Why do we believe things that aren't true? | Philip Fernbach | TEDxMileHigh

It seems like we're living in an epidemic of false belief. Clearly the other side just doesn’t have all the facts, right? Or are they really that stupid? In this fascinating and hilarious talk, cognitive scientist Philip Fernbach peels back the layers of what we really know and reveals some surprising truths about the human mind.

Philip Fernbach is a cognitive scientist and professor in the Leeds School of Business at the University of Colorado, Boulder. Co-author of "The Knowledge Illusion: Why We Never Think Alone," Philip's research focuses on why we think we know more than we actually do and the implications this has on individuals and society. He lives in Boulder with his wife and two children. In his free time, he plays bluegrass music and ice hockey.

This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at https://www.ted.com/tedx

A few months ago,

the Internet exploded when a rapper
named Bobby Ray Simmons,

aka B.o.B,

started twitting out reasons
why he thought the world was flat.

(Laughter)

Now, the story really took off

when Neil deGrasse Tyson,
the astrophysicist,

started twitting back at him,
explaining the apparent discrepancies.

But guess what?

B.o.B held his ground.

(Laughter)

He didn't give in.

Now, it turns out
that B.o.B is not the only one.

Believe it or not, there's
actually a flat Earth society,

with roots going
all the way back to the 1800s.

Their model is amazing.

"We man the guns
against oppression of thought

and the Globularist lies of a new age."

(Laughter)

When I first read this,
I thought it said "Globalist lies,"

but it's actually "Globularist,"

i.e. those nutty folks
who think the Earth is a sphere.

(Laughter)

"Standing with reason,

we offer a home to those wayward thinkers

who march bravely on with reason and truth

in recognizing the true
shape of the Earth."

Flat!

(Laughter)

This is not some elaborate hose.

B.o.B and the flat-earthers
really believe that the Earth is flat,

despite all evidence to the contrary.

So, why am I showing you this?

Because your natural reaction
to this story is wrong!

Your first instinct is to laugh
at the flat-earthers

and assume they must be
incredibly dense or crazy,

but actually, they're not all
that different than you and I.

As human beings,
false belief is our birth right.

It stands from fundamental principles

that govern the way our minds work
and the way we store knowledge.

Consider how common it is

for groups of people to believe things
that just aren't true.

Right now, in this moment,

it feels like we're
in the midst of an epidemic.

The explosion of fake news

shows how easy it is to do people
on the left and the right,

and science denial has gone mainstream.

Significant proportions of the population

maintain beliefs counter
to the scientific consensus

on critical issues
like vaccination, global warming

and the safety of genetically
modified foods.

Public attitudes about these issues
literally determine

whether we can feed ourselves,
whether we can raise healthy children

and whether we can forestall
a climate disaster.

The stakes could not be higher,

which is why it's just not good enough

to chalk all this up
to lunacy or stupidity.

Simplistic explanations like that
aren't getting us anywhere.

If we really want to improve
the way we grapple with these challenges,

we have to go deeper,

we have to understand
what it is about the way we think

that makes us so susceptible
to believing things that aren't true.

And that explanation actually begins
with a kind of shocking observation.

As individuals,

we do not know enough
to justify almost anything we believe.

Now, I know that might
sound crazy to you,

but let's think about a couple
of really obvious facts.

We all believe that the Earth
revolves around the Sun.

Of course we do, it's the most
basic fact in the world.

But on what basis?

Can you explain the astronomical
observations that support that belief?

I know I can't.

What about smoking?

We all know it's terrible for us, right?

But what's actually
in cigarette smoke that's bad?

And what does it do
to our bodies and ourselves?

What's cancer really?
How does it even form?

These are not isolated examples.

Most of what we believe is not based
on what's in our heads,

and there's a good reason for that.

There's not much in our heads!

(Laughter)

As human beings,

we are just not made
to store a lot of detailed information.

In the 1980s, a psychologist named
Thomas Landauer set out to estimate

the size of an individual's
knowledge base in bytes,

the same scale that's used
to measure computer memories.

One approach he took was to analyze
the result of memory experiments

where people were asked to study
some pictures, or words, or bits of music,

and then later test it
to see if they recognized them.

Using the data, he was able to estimate
the rate at which we can acquire knowledge

and also the rate at which
we forget what we learn.

And then, he extrapolated
to a 70-year lifespan.

So, how much do you know?

Landauer's estimate:

1 gigabyte.

(Laughter)

I think this is an amazing result,

mind-blowing really.

One gigabyte is a tiny amount!

By comparison,

you can buy a thumb drive
on Amazon.com for less than 18 bucks,

that holds 64 gigabytes.

(Laughter)

Now, at this point, some of you guys
might be freaking out a little bit,

feeling a little bit concerned.

After all, we all think it's the most
important thing in the world

to know a lot and have great memories.

But really, this is a misconception.

We do not have to know a lot

because we're not made
to think on our own.

It's natural to think about thinking
as what happens between your ears,

but that's not where
the magic really happens.

This video comes from a psychologist
by the name of Michael Tomasello

and his colleagues.

They study human children's
cognitive abilities

in comparison to other animals
like chimpanzees.

The goal is to understand
what really makes us special.

What abilities do we excel at
that other animals just cannot master?

You see how easily this young child
reads the mind of the experimenter

and then figures out how to coordinate
his behavior to achieve the goal.

(Laughter)

He even makes eye contact at the end
as if to say, "I've got your back, man!"

(Laughter)

This is so natural to us
that it seems like nothing,

but it's actually incredibly difficult

to design a cognitive system
that's capable of collaboration.

This is really the secret to our success,

it's what separates us
from all other thinking creatures.

