August 7, 2023 • 38 mins
Why do we so naturally form ingroups and outgroups? And what does that have to do with evolution, monkeys, Greeks, psychopaths, Syndrome E, and propaganda posters? Join Eagleman to learn why our brains are so wired for tribalism, what the consequences are for the world, and how a bit of knowledge goes a long way to making us more immune to propaganda.
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Episode Transcript
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Speaker 1 (00:04):
Why does your brain care more about some groups of
people than others? Why do we so naturally form in
groups and out groups? And what does any of that
have to do with George W. Bush's political commercials, or
the Greeks or psychopaths or syndrome E or propaganda posters
(00:25):
and how to develop immunity against them. Welcome to Inner
Cosmos with me David Eagleman. I'm a neuroscientist and an
author at Stanford and in these episodes we sail into
our three pound universe to understand why and how our
lives look the way they do.
Speaker 2 (00:55):
Today.
Speaker 1 (00:56):
We're going to talk about why we're so wired to
have in groups and out groups, and what the consequences are,
and how some knowledge on this goes a long way
to making us a little smarter in the face of propaganda.
This is a topic of enormous importance, in no small
(01:16):
part because repeatedly throughout history, groups of people have inflicted
violence on other members of their population. Think of the
Nazis and they're killing of millions of people Jewish communities
and Gypsies and others based on religious and ethnic and
political affiliations. Or look at the Nanking massacre, in nineteen
(01:38):
thirty seven when the Japanese invaded China and killed hundreds
of thousands of unarmed civilians and systematically raped between eighty
and one hundred thousand people. And in nineteen fifteen there
was a systematic killing of the Armenian population by the
Ottoman Empire. It's estimated that about one million Armenians were
(02:00):
killed during this. And then in nineteen ninety four, in
a period of one hundred days, the Hutu in Rwanda
killed eight hundred thousand Tutsi and this was accomplished mostly
with machetes, and at the peak of this they were
actually achieving a higher killing rate with machetes than the
(02:20):
Nazis had accomplished with gas chambers. And so the question
is what is going on here? We see this kind
of thing over and over in history, and often people
will inflict this kind of violence in coordination with the
authorities and against groups of people in their society that
were no direct threat to them and were defenseless. So
(02:42):
how can we understand this characteristic of human behavior, Because
it's of deep importance for us to understand this if
we want to have any hope of preventing this in
the future. Now, historians look for explanations by digging into
issues of political and civil strife and economic troubles. But
(03:03):
the real issue is that the only way these events
can happen is when there's a distinct change in the
behavior of individuals, and how can we understand that change
in behavior. What I want to talk about today is
the science of what we understand about that about genocide.
I want to put together a new framework to see
(03:25):
how we can come to understand events like this, and
I'm going to end by saying what we can do
about it. So let's start in the distant past. When
we think about human evolution. The story we all know
about Darwinian evolution is that it's survival of the fittest. Right,
you have to be a strong competitor to survive and thrive,
(03:48):
and that's a pretty good framework. But people started realizing
there was a little bit of a problem because the
issue is altruism. That is, when you give your own
resources to help other people. How does the basic Darwinian
story of survival of the fittest explain why people help
each other out. You can't understand that just by thinking
(04:10):
about individual selection. And that got people thinking about kin selection,
So you may have heard of this notion of the
selfish gene. The idea is that if I share some
genetic material with my brother, then maybe that explains why
I want to help him out. The genes want to survive,
(04:30):
and I share a little bit less genetic material with
my cousins, and so all sacrifice for them, but maybe
a little bit less so and so on through my
family tree. The evolutionary biologist J. S. Haldane famously said
I would gladly jump in a river to save two
of my brothers or eight of my cousins. So this
(04:51):
is known as kin selection rather than individual selection. But
it turns out even that's not enough to explain the
world of humans, because in fact, what distinguishes our species
is that humans get together and cooperate irrespective of kinship.
So that led people to think about group selection, which
(05:15):
is to say, if you and your fellow tribe members
are the type who cooperate, then as a group you
all increase your chances of survival. Your tribe has a
better chance of surviving than the other tribe on the
other side of the mountain, who are not very cooperative
with each other, no matter how strong they may be
(05:35):
as individuals. So the term for this is you sociality
You you meaning good or positive. So if a species
is you social, then there's this glue that allows them
to build tribes and groups and nations irrespective of kinship.
My colleague Jonathan Hate gave a nice analogy for this.
(05:59):
He said, as a result of the evolutionary history of humans,
we're sort of ninety percent primate and ten percent honeybee.
By primates, he means we're mostly about individual competition, but
by honeybee he means sometimes we work together for the
good of the hive. So our strong youth social nature
(06:20):
can't be explained just by individual selection, but instead it
seems to require this selection for groups who want to work.
Speaker 2 (06:28):
With one another.
Speaker 1 (06:29):
Now, this massively social nature is what underlies our ability
to build and operate cities and industry and do science
and so on. Humans say, hey, let's link arms and
cooperate with one another and drive things forward together and
enjoy all the benefits of that. This kind of thinking
(06:49):
allows organisms to operate as superorganisms. And by the way,
I should just note something about religion here. Some scholars
compare religion to a pathological virus that spreads across minds.
But that's probably not the optimal way to think about it.
From an evolutionary point of view, things are judged by
(07:11):
what they cause people to do, and what religions cause
is for people to group together, to be usocial. So
what happens with religions is you define a group, you
coordinate the behavior of the group, and you incentivize the
group to cooperate and work together. So, as one evolutionary
biologist in the late eighteen hundred said, religion is just
(07:35):
another weapon in the Darwinian struggle for survival. In other words,
if religion were maladaptive, it would have gone away. But
it usually is adaptive in the sense that it causes
groups to come together and work cooperatively. But one of
the costs of our usociality is that we get in
(07:57):
groups and outgroups. And today we're going to see what
all of this has to do with the brain. Historically, traditionally,
we've always studied the brain by looking at individual parts
and regions of it. So you say, okay, well, this
is how vision works, and this is how hearing works,
and this is how decision making works and so on,
and it's only in recent years that people began to
(08:20):
appreciate that a lot of the circuitry of the brain
has to do with this youth sociality. A lot of
it has to do with how you interact with other
brains in terms of trust and reputation and allegiances. And
I talked a little bit about this in a previous episode.
And this has led to a new field called social neuroscience,
(08:40):
which studies this sort of thing. And that's what I'm
going to tell you about today, and how social neuroscience
can shed light on group behavior.
Speaker 2 (08:49):
So I mentioned in.
Speaker 1 (08:50):
This previous episode about this philosophical problem called the trolley dilemma,
And just as a reminder, there is a trolley barreling
down the.
Speaker 2 (08:59):
Tracks full speed.
Speaker 1 (09:01):
Its brakes are broken, and you see there are five
workmen farther down the track and they're going to get killed.
The trolley is going to run over them. But it
just so happens that you notice you're standing next to
a lever that can switch the track for the trolley,
and on this other track, you see.
Speaker 2 (09:17):
There's only one workman there.
