Hidden Brain - How Much Do We Really Know?
Episode Date: May 19, 2025You probably know someone who thinks they know more about something than they really do. But you could never be described that way . . . could you? This week, cognitive scientist Phil Fernbach explain...s the "illusion of knowledge" — the fact that we think we understand the world in much greater detail than we actually do. He'll explore why this happens, and how to close the gap between what we know and what we think we know. Hidden Brain is about to go on tour! Join Shankar in a city near you as he shares key insights from the first decade of the show. For more info and tickets, go to https://hiddenbrain.org/tour/
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This is Hidden Brain. I'm Shankar Vedant.
Some months ago, I brought seven key insights from the first decade of Hidden Brain to live
stage performances in San Francisco and Seattle. The evenings were electric.
Electric. We got so much positive feedback from those two sold out shows that we've decided to
launch a tour to more than a dozen cities in the coming months.
I'll be coming to Portland, Denver, Minneapolis, Chicago, Austin, Dallas, Boston, Toronto, Clearwater, Fort Lauderdale, Phoenix, Baltimore, Washington,
D.C., and Los Angeles.
To snap up your tickets, please go to hiddenbrain.org slash tour.
You can also sign up to say hello and get a photo with me.
In some places, you can sign up for an intimate chat with me and a handful of other
fans. I'd love to see you there. Again, go to hiddenbrain.org slash tour.
Okay, on to today's show.
This is Hidden Brain. I'm Shankar Vedantam. Almost exactly a century ago, a British ship, the Endurance, became trapped in Antarctic sea ice.
Aboard were 28 men, led by the explorer, Ernest Shackleton.
On October 27th, 1915, the pressure of the ice crushed the keel of the Endurance.
Freezing water rushed in.
The sailors dragged lifeboats and supplies from the ship onto the ice.
Carrying the lifeboats, they started hiking toward open water.
After a week with little progress, Ernest Shackleton realized they would be better off camping on an ice flow
and waiting for it to drift toward open water.
What followed was an extraordinary story of knowledge and resourcefulness.
The explorers managed to get their lifeboats into the water and row to dry land,
a place called Elephant Island.
But the desolate island offered little by way of resources and no hope of rescue.
So Ernest Shackleton and a smaller group took one of the lifeboats and set out for a whaling
station.
It was 800 miles away.
Across seas were towering waves and deadly storms. The explorers had only basic navigation equipment.
Somehow, using the stars to guide them,
they made it to the island of South Georgia.
But storms had blown them to the wrong side of the island
as the whaling station.
They now had to hike across the island, across frozen mountains and icy glaciers to
reach help. Ernest Shackleton eventually commanded a ship back to Elephant Island
to rescue the remainder of his crew. He saved every last man.
This is the kind of story that is popular in novels and movies. The explorers came up
with creative solutions to problems and displayed a deep understanding of the challenges before
them. They kept their heads and saved themselves. Stories like this obscure how much we understand
about our own worlds. When we face obstacles, even simple problems
like a puncture a tire, a malfunctioning phone, or an odd pain in our stomachs, are
we any good at figuring out what to do?
Closing the gap between what we know and what we think we know.
This week on Hidden Brain.
Human beings are, as far as we know, the most intelligent creatures ever produced by evolution. Our brains are unimaginably complex and capable of extraordinary feats of invention and creativity.
And yet, these amazing minds also come with certain limits.
At the University of Colorado Boulder, Philip
Fernbach is a cognitive scientist. He has spent many years studying a rather
humbling question. How much do we actually know about the world in which
we live? Phil Fernbach, welcome to Hidden Brain. It's great to be with you, Shankar.
Thank you. Phil, in 1946, eight men gathered in a nuclear lab in Los Alamos, New Mexico.
They were there to watch a distinguished researcher perform a maneuver known as tickling the dragon's
tail.
Who were these people, Phil?
What was going on?
This was one of the most fascinating periods in American history.
It was the development of the nuclear bomb at Los Alamos in New Mexico.
And these were very eminent physicists
who were testing the reaction
of the fissile material in the bomb, the plutonium.
And this particular experiment,
which the physicist Richard Feynman, as you said,
called tickling the Dragon's Dale.
It was a very delicate experiment that involved taking two
hemispheres of beryllium that were surrounding the plutonium
core and moving them closer and closer together to test the
reactivity of the plutonium.
So the plutonium is radioactive and gives off neutrons.
Those neutrons rebound off of the beryllium and create the reaction.
As the hemispheres get closer together,
you get more of that reaction.
