic stimulation or tms.
Magnetic coils were placed next to his head to generate minute electrical currents in the brain and alter its activity.
The researchers targeted different regions of John's brain to see whether interfering with his brain activity had any effect on his behavior.
They would test me after the session.
I would go home kind of not knowing what to expect.
Eagleman, voice-over: At first there was no result.
But then they targeted the dorsolateral prefrontal cortex a region involved in flexible thinking and abstraction.
And something dramatic happened.
Somehow I became different.
He contacted us, uh very excited to say, you know, "the effects of the stimulation "seemed to have unlocked something.
"And the effects is still lasting.
And I now can do things that I could never do.
" After tms, I was able to, uh, sort of read signals from other people and understand what was going on.
So I listened to that, fascinated by it, and thought, "ok, well, whatever.
It'll go away.
" Uh, but it didn't.
It It actually, um, remains something that that had really fundamentally changed in In him.
Eagleman, voice-over: Somehow, and entirely accidentally, the tms had unlocked a whole new world for John.
vegetable sandwich to bring home.
What have you got Robison, voice-over: I'd be tempted to say, "I couldn't read people and now I can," but that's not really true.
Ok.
How about a full-size one of them Sure.
It's more accurate to say I had no idea there were these messages emanating from other people.
Tms showed me those messages.
And now that I'm aware that they're out there, everything I do is different.
All of a sudden, you can walk around and engage the world.
And it's a big, big thing.
Ok, thanks! We don't know exactly what happened neurobiologically.
Um But I think it now offers the opportunity for us to understand what behavioral modifications, what interventions might be possible to learn from him that we can then teach others.
Eagleman, voice-over: John's transformation is a reminder that all the activities of the human brain, including the subtle interplay of emotions and relationships, are rooted in the detailed patterns of trillions of electrochemical signals.
Eagleman, voice-over: Somehow, humans can look at each other and study the arrangement of facial muscles and then process that information into an understanding of other people's thoughts and emotions.
Eagleman, voice-over: It's an astonishing skill because the cues are so subtle.
And the processing is so rapid that the whole operation runs under your radar.
It only takes 33 milliseconds for your brain to process basic information about someone's facial expression and start reacting to it.
So we're gonna put one electrode right above your eyebrow Eagleman, voice-over: So how does it do that? And the other right on your cheek.
Here we go.
Great Eagleman, voice-over: I've invited a group of people to run an experiment.
I've wired them up to a machine that measures movements in their facial muscles.
And I've asked them to look at photographs of faces.
When participants are looking at a photograph with a smile or a frown, we see this activity on the graph which indicates that their own facial muscles are moving.
Why? Well, it turns out that they are automatically mirroring with their own faces the expressions that they're seeing.
That was fun, right? The last one? Yeah.
Yeah, it was a fun test.
Eagleman, voice-over: But what purpose does this mirroring serve? I've invited a second group of people.
They're similar to the first group, except for one thing.
This is the most lethal neurotoxin on the planet.
If you were to ingest even a fraction of this, your brain could no longer tell your muscles how to contract and you would die of total paralysis.
So it seems unlikely that anyone would pay to have this injected into themselves, but they do.
This is known as botulinum toxin or Botox.
If you put it into your forehead muscles, it paralyzes them to reduce wrinkling.
But there's a less well known side-effect.
Eagleman, voice-over: When our participants with Botox went through the same tests, their facial muscles responded less.
No surprise there.
But replicating an experiment out of Duke university, we had both groups look at facial expressions.
And now they were asked to choose the word that best described the emotion they were seeing.
Panic.
Panicked.
Upset.
Eagleman, voice-over: On average, the Botox group was worse at identifying the emotions correctly.
Skeptical? Eagleman, voice-over: It seems that the lack of feedback from their facial muscles impairs their ability to read other people.
The paralyzed faces of Botox users not only makes it hard for us to tell what they're feeling, those same frozen muscles make it hard for them to read us.
And that tells us something.
When I'm happy or sad, part of that feeling relies on the unconscious feedback from muscles in my face.
And our social brains take advantage of that so when we're trying to understand what someone else is feeling, we try on their facial expression.
This automatic mirroring of expressions is just one way in which we understand others.
The brain also has a deeper way one that's best explained at the movies.
One ticket, please.
Thank you.
Eagleman, voice-over: When we go to the movie theater, we know full well that it's make-believe.
The people on the screen are just acting.
And yet we still react.
We gasp and flinch and cry.
Why do we fall for it? To understand why we care about other people getting hurt, you need to understand what happens in your brain when you get hurt.
So imagine that somebody were to stab your hand with a syringe needle.
That activates a network of areas in your brain that we call the pain matrix.
Eagleman, voice-over: There's no single spot in the brain where pain is processed.
Instead, the perception of pain arises from several different areas networking together.
Strangely enough, this pain matrix is at the heart of how we connect with others.
Eagleman, voice-over: Now, when you watch someone else get stabbed, your pain matrix becomes activated.
Not the parts that tell you you've actually been touched, but the parts involved in the emotional experience of pain.
In other words, watching someone else in pain and being in pain use the same neural machinery.
And that's the basis of empathy.
To empathize with another person is to literally feel their pain.
You run a compelling simulation of what it would be like if you were in that situation.
And our capacity to do this is why stories and movies and novels are so absorbing and why they're so pervasive across human culture.
Because whether it's about total strangers or made-up characters, you experience their agony and their ecstasy.
You fluidly become them and live their lives and stand in their vantage points.
You can tell yourself that the stories aren't real, but some neurons deep in your brain can't tell the difference.
Eagleman, voice-over: Our capacity to feel another person's pain is part of what makes us so good at taking other people's perspective to step out of our shoes and into their shoes, neurally speaking.
Eagleman, voice-over: We can't help but connect with others.
We're hardwired to be extremely social creatures.
And that raises a question.
What would happen if the brain were starved of human contact? In 2009, peace activist Sarah shourd and her two companions were hiking in the mountains of northern Iraq an area that was at the time peaceful.
But they accidentally strayed into Iran, and they were arrested.
They pulled us apart and threw us in separate cells and slammed the door.
And, um, that was the beginning of of the next 410 days of my life in that cell.
Well, in the early weeks and, really, months of solitary confinement, you're reduced to an animal-like state.
I mean, you are an animal in a cage.