Speaker 1 (09:19):
So the question is will you switch the track over
so it kills only one person instead of five? So
think about what you would do here. Now, here's scenario
number two. It's the same thing. The trolley is barreling
down the track. You see the five workmen. They're going
to get killed. But this time you're standing on a
little footbridge over the tracks, and you realize that there
(09:41):
is a man standing in front of you, and if
you push him over the edge of the tracks, his
weight will be sufficient to stop the trolley and save
the five men. So the question is do you push
the man or not? Now, in most cases people will
do it. But the thing to notice is that it's
(10:02):
exactly the same question. In both cases, will you trade
one life for five lives or won't you Most people
will do that in the first case, but they won't
in the second case, which is interesting, right, it's the
same math. So my colleagues Joshua Green and Jonathan Cohen
got interested in this question some years ago and they
(10:22):
did neuro imaging on people. They put them in the
brain scanner while they had the people walking through the
trolley dilemma problem, and essentially what they found is there
are areas of your brain that are involved in math
problems that are saying, okay, well, one versus five and
so on. They make a calculation, and you have other
areas of your brain that care about emotional issues. They're
(10:44):
simulating situations and assessing how those make you feel. Those
areas are generally along the midline of the brain if
you drew a line from your nose to the back
of your head. And it turns out that in this
second scenario where you're asking if you're going to push
the guy, these emotional areas come online, and that changes
your decision making. In other words, emotions, how you feel
(11:07):
about something is a very important part in navigating the decision.
The first scenario is just an easy math problem. The
second one is an emotional problem, and it changes what
you decide. And in fact, the idea that reason and
emotion are fighting with each other. That's a very old idea.
The Greeks had this metaphor that life is as though
(11:30):
you are a charioteer and you're being pulled along by
the white horse of reason and the black horse of passion,
and they're always trying to pull you off in opposite directions,
and your job as the charioteer is to.
Speaker 2 (11:44):
Stay down the middle of the road.
Speaker 1 (11:46):
And it's not easy, right because you've got these two
different polls going on all the time. So emotions are
tightly involved in decision making. They serve an important role
in how we navigate our life.
Speaker 2 (12:00):
And you wouldn't want to live in a world.
Speaker 1 (12:02):
Where everybody is like mister Spock and Star Trek and
doesn't have emotions, right, because everybody would just push the
man off the bridge and that would be.
Speaker 2 (12:10):
The end of it.
Speaker 1 (12:11):
But instead, we use emotions to steer the decisions we make,
and if something feels wrong, we try not to do it.
(12:35):
So the question is how do we understand or interpret
the things that we see during wartime. There's a horrifying
photograph from World War Two where there's a crying mother
who's clutching her small child to her chest, and there's
a German soldier about six feet behind her with his
(12:55):
rifle poised aimed at her head, ready to execute her
while she's holding her baby in her arms. Now, there
are several things to note about this photograph. First, the
fact that he's doing this in front of someone in
front of the cameraman suggests that he has a diminished
emotional reactivity to this situation. He's not distressed by the situation.
(13:17):
He's not feeling like you felt when you thought about
pushing the man off the bridge. Now, if this were
the one guy committing atrocities during wartime, we might just
write him off as a psychopath.
Speaker 2 (13:28):
But there were hundreds of.
Speaker 1 (13:30):
Thousands of young men doing awful stuff everywhere you looked,
including running the concentration camps, or raping women in the towns,
or lining up dozens of people along ditches and machine
gunning them. So it wasn't just one psychopath. What was
going on here? The neurosurgeon you talk Freed in the
(13:50):
late nineties started thinking about this question a lot, and
he said, you know, when you look across all these
different events in the world, you find this kind of
behavior everywhere. People seem to lose their normal way that
their brain functions, and they become different in how they
make decisions, they act differently than they would under normal circumstances.
(14:12):
And he said, when you look at the signs and
the symptoms of their behavior, it's like there's a medical
condition going on here. So he named this syndrome E,
and he said there are very particular signs and symptoms
that you look for here, just like you would look
for coughing or fever with pneumonia. You look for particular
(14:33):
things that characterize people's behavior during wartime. First, there's diminished
emotional reactivity that gives people this ability to do repetitive
acts of violence. Maybe people start off having a little
bit of a hard time with it, but they rapidly
desensitize it doesn't bother them anymore. Second, he noticed there's
(14:57):
a hyper arousal or as the Germans called it, raush,
which is this feeling of elation when committing these horrific acts.
Another sign is group contagion, which is an important one
that I'll come back to. The issue is everybody's doing
something and it catches on and it spreads. He also
(15:18):
pointed to compartmentalization. Someone can care about their own family
and yet at the same time do this sort of
thing to another family. So these are the signs of
syndrome E. Diminished emotional reactivity, repetitive acts of violence, hyper arousal,
group contagion, compartmentalization. And the interesting thing from a neuroscience
(15:40):
point of view is that the other functions of the
brain are working just fine. Things like language and memory
and problem solving, those are completely intact so that gives
us a clue into what's happening under the hood. And
what's happening in the case of syndrome E is something
like this. The emotional networks of the brain are short circuited.
(16:04):
They are not participating in the decision making anymore. They
are now sidelined. They're out of the equation. So that
allows a soldier to execute a woman clutching her baby,
just like it would allow you to push the man
off the bridge without really thinking twice about it. In
other words, their decision making is being steered by parts
(16:24):
of the brain that can do logic and reasoning and
memory and so on, but not the parts of the
brain that normally navigate things with emotion. And what this
leads to is a moral disengagement. A person becomes like
a car that's in neutral going down the hill. He
doesn't have all these systems anymore that tell him the
right way to steer his actions. Now, can this sort
(16:47):
of thing be studied in the laboratory, Yes it can.
So consider this study. People are shown photographs of other
people and you measure what's going on in their brain.
And what the researchers found is that if you show
participants pictures of people they admire, Olympic athletes and hard workers,
(17:08):
and so on. Various parts of the brain light up,
and the area I want to draw attention to is
a part along the brain's midline called the medial prefrontal cortex.
The medial prefrontal cortex is involved in these emotional systems,
and it's also involved in social cognition. In other words,
this area is active whenever you're dealing with another person
(17:31):
as opposed to an object like a coffee cup or
a laptop. Even if you show participants photographs of people
they don't like very much, like people they envy or
people they pity, you still get medial prefrontal cortex activation.
In other words, people still see them as humans even
though they're maybe not in their in group. But if
you go even further along the spectrum of outgroups and
(17:54):
show pictures of people that they feel very separated from,
like homeless people are drug addicts, the medial prefrontal cortex
turns off. It just doesn't come online in the same way.