What's so delicate and dangerous about this experiment
is that if the hemispheres get too close together,
it can create a chain reaction
that releases a burst of radioactivity
that can be very dangerous.
releases a burst of radioactivity that can be very dangerous. So the lead scientist who was running this experiment, who was tickling the dragon's
tail, if you will, was named Lewis Slotin, and he was a very experienced physicist, was
he not?
He was.
He was one of the developers of the bomb and was an extremely eminent and
experienced physicist. He was the most important member of this experimental team because he was
the one who was actually engaged in the process of bringing those hemispheres of beryllium closer
together. How was he doing it?
What was he doing?
Well, this is the crazy part of the story.
He was actually using a common flathead screwdriver
to keep the two sections of beryllium apart.
Unfortunately, at the critical moment,
the screwdriver slipped.
The two hemispheres of beryllium crashed
together and they released this intense burst of radioactive radiation.
Slotin who was right next to the apparatus took the worst of it and he
actually died in the infirmary eight days later of radiation poisoning. The rest of the physicists in the room, all eminent
scientists, all survived the initial burst. Some of them unfortunately died before their
time potentially due to the radiation dose that they received. Was there a way of conducting this experiment more safely?
There certainly was.
For instance, an obvious way to do it would have been to suspend one of the hemispheres
of beryllium and then the other hemisphere could be raised from the bottom.
In that case, if anything slipped or there was any problem, gravity would have just pulled
the two hemispheres apart.
And that would have been much less of a dangerous way to conduct the experiment.
Why do you think Lewis Slotin didn't do it that way, Phil? I think, um, Slocum, like any other person, um, by virtue of his experience, did not foresee
this potential problem.
He became overconfident in his ability to conduct this experiment because he had done
it so many times before and he had so much experience in this domain.
I want to ask you about another incident that took place many years later. In 2009,
Air France flight 447 crashed into the ocean killing more than 200 passengers
on board. When the
black box of the plane was recovered it appeared that the aircraft had stalled.
Can you first explain what a stall is and what you're supposed to do when the
plane stalls and what the pilots of flight 447 actually did? A stall is a
very scary thing. So that's when an airplane loses airspeed and literally starts falling out of the sky.
Every pilot, when they learn how to fly an airplane,
this is one of the most important things
that they train for.
So they actually will purposely put the airplane
into a stall and then learn how to take it out of the stall.
How do you take a plane out of a stall?
Well, actually what you need to do
is point the nose of the plane down, counter-intuitively.
You wanna go up, but you actually have to point
the plane down.
You have to increase your acceleration.
You have to regain airspeed,
and then you can actually achieve an altitude correction.
When they recovered the black box from this airplane,
surprisingly what they found was
that this very experienced pilot had done was exactly the opposite of what you're supposed
to do in a stall situation.
He was actually trying to pull the plane up, but without any airspeed, that's just impossible.
There's no way that the plane could recover.
And so unfortunately, this led to this devastating outcome.
I'm wondering whether the Federal Aviation Administration or other safety organizations evaluated
why the error had come about.
Did they look into that film?
Yeah, they did very extensive analyses
to try to figure out what went wrong.
And one of their overall conclusions
was that pilots
in general have become too reliant on automation
and have lost some of their basic flying skills.
Modern airplanes, especially modern jetliners,
are so technologically sophisticated
that a lot of the time the software
and the airplane are doing most of the work.
The pilot is almost like an observer watching the airplane do the job.
The pilot of course has to be there to intervene in unusual situations when something goes wrong.
The problem is that those situations are becoming more and more rare because the software is becoming more and more capable.
So in cases where an intervention is necessary,
the pilot might not be as prepared as they should be
because they become too reliant on the automation.
I mean, I'm thinking in a much, much smaller scale.
I am so reliant on my navigation tools
and GPS technology
to get me around that on the occasions when my phone dies,
I suddenly feel like I can't find my way
out of a paper bag these days.
I've had the exact same experience.
In fact, I've heard stories of people driving into lakes
because that's what the GPS tells them to do.
My own personal experience with this is
I use self-driving software all the time
when I'm driving now.
It works remarkably well.
But one thing I've noticed over the last few years
is that I've actually become a worse driver.
No one wants to admit to themselves
that they become a worse driver.
But for me, the evidence is kind of incontrovertible
at this point because I've gotten into a few fender benders
over the last few years, which I've never done before.
And so I've asked myself, what is going on here?
And I really think it's because I've become so reliant
on the car doing the work,
that I've lost my situational awareness.
And then when something unusual happens
and I need to take over, I'm not ready to do it.
Just like a pilot on an automated airline.
Both the Los Alamos accident and the Air France crash
involved highly experienced people
who made seemingly elementary mistakes.
