This is a thought experiment.
You ’ re going to have to make some quick decisions,
so listen carefully.
Imagine you’re on a bridge that overlooks some train tracks.
The tracks split in two and you notice there ’s
one person tied to one of the tracks,
and five people tied to the other.
And there ’ s a runaway trolley that’s
coming right for the five people.
On the bridge there ’ s a switch
– you can hit it to change the course of the trolley
from killing five people to killing one person.
What do you do?
Okay, now things get interesting –
so interesting I think we need to add a little Vsauce.
Vsauce, I’m Jake
and you are going to have to make another choice.
You’re back on the same bridge overlookingthe same train tracks.
There ’ s another guy on the bridge with you,
who ’ s really, well, rather large.
And this time there’s five people tied tothe tracks.
All of a sudden there ’ s a runaway trolley – coming right for them.
If you pushed the large man off the bridge,
you know he would land in front of the trolley and stop it.
He would die, but it would save the five people on the tracks.
What would you do? No, seriously,
quickly write in the comments what you would do for each scenario.
I’ll give you a second.
Oh, gotta go!
This is “ The Trolley Problem ”,
a classic thought experiment in ethics, posed by philosophers
Philippa Foot and Judith Thomson.
In the first scenario,
90 % of those asked say they would pull the switch
– sacrificing one person to save five seems logical.
But in the second scenario,
90 % of those asked say they wouldn ’ t push the man.
And this response is consistent for men,
women and people with different levels of education.
The Trolley Problem brings up this old debate in philosophy,
where moral rationalism says
our decisions should be based on pure reason.
On the other hand,
moral sense theory or sentimentalism says our emotions should guide our moral decisions.
Rationalists would say that these two scenarios in the Trolley Problem are pretty similar.
So why are our answers so universally different?
In 2001, neuroscientist Joshua Greene
posed some moral dilemmas to participants while
their brains were being scanned by an fMRImachine.
These dilemmas were labelled impersonal;
like, should you travel by bus or train if you ’ re running late?
Impersonal and moral;
so, should you keep money you found in a lost wallet?
And personal and moral;
like, should you throw a sick person off a lifeboat
to save a healthy person in the water?
The researchers found different brain areas responded to impersonal and personal dilemmas.
The prefrontal cortex was more active in theimpersonal dilemmas.
It ’ s our centre of reasoning,
where we weigh up the costs and benefits of,
say, keeping a lost wallet.
In the personal dilemmas, the amygdala wasmore active.
It ’ s our centre of emotions and we feel empathy when we think about killing someone,
even if they’re sick and taking up spacein a lifeboat.
Greene suggested that moral decision making is a dual process
– now known as dual process theory.
We have emotion-based and rationally-based
neural systems that compete in the reasoning process.
We use both of them when we make a decision
– one just wins out.
Basically, if you did hit the switch
or pushed the man your rational system won.
Your prefrontal cortex added up the numbers
– saving 5 lives over 1 life is good, right?
And if you didn ’ t do either of those things,
your emotional system won.
It shouted a big “no!” to personally killingsomeone.
But does your decision tell us if you’remorally just?
Were you being a hero, or a villain?
The purpose of thought experiments is to help test
what you really believe about something.
A hypothetical situation forces you to make a judgement,
which is often different from what you think you believe.
In his book, The Wisdom of Psychopaths,
psychologist Kevin Dutton writes that psychopaths easily
push the very large man off the bridge.
The brain activity of psychopaths is the same in the first,
impersonal dilemma and the second, personal dilemma.
They purely use their rational neural system,
the emotional system doesn ’ t respond.
We tend to believe psychopaths are villains,
but in this case, their cold and calculated actions save more lives.
So, are they be heroes here?
You will probably find a way to justify your response in the Trolley Problem,
so you think that you’re right,
but someone else will think that you’re wrong.
Really there’s no way to say
what is right and what is wrong in the Trolley Problem.
That’s why it’s a moral dilemma.
When you think back to that philosophical debate,
neither rationalism nor sentimentalism wins.
It all depends on your brain.
And the Trolley Problem has it’s own problems.
Why are there always five people stuck on the tracks?
Why do you keep frequenting this bridge?
Is one person really big enough to stop a trolley?
And who uses the word trolley anyway?
Really, the Trolley Problem is just a game.
Let’s go back to the first scenario.
And imagine the person tied up is Mario,
and the other five are Koopa Troopas.
Do you still hit the switch?
Is sacrificing Mario worth the lives of five KoopaTroopas?
Your actions in a game like Super Mario Bros. are
what philosophy would call “ consequentialist ”
– where you do everything possible to reachthe next level.
Even if it means killing some of adorable little turtles.
And then you, or the character you play,
Mario, is considered a hero because of the consequences of their actions,
like saving one person, the princess.
But, are you really a hero?
Or are you a villain?
Follow me over to Vsauce3,
where Jake asks, Is Mario Evil?
And see you next Thursday.
And subscribe for more brainy videos.