we speak about their crimes to increase

the impact, the virtual blast radius, massively,

from a small town to the whole nation.

"Once again in America, we are waking up

to horrifying news."

"Mass shooting with casualties."

"In El Paso, Texas, new details

about the carnage at a Wal-Mart."

The Shooting in El Paso, Texas, was

one of several deadly attacks in the U.S. last year

and beyond.

We have a power and responsibility to save lives,

but it means changing the way we

talk in the aftermath of an attack.

You see, I'm a cognitive scientist,

and I've spent the last seven years interviewing

radicalized people —

members and supporters of groups

like Al Qaeda and ISIS.

My colleagues and I carried out

a bunch of psychological tests,

including the first-ever brain scans of radicalized people.

We didn't find any evidence of mental illness,

but what we did find were clues

to what makes people willing to fight and die

for their beliefs.

To show you how, I need to tell you about these brain

scans, and that means taking you here.

[MUSIC PLAYING]

This is where our fieldwork began,

looking for young men between the ages of 18 and 40,

all on the path to radicalization.

And under the promise of anonymity,

they agreed to step inside an MRI machine.

I need to stop here for a second,

because it's important that you

know about what cognitive scientists call

sacred values.

We all have beliefs that we care so passionately

about that we'd be willing to go to extreme lengths

to defend them.

Well, guess what?

Jihadists also have sacred values,

and they're willing to use violence to defend them.

And white nationalists have sacred values, too.

[MUSIC PLAYING]

It starts with one of these.

We put some of our participants,

the less radicalized ones, into a virtual ballgame

with three other players.

They threw the ball to each other like this.

After a couple of rounds, half the players

were excluded from the game.

The other players ignored them.

And that's when we put them into the MRI scanner.

We know from previous research that when

people are processing their sacred values,

this part of the brain right here is very active.

And when our subjects were thinking

about their sacred values, sure enough, it lit up.

But after they were ejected from the ballgame,

something weird happened.

It lit up for non-sacred values, too.

In other words, when they felt excluded,

the list of things they're willing to fight and die for

got longer.

Of course, people don't commit terrorist attacks

just because nobody plays ball with them.

But our research shows that if someone

is at the early stage of radicalization,

excluding them can make them more willing to use violence.

[MUSIC PLAYING]

In the next study, we took 30 highly radicalized supporters

of an Al Qaeda associate and showed

them a scale like this.

We asked them to rate their willingness

to fight and die for a series of sacred values,

and then we showed them where their peers--

other Muslims in the community —

fell on the scale.

And while they were doing this,

we scanned their brains.

We found that when our subjects were highly

willing to use violence, this part of the brain

was deactivated.

And that's a problem, because it

could mean that they're not as open to negotiation

or persuasion.

So how do we reopen this person's mind?

Well, when we told our participants

that their wider social group were not as willing

to commit violence as they were, this part of the brain

reactivated.

And get this — they lowered their explicit willingness

to fight and die for these values just

to match their peers.

The lesson here is that people can be turned away

from violence if they believe that a wider

social group disapproves.

This is only the first glimpse into the minds

of radicalized people, but I do

think it tells us something important about the role we

play in preventing terrorism.

In the days after the El Paso shooting,

I saw a lot of tweets like this —

prominent figures saying Trump's base

is white nationalist, or if you support Trump,

you support terrorism.

Now, I'm not saying you shouldn't call out racism,

but in a case like this, blaming all conservatives

risks making someone out there feel more excluded.

And if they're at the early stages of radicalization,

it could push them closer to violence.

At the very least, it creates divisions

in society, which is exactly what terrorists

want to achieve.

No. 1, don't blame whole groups.

And if you see or hear friends, family

or people you follow online talking that way,

challenge them.

And number two, seek out and amplify voices

on the right who are condemning violence.

I still remember this tweet from a Trump supporter

urging him to make a statement about white nationalism.

He said, "We have to tell them we do not want them to be

part of us."

Voices like this have the power to turn someone away

from violence.

We're not responsible for the actions of terrorists,

but we all have the power to limit the blast

radius of an atrocity and maybe even prevent

the next one.