Phil's research suggests there are many other instances
where less experienced people also make blunders,
in part because they assume that other smart people
know what they're doing. Take, for instance, the 2008 financial crash in the United States.
The financial crash in 2008 was in a great part due to a massive decline in the value
of these financial products, a certain kind of financial product called a derivative.
Derivatives are really complicated financial instruments, and it's really hard to predict
exactly how they're gonna behave.
Traders like derivatives because they can often generate
really good returns.
In financial markets, return is always correlated with risk.
So if something has a high return,
it's also gonna have a high risk.
The problem with derivatives
is because they're so complicated,
it's often impossible to see the risk, or it's very hard to see high risk. The problem with derivatives is because they're so complicated, it's often impossible to see the risk
or it's very hard to see the risk.
The risk only emerges in sort of unusual situations.
So it's like the product is, you know,
it seems to be behaving just very safely,
but then something changes and all of a sudden,
instead of losing 10% of its value,
it loses 90% of its value or something like that.
Now, what ended up happening in the financial crisis
was that these derivative products were ending up
in places where they didn't belong,
in places that should not have been taking on
this amount of risk.
Things like pension funds
that should be relatively safe investments.
Why did they end up there? Because the people buying them just did not appreciate or realize how complicated they were and so
what happened was when the price of
What real estate in the United States?
started going down
these products which were tied to the value of real estate and like the default probabilities on mortgages,
they crashed in value.
And there was this huge amount of risk
in our financial system because these products
had entered into all these different areas
and they were highly represented
in all these different areas.
And all of a sudden, kind of everybody was caught
by surprise that the pension fund
was losing a huge amount of its value
because it had exposure to these very risky things,
because people didn't realize that the risk was there.
I mean, in some ways, it's analogous
to what happened on the plane.
You know, the planes are getting so complex
that the pilots, in fact, are trusting the plane
most of the time to fly itself.
And perhaps traders or people who manage pension funds
are basically looking out of the market
and the market has gotten so complex
that they basically are saying,
okay, we trust that these big banks know what they're doing,
these big hedge funds know what they're doing.
And in some ways they're outsourcing
or reducing their own capabilities
to actually deal with a crisis,
partly because the situation has gotten so complex.
That's absolutely right.
And I think it happens at more than one level.
So if you think about a pension fund manager who knows what a derivative is, but isn't
a super expert in a derivative, he's relying on the people who do the analysis of the derivatives
to kind of think, oh, this is potentially like a good investment vehicle for my portfolio.
He's not thinking in super careful detail
about what the risk profile is of that instrument.
And maybe he or she should be, but they obviously didn't.
But it also occurs at another level,
which is the person who actually is the super expert
on the derivative, even that person, it turned
out, didn't understand completely how these things were going to behave.
So the big banks who were developing these instruments and selling them, they would have
a mathematical model that would determine exactly how these things would behave.
The problem is that those mathematical models work really well most of the time, like an airplane that's highly automated, but they actually break down in very unusual situations, a black swan event, so to speak. The models failed and so the super experts on derivatives even they completely misunderstood
the amount of risk that was present in these products.
So it was across the entire financial system that there was these sort of miscalibrations
in understanding and there was this cascade effect that started with some slight decreases
in the price of housing and then just cascaded into this
massive crash and devastation that not only affected the United States but affected
countries all over the world because the entire global system is so connected nowadays.
When we come back, why we imagine we know more than we do and what we can do about it. You're listening to Hidden Brain.
I'm Shankar Vedantam.
Perhaps you've had the experience of driving to an important event.
You're running late and you decide you want to outsmart all the other drivers who are
stuck in traffic.
You take a side street because you know it's a shortcut around the traffic jam.
Three blocks later, you realize the shortcut isn't a shortcut.
In fact, it doesn't get you where you need to go.
What do you tell yourself in moments like that?
Do you say, oh, I got that really wrong?
Or do you say, my sense of navigation is impeccable,
except for this one tiny misstep.
Philip Funback is a cognitive scientist at the Leeds School of Business at the University
of Colorado Boulder.
Phil, as a cognitive scientist, you've studied how humans can be so brilliant, but also really
dumb.
That feels like a paradox.
That is a paradox, and that is the paradox at the heart of humankind, I think. On the
one hand, we've visited the moon and created incredible artificial intelligence and all
these other sort of almost magical abilities. On the other hand, everybody knows that people can engage in behavior that's incredibly ignorant and extreme and foolish.
And we've all done it ourselves and we've all seen it in others.
So, researchers who study the mind have come up with a term to describe why our own ignorance is often hidden from us.
They call it the illusion of knowledge.
What is this illusion, Phil?
The illusion of knowledge is the idea that we think that we understand the world in much
greater detail than we actually do.