And what that means is that they're viewing these people
the same way that they do objects. So again, when
you view objects, this area doesn't come online, and it
(18:17):
comes online when you're looking at humans, except for really
outgroup humans, when it simply doesn't activate anymore. So when
we talk about dehumanization, what we're really talking about are
regions of the brain that think about other humans that
don't come online anymore. These regions are now out of
(18:38):
the equation, and in this scenario, when you are making
moral decisions about people who are in your outgroup, you
don't have these use social mechanisms steering your behavior. With psychopaths,
by the way, there are many subtle differences in their brains,
but one of the issues you see is this, they
just don't have these areas like the medial pre frontal
(19:00):
cortex emotionally steering their behavior, and so they're capable of
doing things like violence and murder because they don't care
about you. They're not simulating what it is like to
be you. They don't have the emotional feeling that's steering
around their decisions. And this is what happens when groups
(19:20):
dehumanize their neighbors. I have a photograph of a group
of German citizens and soldiers at the beginning of World
War Two making their Jewish neighbors scrub the pavement with toothbrushes,
and the Germans watching are having a great time posing
and laughing. And what's happening is that, because of the
social context that allows syndrome E, these emotional regions are
(19:45):
no longer online, and so their neighbors are not like
humans to them anymore. And this situation typifies genocides. Here's
a quotation from a Japanese general talking about his behavior
during the invasion of China. He explained his soldier's behavior
by saying, it was quote because we thought of them
(20:07):
as things, not as people like us.
Speaker 2 (20:10):
End quote.
Speaker 1 (20:11):
Here's a statement from a woman in Rwanda who orchestrated
the killing of thousands of Tutsi. She said, quote, we
thought of them as nothing more than insects or cockroaches.
Here's a quotation from an American sergeant stationed in Iraq.
He says, quote, you just sort of tried to block
out the fact that they're human beings and you see
(20:32):
them as enemies. So what we're talking about here is
the same neural issue across place and time. Dehumanization is
about turning off the parts of your brain that allow
you to understand what it is like to be someone else.
You may remember Anders Bravik, the Norwegian who murdered seventy
(20:54):
seven young people in twenty eleven. So back in twenty twelve,
I was following his trial closely, and here's what he said.
One might say I was quite normal in two thousand
and six when I started training, when I commenced de emotionalizing.
He said, I've had a dehumanization strategy towards those I
(21:15):
considered valid targets so I could come to the point
of killing them. He nailed it here. He knew that
his own training regime was about de emotionalizing. I mean,
he phrased exactly what we've been talking about here so far.
He worked, for example, with meditation, to hammer away any
(21:36):
emotional response he had to the idea of killing someone.
That's the way he trained. He worked to diminish the
response of his medial prefrontal cortex in other areas and
the networks involved in emotion. Now, we might lament the
fact that these programs are able to be overridden, but
we should be thankful for the fact that they're so
(21:57):
so difficult to override. Act like bravics is extremely rare.
Despite the logical ease of anyone pulling it off. Now,
if you're not that good at turning off your own
medial prefrontal cortex, you should know that there are always
groups that are willing to do this for you, and
that is the art and science of propaganda. So something
(22:19):
that I have always found amazing is looking at war posters.
For example, I have an American poster from World War One.
It shows a giant, crazy looking ape wearing a German helmet,
and on the helmet it reads militarism. And in one
hand the ape is carrying a huge club, and in
the other arm he's holding a beautiful woman whose arms
(22:41):
are flung over her head, and the poster reads, destroy
this mad brute enlist US Army. Now, I want to
point out that if you look at any propaganda poster
from any war at any time, on any side, you'll
see a common theme. You make your enemy less than human,
and making them explicitly an animal.
Speaker 2 (23:04):
Is a very popular choice.
Speaker 1 (23:06):
So in this case, the Germans are portrayed as a
bellicose ape coming onto American shores, and the fact that
he's stealing away a half naked, beautiful American woman makes
you even more mad about the whole thing. And this
is typical of propaganda posters. You always give the enemy
fangs and feral features. And the idea is you want
(23:28):
to shut off the networks that are involved in humanization.
You want your population to feel like we can do this,
We can go to war with these guys because they're
not like us, they're animals. Or consider this other propaganda
poster I have from Germany during World War Two, which
represents America as a giant mechanical robot monster toting guns
(23:52):
and bombs and destroying Europe. So it doesn't have to
be animals, just anything that's not human. And in fact,
when our Winian thinking got introduced in the eighteen hundreds,
lots of people took the opportunity to generate pseudoscience, suggesting
that whoever their enemy was, they were less than human.
This is a typical strategy to implement, and it can
(24:16):
even be done subtly. Some of you may remember that
when George W. Bush was running for president against Al Gore,
he did the same thing. His commercial ran and said
the Gore prescription plan, and then you see this big
word rats on the screen, and then after about half
a second is the word zooms out. You see it
(24:36):
actually says bureaucrats, and eventually, when it's all zoomed out,
it says bureaucrats decide. But what it starts with is
this giant word rats. The strategy of dehumanization is one
that people use to make your brain feel like it
doesn't have to think about the other person as a
fellow human. And I have a lot of goals with
(24:58):
this podcast, but one of them is to expose this
simple neural tricks that have been employed forever so that
you can know what to watch for. We'll come back
to this at the end. But the thing I want
you to keep an eye out for as you move
forward is when is someone using the technique of trying
to manipulate your assessment about some other group by making
(25:19):
them less than human, like animals or machines, or viruses
or insects. Once you start seeing the tricks of propaganda,
you'll find yourself more immune to them. So how does
the issue of dehumanization get studied in the laboratory? While
in nineteen seventy five, a researcher named Albert Bandura set
(25:41):
up a simple study. He had college students come in
to do an experiment. So you come into a room
and you're told that in this other room are three
college students and they're trying to learn some associations with words,
and you're there to help teach them. Whenever they get
a wrong answer, you you are to send an electrical
(26:01):
shock to them in the other room, but you get
to choose how high the level of that shock is
from one to ten, and you get to choose each
time they make a mistake.
Speaker 2 (26:10):
So those are the rules of the game.
Speaker 1 (26:12):
And what happens is just before the experiment starts, the
experiment to running, it accidentally leaves the intercom on and
you overhear him say these guys meaning the students that
you don't see, these guys are a bunch of animals,
or in a different condition he says, oh, those guys
are really nice, or in a third condition, he doesn't
(26:35):
say anything at all.
Speaker 2 (26:35):
So that's it.
Speaker 1 (26:36):
The only experimental variable is what you overhear him say.
Speaker 2 (26:41):
So the experiment begins, and every time they get.
Speaker 1 (26:43):
A wrong answer, you get to decide between one and
ten what level of electrical shock you're going to send.
And what Bandura found was striking in the dehumanized condition
where they're called animals, people send stronger sho the only
difference being that they heard them described as animals at
(27:03):
the beginning. In the neutral condition, where nothing is overheard,
they send milder shocks, And in the humanized condition, where
they overheard the compliment that they were nice, they sent
even smaller shocks on average, just by dint of having
heard a simple sentence that humanized them. So I want
(27:40):
to be clear that the issue of humanization is not
something that's just turned on or off. It's more subtle.
It's not just human or nonhuman. Your notion of what
you think about someone can be modulated quite subtly, and
this is one of the things we've studied in my laboratory.
So for me to explain this, let's talk for a
second about pain. Let's say you put your hand on
(28:03):
the table and I stab your hand with a syringe
needle that activates a particular series of areas in your brain,
a network that we summarize as the pain matrix, and
that network says out, I'm feeling pain.
Speaker 2 (28:19):
Now. If you watch somebody else's hand get stabbed, it's
not your hand.
Speaker 1 (28:24):
You're watching a video of someone else's hand get stabbed
with a syringe.
Speaker 2 (28:28):
Needle.