And the majority of your hours are pacing.
And the animal-like state sort of eventually transformed into a more plant-like state When your mind starts to slow down and your thoughts become repetitive.
Shourd, voice-over: Your brain turns on itself.
And it becomes the the source of your worst pain and your worst torture.
I would relive every detail of my life.
And eventually, you run out of of memories.
And you've told them all to yourself so many times, and it doesn't take that long.
Eagleman, voice-over: Extreme social depravation causes deep psychological pain.
Without interaction, the brain suffers.
Solitary confinement is designed to eat away at and really attack what essentially makes us human.
Eagleman, voice-over: Sarah's brain used the scant sensory information it had to construct a reality.
The sun would come in at a certain time of day at an angle through my window.
And all of the little dust particles in my cell were illuminated by the sun.
I saw all of those particles of dust as being other human beings occupying the planet.
And they were in the stream of life.
They were interacting.
They were bouncing off one another.
They were doing something collective.
And I saw myself as off in a corner, you know, walled off by by myself out of the stream of life.
Eagleman, voice-over: In September 2010 after 410 days in solitary confinement, Sarah was finally released and allowed to rejoin the world.
But for a long time, she suffered from extreme post-traumatic stress.
The philosopher Martin heidegger said we can't talk about being.
We can only talking about being in the world.
In other words, the world around you is a part of who you are.
In a vacuum, you lose your sense of self.
It's not easy for science to study people while they're experiencing solitary confinement, but a simple experiment designed by neuroscientist Naomi eisenberger can give us an insight into what's happening in the brain when we feel excluded.
It's based on a game of catch.
While volunteers played a computer game of catch, eisenberger and her team scanned their brains.
The volunteers thought the other characters were controlled by other participants, but, in fact, they were just part of the computer program.
At first, the other characters played nicely, but after a while, they'd cut the volunteer out of the game and simply play between themselves.
She found that being left out of the game activated the pain matrix.
Not getting the ball might seem insignificant, but to the brain, social rejection is so meaningful that it hurts.
Eagleman, voice-over: But that pain, in turn, is useful.
It pushes us in the direction of bonding with others.
We all seek out alliances.
We join with friends, with family, with colleagues.
It could be which team we support What style we go for What our hobbies are.
It gives comfort to belong to a group.
And that gives us a critical clue into our success as a species.
Survival of the fittest isn't just about individuals.
It's also about groups.
We're safer.
We're more productive.
We overcome challenges.
The drive to work in groups has helped human populations thrive across the planet and build entire civilizations.
And yet there's a flipside to this drive to come together.
Because for every "in" group, there are outsiders.
And the consequences of that can be very dark.
History is plagued with examples of one group turning on another that was defenseless and posed no threat.
If you were to look at my family tree, you would see that most of the branches end in the early 1940s.
This is because my family is ethnically Jewish.
That small social marker was enough to prompt Nazi genocide.
Under normal circumstances, you wouldn't find it conscionable to go murder your neighbor.
So what is it that allows hundreds or thousands of people to suddenly do exactly that? What is it about certain situations that short-circuits the normal social functioning of the brain? While the Nazi holocaust was on an unprecedented scale, it wasn't unique.
Genocide continued to occur all over the world.
And within a generation, it returned to eastern Europe.
This time, it was in yugoslavia.
The Bosnian war from 1992 to '95 saw atrocities on both sides.
In one of the worst, more than 100,000 Bosnian muslims, known as bosniaks, were slaughtered by serbians in actions known as ethnic cleansing.
One of the most horrible incidents happened here at srebrenica.
Eagleman, voice-over: Over the course of just 10 days, 8,000 people were systematically killed.
How does something like this happen? Here in 1995, thousands of bosniaks took refuge inside this united nations compound, because this village was surrounded by siege forces.
But then on July 11th, the u.
N.
Commanders made the decision to expel all the refugees.
And they delivered them right into the hands of their enemies, who were waiting just outside this gate.
Women were raped, and men were executed, and even children were killed.
And this was just the beginning of what would be the largest genocide on European soil since the holocaust.
The Dutch were there.
I mean, the world was there.
You know, the u.
N.
The serbs were there as perpetrators.
Everything was mixed.
The refuges were there, the babies were crying.
I was there being protected with that u.
N.
I.
D.
Card that said "u.
N.
Language assistant," whatever.
Eagleman, voice-over: Hasan nuhanovic's status as a u.
N.
Translator made him part of a protected group.
But his family members were marked out by their identity as muslims.
At that very moment when my family was being sent out of the compound to actually die, I lost my I lost my mother, my brother, and my father.
You know, like, you are in a situation when your family is being killed.
And I was thinking, my god I mean, why? Eagleman, voice-over: One of the most striking things is that the perpetrators weren't strangers.
They were people with whom his family had previously shared a great deal.
The continuation, you know, of Of the killings, of torture, was perpetrated by our neighbors.
You know? The very people we have been living with for decades.
They were capable of killing their own school friends.
I remember they said they arrested a dentist who was a bosniak, the best dentist in the town.
They tied him up from a light pole, like this in front of the post office.
He was hanging there like this.
And they beat him with a metal bar.
They broke his spine.
And he was there dying for days while serb children went to school, walking by his body, you know? I mean, there are universal values.
And these universal values are kind of very basic: Don't kill April '92, this don't kill suddenly disappeared.
It was like, "go and kill.
" It was, allowed to kill.
This is where hasan's family is buried.
And each year, there are new bodies that are found and identified, and they're brought here.
Many of these graves are fresh.
And across the human species, this is just one genocide of many.
Genocides keep happening Rwanda, Darfur, nanking, Armenia.
And my interest is in understanding why.
Traditionally we ask this question through the lens of history or economics or politics.
And those are all important vantage points.
But I think for a complete picture, one more lens is needed.
We need to understand genocide as a neural phenomenon.
I've been researching this back in my laboratory.
And here is my main question, when we interact with someone, does our brain function differ according to which group they are in? For every "in" group we belong to, there's at least one group that we don't.
And that division can be based on anything race or gender or wealth or religion.
We put 130 participants in this scanner.
Eagleman, voice-over: And here's what they saw six hands on the screen.
And the computer randomly picks one of these.
And then that hand gets stabbed by a syringe needle.
Now, that activates the pain matrix, which is what comes on line when you're in pain or you see someone else in pain.