In cognitive science, this is sometimes called the illusion of explanatory depth.
There was great research done by a psychologist at Yale named Frank Kyle and his colleagues
in the 1990s.
And that's precisely what they were interested in.
How well do people understand how everyday objects
work? Things like toilets or ballpoint pens or zippers. And in these studies
what they asked people to do was to first just give a sort of impression of
how well they understand things. And what's fun about this experiment is that
your listeners can actually do this experiment on themselves right now. So
think about it.
How well do you understand how a toilet works?
And if you're like most people,
you're kind of nodding your head right now and saying,
well, I have a decent understanding
of how a toilet works.
You think that somewhere in your mind
is something like an annotated plumbing diagram
that you could tell us about.
But here's the trick.
In the next part of the experiment, what I'm going to do is I'm going to ask you to explain to me in detail exactly how it works.
And when I do that, something really remarkable happens.
People reach inside and they realize they have just about nothing to say.
It turns out that we tend to know remarkably little about the way that the world works.
And yet, that initial impression we have is that we do understand in a lot of depth.
And that's what Kyle called the illusion of explanatory depth,
and is sometimes referred to more simply as an illusion of knowledge or an illusion of understanding.
So when it comes to something like a toilet, I think most people imagine, you know, you
press a handle and water flows into the bowl and the toilet
flushes and that's how the toilet works. So that's actually most of the time
pretty much all you need to know about how a toilet works until the toilet
breaks and you have to fix it and then you realize actually there's a lot more
going on.
At this point, you may be asking yourself, how do toilets work?
I asked Phil to test his own knowledge,
but he declined to offer an explanation from memory.
As he put it, he's learned it about 10 million times,
but can never retain it.
So here he is reading the explanation.
So the most popular flush toilet in North America
is the siphoning toilet.
And by the way, this is a really ingenious mechanism
that was created.
Its most important components are a tank,
a bowl, and a trapway.
The trapway is usually S or U-shaped,
and it curves up higher than the outlet of the bowl
before descending into the drainpipe
that eventually feeds the sewer. The tank is initially full of water and when the
toilet is flushed the water flows from the tank quickly into the bowl raising
the water level above the highest curve of the trapway. This purges the trapway
of air filling it with water. As soon as the trapway fills the magic occurs. A
siphon effect is created that sucks the water out of the bowl
and sends it through the trapway down the drain.
It's the same siphon action that you can use to steal gasoline out of a car
by placing one end in the tank and sucking on the other end.
Let me try and say it back to you to see if I can test my own illusion of knowledge here.
What I think it's saying is that you have this S-shaped curve in the pipe behind the
toilet bowl and as you flush the toilet, it fills with water, it starts to fill up this
S-shaped pipe and as it fills up the pipe with water, the water basically pushes out
the air creating something of a vacuum on the
back end of this S-shaped pipe and the vacuum then suctions the rest of the water inside the bowl
out into the drain. How did I do, Phil? Well, I think we should test that with a plumber,
not with me, but I think you did a pretty good job.
What you're saying is I should stick to podcasting and not plumbing is the advice
I'm hearing you give me. I think we both should. But what this highlights is just how complicated
the world is. Whoever thought, you know, there's this ingenious mechanism in this object that
we use every single day and we never think about. So talk a moment about how the illusion of knowledge in some ways is a product of the
way the human mind works and its limitations as it interacts with this extremely complex
world.
Why is it that the workings of the world are so hard for us to wrap our heads around, Phil?
I think this reflects a really deep fact about the nature of the mind are so hard for us to wrap our heads around, Phil. I think this reflects a really deep fact
about the nature of the mind and what thinking is actually for.
Thinking evolved to make us more effective
at acting in the world.
The world is extremely complex.
And to be able to choose effective actions in the world
really requires acting in environments that are very different
from one another.
We almost never see the same exact situation arise twice.
And so our minds have to be really effective
at generalization.
They have to understand that this situation is similar
to this situation in some way to be able
to act effectively.
So storing a huge amount of detail about the world
and the way that it works is actually counterproductive.
What we really wanna do is throw away
all of the irrelevant detail
and just retain the deeper principles,
the deeper generalizable structures
that are going to allow us to choose effective actions.
And of course this must be true for all manner of different things in the world.
Everything from you know bacteria to how trees work to how a hurricane works. All
of these in some ways are complex phenomena where we have a general
understanding of what bacteria do, a general understanding of what a
hurricane is, but not the exact mechanics of what's actually happening at a granular level
That's exactly right. The world is so complex when you start
When you start digging into the details of almost anything
You realize how complicated it is and that you don't necessarily appreciate that complexity off to that
I remember hearing a story about
a rock paper scissors tournament. Do you know the game Rock Paper Scissors?
