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Jonathan Levav - Prisoners of our own Resources
So, some decisions in life are really easy,
like the decision of which of these jerseys I should wear.
Do I wear this Brazil national team jersey?
Nah.
How about this one? (Applause)
"Vamos, vamos Argentina!" You're not helping me out.
So now I'm dressed and I'm going to dinner,
and I have a choice between this salmon or this piece of delicious, juicy, amazing Patagonian beef.
Easy choice: I take the beef.
And then I ate, I'm almost full
or maybe I'm full but I'll make space for dessert.
And I can have this apple pie or this amazing thing from heaven,
and the choice is really easy.
I'm gonna have that amazing thing from heaven.
So, why are these choices easy?
Because I know what I like about them. My preferences are already worked out.
You wake me up in the middle of the night and you ask me what do I wanna eat,
it's gonna be steak. And it'd better be steak from Argentina.
And then when you ask me what I want for dessert it's always gonna be an alfajor. Always.
Because that other thing, that's just fruit. Fruit is not dessert. That's a snack.
(Applause)
And I'll go hungry if I have to to wear the blue and white.
That's really easy.
Some decisions are more complicated. Let's take this one for example.
So, imagine you're going out and you're gonna buy a suit.
This is actually a decision that I was faced before I was getting married.
My fiancée at the time, now wife, said "Look, you know, it's our wedding,
maybe you should think about going to get a custom-made suit.
Go to the tailor, you know, get something that fits your body exactly right, you know,
it's the wedding." So I said "You know, it's my wedding, I have to make my mother-in-law happy,
I'm gonna go do this."
So, I went to this tailor on 57th Street in New York.
I walked in and this is the decision I was faced with.
It was actually about five times worse than this because there were about fifteen racks
of swatches of suits.
And, I'm a 'jeans and a t-shirt' guy.
The only reason I'm wearing a button-down shirt today is because my mother is watching
on the webcast and she'd be really upset if I wasn't better dressed. So, I... this is for mum.
So, I walk into this thing and, you know, I don't know anything about suits
and, so, I talk to the tailor and he says "well, you know, let's take a look"
and we start going through all these suits and he says "well, do you like grey? do you like blue?"
I said "I don't know. Let's test it against my skin."
I'm kind of light skinned. I didn't want a colour that's gonna wash me out.
It's my wedding, you really want to pop in the pictures.
So, we go through this thing, and it's just going and going
and looking through all these options and I'm starting to get a little tired,
and then we finally converge on something that looks defensible, you know?
The other side that I'm marrying into wasn't gonna hate it, right?
So that was the objective.
And so I said "Great. I'm done." He goes "You're not done.
You need to wear a tie, son. You can't wear a suit without a tie."
Now... I've owned ties, but only because they were given to me.
I've never actually purchased a tie. To this day, in fact, I haven't purchased a tie.
But this was the day I had to purchase a tie and we start going through all these ties
and I'm going through these decisions sort of: Do I want this one? Do I want that one?
Does it look good with the suit that I chose?
And I'm sort of progressively getting mentally burned-out, right?
And so, things are starting to look the same to me.
We finally converge on a tie.
Or a set of ties, because basically the tailor said "you should really consider these."
And then I said "Great. I'm done." He goes "You're not done. You need to pick a style."
Are you gonna wear athletic cut? Is it gonna be boxy, more modern, more classic? And so on.
I said "You know what? Forget about it."
I walked three blocks away to Columbus Circle in Manhattan,
I walked into the shopping mall there, bought a suit off the rack
that the salesperson said "Yeah yeah, this looks good" and I got married without a tie.
I made my life easy.
And, so, those are the kind of decisions that I study.
What happens when you're making decisions about things
that you don't have your preferences worked out for yet?
Right? And in particular what happens when you make
a lot of those decisions in a row?
What is this feeling that I had of mental fatigue,
of decision fatigue, of feeling depleted?
The mental model that I study is one that kind of resembles a gas tank of a car.
The idea is that you have a set of cognitive resources, right?
That you can apply towards making a decision.
And as you make decisions,
and particularly when you make very complex decisions,
you drain that set of resources, right?
So, your gas tank starts moving towards empty.
Now, what happens as you're heading towards empty? What do you do?
I was still getting married, right?
I wasn't not gonna get married because I couldn't figure out a suit, right?
That wasn't gonna fly.
But so... I'm there. I have to make this choice.
And we face a lot of these choices every day. What do I do?
I start looking for ways to simplify my choice, right?
So, in my case, the simplification was just to walk out, go somewhere else,
have some sales guy make a recommendation for me.
This is the phenomenon that I study.
How do people simplify decisions after they make a lot of them?
How they change their decision strategies.
So, we've run a bunch of experiments in this domain.
I'm gonna talk about one today. I'll show you data from one.
We've run, for instance, experiments with car buy.
With car buyers in Germany for entry level luxury Sedans.
And it turns out that in Germany you don't actually buy a car off the lot
like you would, for, say, example, in the United States.
You actually configure the car.
And, so, this car had about sixty attributes to configure.
Everything from the colour to the wheel type, to the mirrors,
to the radio, whatever you like.
And, so, what we found is that as people were going through this
rather difficult process, right? There's a lot of money on the line.
In this case it was about €35.000 cars.
Very expensive, right? It's a really important decision.
People, as they were going through this process, tended to go more and more
with what the manufacturer offered them as the default for that attribute.
In other words, what I mean by default is that
If I don't do anything, if I don't choose anything different,
the engine that I'm gonna get is a 1.6L engine. Okay?
And so, (what) we found is this: people were going through this process,
particularly after they looked at decisions that were really complex,
they tended to start taking the default more and more.