Now here's the trick we now added a label to each hand Jewish, Christian, Muslim, hindu, atheist, scientologist.
Would they care as much when they see a member of their out group getting stabbed? So here's what we found: Here's a subject.
And when he watched a member of his "in" group getting stabbed, there was a large neural response in this area of his brain.
But when he watched a member of one of his "out" groups get stabbed, there was essentially a flat line.
We scanned a range of volunteers.
And there are individual differences, but the trend is clear.
A single word label is enough to change your brain's basic pre-conscious response to another person in pain in other words, how much you care about them.
Now, you might have opinions about religion and its historical divisiveness, but even atheists here care more about other atheists' hands getting stabbed than they do about other people.
So it's not really about religion.
It's about which team you're on.
This is just the first step in understanding how we get to this.
To understand how groups of people can commit atrocities, it can help to look at the behavior of individuals like psychopaths.
Some of the most callous, inhumane crimes ever recorded have been committed by psychopaths.
But what's different about their brains that allows them to act that way? There are networks in the medial prefrontal cortex that underlie social interaction.
When we interact with other people, this area becomes active.
But in the brain of someone with extreme psychopathy, this area has a lot less activity.
A psychopath doesn't care about you.
He might be able to run a simulation of what you're going to do or how you might react, but when it comes to an emotional understanding of what it's like to be you, he doesn't get that.
To him you're just an obstacle to be worked around or manipulated rather than a fellow human being.
So what accounts for genocide? Is it driven by armies of psychopaths? Well, that can't be it because psychopaths only make up a small fraction of the population, but genocide typically engages a wider community.
So here's the question: How do you get ordinary citizens on board? At the university of leiden in Holland, Dr.
lasana Harris has been conducting an experiment to understand a piece of this puzzle.
So now we're going to start the experiment.
What you're going to see is a bunch of pictures of different people.
Your job is just to react naturally to those pictures.
Eagleman, voice-over: Lasana is looking at activity in the brain areas involved in human social interaction, in particular, the medial prefrontal cortex.
This comes on line when we think about other people.
It's less active when dealing with something inanimate, like a cup.
What lasana found is that this region has a similarly low response when we deal with certain types of other people.
What he sees now are stereotypical images of people from different social groups.
What we see here is at this network of brain regions, including medial prefrontal cortex, is less active when our participant looks at the homeless people.
So what this pattern of activity suggests is a type of mental avoidance.
They are not thinking about the mind of the homeless person in the same way they thought about the mind of the college students that they saw or the businesspeople.
So if for instance you imagine that interacting with a homeless person will be unpleasant, it will make you will feel bad.
You may feel some demand to donate some of your money and all of these unpleasant pressures that come along with it.
By shutting off those systems, you never experience those feelings.
Eagleman, voice-over: To a brain that responds this way, homeless people are dehumanized.
They're viewed more like objects.
And that can enable us to not care.
Of course if you don't properly diagnose this person as a human being, which is happening here, then the different moral rules we have that are reserved for human people may not apply.
Eagleman, voice-over: So under the right circumstances, our brain activity can look more like a psychopath's.
But to understand how we can get to genocide, we need to understand one more thing about group behavior.
Genocide is only possible when dehumanization happens on a massive scale.
Not just a few individuals, but whole sections of the population.
We're talking about a group of people committing atrocities.
Eagleman, voice-over: And if all the members of that perpetrating group are complicit, it's as if they've all somehow experienced the same reduction in brain activity when they think about their "out" group.
This can be understood and studied like a disease outbreak, a kind of group contagion one that's most often spread deliberately.
The perfect tool for this job is propaganda.
It plugs right into neural networks, and it dials down the degree to which we care about other people.
Just like all sites of genocide, that's what happened in the former yugoslavia.
The people who went on to torture and kill their neighbors were bombarded with propaganda.
State-controlled broadcasters demonized the Bosnian muslims with distorted news stories.
I read you from the beginning that somebody is, uh, helping muslims, uh, and arming them.
Eagleman, voice-over: They went so far as to claim that the muslims were feeding serbian children to the lions at the zoo.
Across place and time, the language of propaganda changes very little.
It always plays the familiar tune of dehumanization: Make your enemy less than human, make them like an animal.
Propaganda is a weapon.
And over the course of human history, it's become an art and a science.
And it's become ever more dangerous.
Eagleman, voice-over: In our connected age, any extremist group can reach millions of people with a keystroke.
The Internet is the perfect carrier for propaganda messages to reach the people most likely to act upon them young men.
Eagleman, voice-over: The political agendas around us actually manipulate the brain activity inside of us.
So is there any way to stop what's happened in the past from continuing into the future? One possible solution lies in a 1960s experiment that was conducted not in a science lab but a school.
Eagleman, voice-over: It was 1968, the day after the assassination of Martin Luther King.
Is there anyone in this United States that we do not treat as our brothers? - Yeah.
- Who? The black people.
The black people.
Who else? Eagleman, voice-over: Jane Elliott was a teacher in a small town in Iowa.
And she wanted to show her class what prejudice really felt like.
How are black people treated? They don't get anything in this world.
Why is that? Because they're a different color.
Eagleman, voice-over: These two men were in that class.
This was Rex back then And this was ray.
How many in here have blue eyes? Ok.
How many in here have brown eyes? Ray, voice-over: Jane says we're going to have this exercise.
And she right away launches into the propaganda of blue eyes are better than brown eyes.
Blue-eyed people are better than brown-eyed people.
Eagleman, voice-over: Ray and Rex both have blue eyes.
You brown-eyed people are not to play with the blue-eyed people on the playground because you are not as good as blue-eyed people.
Eagleman, voice-over: The brown-eyeds were denied privileges given to the blue-eyeds, and they had to wear special collars.
You'll begin to notice today that we spend a great deal of time waiting for brown-eyed people.
Do you remember, uh What your own behavior was like when you were on top? I was tremendously evil to my friends.
How so? I was going out of my way to pick on my brown-eyed friends for the sake of my own promotion.
What did you do? I recall telling Mrs.
Elliott, Jane, that she should keep the yardstick at hand in case those brown-eyeds got out of control.
I don't see the yardstick.
Do you? It's down over there.
Hey, miss Elliott, you better keep that on your desk.
Don't let the brown-eyed people get out of hand.
At that time, my hair was quite blond and my eyes were quite blue.