Yes, yeah.
Very simple game, right?
It seems like there's nothing to learn
and nothing to understand about that game.
How could you have a tournament?
You just throw randomly.
Well, actually it turns out that there's a group of people
who have gotten really good at rock paper scissors.
And what do they do?
They master the details of how the human mind chooses
what to throw and how it engages in pattern matching
and other kinds of things.
And they can identify certain kinds of patterns
in what a more novice rock, paper, scissors player will do
and take advantage of that. I see. So in other words, if I'm a novice there might be
certain patterns that I slip into unconsciously without realizing I've
slipped into the pattern and if you're an expert you sort of can take advantage
of that. That's exactly right. It's a funny kind of dumb example but
something where when I first looked at it I said there is no way that somebody could develop
any level of expertise in that area.
But it turns out, no, there is actually
something to be learned there.
So we can see the problem with mastering too much detail
about the world.
When we look at people with a very rare condition
called hyperthymesia, what is this condition, Phil?
How does it work?
Yeah, this is a super fascinating example.
So hyperthymesia is also called highly superior autobiographical memory.
And these are people who literally remember everything that's ever happened to them.
And so you could talk to a person with hyperthymesia and say, what happened to you at 10.30 on
the morning
on August 15th, 1985? And they can relate to exactly what occurred.
They basically have perfect recall.
So before I described how our minds are very good
at throwing away irrelevant detail.
If you have hyperthymesia, it's the opposite.
You retain everything that's ever happened to you. It sounds like a superpower, but it actually makes life really difficult.
And there's an amazing short story by the Argentinian writer Borges, which is called
Funes the Memorious. And it describes exactly this, a man who falls off a horse
and develops perfect autobiographical memory
so that he remembers every little detail of his life
and it drives him crazy.
And that's because the purpose of thinking,
the purpose of cognition is really not to store detail,
it's to throw the detail away to be able to generalize.
And that's such an important function of cognition.
If you have this hyperthymesia,
it actually makes life really difficult.
So what I hear you saying, Phil,
is that in many ways it's actually more efficient
and more effective for us to discard a lot of details or maybe even never learn the details in the first
place and stick with this very generalized you know understanding of
the world. So the problem is not that we don't know everything that's just the
human condition the problem is that most of us think we know more than we
actually do. In fact it would be futile to try to know everything. The world is just way
too complex. We've already talked about that. There's just no way that an
individual can know enough about the world that it would be effective to
store all the details about everything. That's just part and parcel of what it
means to be a human being. It is a problem that we don't appreciate the
extent to which we don't understand.
So in April 1995, a man named MacArthur Wheeler came up with what seemed to him
to be a foolproof way to rob banks and get away with it.
Tell me what he did, Phil.
This is a crazy story. So this guy was under the impression that he would be invisible
to the cameras if he put lemon juice on his face. You remember when you were a kid, you
could create invisible ink by putting lemon juice on the paper. So he thought for some
reason that this would apply to making him invisible to the camera.
So he actually went in to try to rob a bank with no mask,
no subterfuge whatsoever, just lemon juice on his face.
So his image is broadcast on the news.
Within minutes, the police arrive at his door to arrest him
and he is completely incredulous.
How could they have possibly known it was him
because he had the lemon juice on his face?
And in fact, it turned out that he had tested the method
by taking a Polaroid of himself
and making sure that his face was indeed invisible
to the Polaroid camera.
It's never been discovered
why the Polaroid camera. It's never been discovered why the Polaroid didn't
show his face, but one possibility is that he missed because his eyes were filled with lemon juice.
So what you're saying is he was not just a terrible bank robber,
he was a terrible photographer as well. Apparently so.
Phil has also found that our faulty memories play a role in the illusion of knowledge. Take for instance the research into how good people think they are when it comes to making smart investments in the stock market.
when it comes to making smart investments in the stock market. It's been well documented that people tend to be very overconfident in their
capabilities in terms of beating the market and that can lead to really
disastrous outcomes like people take on too much risk and it actually turns out
that the more people actively trade the worse they do and active trading is sort
of an indicator of being overconfident in your ability to beat the market.
This is a paper that I wrote with Dan Walters.
And what we found in this paper
is that one reason for the overconfidence,
the reason that people feel that they can beat the market
is because they tend to remember the good outcomes
and forget the bad outcomes.
So if I make a trade and I do great on it,
that one's gonna stick in my memory,
more so than when I make a trade and it does poorly.
That's not to say that if you have a really disastrous trade
that you're not gonna remember that, you certainly would.