Speaker 1 (28:29):
What happens in the brain, most of this same network
becomes active. So these areas respond when you're in pain
or when you're watching somebody else in pain, and this
is the neural basis of empathy. Watching someone else in
pain and simulating what it is like for them. You're
(28:51):
running a simulation as if it were your hand. That's
what empathy is. You're literally simulating what it is like
to be the other person. Now, the surprise is, even
though this is a very low level neural response, it
can be modulated by what you think about the other person.
So there was an experiment done by my colleague Tania
(29:13):
Singer in which she had people play a little game
with other people where they're making decisions about exchanging money.
Speaker 2 (29:20):
With each other.
Speaker 1 (29:21):
What's called an economic decision game. I'll skip to details.
The important part is that the other person that you're
playing with is a shill, someone who's secretly working with
the experimenter, and they can either play fairly or unfairly.
So you're either playing with someone who you feel does
the right thing or against the person that you conclude
is a bit of a cheat. And then you get
(29:43):
to see the person get an electrical shock. Now the
question is how much does your brain care? Just based
on their behavior, whether they're fair or a cheater, your
empathy can be modulated you care more or less about
their pain. Now, I'll link to all these papers on
Eagleman dot com slash podcast, but I'll just mention there
(30:06):
are a lot of individual differences between the participants, and
on average, men showed this effect of losing their empathy
more than women did. But once again, the point is
that this very basic neural response about seeing someone else
in pain can get modulated. Now, this is based on
their behavior. And one of the things that I started
(30:27):
wondering about in my work was could this be based
on something that's not even behavior. You never even meet
the person, You never see the person, but it's just
based on the in group or outgroup that they're in.
Could that modulate empathy? So my student Don Vaughan and
I put people into the brain scanner and we show
you six hands on the screen. Then on each round,
(30:50):
the computer goes around and randomly picks one of those hands,
and that hand expands to the middle of the screen,
and then you see that hand get touched with a
Q tip or stabbed with a syringe needle. We can
trast those two conditions to find those areas of the
brain that are just involved in that difference. And as
I mentioned before, this is where we find a network
(31:12):
that we summarize as the pain matrix. Now that we've
established this baseline condition, we just make one very simple change,
which is now we label the six hands on the
screen with a one word label Christian, Jewish, Atheist, Muslim, Hindu, scientologist.
(31:33):
A hand gets selected, comes to the middle of the screen,
and then you either see if get touched with a
Q tip or stabbed. And the question is what's your
in group and how does your brain respond to seeing
that hand get hurt as opposed to one of the
other hands get hurt. So in the baseline case, where
there's no label, your brain shows a lot of activity
(31:55):
in this network. This is the empathic response. When you
watch your in group gets stabbed, you see this response
but larger. Your brain really really cares about your in
group in pain. And when you watch a hand labeled
as one of your out groups get stabbed, the response
is diminished, so you care a lot about your in
(32:17):
group and less about your out groups. And by the way,
we recruited participants of all different religions, and we see
this same in group out group effects for everyone. And
by the way of interest, is that we see the
same effect even.
Speaker 2 (32:32):
For that atheists.
Speaker 1 (32:34):
Atheists care when they see an atheist hand get stabbed,
and they don't care as much when they see someone
else's hand get stabbed. So this is a very basic
issue about labels. It's about who's team you're on. Now,
something that got me interested is understanding how flexible these
sorts of designations are. So if you look, for example,
(32:56):
before World War Two, the Americans and the Soviets hated
each other, and then during World War two they were
both allied against the Axis powers. So now they were
buddies and fighting side by side, and when the war ended,
they went back to a position of enmity. And I thought,
it's interesting how flexible labels are. So we did the
same experiment. We put you in the scanner, and now
(33:18):
it says the year is twenty thirty two, and three
of these religions have teamed up against the other three religions,
and it's randomly selected every time. Okay, so now you're
in the scanner and you see the six hands on
the screen. But now you have teammates, allies, these other
religions that you didn't care about a minute ago, Now
(33:39):
they're on your team. And the question is what happens
when you see someone else's hand get stabbed if they're
an in group but happen to be an ally And
the answer is we find particular regions in the brain
that are sensitive to these alliances, which is to say,
you know, five minutes ago, you didn't care at all
about this outgroup, and now just because we've told you
(34:01):
in a single sentenced narrative that this outgroup is on
your team, now you care a little more about them
when you see them get stabbed. So, even though labels,
like religious labels, run so deep, things are flexible, and
that got me interested in a third phase of the
experiment to really understand about the arbitrariness of labels. So
(34:23):
what we do is we have you come into the
lab and I hand you a coin, and I say
you're going to toss this coin. And if it's heads,
you're an Augustinian, if it's tails, you're a Justinian. That's
all I tell you. I don't tell you anything else.
So you toss the coin, let's say you're a Justinian.
So I now hand you a bracelet according to which
team you're on, and you put it on, and you
(34:44):
go into the scanner, and we give you a one
sentence narrative that the Justinians and Augustinians are two warring tribes,
and it's the same thing. And the computer chooses a
hand and you either see the Justinian hand get stabbed
or the Augustinian hand get stabbed. And the question is
does your brain care more about a team that you
(35:06):
were arbitrarily assigned to and you know it was arbitrary
because you're the one who flipped the coin. And the
answer is yes, it's a smaller effect, but a totally
arbitrary team label is sufficient to make you care more
for your in group. And this is at a very
low level. This is a very basic neural response. So
(35:28):
this is the kind of thing we've been studying, and
it's important not only for what it reveals about human nature,
but also because it gives us a diagnostic tool for
measuring the degree of in group outgroup. In other words,
how much do you care about your in group and
how much do you not care about your outgroup? We
can quantify that difference, and that gives us a tool
(35:50):
into the future to measure the effect of rehumanizing narratives.
In other words, what are the different interventional strategy that
we can use to actually make groups reconverge. So we'll
come back to that in next week's episode. What I've
told you about today is the issue of dehumanization and
(36:11):
how your brain dials up and down the degree to
which you view another person as human. And in next
week's episode, part two, I'm going to expand these points
to dive deeper into our brains to understand what we
can do about it. I've said this before, but I
want to be really clear about this point. The reason
we work to understand the science of human behavior is
(36:34):
because our psychology has been carved by millions of years
of evolutionary pressures, and what we see in history is
the same events playing out over and over again, wherein
groups of individuals turn on their neighbors and devour them.
And this is not academic stuff that makes no difference.
This is the most important work that we can devote
(36:56):
ourselves to understanding because as we come to understand the
detail of our psychology and the tools of propaganda. We
develop our capacity to at least recognize when we are
getting manipulated. So when a government or rebel group, or
your neighbor tells you something about the members of some
(37:16):
other country, or some other religion or some other group,
we can at least be a step ahead of our
predecessors in previous generations, who fell for the most basic
tricks over and over.
Speaker 2 (37:29):
We can work to strengthen our.
Speaker 1 (37:31):
Societies and improve our world by better understanding the fabric
of our own psyches. Go to Eagleman dot com slash
podcast for more information and further readings. Send me an
email at podcasts at eagleman dot com with questions or
(37:52):
any discussions, and I'll be making an episode soon in
which I address those. And check out and subscribe to
Inner Cosmos on YouTube for videos of each episode, and
you can leave comments there.