And I was the perfect little Nazi.
I looked for ways to be mean to my friends, who minutes or hours earlier had been very close to me.
Eagleman, voice-over: But the next day, there was a reversal of fortune.
Yesterday I told you that brown-eyed people aren't as good as blue-eyed people.
That wasn't true.
I lied to you yesterday.
Oh, boy The truth is that brown-eyed people are better than blue-eyed people.
Rex, voice-over: A person you trust stands before you and says, "I was wrong.
" Now here's the truth," takes your world and shatters it like you've never had your world shattered before.
You blue-eyed people are not to play with the brown-eyed people.
Blue-eyed people go to the back.
The brown-eyed people come to the front.
Tell me a little more about what it was like when you were in the down group.
You have such a sense of loss of personality and self that it makes it almost impossible to function with what's going on in the room.
Should the color of some other person's eyes have anything to do with how you treat them? No, no.
All right.
Then should the color of their skin? No.
Should you judge people No By the color No Of their skin? No.
Eagleman, voice-over: If I were just gonna riff guess at it it's that, uh, one of the most important things we learn as humans is perspective taking.
And kids don't often get a really meaningful exercise in that.
And when you're forced into understanding what it's like to stand in someone else's shoes, that opens up a lot of cognitive pathways for you.
I remember saying something to my dad about a comment he made, saying, "no, that's not appropriate.
" And it did change within the family.
But you talk about a little kid making that statement, it's huge.
But it reaffirmed that you could do that you could begin to change.
The brilliance of the blue eyes/brown eyes experiment is that the teacher, Jane Elliott, switched which group was on top.
And that allowed the students to extract the larger lesson, which is that systems of rules can be arbitrary.
They learned that the truths of the world are not fixed, and they're not even necessarily truths.
And this is what empowered the children as they grew to see through the smoke and mirrors of other people's political agendas and to form their own opinions surely a skill that we should be teaching to all of our children.
Should the color of some other person's eyes have anything to do with how you treat them? No.
Eagleman, voice-over: When people are armed with an understanding of how propaganda works, the power of propaganda is reduced.
As we come to understand the deep importance of cooperation, we stand a chance not only of reducing dehumanization, but achieving our potential as a species.
Genocide doesn't have to be the norm.
Instead our fundamentally social nature can hold the key to our success as a species.
Our future, our survival is intimately, permanently bound up with that of the people around us.
Our social drive is at the root of extraordinary acts of bravery and generosity.
Who you are has everything to do with who we are.
Our brains are so fundamentally wired to interact that it's not always clear where each of us begins and ends.
Our species is more than just 7 billion individuals spread out across the planet.
We're something more like a single vast super-organism.
Because what your friends know and love as you is really a neural network embedded in a far larger web of other neural networks.
In this age of digital connection, we desperately need to understand the links between humans.
If we want our civilizations to have a bright future, we'll need to understand how human brains interact the dangers and the opportunities.
Because there's no avoiding the truth that's etched into our neural circuitry: We need each other.
It needs other people.
Human beings are extremely social creatures.
We come together, we team up, we share moments of intense joy and disappointment.
We don't just seek out other people to have a good time.
Your brain function depends on the social web that you're in.
Your neurons require other people's neurons to thrive and survive.
I want to show you how our brains are fundamentally wired to work together How this social network that envelops us from birth is vital for our survival.
Yeah? Ok! Eagleman, voice-over: Understanding how brains deal with each other allows us to understand what bonds our species, driving us to help one another.
And what makes us hate What allows acts of human violence.
It helps us to make sense of our past and holds the key to our future.
There are 7 billion people living today 7 billion brains moving, choosing, acting, believing, and connecting with other brains.
Brains are traditionally studied in isolation.
But, in fact, much of circuitry of the brain has to do with other brains.
We're fundamentally social creatures.
And our society is a complex web of interaction.
On any normal day, we intersect with an enormous number of people.
Eagleman, voice-over: Our lives are built on these intersections, not just between us and our family and friends and work colleagues, but also between them and the people they meet.
Even the most basic encounter Like getting a cup of coffee Eagleman, voice-over: Relies on trust with a stranger.
Can I get a latte, please? Definitely.
Thanks.
Eagleman, voice-over: Everywhere we look, we see complex social interactions relationships forming and breaking, bonds of love and support, social networking.
We clump into large groups to share our knowledge.
We got all these random spots in your brain that get wired up into an associative neural network.
Eagleman, voice-over: We work to impress each other.
And we swap ideas.
I'll stick around for any questions that anyone has.
Thank you.
Eagleman, voice-over: Most research looks at one brain at a time, but that misses the fact that a great deal of our brain activity is dedicated to communicating with each other, interpreting each other.
Our social drive is deeply rooted in our neural circuitry.
Take a look at this film from the 1940s.
What do you see happening here? Is this just a simple animation of some shapes or something more? Do you see a chase? A fight? A love story? The big one seems to be pushing the little one around.
Seems like the two triangles are in a little bit of a squabble.
There are relationships re in terms of one is more dominant than the other.
Eagleman, voice-over: Back in the 1940s, psychologists Fritz heider and marianne simmel created this film as part of an experiment.
The ball doesn't seem to want to be in there.
It's freaking out.
It's scared.
It looks like a trap to me.
It looks like the small triangle is being shut out and, like, trying to peer in.
They are paired in a way that seems friendly.
Yeah! This is really fun.
It's fun, right? Ha ha! Eagleman, voice-over: What heider and simmel found, as I did, is how easy it is to look at moving shapes and to see meaning and motives and emotion all in the form of a social narrative.
I kind of get the sense that they're cats and dogs.
It seemed like the big one might have been, like his, uh, his dad or something.
Just call it more of, like, a mating ritual two competitors going for one possible mate.
These are just shapes on a screen, but we can't help but tell stories about them.
Why? It's because our brains are so primed for social interaction that we look for intention and relationships all around us.
One way we navigate the social world is by judging other people's intentions.
Is she trying to be helpful? Are we a trustworthy team? Our brains are good at making these sorts of judgments.
And we do it constantly.
But do we learn this skill from life experience, or are we born with it? To figure out which one it is, I've invited over some people who don't have much experience with the world.
I've invited them to a puppet show.
These babies are all under 12 months old.
They're just beginning to explore the world around them.
You could say they're all a little short on life experience.