But on average, you're gonna tend to inflate
the good over the bad. And one average, you're going to tend to inflate the good over the bad.
And one reason for that is because we tend to remember the things that help us maintain a
positive self-image. We want to believe that we're smart and good at investing. That's a very natural
human tendency to want to remember the good and kind of forget the bad. And so this doesn't just
occur in the domain of investing, but can occur in other domains
as well.
So we've looked at how the illusion of knowledge and the illusion of explanatory depth applies
to physical objects, things like bicycles or toilets.
Can they also apply to historical events or public policy in that we imagine that we understand
things better than we actually do, Phil? Yes, and that is what made me so passionate
about these ideas, because it turns out that the reason
that we should care about this illusion is not
because people don't understand how a ballpoint pen
or a toilet works.
But I realized at some point that the illusion applies
to just about everything that we grapple with as a society
and as individuals.
I was doing this work in the midst of a political environment
in the United States that was becoming
more and more polarized.
And as I was doing this work, I had this big insight
that wow, we are arguing with incredible vitriol across the aisle about
issues that are extremely complex and that nobody understands in a lot of depth and detail.
And yet we have these passionate, strong views and are unable to compromise across the political
divide.
And that was a core issue that really got me interested
in this stuff.
Now, I think if you talk to a lot of people
with strong political opinions, they will say,
well, you know, I do understand the issues.
I do understand what it means to have, you know,
universal healthcare.
I do understand the consequences of a flat tax.
Are they wrong?
I think in many cases they are wrong.
And actually we've demonstrated that in experiments.
So what we've done is something very akin
to the toilet experiment that I described earlier.
We bring people into the lab and we ask them
about their position on the issues of the day,
the things that we're arguing about as a society.
And then we ask them how well they understand those issues.
People tend to say, oh yeah, I understand it pretty well.
And then we ask them to explain the mechanism,
explain in detail how it works.
And we find this large decrease
in the sense of understanding.
So people are humbled by that because they try to explain
and they realize, wow, I just have a talking point or two.
I actually don't understand this thing in detail.
You've also found that people who have
some of the strongest views on an issue
are sometimes also those with the lowest levels
of knowledge about the issue.
Why would this be the case, Phil?
So I've studied this in the context
of controversial scientific issues.
So things like the safety of genetically modified foods
or the reality of climate change.
In those cases, there's a substantial minority
of the population who expresses really extreme,
strong counter-consensus views,
views that are counter to the scientific consensus.
And what we find in that case is that the people
who have the strongest counter-consensus views
have the highest levels of subjective understanding.
They feel like they understand these issues the best,
which makes sense because if I feel like I understand it
really well, I'm gonna have a strong opinion.
But when we measure their actual understanding
of the issue in a variety of ways,
they actually have the lowest levels of objective knowledge.
So when you put those things together,
the people who have the most extreme counter consensus views
have this huge gap between what they think they know
and what they actually know.
Why do you think that's happening?
The fact itself, of course, is striking and surprising,
but is there a relationship between the two?
Is the fact that they don't know
partly what causes their certainty?
I think that that's right.
So if I feel like I understand something
and I feel like I know it well,
I'm gonna be less likely to listen to counter-evidence
and counter-explanations,
or to do more research into the issue
to learn more about it.
If I already feel like I understand it,
it's really hard to reach me with counter-evidence.
And so the people whose views seem to be the most out of line
with what the scientific community says
are the ones who are hardest to reach
because they already feel like they understand the issue.
It turns out that many of the problems that beset us in the modern world have a common source.
We think we know something when actually we don't.
When we come back, combating the knowledge illusion.
You're listening to Hidden Brain.
I'm Shankar Vedanta.
This is Hidden Brain.
I'm Shankar Vedanta.
Philip Fernbach is a cognitive scientist at the Leeds School of Business at the University
of Colorado Boulder.
Phil, you say that in the face of the knowledge illusion,
one effective way to better align what we think we know
with what we actually know is to challenge ourselves
to explain technologies, procedures, and policies
in our own words.
Why does this dispel the knowledge illusion?
So we're not in the habit of engaging in a lot of explanation most of the time.
We just take things for granted as we've been discussing.
And so when we get in the habit of doing that, it's sort of hard to hide from ourselves that
we don't understand things as well as we thought we did.
A great example of this comes from work by Rebecca Lawson on people's understanding of bicycles.
So if you ask somebody, do you know how a bicycle works?
A lot of people say, oh yeah, I kind of know how that works.
But then in the study, what she did was she asked people
to draw a bicycle.
And if you sit down and try to do it,
I encourage the listeners to try to do it.