Speaker 2 (38:04):
Until next time. I'm David Eagleman, and this is Inner
Cosmos
Why does your brain care more about some groups of
people than others? Why do we so naturally form in
groups and out groups? And what does any of that
have to do with George W. Bush's political commercials, or
the Greeks or psychopaths or syndrome E or propaganda posters
(00:25):
and how to develop immunity against them. Welcome to Inner
Cosmos with me David Eagleman. I'm a neuroscientist and an
author at Stanford and in these episodes we sail into
our three pound universe to understand why and how our
lives look the way they do.
Speaker 2 (00:55):
Today.
Speaker 1 (00:56):
We're going to talk about why we're so wired to
have in groups and out groups, and what the consequences are,
and how some knowledge on this goes a long way
to making us a little smarter in the face of propaganda.
This is a topic of enormous importance, in no small
(01:16):
part because repeatedly throughout history, groups of people have inflicted
violence on other members of their population. Think of the
Nazis and they're killing of millions of people Jewish communities
and Gypsies and others based on religious and ethnic and
political affiliations. Or look at the Nanking massacre, in nineteen
(01:38):
thirty seven when the Japanese invaded China and killed hundreds
of thousands of unarmed civilians and systematically raped between eighty
and one hundred thousand people. And in nineteen fifteen there
was a systematic killing of the Armenian population by the
Ottoman Empire. It's estimated that about one million Armenians were
(02:00):
killed during this. And then in nineteen ninety four, in
a period of one hundred days, the Hutu in Rwanda
killed eight hundred thousand Tutsi and this was accomplished mostly
with machetes, and at the peak of this they were
actually achieving a higher killing rate with machetes than the
(02:20):
Nazis had accomplished with gas chambers. And so the question
is what is going on here? We see this kind
of thing over and over in history, and often people
will inflict this kind of violence in coordination with the
authorities and against groups of people in their society that
were no direct threat to them and were defenseless. So
(02:42):
how can we understand this characteristic of human behavior, Because
it's of deep importance for us to understand this if
we want to have any hope of preventing this in
the future. Now, historians look for explanations by digging into
issues of political and civil strife and economic troubles. But
(03:03):
the real issue is that the only way these events
can happen is when there's a distinct change in the
behavior of individuals, and how can we understand that change
in behavior. What I want to talk about today is
the science of what we understand about that about genocide.
I want to put together a new framework to see
(03:25):
how we can come to understand events like this, and
I'm going to end by saying what we can do
about it. So let's start in the distant past. When
we think about human evolution. The story we all know
about Darwinian evolution is that it's survival of the fittest. Right,
you have to be a strong competitor to survive and thrive,
(03:48):
and that's a pretty good framework. But people started realizing
there was a little bit of a problem because the
issue is altruism. That is, when you give your own
resources to help other people. How does the basic Darwinian
story of survival of the fittest explain why people help
each other out. You can't understand that just by thinking
(04:10):
about individual selection. And that got people thinking about kin selection,
So you may have heard of this notion of the
selfish gene. The idea is that if I share some
genetic material with my brother, then maybe that explains why
I want to help him out. The genes want to survive,
(04:30):
and I share a little bit less genetic material with
my cousins, and so all sacrifice for them, but maybe
a little bit less so and so on through my
family tree. The evolutionary biologist J. S. Haldane famously said
I would gladly jump in a river to save two
of my brothers or eight of my cousins. So this
(04:51):
is known as kin selection rather than individual selection. But
it turns out even that's not enough to explain the
world of humans, because in fact, what distinguishes our species
is that humans get together and cooperate irrespective of kinship.
So that led people to think about group selection, which
(05:15):
is to say, if you and your fellow tribe members
are the type who cooperate, then as a group you
all increase your chances of survival. Your tribe has a
better chance of surviving than the other tribe on the
other side of the mountain, who are not very cooperative
with each other, no matter how strong they may be
(05:35):
as individuals. So the term for this is you sociality
You you meaning good or positive. So if a species
is you social, then there's this glue that allows them
to build tribes and groups and nations irrespective of kinship.
My colleague Jonathan Hate gave a nice analogy for this.
(05:59):
He said, as a result of the evolutionary history of humans,
we're sort of ninety percent primate and ten percent honeybee.
By primates, he means we're mostly about individual competition, but
by honeybee he means sometimes we work together for the
good of the hive. So our strong youth social nature
(06:20):
can't be explained just by individual selection, but instead it
seems to require this selection for groups who want to work.
Speaker 2 (06:28):
With one another.
Speaker 1 (06:29):
Now, this massively social nature is what underlies our ability
to build and operate cities and industry and do science
and so on. Humans say, hey, let's link arms and
cooperate with one another and drive things forward together and
enjoy all the benefits of that. This kind of thinking
(06:49):
allows organisms to operate as superorganisms. And by the way,
I should just note something about religion here. Some scholars
compare religion to a pathological virus that spreads across minds.
But that's probably not the optimal way to think about it.
From an evolutionary point of view, things are judged by
(07:11):
what they cause people to do, and what religions cause
is for people to group together, to be usocial. So
what happens with religions is you define a group, you
coordinate the behavior of the group, and you incentivize the
group to cooperate and work together. So, as one evolutionary
biologist in the late eighteen hundred said, religion is just
(07:35):
another weapon in the Darwinian struggle for survival. In other words,
if religion were maladaptive, it would have gone away. But
it usually is adaptive in the sense that it causes
groups to come together and work cooperatively. But one of
the costs of our usociality is that we get in
(07:57):
groups and outgroups. And today we're going to see what
all of this has to do with the brain. Historically, traditionally,
we've always studied the brain by looking at individual parts
and regions of it. So you say, okay, well, this
is how vision works, and this is how hearing works,
and this is how decision making works and so on,
and it's only in recent years that people began to
(08:20):
appreciate that a lot of the circuitry of the brain
has to do with this youth sociality. A lot of
it has to do with how you interact with other
brains in terms of trust and reputation and allegiances. And
I talked a little bit about this in a previous episode.
And this has led to a new field called social neuroscience,
(08:40):
which studies this sort of thing. And that's what I'm
going to tell you about today, and how social neuroscience
can shed light on group behavior.
Speaker 2 (08:49):
So I mentioned in.
Speaker 1 (08:50):
This previous episode about this philosophical problem called the trolley dilemma,
And just as a reminder, there is a trolley barreling
down the.
Speaker 2 (08:59):
Tracks full speed.
Speaker 1 (09:01):
Its brakes are broken, and you see there are five
workmen farther down the track and they're going to get killed.
The trolley is going to run over them. But it
just so happens that you notice you're standing next to
a lever that can switch the track for the trolley,
and on this other track, you see.
Speaker 2 (09:17):
There's only one workman there.