We decided to run a simple experiment developed at Yale university.
Here's a duck struggling to open a box.
One bear helps the duck.
The other is mean to the duck.
Ok, bowie, here you go.
There are two puppets Eagleman, voice-over: When the show's over, I let the babies choose a bear to play with.
want to play with? Yeah? Ok, is that the one you want? All right.
Eagleman, voice-over: Almost every one of them chooses the bear that's been kind.
These babies can't walk or talk.
And yet they already have the tools to make judgments about others.
Yeah? Ok! It's often assumed that trust is something that we learn from our experience in the world.
But these experiments demonstrate that even as babies, we come equipped with social antennae for feeling our way through the world.
The brain comes with inborn instincts for figuring out who's trustworthy and who's not.
Eagleman, voice-over: As we grow, our social challenges become even more subtle and complex.
Understanding others is one of the most demanding operations that our brains perform.
They have to interpret words.
And, more than that, inflection, facial expressions, body language.
"Does she like me?" "Is he interested in what I'm saying?" "Do they want my help?" Society runs on our ability to read each other's social signals.
Take that ability away and the world becomes a very strange place.
Car enthusiast John robison has always struggled to read other people.
Robison, voice-over: When I was a little boy, I was bullied and rejected by other kids.
And that didn't happen with machines.
You know, I could stand, uh, by, uh, a tractor on my grandparents' farm.
And I could learn how to adjust it.
And it wouldn't tease me or do anything bad.
It wouldn't run away.
It would always be there.
And I could count on it.
And i i guess I learned to make friends with the machines before I learned how to make friends with other people.
Eagleman, voice-over: In time, John's affinity for technology took him to places his bullies could only dream of.
By 21, he was a roadie for the band kiss.
This was me back with, uh, kiss in the seventies.
Uh, I look older and fatter and stuff.
I don't look the same anymore.
Eagleman, voice-over: Surrounded by legendary rock and roll excess, his outlook remained different from other people's.
People would come up to me all the time.
And they would say, "what's this guy like," or, "what's that guy like?" I would say, "yeah, their stage setup, "they had sunn 2000s bass amps," or Or, "gene played sunn coliseums", and we had seven bass amps chained together.
"We had 2,200 watts in the bass system for that.
" But I maybe couldn't tell you the first thing about the musicians who sang through them.
Now I realize that shows that I did kind of live in a different world all those years a world of machines and equipment.
Eagleman, voice-over: When he was 40, John was diagnosed with asperger's a form of autism.
Many regions of the brain are engaged during social interaction.
But in autism that brain activity isn't seen as strongly.
And that's paralleled by diminished social skills.
I didn't really understand that there were complex messages in faces until I was well into adulthood and learned about autism.
I knew that people could, uh, display signs of crazed anger.
But if you, um, asked about more subtle expressions you know, "I think you're sweet", "and I wonder what you're hiding," or, "I'd really like to do that," or, "I wish you'd do this" Or that.
II had no idea about things like that.
Eagleman, voice-over: But then came a transforming moment in John's life.
In 2008, he was invited to Harvard medical school to take part in an experiment on his brain overseen by Dr.
Alvaro pascual-Leone.
It was an attempt to try to understand how activity in one area affects activity in an area In another area and how that affects behavior.
Eagleman, voice-over: The experiment was only meant to help the scientists gain greater knowledge about the autistic brain, but then something unexpected happened.
John was given transcranial magnetic stimulation or tms.
Magnetic coils were placed next to his head to generate minute electrical currents in the brain and alter its activity.
The researchers targeted different regions of John's brain to see whether interfering with his brain activity had any effect on his behavior.
They would test me after the session.
I would go home kind of not knowing what to expect.
Eagleman, voice-over: At first there was no result.
But then they targeted the dorsolateral prefrontal cortex a region involved in flexible thinking and abstraction.
And something dramatic happened.
Somehow I became different.
He contacted us, uh very excited to say, you know, "the effects of the stimulation "seemed to have unlocked something.
"And the effects is still lasting.
And I now can do things that I could never do.
" After tms, I was able to, uh, sort of read signals from other people and understand what was going on.
So I listened to that, fascinated by it, and thought, "ok, well, whatever.
It'll go away.
" Uh, but it didn't.
It It actually, um, remains something that that had really fundamentally changed in In him.
Eagleman, voice-over: Somehow, and entirely accidentally, the tms had unlocked a whole new world for John.
vegetable sandwich to bring home.
What have you got Robison, voice-over: I'd be tempted to say, "I couldn't read people and now I can," but that's not really true.
Ok.
How about a full-size one of them Sure.
It's more accurate to say I had no idea there were these messages emanating from other people.
Tms showed me those messages.
And now that I'm aware that they're out there, everything I do is different.
All of a sudden, you can walk around and engage the world.
And it's a big, big thing.
Ok, thanks! We don't know exactly what happened neurobiologically.
Um But I think it now offers the opportunity for us to understand what behavioral modifications, what interventions might be possible to learn from him that we can then teach others.
Eagleman, voice-over: John's transformation is a reminder that all the activities of the human brain, including the subtle interplay of emotions and relationships, are rooted in the detailed patterns of trillions of electrochemical signals.
Eagleman, voice-over: Somehow, humans can look at each other and study the arrangement of facial muscles and then process that information into an understanding of other people's thoughts and emotions.
Eagleman, voice-over: It's an astonishing skill because the cues are so subtle.
And the processing is so rapid that the whole operation runs under your radar.
It only takes 33 milliseconds for your brain to process basic information about someone's facial expression and start reacting to it.
So we're gonna put one electrode right above your eyebrow Eagleman, voice-over: So how does it do that? And the other right on your cheek.
Here we go.
Great Eagleman, voice-over: I've invited a group of people to run an experiment.
I've wired them up to a machine that measures movements in their facial muscles.
And I've asked them to look at photographs of faces.
When participants are looking at a photograph with a smile or a frown, we see this activity on the graph which indicates that their own facial muscles are moving.
Why? Well, it turns out that they are automatically mirroring with their own faces the expressions that they're seeing.
That was fun, right? The last one? Yeah.
Yeah, it was a fun test.
Eagleman, voice-over: But what purpose does this mirroring serve? I've invited a second group of people.
They're similar to the first group, except for one thing.
This is the most lethal neurotoxin on the planet.