Chimpanzees routinely fail at tasks

that require sharing knowledge
and working together to pursue goals,

tasks that young children
master with ease.

Now, for me,

this realization was a major wake-up call.

It really changed my perspective
on the nature of the mind.

I'm a cognitive scientist.

I'm used to studying how individuals make
decisions or solve problems in isolation.

But thinking is a social process.

Rather than happening inside your head,

it emerges from your interactions
with those around you.

People are a little more like bees
than we often realize.

In a beehive, you have an incredibly
complex cluster of behaviors

that is achieved despite no individual
being responsible for it all.

Food is collected and stored,

the hive is protected from intruders,

genetic diversity is introduced.

The key is specialization:

each individual does its own little part,
and the complexity emerges.

The same is true of people.

On our own, none of us
knows all that much,

we don't have to.

We each have our own
little slice of expertise,

and our minds are built to collaborate
and to share knowledge,

which allows us to pursue
incredibly complex goals

when none of us has anything approaching
the knowledge to understand it all.

This is the Milan Cathedral.

It's one of humanity's great works.

Construction began in 1386,

and the facade was completed,
get this, under Napoleon, in the 1800s.

It turns out that cathedrals
have a punch list,

like a home renovation.

The punch list was completed

when they consecrated
the final gate in the 1960s.

Six hundred years.

In that time,

there were 75 chief engineers
responsible for the project

and thousands upon thousands
of people involved.

None of those people had anything

remotely approaching the knowledge
to understand it all,

not even close.

Everything great we do as human beings

depends on this ability to share
knowledge and to collaborate.

So, that's the positive side
of the knowledge-sharing story.

When we put our minds together,
we can do incredible things.

But there's also a dark side.

Because we are built to so seamlessly
draw on knowledge outside of our heads,

we often fail to realize the limits
of our own understanding.

Let me tell you about a study that
my colleague Steven Sloman recently ran.

He told his study participants
about some new scientific discoveries

that he completely made up.

For instance, a kind of glowing rock.

He told one group of people

that scientists had not yet
explained why the rocks glow,

and then he asked them,
"How well do you understand?"

Unsurprisingly, they said
they had no clue!

This makes perfect sense,
they knew nothing about the rocks.

The more surprising result
is what happened

when he told a different group of people
about the same discovery,

but this time he told them

that scientists had explained
exactly how the rocks glowed.

Now the participants claimed to understand
the rocks a little bit better themselves,

which is kind of weird

because just like the other group,
they knew nothing about the rocks.

It was as if the scientists' knowledge
had been directly transmitted to them,

even though it was never described.

And it turns out that a similar thing
happens when you surf the Internet.

Just having access
to all of that information

makes you feel like you know
a lot more than you do.

This sense of understanding is contagious.

(Laughter)

And when contagious understanding
is paired with individual ignorance,

it can be a toxic recipe.

(Laughter)

The danger is that I may
express a strong belief

because I feel like I understand.

But my sense of understanding is false.

It comes from those around me,
expressing strong beliefs,

because they feel like they understand.

But their sense of understanding
comes from those around them and so on.

Individually, none of us knows enough
to tell what's true and what's false.

And yet, because we feel
like we're on firm ground,

we don't do enough to verify,

and that is how entire groups of people
can come to believe things

that aren't true.

We can build cathedrals,
but we can also build houses of cards.

Now, the real tragedy occurs
in how we relate to people

who have different beliefs than us.

We live in the illusion

that we have arrived at out own positions
via a serious analysis

and that we can support and justify
what we believe based on what we know.

Therefore, when someone
doesn't believe what we believe,

it's obvious what the problem is:

"They're too stupid to see the truth!"

(Laughter)

And there's actually a sense
in which you're right when you think that.

It's true!

They did not arrive at their position

via a rational process
of evidence evaluation

and they don't understand
the issue in depth.

But neither do you!

(Laughter)

Think about how we talk
about a complex issue like healthcare.

If you're a liberal,

the Affordable Care Act
is the bee's knees.

If your a conservative,
"It's destroying America."

But most of the time,

arguments about the policy's merits
amount to little more

than repetition of sound bites
that we heard from someone else.

As non-experts,

we can't possibly do justice
to the complexity of an issue like that.

When we express our beliefs,

we are all just channeling
our communities of knowledge.

That's what we do.

Knowledge is not in my head
and it's not in your head.

Knowledge is shared,

and therefore, the things
that you really care about,

those things are shared too.

Now, the point is decidedly
not that people are stupid.

It's true, we are all ignorant,

but that's not something
we should hide from.

The world is far too complex for anyone
of us to understand much of it.

What makes us special is the ability
to thrive amidst that complexity

by sharing knowledge.

From our individual ignorance
can arise collective genius.

Ignorance is a feature
of the human mind, not a bug,

but we don't have to be so darn sure
about things we don't understand.

Of course,

we have to take positions on issues
without knowing everything about them,

and if we have good sources
of expertise in our communities

and a culture that values truth,

we'll get things right
more often than not.

But when we go through life feeling like
we individually have it all figured out,

it can lead to a warped
and simplistic view of the world:

"My way is perfect.
Yours is crazy, or evil."

In reality,

most issues are complicated
and most people have good intentions.

Okay, now the bad news:

we can't eradicate false belief.

It's too basic to the way that we think.

What we can do is practice
a little more intellectual humility,

to open our minds to the possibility

that some of those false beliefs
probably reside in our own communities.

We have a tremendous opportunity,

an opportunity to improve
the quality of our discourse

by recognizing the limits
of our understanding

and by appreciating

just how much of what we believe
depends on those around us.

Thank you.

(Applause)