It's much more difficult than you might have
anticipated and that's just a great example of in that case it's impossible
to hide from yourself the gaps in your knowledge. They've just become revealed
on the page as you try to draw.
I mean in some ways this is not hugely different from what happens in a school setting where
you're giving a student a test and you're basically saying, produce for me your knowledge.
You think that you know how differential equations work.
Produce for me that knowledge by solving this problem.
That's right.
A test that is designed to actually gauge understanding of the way things work,
as opposed to a test that is merely regurgitating facts. So a test that's well designed to actually
evaluate whether somebody understands the details or mechanisms of the way that something works
would indeed reveal those gaps. I have a colleague who was recently telling me a story
about one of his classes where he was just imploring
students, if you are using artificial intelligence
to try to help you with the class,
make sure that you understand this
and not just are using the artificial intelligence.
And yet when the test came around
and they'd all been using ChachiBT, they learned that
they did not understand the material as well as they thought that they did because they
had been relying on the artificial intelligence.
And they got very upset with him and he sort of explained to them, look, I tried to tell
you but this is such a natural human thing to overestimate our understanding that it's very hard to actually
appreciate the gaps in our knowledge.
We often, it's so natural for us to go through life
just not really questioning and assuming we know more
than we do, that we don't really see it.
And that's why getting into this habit
of questioning yourself and questioning your understanding
is a very powerful tool for dispelling the illusion.
So you've asked people with strong views on political issues to explain public policies
in detail.
What effect does this have on their certainties, Phil? So in our studies, we've often compared two different types of explanations.
One is this mechanistic explanation, how does it work?
And the other is more about why you believe what you do, so reasons.
And you can think about those two modes of thinking as being more explanatory or mechanistic
on the one hand, and then more argumentatory or mechanistic on the one hand and then more
argumentative or
Advocacy based on the other hand. I think we are much more
commonly engaged in this argumentation or advocacy
When we're talking about things like political issues, we very rarely engage in this kind of mechanistic
or explanatory kind of discussion
in this kind of mechanistic or explanatory kind of discussion.
But it turns out that the mechanistic or explanatory mode leads to a little more open-mindedness. It gets people to be a little less certain about their positions because it reveals the complexity of issues.
And this has been demonstrated to some extent in our work where we simply ask people,
how do you feel about these issues afterwards?
But I think even more interestingly and meaningfully,
there was a great paper by El-Nakori Hun and Grossman
a few years ago,
and they asked people on different sides
of the political divide to have political discussions.
And then they measured different things
about the discussion, like how well it went
and how open-minded
people seemed to be and how much they were listening to the other side and those kinds
of things.
I mean, what they found is that the discussions were more productive when people engaged in
this more explanatory kind of discussion.
Did you find that when people are asked to engage in this more explanatory style of conversation, that political polarization
goes down because some of people's political certainties go down?
It does.
They move to the middle a little bit.
The challenge with that is that people get defensive as well.
So if you challenge people with their understanding, they might actually double down and say, no,
I know what I'm talking about.
Because people naturally tend to be a little bit defensive. So the way to actually implement such an intervention
can be a little bit challenging in its details.
Because again, human beings are not simple, they're complex.
So if you reveal people's lack of understanding to them,
it may have the effect of making them
a little bit more humble or more moderate,
but it could also make them double down on their the effect of making them a little bit more humble or more moderate,
but it could also make them double down on their position a little bit.
I'm wondering whether you might have advice for people who are sitting across a table
with a friend or family member with whom they're having a really strenuous disagreement or debate.
How would you encourage them to invite the other person to engage in explanatory thinking as opposed to
argumentative thinking?
The key is to be curious about
the other side's position. So if you start from a perspective of
the other side is not as smart as me, is not as ethical or moral as me, they're bad,
they're stupid, then you're not gonna be likely
to have a very productive discussion.
If you start instead with the perspective of
the person that I'm talking to is as smart as me
and as moral as me, then you become curious.
Why is it that they maintain a strong position
that's so different from yours
when it seems like the right answer
is just so
obvious to you and then when you become curious and if both sides are mutually curious and they
want to understand what is behind the other side's position then you can have a more productive
discussion and I think what you will find is that when you engage jointly in this explanatory kind
of discussion it's more of a collaboration than it is an argument.
And that collaboration is gonna reveal,
likely, that both sides don't know
as much as they thought they did at the beginning.
That's gonna be the most common outcome.
I mean, I think one thing that I take away from that
is that even when we encounter people with beliefs that are very different from our own or even
beliefs that we can prove are certifiably wrong, perhaps the right
response actually is is some degree of compassion because in some ways I think
what I hear you saying is that the process by which they are arriving at
their erroneous beliefs is not different than the process at which I arrive
at what might be correct beliefs.