If you were to ingest even a fraction of this, your brain could no longer tell your muscles how to contract and you would die of total paralysis.
So it seems unlikely that anyone would pay to have this injected into themselves, but they do.
This is known as botulinum toxin or Botox.
If you put it into your forehead muscles, it paralyzes them to reduce wrinkling.
But there's a less well known side-effect.
Eagleman, voice-over: When our participants with Botox went through the same tests, their facial muscles responded less.
No surprise there.
But replicating an experiment out of Duke university, we had both groups look at facial expressions.
And now they were asked to choose the word that best described the emotion they were seeing.
Panic.
Panicked.
Upset.
Eagleman, voice-over: On average, the Botox group was worse at identifying the emotions correctly.
Skeptical? Eagleman, voice-over: It seems that the lack of feedback from their facial muscles impairs their ability to read other people.
The paralyzed faces of Botox users not only makes it hard for us to tell what they're feeling, those same frozen muscles make it hard for them to read us.
And that tells us something.
When I'm happy or sad, part of that feeling relies on the unconscious feedback from muscles in my face.
And our social brains take advantage of that so when we're trying to understand what someone else is feeling, we try on their facial expression.
This automatic mirroring of expressions is just one way in which we understand others.
The brain also has a deeper way one that's best explained at the movies.
One ticket, please.
Thank you.
Eagleman, voice-over: When we go to the movie theater, we know full well that it's make-believe.
The people on the screen are just acting.
And yet we still react.
We gasp and flinch and cry.
Why do we fall for it? To understand why we care about other people getting hurt, you need to understand what happens in your brain when you get hurt.
So imagine that somebody were to stab your hand with a syringe needle.
That activates a network of areas in your brain that we call the pain matrix.
Eagleman, voice-over: There's no single spot in the brain where pain is processed.
Instead, the perception of pain arises from several different areas networking together.
Strangely enough, this pain matrix is at the heart of how we connect with others.
Eagleman, voice-over: Now, when you watch someone else get stabbed, your pain matrix becomes activated.
Not the parts that tell you you've actually been touched, but the parts involved in the emotional experience of pain.
In other words, watching someone else in pain and being in pain use the same neural machinery.
And that's the basis of empathy.
To empathize with another person is to literally feel their pain.
You run a compelling simulation of what it would be like if you were in that situation.
And our capacity to do this is why stories and movies and novels are so absorbing and why they're so pervasive across human culture.
Because whether it's about total strangers or made-up characters, you experience their agony and their ecstasy.
You fluidly become them and live their lives and stand in their vantage points.
You can tell yourself that the stories aren't real, but some neurons deep in your brain can't tell the difference.
Eagleman, voice-over: Our capacity to feel another person's pain is part of what makes us so good at taking other people's perspective to step out of our shoes and into their shoes, neurally speaking.
Eagleman, voice-over: We can't help but connect with others.
We're hardwired to be extremely social creatures.
And that raises a question.
What would happen if the brain were starved of human contact? In 2009, peace activist Sarah shourd and her two companions were hiking in the mountains of northern Iraq an area that was at the time peaceful.
But they accidentally strayed into Iran, and they were arrested.
They pulled us apart and threw us in separate cells and slammed the door.
And, um, that was the beginning of of the next 410 days of my life in that cell.
Well, in the early weeks and, really, months of solitary confinement, you're reduced to an animal-like state.
I mean, you are an animal in a cage.
And the majority of your hours are pacing.
And the animal-like state sort of eventually transformed into a more plant-like state When your mind starts to slow down and your thoughts become repetitive.
Shourd, voice-over: Your brain turns on itself.
And it becomes the the source of your worst pain and your worst torture.
I would relive every detail of my life.
And eventually, you run out of of memories.
And you've told them all to yourself so many times, and it doesn't take that long.
Eagleman, voice-over: Extreme social depravation causes deep psychological pain.
Without interaction, the brain suffers.
Solitary confinement is designed to eat away at and really attack what essentially makes us human.
Eagleman, voice-over: Sarah's brain used the scant sensory information it had to construct a reality.
The sun would come in at a certain time of day at an angle through my window.
And all of the little dust particles in my cell were illuminated by the sun.
I saw all of those particles of dust as being other human beings occupying the planet.
And they were in the stream of life.
They were interacting.
They were bouncing off one another.
They were doing something collective.
And I saw myself as off in a corner, you know, walled off by by myself out of the stream of life.
Eagleman, voice-over: In September 2010 after 410 days in solitary confinement, Sarah was finally released and allowed to rejoin the world.
But for a long time, she suffered from extreme post-traumatic stress.
The philosopher Martin heidegger said we can't talk about being.
We can only talking about being in the world.
In other words, the world around you is a part of who you are.
In a vacuum, you lose your sense of self.
It's not easy for science to study people while they're experiencing solitary confinement, but a simple experiment designed by neuroscientist Naomi eisenberger can give us an insight into what's happening in the brain when we feel excluded.
It's based on a game of catch.
While volunteers played a computer game of catch, eisenberger and her team scanned their brains.
The volunteers thought the other characters were controlled by other participants, but, in fact, they were just part of the computer program.
At first, the other characters played nicely, but after a while, they'd cut the volunteer out of the game and simply play between themselves.
She found that being left out of the game activated the pain matrix.
Not getting the ball might seem insignificant, but to the brain, social rejection is so meaningful that it hurts.
Eagleman, voice-over: But that pain, in turn, is useful.
It pushes us in the direction of bonding with others.
We all seek out alliances.
We join with friends, with family, with colleagues.
It could be which team we support What style we go for What our hobbies are.
It gives comfort to belong to a group.
And that gives us a critical clue into our success as a species.
Survival of the fittest isn't just about individuals.
It's also about groups.
We're safer.
We're more productive.
We overcome challenges.
The drive to work in groups has helped human populations thrive across the planet and build entire civilizations.
And yet there's a flipside to this drive to come together.
Because for every "in" group, there are outsiders.
And the consequences of that can be very dark.
History is plagued with examples of one group turning on another that was defenseless and posed no threat.
If you were to look at my family tree, you would see that most of the branches end in the early 1940s.
This is because my family is ethnically Jewish.
That small social marker was enough to prompt Nazi genocide.
Under normal circumstances, you wouldn't find it conscionable to go murder your neighbor.
