- There are a million films that investigate
whether the JFK assassination was a conspiracy.
This is not one of them.
This is an investigation into why so many people
are still debating the JFK assassination,
more than 50 years later.
The answers tell us a lot about
why we believe conspiracy theories,
and anything else for that matter.
It turns out our brains have evolved
these fascinating quirks that prime us
for conspiracy thinking.
All we need is the right set of circumstances to set us off.
- President Kennedy died at 1pm Central Standard Time,
some 38 minutes ago.
- [Cara] In Episode One, we learned that conspiracy theories
can be tools for dealing with loss and anxiety.
And few events created a bigger sense of loss for America
than Kennedy's assassination.
How could we possibly feel safe
if our government couldn't even protect its own president?
- Every time the government fails to predict an attack,
there is a conspiracy theory.
Americans say how could they have failed so badly?
Perhaps they were actually in on it.
- [Cara] The JFK assassination set off
alarm bells in our brains, Something just didn't feel right.
- That is intuitively unsatisfying to say that
a lone gunman who get out of bed one day
and change the course of history,
And so we go looking for bigger explanations
and a vast faceless, old, powerful conspiracy
that fits with our intuition,
that such a big event must have had a big cause.
- Cognitive scientists have a name for this intuition.
They call it proportionality bias,
the tendency to believe that a cause must be equal
in magnitude to the effect.
Most of the time small efforts yield small results,
and big efforts yield big results.
So our brains assume this relationship holds true,
even when it doesn't.
- JFK, you know, the leader of the free world
is assassinated by who?
Some lone nut never heard of.
Here's JFK, here's Oswald, there's an imbalance there
so you have to balance it.
- [Cara] This man, James Fetzer,
says there were no fewer than six gunmen in Dealey Plaza.
- Of the four shots that hit JFK, the first was fired
from the top of the county records building,
the second was fired for the inside of the triple underpass,
The third shot was fired for the Dal-Tex,
the fourth shot fired from the intersection
of the triple underpass in the picket fence.
- Pretty soon Madison Square Garden couldn't fit everybody
that was involved in the JFK case,
but they kind of balances it out.
- [Cara] By contrast, let's consider a different day,
and a different lone gunman.
- The president was hit, shots were fired,
apparently got President Reagan
as he was coming out of the
- The attempted assassination of Ronald Reagan
was a similar event in all regards,
except that the president survived.
It was a smaller event in terms of its outcome,
and therefore, we're satisfied with smaller explanations.
And so there have been almost no conspiracy theories
about the attempted assassination of Ronald Reagan
either at the time or subsequently.
- After proportionality bias
primes us for conspiracy thinking,
another mental shortcut helps us confirm our suspicions.
Once we form a belief we cling to it no matter the facts.
It's called confirmation bias.
And study after study shows that
we all experience it all the time.
In one study, people were asked whether they thought
the JFK assassination was a conspiracy.
Then they were shown a mix of evidence both for and against
both sides claim that the same evidence
confirmed their beliefs.
Each side trusted the data that supported their theory
and discounted data that didn't.
- Their minds operate more like lawyers than scientists,
and the point of lawyers to defend your client
to the best of your ability even if that means
distorting evidence, burying evidence, slanting evidence.
- We evolved confirmation bias for a good reason.
Most of what was true yesterday is still true today.
And if we changed our minds every time
a new piece of information came our way,
our heads would explode.
But in today's world of alternative facts,
it's a little too easy to find evidence
that confirms any hunch.
The JFK assassination has produced
thousands of public documents that can be
scammed for confirming evidence,
like this photo of the presidential motorcade
at the time of the assassination.
Here in the background is the doorway
to the Dallas Book Depository, who is this blurry figure?
Some say it looks an awful lot like Lee Harvey Oswald,
which would be significant because at this moment,
he should be six flights up shooting the president.
- Lee Oswald was framed, we've even been able to prove
that he was actually standing in the doorway
of the Book Depository.
- But to a lot of cognitive scientists,
this connection shows another
quirk in our brains called patternicity.
- So patternicity is the tendency
to find meaningful patterns in both
meaningful and meaningless noise.
The reason for this is that our brains
are pattern seeking devices.
- [Cara] And it took them millions of years of evolution
to get that way.
- Imagine you're a hominid 3 million years ago,
and you hear a rustle in the grass.
What is that?
Is it just the wind?
Or is it a dangerous predator?
If you assume that pattern,
that noise is a dangerous predator,
and turns out it's just the wind,
that's a low cost error to make.
You just become more vigilant and cautious.
But if you assume that the rustle in the grass
is just a wind and turns out it's a dangerous predator,
congratulations, you're lunch.
So it's a good thing to assume patterns are real.
- We oversee patterns because it helped us survive
when quick decisions meant life or death.
But it also leads us to connect dots
that aren't really connected.
I mean is this photo a clue to cracking the JFK conspiracy?
Or is it Billy Lovelady?
A guy who was laying flooring at the Book Depository
that day in 1963.
He and several witnesses testified to the Warren Commission
that it was him in the photo.
All of us, left, right, street smart, and book smart,
have the same cognitive quirks baked into our brains
just waiting for the right set of circumstances
to send us down the conspiracy rabbit hole.
But there's one more element any good conspiracy theory
requires that doesn't live in our brains.
- The new President Lyndon Johnson pointed a commission
to investigate who killed Kennedy.
- When the assassination happened,
LBJ suspected people would blame the Russians,
and it would lead to a nuclear war.
So he tried to hurry the inquiry through.
And so when people feel that it wasn't done
entirely properly, they're onto something.
- That rushed investigation planted the seeds of suspicion,
then a few years later.
- People have got to know whether or not
their president's a crook.
Well I'm not a crook.
- Watergate spurred a number of investigations
by the press, and Congress, that then disclosed
a whole lot of other real government conspiracies.
- [Cara] By the late 70s, the percentage of Americans
who believe JFK conspiracy theories spiked at over 80%.
In 2017, when the government finally unsealed
more classified JFK documents,
It only made some people more suspicious.
- Some of this material's still redacted.
And you're not really seeing
a meaningful effort on their part to tell the truth.
- Conspiracies happen and governments keep secrets.
So how do we know where to draw the line
between being prudent and being paranoid?
More on that in our next episode.
- When you have your grandfather telling you
about growing up in Mississippi or Alabama,
and how the white doctors did A, B and C,
automatically in your brain, you're going to be thinking
like "I can't trust these people."