Speaker 1 (09:19):
So the question is will you switch the track over
so it kills only one person instead of five? So
think about what you would do here. Now, here's scenario
number two. It's the same thing. The trolley is barreling
down the track. You see the five workmen. They're going
to get killed. But this time you're standing on a
little footbridge over the tracks, and you realize that there
(09:41):
is a man standing in front of you, and if
you push him over the edge of the tracks, his
weight will be sufficient to stop the trolley and save
the five men. So the question is do you push
the man or not? Now, in most cases people will
do it. But the thing to notice is that it's
(10:02):
exactly the same question. In both cases, will you trade
one life for five lives or won't you Most people
will do that in the first case, but they won't
in the second case, which is interesting, right, it's the
same math. So my colleagues Joshua Green and Jonathan Cohen
got interested in this question some years ago and they
(10:22):
did neuro imaging on people. They put them in the
brain scanner while they had the people walking through the
trolley dilemma problem, and essentially what they found is there
are areas of your brain that are involved in math
problems that are saying, okay, well, one versus five and
so on. They make a calculation, and you have other
areas of your brain that care about emotional issues. They're
(10:44):
simulating situations and assessing how those make you feel. Those
areas are generally along the midline of the brain if
you drew a line from your nose to the back
of your head. And it turns out that in this
second scenario where you're asking if you're going to push
the guy, these emotional areas come online, and that changes
your decision making. In other words, emotions, how you feel
(11:07):
about something is a very important part in navigating the decision.
The first scenario is just an easy math problem. The
second one is an emotional problem, and it changes what
you decide. And in fact, the idea that reason and
emotion are fighting with each other. That's a very old idea.
The Greeks had this metaphor that life is as though
(11:30):
you are a charioteer and you're being pulled along by
the white horse of reason and the black horse of passion,
and they're always trying to pull you off in opposite directions,
and your job as the charioteer is to.
Speaker 2 (11:44):
Stay down the middle of the road.
Speaker 1 (11:46):
And it's not easy, right because you've got these two
different polls going on all the time. So emotions are
tightly involved in decision making. They serve an important role
in how we navigate our life.
Speaker 2 (12:00):
And you wouldn't want to live in a world.
Speaker 1 (12:02):
Where everybody is like mister Spock and Star Trek and
doesn't have emotions, right, because everybody would just push the
man off the bridge and that would be.
Speaker 2 (12:10):
The end of it.
Speaker 1 (12:11):
But instead, we use emotions to steer the decisions we make,
and if something feels wrong, we try not to do it.
(12:35):
So the question is how do we understand or interpret
the things that we see during wartime. There's a horrifying
photograph from World War Two where there's a crying mother
who's clutching her small child to her chest, and there's
a German soldier about six feet behind her with his
(12:55):
rifle poised aimed at her head, ready to execute her
while she's holding her baby in her arms. Now, there
are several things to note about this photograph. First, the
fact that he's doing this in front of someone in
front of the cameraman suggests that he has a diminished
emotional reactivity to this situation. He's not distressed by the situation.
(13:17):
He's not feeling like you felt when you thought about
pushing the man off the bridge. Now, if this were
the one guy committing atrocities during wartime, we might just
write him off as a psychopath.
Speaker 2 (13:28):
But there were hundreds of.
Speaker 1 (13:30):
Thousands of young men doing awful stuff everywhere you looked,
including running the concentration camps, or raping women in the towns,
or lining up dozens of people along ditches and machine
gunning them. So it wasn't just one psychopath. What was
going on here? The neurosurgeon you talk Freed in the
(13:50):
late nineties started thinking about this question a lot, and
he said, you know, when you look across all these
different events in the world, you find this kind of
behavior everywhere. People seem to lose their normal way that
their brain functions, and they become different in how they
make decisions, they act differently than they would under normal circumstances.
(14:12):
And he said, when you look at the signs and
the symptoms of their behavior, it's like there's a medical
condition going on here. So he named this syndrome E,
and he said there are very particular signs and symptoms
that you look for here, just like you would look
for coughing or fever with pneumonia. You look for particular
(14:33):
things that characterize people's behavior during wartime. First, there's diminished
emotional reactivity that gives people this ability to do repetitive
acts of violence. Maybe people start off having a little
bit of a hard time with it, but they rapidly
desensitize it doesn't bother them anymore. Second, he noticed there's
(14:57):
a hyper arousal or as the Germans called it, raush,
which is this feeling of elation when committing these horrific acts.
Another sign is group contagion, which is an important one
that I'll come back to. The issue is everybody's doing
something and it catches on and it spreads. He also
(15:18):
pointed to compartmentalization. Someone can care about their own family
and yet at the same time do this sort of
thing to another family. So these are the signs of
syndrome E. Diminished emotional reactivity, repetitive acts of violence, hyper arousal,
group contagion, compartmentalization. And the interesting thing from a neuroscience
(15:40):
point of view is that the other functions of the
brain are working just fine. Things like language and memory
and problem solving, those are completely intact so that gives
us a clue into what's happening under the hood. And
what's happening in the case of syndrome E is something
like this. The emotional networks of the brain are short circuited.
(16:04):
They are not participating in the decision making anymore. They
are now sidelined. They're out of the equation. So that
allows a soldier to execute a woman clutching her baby,
just like it would allow you to push the man
off the bridge without really thinking twice about it. In
other words, their decision making is being steered by parts
(16:24):
of the brain that can do logic and reasoning and
memory and so on, but not the parts of the
brain that normally navigate things with emotion. And what this
leads to is a moral disengagement. A person becomes like
a car that's in neutral going down the hill. He
doesn't have all these systems anymore that tell him the
right way to steer his actions. Now, can this sort
(16:47):
of thing be studied in the laboratory, Yes it can.
So consider this study. People are shown photographs of other
people and you measure what's going on in their brain.
And what the researchers found is that if you show
participants pictures of people they admire, Olympic athletes and hard workers,
(17:08):
and so on. Various parts of the brain light up,
and the area I want to draw attention to is
a part along the brain's midline called the medial prefrontal cortex.
The medial prefrontal cortex is involved in these emotional systems,
and it's also involved in social cognition. In other words,
this area is active whenever you're dealing with another person
(17:31):
as opposed to an object like a coffee cup or
a laptop. Even if you show participants photographs of people
they don't like very much, like people they envy or
people they pity, you still get medial prefrontal cortex activation.
In other words, people still see them as humans even
though they're maybe not in their in group. But if
you go even further along the spectrum of outgroups and
(17:54):
show pictures of people that they feel very separated from,
like homeless people are drug addicts, the medial prefrontal cortex
turns off. It just doesn't come online in the same way.
And what that means is that they're viewing these people
the same way that they do objects. So again, when
you view objects, this area doesn't come online, and it
(18:17):
comes online when you're looking at humans, except for really
outgroup humans, when it simply doesn't activate anymore. So when
we talk about dehumanization, what we're really talking about are
regions of the brain that think about other humans that
don't come online anymore. These regions are now out of
(18:38):
the equation, and in this scenario, when you are making
moral decisions about people who are in your outgroup, you
don't have these use social mechanisms steering your behavior. With psychopaths,
by the way, there are many subtle differences in their brains,
but one of the issues you see is this, they
just don't have these areas like the medial pre frontal
(19:00):
cortex emotionally steering their behavior, and so they're capable of
doing things like violence and murder because they don't care
about you. They're not simulating what it is like to
be you. They don't have the emotional feeling that's steering
around their decisions. And this is what happens when groups
(19:20):
dehumanize their neighbors. I have a photograph of a group
of German citizens and soldiers at the beginning of World
War Two making their Jewish neighbors scrub the pavement with toothbrushes,
and the Germans watching are having a great time posing
and laughing. And what's happening is that, because of the
social context that allows syndrome E, these emotional regions are
(19:45):
no longer online, and so their neighbors are not like
humans to them anymore. And this situation typifies genocides. Here's
a quotation from a Japanese general talking about his behavior
during the invasion of China. He explained his soldier's behavior
by saying, it was quote because we thought of them
(20:07):
as things, not as people like us.