So what is it that allows hundreds or thousands of people to suddenly do exactly that? What is it about certain situations that short-circuits the normal social functioning of the brain? While the Nazi holocaust was on an unprecedented scale, it wasn't unique.
Genocide continued to occur all over the world.
And within a generation, it returned to eastern Europe.
This time, it was in yugoslavia.
The Bosnian war from 1992 to '95 saw atrocities on both sides.
In one of the worst, more than 100,000 Bosnian muslims, known as bosniaks, were slaughtered by serbians in actions known as ethnic cleansing.
One of the most horrible incidents happened here at srebrenica.
Eagleman, voice-over: Over the course of just 10 days, 8,000 people were systematically killed.
How does something like this happen? Here in 1995, thousands of bosniaks took refuge inside this united nations compound, because this village was surrounded by siege forces.
But then on July 11th, the u.
N.
Commanders made the decision to expel all the refugees.
And they delivered them right into the hands of their enemies, who were waiting just outside this gate.
Women were raped, and men were executed, and even children were killed.
And this was just the beginning of what would be the largest genocide on European soil since the holocaust.
The Dutch were there.
I mean, the world was there.
You know, the u.
N.
The serbs were there as perpetrators.
Everything was mixed.
The refuges were there, the babies were crying.
I was there being protected with that u.
N.
I.
D.
Card that said "u.
N.
Language assistant," whatever.
Eagleman, voice-over: Hasan nuhanovic's status as a u.
N.
Translator made him part of a protected group.
But his family members were marked out by their identity as muslims.
At that very moment when my family was being sent out of the compound to actually die, I lost my I lost my mother, my brother, and my father.
You know, like, you are in a situation when your family is being killed.
And I was thinking, my god I mean, why? Eagleman, voice-over: One of the most striking things is that the perpetrators weren't strangers.
They were people with whom his family had previously shared a great deal.
The continuation, you know, of Of the killings, of torture, was perpetrated by our neighbors.
You know? The very people we have been living with for decades.
They were capable of killing their own school friends.
I remember they said they arrested a dentist who was a bosniak, the best dentist in the town.
They tied him up from a light pole, like this in front of the post office.
He was hanging there like this.
And they beat him with a metal bar.
They broke his spine.
And he was there dying for days while serb children went to school, walking by his body, you know? I mean, there are universal values.
And these universal values are kind of very basic: Don't kill April '92, this don't kill suddenly disappeared.
It was like, "go and kill.
" It was, allowed to kill.
This is where hasan's family is buried.
And each year, there are new bodies that are found and identified, and they're brought here.
Many of these graves are fresh.
And across the human species, this is just one genocide of many.
Genocides keep happening Rwanda, Darfur, nanking, Armenia.
And my interest is in understanding why.
Traditionally we ask this question through the lens of history or economics or politics.
And those are all important vantage points.
But I think for a complete picture, one more lens is needed.
We need to understand genocide as a neural phenomenon.
I've been researching this back in my laboratory.
And here is my main question, when we interact with someone, does our brain function differ according to which group they are in? For every "in" group we belong to, there's at least one group that we don't.
And that division can be based on anything race or gender or wealth or religion.
We put 130 participants in this scanner.
Eagleman, voice-over: And here's what they saw six hands on the screen.
And the computer randomly picks one of these.
And then that hand gets stabbed by a syringe needle.
Now, that activates the pain matrix, which is what comes on line when you're in pain or you see someone else in pain.
Now here's the trick we now added a label to each hand Jewish, Christian, Muslim, hindu, atheist, scientologist.
Would they care as much when they see a member of their out group getting stabbed? So here's what we found: Here's a subject.
And when he watched a member of his "in" group getting stabbed, there was a large neural response in this area of his brain.
But when he watched a member of one of his "out" groups get stabbed, there was essentially a flat line.
We scanned a range of volunteers.
And there are individual differences, but the trend is clear.
A single word label is enough to change your brain's basic pre-conscious response to another person in pain in other words, how much you care about them.
Now, you might have opinions about religion and its historical divisiveness, but even atheists here care more about other atheists' hands getting stabbed than they do about other people.
So it's not really about religion.
It's about which team you're on.
This is just the first step in understanding how we get to this.
To understand how groups of people can commit atrocities, it can help to look at the behavior of individuals like psychopaths.
Some of the most callous, inhumane crimes ever recorded have been committed by psychopaths.
But what's different about their brains that allows them to act that way? There are networks in the medial prefrontal cortex that underlie social interaction.
When we interact with other people, this area becomes active.
But in the brain of someone with extreme psychopathy, this area has a lot less activity.
A psychopath doesn't care about you.
He might be able to run a simulation of what you're going to do or how you might react, but when it comes to an emotional understanding of what it's like to be you, he doesn't get that.
To him you're just an obstacle to be worked around or manipulated rather than a fellow human being.
So what accounts for genocide? Is it driven by armies of psychopaths? Well, that can't be it because psychopaths only make up a small fraction of the population, but genocide typically engages a wider community.
So here's the question: How do you get ordinary citizens on board? At the university of leiden in Holland, Dr.
lasana Harris has been conducting an experiment to understand a piece of this puzzle.
So now we're going to start the experiment.
What you're going to see is a bunch of pictures of different people.
Your job is just to react naturally to those pictures.
Eagleman, voice-over: Lasana is looking at activity in the brain areas involved in human social interaction, in particular, the medial prefrontal cortex.
This comes on line when we think about other people.
It's less active when dealing with something inanimate, like a cup.
What lasana found is that this region has a similarly low response when we deal with certain types of other people.
What he sees now are stereotypical images of people from different social groups.
What we see here is at this network of brain regions, including medial prefrontal cortex, is less active when our participant looks at the homeless people.
So what this pattern of activity suggests is a type of mental avoidance.
They are not thinking about the mind of the homeless person in the same way they thought about the mind of the college students that they saw or the businesspeople.
So if for instance you imagine that interacting with a homeless person will be unpleasant, it will make you will feel bad.
You may feel some demand to donate some of your money and all of these unpleasant pressures that come along with it.
By shutting off those systems, you never experience those feelings.
Eagleman, voice-over: To a brain that responds this way, homeless people are dehumanized.
They're viewed more like objects.
And that can enable us to not care.
Of course if you don't properly diagnose this person as a human being, which is happening here, then the different moral rules we have that are reserved for human people may not apply.