I agree with that 100% because we all have beliefs
that are incorrect and we all have beliefs
that we have much more strength and conviction in
than we should.
And conspiracies are a bizarre sort of extreme example
of this, but they're part and parcel
of the same kind of mechanisms
that lead to all of our beliefs.
So another way to better grasp what we don't know
So, another way to better grasp what we don't know is to engage in a practice of considering the unknowns.
What is this practice, Phil?
Yes.
So, there's been a lot of research in the psychology literature on overconfidence.
People tend to be overconfident in a lot of different ways.
The reason for overconfidence is
what's called confirmation bias.
That is we're preferentially disposed to find evidence
for the position that we start with, the one that we want.
Some of the work that I've done
is looking at another reason that we're overconfident.
It's not just because we tend to preferentially
weight the evidence
for our positions,
but also that we tend to neglect
all of the unknown information.
And that's part and parcel of all of the themes
that we've been talking about today,
that the world just seems simpler than it is.
If the world seems simpler,
and we're confronted with an issue,
then we're gonna tend not to think about
all of the stuff that we don't know.
We're gonna tend to think about the stuff that we do know.
And if we thought about all the stuff that we don't know,
it would make us more moderate in our positions
because, wow, there's a lot more to know about this. There is another dimension of the illusion of knowledge that affects organizations and
groups and it affects us when we are part of large groups.
This aspect of the illusion of knowledge shapes gyrations in the stock market and your retirement
portfolio.
What we find is that when people search the internet for financial information, they become
overconfident in their knowledge.
And not only they become overconfident in their knowledge, but that leads to downstream behaviors
like taking on more risk.
To listen, please check out the episode titled Smarter Together, Dumber Together in our subscription
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Philip Fernbach is a cognitive scientist at the Leeds School of Business
at the University of Colorado Boulder.
With Stephen Sloman, he is co-author
of the Knowledge Illusion, Why We Never Think Alone.
Phil, thank you so much for joining me today on Hidden Brain.
This has been a really fun conversation, Shankar.
Thank you so much.
today on Hidden Brain. This has been a really fun conversation Shankar, thank you so much.
Do you have follow up questions for Phil Fernbach?
If you'd be willing to share your questions with a Hidden Brain audience, please record
a voice memo on your phone and email it to us at ideas at hiddenbrain.org. That email address again
is ideas at hiddenbrain.org. Use the subject line knowledge.
Hidden Brain is produced by Hidden Brain Media. Our audio production team includes Annie Murphy-Paul,
Kristen Wong, Laura Quirrell, Ryan Katz, Autumn Barnes, Andrew
Chadwick, and Nick Woodbury. Tara Boyle is our executive producer. I'm Hidden Brains executive editor.
We end today with a story from our sister podcast, My Unsung Hero. This My Unsquero segment is brought to you by Discover. Our story comes from Kara Beth Rogers.
In 2008, Kara Beth's brother Luke passed away unexpectedly.
Kara Beth was 20 years old at the time, studying abroad in Morocco.
The shock of the news made it nearly impossible for her to form a sentence,
let alone fly all the way back to the U.S.
She managed to get to the airport, but as soon as she boarded the plane, the grief became unbearable.
I was sitting on an aisle and I will never forget the way that it felt to try to sit still. It was
impossible. I couldn't stop moving. The like strength of the emotions was so intense.
I really stood out and I felt like people were avoiding
eye contact with me.
They weren't really sure what to do with me.
And partway through the flight, this man came up to me.
I was sitting on the aisle on the right side of the plane
so he came up to me and he crouched down next to me on my left side and
He was so gentle
he made direct eye contact with me and he spoke softly and slowly and
He was really sincere
and
He said I don't I know you don't know me and I don't know what's going on
for you. But I want you to know that if you need anything, I'm here. And I said, thank you. I never
ended up going to him during that flight. But knowing he saw me, you know, I felt like I was in this cavern of just like untenable
emotion and that I was deeply, deeply alone.
And you know, having lost a brother, we were so close in age, we grew up just one year
in school apart and knowing that I was on a plane with somebody
that could see me and that knew that I needed something, even if I didn't know what it was,
even if they didn't know what it was, was an incredibly powerful experience.
I will forever be grateful for him.
It was a really powerful moment for me.
Kara Beth Rogers lives in Los Angeles.
This segment of My Unsung Hero was brought to you by Discover.
Discover believes everyone deserves to feel special
and celebrates those who exhibit the spirit in their communities.
I'm a long-standing card member myself.
Learn more at discover.com slash credit card.
I'm Shankar Vedantam. See you soon. you