Speaker 2 (20:10):
End quote.
Speaker 1 (20:11):
Here's a statement from a woman in Rwanda who orchestrated
the killing of thousands of Tutsi. She said, quote, we
thought of them as nothing more than insects or cockroaches.
Here's a quotation from an American sergeant stationed in Iraq.
He says, quote, you just sort of tried to block
out the fact that they're human beings and you see
(20:32):
them as enemies. So what we're talking about here is
the same neural issue across place and time. Dehumanization is
about turning off the parts of your brain that allow
you to understand what it is like to be someone else.
You may remember Anders Bravik, the Norwegian who murdered seventy
(20:54):
seven young people in twenty eleven. So back in twenty twelve,
I was following his trial closely, and here's what he said.
One might say I was quite normal in two thousand
and six when I started training, when I commenced de emotionalizing.
He said, I've had a dehumanization strategy towards those I
(21:15):
considered valid targets so I could come to the point
of killing them. He nailed it here. He knew that
his own training regime was about de emotionalizing. I mean,
he phrased exactly what we've been talking about here so far.
He worked, for example, with meditation, to hammer away any
(21:36):
emotional response he had to the idea of killing someone.
That's the way he trained. He worked to diminish the
response of his medial prefrontal cortex in other areas and
the networks involved in emotion. Now, we might lament the
fact that these programs are able to be overridden, but
we should be thankful for the fact that they're so
(21:57):
so difficult to override. Act like bravics is extremely rare.
Despite the logical ease of anyone pulling it off. Now,
if you're not that good at turning off your own
medial prefrontal cortex, you should know that there are always
groups that are willing to do this for you, and
that is the art and science of propaganda. So something
(22:19):
that I have always found amazing is looking at war posters.
For example, I have an American poster from World War One.
It shows a giant, crazy looking ape wearing a German helmet,
and on the helmet it reads militarism. And in one
hand the ape is carrying a huge club, and in
the other arm he's holding a beautiful woman whose arms
(22:41):
are flung over her head, and the poster reads, destroy
this mad brute enlist US Army. Now, I want to
point out that if you look at any propaganda poster
from any war at any time, on any side, you'll
see a common theme. You make your enemy less than human,
and making them explicitly an animal.
Speaker 2 (23:04):
Is a very popular choice.
Speaker 1 (23:06):
So in this case, the Germans are portrayed as a
bellicose ape coming onto American shores, and the fact that
he's stealing away a half naked, beautiful American woman makes
you even more mad about the whole thing. And this
is typical of propaganda posters. You always give the enemy
fangs and feral features. And the idea is you want
(23:28):
to shut off the networks that are involved in humanization.
You want your population to feel like we can do this,
We can go to war with these guys because they're
not like us, they're animals. Or consider this other propaganda
poster I have from Germany during World War Two, which
represents America as a giant mechanical robot monster toting guns
(23:52):
and bombs and destroying Europe. So it doesn't have to
be animals, just anything that's not human. And in fact,
when our Winian thinking got introduced in the eighteen hundreds,
lots of people took the opportunity to generate pseudoscience, suggesting
that whoever their enemy was, they were less than human.
This is a typical strategy to implement, and it can
(24:16):
even be done subtly. Some of you may remember that
when George W. Bush was running for president against Al Gore,
he did the same thing. His commercial ran and said
the Gore prescription plan, and then you see this big
word rats on the screen, and then after about half
a second is the word zooms out. You see it
(24:36):
actually says bureaucrats, and eventually, when it's all zoomed out,
it says bureaucrats decide. But what it starts with is
this giant word rats. The strategy of dehumanization is one
that people use to make your brain feel like it
doesn't have to think about the other person as a
fellow human. And I have a lot of goals with
(24:58):
this podcast, but one of them is to expose this
simple neural tricks that have been employed forever so that
you can know what to watch for. We'll come back
to this at the end. But the thing I want
you to keep an eye out for as you move
forward is when is someone using the technique of trying
to manipulate your assessment about some other group by making
(25:19):
them less than human, like animals or machines, or viruses
or insects. Once you start seeing the tricks of propaganda,
you'll find yourself more immune to them. So how does
the issue of dehumanization get studied in the laboratory? While
in nineteen seventy five, a researcher named Albert Bandura set
(25:41):
up a simple study. He had college students come in
to do an experiment. So you come into a room
and you're told that in this other room are three
college students and they're trying to learn some associations with words,
and you're there to help teach them. Whenever they get
a wrong answer, you you are to send an electrical
(26:01):
shock to them in the other room, but you get
to choose how high the level of that shock is
from one to ten, and you get to choose each
time they make a mistake.
Speaker 2 (26:10):
So those are the rules of the game.
Speaker 1 (26:12):
And what happens is just before the experiment starts, the
experiment to running, it accidentally leaves the intercom on and
you overhear him say these guys meaning the students that
you don't see, these guys are a bunch of animals,
or in a different condition he says, oh, those guys
are really nice, or in a third condition, he doesn't
(26:35):
say anything at all.
Speaker 2 (26:35):
So that's it.
Speaker 1 (26:36):
The only experimental variable is what you overhear him say.
Speaker 2 (26:41):
So the experiment begins, and every time they get.
Speaker 1 (26:43):
A wrong answer, you get to decide between one and
ten what level of electrical shock you're going to send.
And what Bandura found was striking in the dehumanized condition
where they're called animals, people send stronger sho the only
difference being that they heard them described as animals at
(27:03):
the beginning. In the neutral condition, where nothing is overheard,
they send milder shocks, And in the humanized condition, where
they overheard the compliment that they were nice, they sent
even smaller shocks on average, just by dint of having
heard a simple sentence that humanized them. So I want
(27:40):
to be clear that the issue of humanization is not
something that's just turned on or off. It's more subtle.
It's not just human or nonhuman. Your notion of what
you think about someone can be modulated quite subtly, and
this is one of the things we've studied in my laboratory.
So for me to explain this, let's talk for a
second about pain. Let's say you put your hand on
(28:03):
the table and I stab your hand with a syringe
needle that activates a particular series of areas in your brain,
a network that we summarize as the pain matrix, and
that network says out, I'm feeling pain.
Speaker 2 (28:19):
Now. If you watch somebody else's hand get stabbed, it's
not your hand.
Speaker 1 (28:24):
You're watching a video of someone else's hand get stabbed
with a syringe.
Speaker 2 (28:28):
Needle.
Speaker 1 (28:29):
What happens in the brain, most of this same network
becomes active. So these areas respond when you're in pain
or when you're watching somebody else in pain, and this
is the neural basis of empathy. Watching someone else in
pain and simulating what it is like for them. You're
(28:51):
running a simulation as if it were your hand. That's
what empathy is. You're literally simulating what it is like
to be the other person. Now, the surprise is, even
though this is a very low level neural response, it
can be modulated by what you think about the other person.