Eagleman, voice-over: So under the right circumstances, our brain activity can look more like a psychopath's.
But to understand how we can get to genocide, we need to understand one more thing about group behavior.
Genocide is only possible when dehumanization happens on a massive scale.
Not just a few individuals, but whole sections of the population.
We're talking about a group of people committing atrocities.
Eagleman, voice-over: And if all the members of that perpetrating group are complicit, it's as if they've all somehow experienced the same reduction in brain activity when they think about their "out" group.
This can be understood and studied like a disease outbreak, a kind of group contagion one that's most often spread deliberately.
The perfect tool for this job is propaganda.
It plugs right into neural networks, and it dials down the degree to which we care about other people.
Just like all sites of genocide, that's what happened in the former yugoslavia.
The people who went on to torture and kill their neighbors were bombarded with propaganda.
State-controlled broadcasters demonized the Bosnian muslims with distorted news stories.
I read you from the beginning that somebody is, uh, helping muslims, uh, and arming them.
Eagleman, voice-over: They went so far as to claim that the muslims were feeding serbian children to the lions at the zoo.
Across place and time, the language of propaganda changes very little.
It always plays the familiar tune of dehumanization: Make your enemy less than human, make them like an animal.
Propaganda is a weapon.
And over the course of human history, it's become an art and a science.
And it's become ever more dangerous.
Eagleman, voice-over: In our connected age, any extremist group can reach millions of people with a keystroke.
The Internet is the perfect carrier for propaganda messages to reach the people most likely to act upon them young men.
Eagleman, voice-over: The political agendas around us actually manipulate the brain activity inside of us.
So is there any way to stop what's happened in the past from continuing into the future? One possible solution lies in a 1960s experiment that was conducted not in a science lab but a school.
Eagleman, voice-over: It was 1968, the day after the assassination of Martin Luther King.
Is there anyone in this United States that we do not treat as our brothers? - Yeah.
- Who? The black people.
The black people.
Who else? Eagleman, voice-over: Jane Elliott was a teacher in a small town in Iowa.
And she wanted to show her class what prejudice really felt like.
How are black people treated? They don't get anything in this world.
Why is that? Because they're a different color.
Eagleman, voice-over: These two men were in that class.
This was Rex back then And this was ray.
How many in here have blue eyes? Ok.
How many in here have brown eyes? Ray, voice-over: Jane says we're going to have this exercise.
And she right away launches into the propaganda of blue eyes are better than brown eyes.
Blue-eyed people are better than brown-eyed people.
Eagleman, voice-over: Ray and Rex both have blue eyes.
You brown-eyed people are not to play with the blue-eyed people on the playground because you are not as good as blue-eyed people.
Eagleman, voice-over: The brown-eyeds were denied privileges given to the blue-eyeds, and they had to wear special collars.
You'll begin to notice today that we spend a great deal of time waiting for brown-eyed people.
Do you remember, uh What your own behavior was like when you were on top? I was tremendously evil to my friends.
How so? I was going out of my way to pick on my brown-eyed friends for the sake of my own promotion.
What did you do? I recall telling Mrs.
Elliott, Jane, that she should keep the yardstick at hand in case those brown-eyeds got out of control.
I don't see the yardstick.
Do you? It's down over there.
Hey, miss Elliott, you better keep that on your desk.
Don't let the brown-eyed people get out of hand.
At that time, my hair was quite blond and my eyes were quite blue.
And I was the perfect little Nazi.
I looked for ways to be mean to my friends, who minutes or hours earlier had been very close to me.
Eagleman, voice-over: But the next day, there was a reversal of fortune.
Yesterday I told you that brown-eyed people aren't as good as blue-eyed people.
That wasn't true.
I lied to you yesterday.
Oh, boy The truth is that brown-eyed people are better than blue-eyed people.
Rex, voice-over: A person you trust stands before you and says, "I was wrong.
" Now here's the truth," takes your world and shatters it like you've never had your world shattered before.
You blue-eyed people are not to play with the brown-eyed people.
Blue-eyed people go to the back.
The brown-eyed people come to the front.
Tell me a little more about what it was like when you were in the down group.
You have such a sense of loss of personality and self that it makes it almost impossible to function with what's going on in the room.
Should the color of some other person's eyes have anything to do with how you treat them? No, no.
All right.
Then should the color of their skin? No.
Should you judge people No By the color No Of their skin? No.
Eagleman, voice-over: If I were just gonna riff guess at it it's that, uh, one of the most important things we learn as humans is perspective taking.
And kids don't often get a really meaningful exercise in that.
And when you're forced into understanding what it's like to stand in someone else's shoes, that opens up a lot of cognitive pathways for you.
I remember saying something to my dad about a comment he made, saying, "no, that's not appropriate.
" And it did change within the family.
But you talk about a little kid making that statement, it's huge.
But it reaffirmed that you could do that you could begin to change.
The brilliance of the blue eyes/brown eyes experiment is that the teacher, Jane Elliott, switched which group was on top.
And that allowed the students to extract the larger lesson, which is that systems of rules can be arbitrary.
They learned that the truths of the world are not fixed, and they're not even necessarily truths.
And this is what empowered the children as they grew to see through the smoke and mirrors of other people's political agendas and to form their own opinions surely a skill that we should be teaching to all of our children.
Should the color of some other person's eyes have anything to do with how you treat them? No.
Eagleman, voice-over: When people are armed with an understanding of how propaganda works, the power of propaganda is reduced.
As we come to understand the deep importance of cooperation, we stand a chance not only of reducing dehumanization, but achieving our potential as a species.
Genocide doesn't have to be the norm.
Instead our fundamentally social nature can hold the key to our success as a species.
Our future, our survival is intimately, permanently bound up with that of the people around us.
Our social drive is at the root of extraordinary acts of bravery and generosity.
Who you are has everything to do with who we are.
Our brains are so fundamentally wired to interact that it's not always clear where each of us begins and ends.
Our species is more than just 7 billion individuals spread out across the planet.
We're something more like a single vast super-organism.
Because what your friends know and love as you is really a neural network embedded in a far larger web of other neural networks.
In this age of digital connection, we desperately need to understand the links between humans.
If we want our civilizations to have a bright future, we'll need to understand how human brains interact the dangers and the opportunities.
Because there's no avoiding the truth that's etched into our neural circuitry: We need each other.