So there was an experiment done by my colleague Tania
(29:13):
Singer in which she had people play a little game
with other people where they're making decisions about exchanging money.
Speaker 2 (29:20):
With each other.
Speaker 1 (29:21):
What's called an economic decision game. I'll skip to details.
The important part is that the other person that you're
playing with is a shill, someone who's secretly working with
the experimenter, and they can either play fairly or unfairly.
So you're either playing with someone who you feel does
the right thing or against the person that you conclude
is a bit of a cheat. And then you get
(29:43):
to see the person get an electrical shock. Now the
question is how much does your brain care? Just based
on their behavior, whether they're fair or a cheater, your
empathy can be modulated you care more or less about
their pain. Now, I'll link to all these papers on
Eagleman dot com slash podcast, but I'll just mention there
(30:06):
are a lot of individual differences between the participants, and
on average, men showed this effect of losing their empathy
more than women did. But once again, the point is
that this very basic neural response about seeing someone else
in pain can get modulated. Now, this is based on
their behavior. And one of the things that I started
(30:27):
wondering about in my work was could this be based
on something that's not even behavior. You never even meet
the person, You never see the person, but it's just
based on the in group or outgroup that they're in.
Could that modulate empathy? So my student Don Vaughan and
I put people into the brain scanner and we show
you six hands on the screen. Then on each round,
(30:50):
the computer goes around and randomly picks one of those hands,
and that hand expands to the middle of the screen,
and then you see that hand get touched with a
Q tip or stabbed with a syringe needle. We can
trast those two conditions to find those areas of the
brain that are just involved in that difference. And as
I mentioned before, this is where we find a network
(31:12):
that we summarize as the pain matrix. Now that we've
established this baseline condition, we just make one very simple change,
which is now we label the six hands on the
screen with a one word label Christian, Jewish, Atheist, Muslim, Hindu, scientologist.
(31:33):
A hand gets selected, comes to the middle of the screen,
and then you either see if get touched with a
Q tip or stabbed. And the question is what's your
in group and how does your brain respond to seeing
that hand get hurt as opposed to one of the
other hands get hurt. So in the baseline case, where
there's no label, your brain shows a lot of activity
(31:55):
in this network. This is the empathic response. When you
watch your in group gets stabbed, you see this response
but larger. Your brain really really cares about your in
group in pain. And when you watch a hand labeled
as one of your out groups get stabbed, the response
is diminished, so you care a lot about your in
(32:17):
group and less about your out groups. And by the way,
we recruited participants of all different religions, and we see
this same in group out group effects for everyone. And
by the way of interest, is that we see the
same effect even.
Speaker 2 (32:32):
For that atheists.
Speaker 1 (32:34):
Atheists care when they see an atheist hand get stabbed,
and they don't care as much when they see someone
else's hand get stabbed. So this is a very basic
issue about labels. It's about who's team you're on. Now,
something that got me interested is understanding how flexible these
sorts of designations are. So if you look, for example,
(32:56):
before World War Two, the Americans and the Soviets hated
each other, and then during World War two they were
both allied against the Axis powers. So now they were
buddies and fighting side by side, and when the war ended,
they went back to a position of enmity. And I thought,
it's interesting how flexible labels are. So we did the
same experiment. We put you in the scanner, and now
(33:18):
it says the year is twenty thirty two, and three
of these religions have teamed up against the other three religions,
and it's randomly selected every time. Okay, so now you're
in the scanner and you see the six hands on
the screen. But now you have teammates, allies, these other
religions that you didn't care about a minute ago, Now
(33:39):
they're on your team. And the question is what happens
when you see someone else's hand get stabbed if they're
an in group but happen to be an ally And
the answer is we find particular regions in the brain
that are sensitive to these alliances, which is to say,
you know, five minutes ago, you didn't care at all
about this outgroup, and now just because we've told you
(34:01):
in a single sentenced narrative that this outgroup is on
your team, now you care a little more about them
when you see them get stabbed. So, even though labels,
like religious labels, run so deep, things are flexible, and
that got me interested in a third phase of the
experiment to really understand about the arbitrariness of labels. So
(34:23):
what we do is we have you come into the
lab and I hand you a coin, and I say
you're going to toss this coin. And if it's heads,
you're an Augustinian, if it's tails, you're a Justinian. That's
all I tell you. I don't tell you anything else.
So you toss the coin, let's say you're a Justinian.
So I now hand you a bracelet according to which
team you're on, and you put it on, and you
(34:44):
go into the scanner, and we give you a one
sentence narrative that the Justinians and Augustinians are two warring tribes,
and it's the same thing. And the computer chooses a
hand and you either see the Justinian hand get stabbed
or the Augustinian hand get stabbed. And the question is
does your brain care more about a team that you
(35:06):
were arbitrarily assigned to and you know it was arbitrary
because you're the one who flipped the coin. And the
answer is yes, it's a smaller effect, but a totally
arbitrary team label is sufficient to make you care more
for your in group. And this is at a very
low level. This is a very basic neural response. So
(35:28):
this is the kind of thing we've been studying, and
it's important not only for what it reveals about human nature,
but also because it gives us a diagnostic tool for
measuring the degree of in group outgroup. In other words,
how much do you care about your in group and
how much do you not care about your outgroup? We
can quantify that difference, and that gives us a tool
(35:50):
into the future to measure the effect of rehumanizing narratives.
In other words, what are the different interventional strategy that
we can use to actually make groups reconverge. So we'll
come back to that in next week's episode. What I've
told you about today is the issue of dehumanization and
(36:11):
how your brain dials up and down the degree to
which you view another person as human. And in next
week's episode, part two, I'm going to expand these points
to dive deeper into our brains to understand what we
can do about it. I've said this before, but I
want to be really clear about this point. The reason
we work to understand the science of human behavior is
(36:34):
because our psychology has been carved by millions of years
of evolutionary pressures, and what we see in history is
the same events playing out over and over again, wherein
groups of individuals turn on their neighbors and devour them.
And this is not academic stuff that makes no difference.
This is the most important work that we can devote
(36:56):
ourselves to understanding because as we come to understand the
detail of our psychology and the tools of propaganda. We
develop our capacity to at least recognize when we are
getting manipulated. So when a government or rebel group, or
your neighbor tells you something about the members of some
(37:16):
other country, or some other religion or some other group,
we can at least be a step ahead of our
predecessors in previous generations, who fell for the most basic
tricks over and over.
Speaker 2 (37:29):
We can work to strengthen our.
Speaker 1 (37:31):
Societies and improve our world by better understanding the fabric
of our own psyches. Go to Eagleman dot com slash
podcast for more information and further readings. Send me an
email at podcasts at eagleman dot com with questions or
(37:52):
any discussions, and I'll be making an episode soon in
which I address those. And check out and subscribe to
Inner Cosmos on YouTube for videos of each episode, and
you can leave comments there.
Speaker 2 (38:04):
Until next time. I'm David Eagleman, and this is Inner
Cosmos
Host
David Eagleman
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