And that's consistent with this idea that you're making a lot of decisions,
it's getting you mentally tired, you need to buy a car, right?
So you have to find ways to simplify those decisions. And so, what do you do?
You just go with whatever is given to you there at the moment: the default.
And so, then you tell me "You know what?
I don't care about your wedding or your suit. And Germany is really far away
and I don't really care about their cars. And, anyway, you're just talking about money.
It's not that important. All right? If you buy the wrong car you can just sell it.
That's fine, right?"
So, let me talk to you about a decision that I think all of us
would consider very important and that's a decision about public safety.
Which criminals or which former criminals do we let out on the streets in particular?
What we studied was a set of parole board decisions from Israel,
from one of the largest prisons in Israel.
So, we had multiple judges in our sample. We had fifty days of decisions.
Basically, what happens is you have a judge at its sitting
and you have a social worker and a criminologist that advises him if he needs it,
and prisoners come in, basically, from one room.
It's, basically, a holding pen.
There're lawyers that they have them come from another room,
they discuss the particulars of the case, the judge makes a decision,
you stay or you go, and they go out another door.
And so, we have the actual files, the actual protocol from the parole discussions.
So, we know what the prisoner was in there for. We have all kinds of different criminals,
from brutal murderers to simple thieves. We know how long they've been there,
how many times they've been there in the past,
we know what happens as they get the release.
Is there a rehabilitation program that's gonna be there for them?
Should they be released into society?
So, we know all that and so we also know one more thing:
We know the order in which prisoners were presented in front of the judge.
So I know that you were first, and you were second, and you were third,
and you were forth, and you were fifth, and you were sixth, and you were seventh,
and you were eight, and you were ninth, and you were tenth and so on.
On average they see about 22 to 25 prisoners a day.
Now, should order matter? Of course order shouldn't matter.
We're talking about the law.
When we think about the law we think that there're books, we think of the tablets, right?
It says you're in prison because you stole from a store
and you're in prison because you stole from a store,
you should be in prison for the same amount of time. Right?
Order shouldn't matter.
But if you think of this hypothesis that as people make decisions they get mentally tired
and they look for ways to simplify those decisions,
then you start expecting a certain pattern.
And, bear in mind that what we're looking at is a pattern,
we're looking for a pattern, we set a really high bar for ourselves
because these people that're making these judgements
are people that have 25 years of experience as judges. All right?
They know the law and they're really good at applying it. All right?
So, you really would expect that order shouldn't matter.
This is what we found: what you see on the y-axis
are the proportion of decisions that are favourable to the prisoner,
which is to say a decision to release a prisoner.
On the x-axis what you see is Ordinal Position, right?
So I know, I have my 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, right?
I know everyone of those tick marks represents 3 prisoners,
so it's 1, 2, tick mark 3, 4, 5, tick mark 6, 7, 8, tick mark 9. All right?
And what you see is that it starts pretty high. Your likely of being released
at the very beginning of the order is actually quite high,
so you're most likely to be out, good for you. Right?
Get to go to a TED talk.
Next person, a little less likely. And then a little less likely, a little less likely.
Sometimes it goes down as low as zero,
most of the time it goes down about as low as 20%, right?
So, what you see there at each position is the average proportion
of prisoners who were released at that position. Okay?
So, on average, about 65% were released on the first position
and on the twelfth position, on average, actually no prisoners were released.
Except that's just the beginning of the day.
We said we had about 22 to 25 cases, on average.
They continue making judgements but now it pops back up.
So, again, in the sixties. Right? Moves down.
We're still not done with the day.
Then it pops up again. And goes down.
So, what accounts for those jumps?
It turns out that these judges take a break to eat twice a day.
Around 10 o'clock in the morning, although it varies quite a bit,
they go have a sandwich.
And then, in the afternoon, they go have lunch.
And they come back to this. Right?
So, what's happening? What we think that was happening
is that you're getting mentally fatigued and then you take a break,
you replenish these mental resources, you come back to making decisions, right?
So, now it's like your gas tank, it's like you went to the gas station.
Now you're reset and then you see this pattern again:
you get tired, go to eat, and you see this pattern again.
Think about it. These are real experts and real prisoners,
and the decisions they're making are extremely significant, you know?
This is: do you let criminals or former criminals,
allegedly reformed criminals, out to the street?
Or, alternatively, are you keeping people in prison that shouldn't be kept in prison?
That's also a huge social and personal cost.
So, you could ask yourself "well, wait a second. Maybe this is happening
because they're putting the easy prisoners first", right?
The guys that just pickpocketed first and the murderers last. Right?
And, so, obviously you're less likely to let out a murderer than you are a pickpocket.
In fact, that's not the case. The order is, essentially, arbitrary.
Now, we don't know for a fact that some mental resources being depleted.
Until we get neurological evidence or
functional magnetic resonance imaging evidence,
it's gonna be very hard to say that.
But certainly the pattern is consistent with this gas tank idea.
You've spent it, you go back to the gas station, take a break,
maybe you need to eat, maybe not, go back
and you now are replenished to deal with a new set of questions.
So, I was thinking, well, you know, what should I tell an audience like this
about what kind of takeaway can you have from this kind of research,
other than the fact that if you ever get in trouble with the law
you should show up after lunch or in the first thing in the morning.
So, you know, that set aside...
So, when you're an academic, what you do is you actually consult the literature
and so, I know a lot of you guys think that, you know,
a professor probably reads serious books, philosophy, you know, serious magazines.
In fact, like you, I read the sports pages,
and so, I stumbled across this article on ESPN,
which is one of the largest sports information channels online.
And I found this article about Barack Obama.
You may have heard of him, he's the former senator from the state of Illinois.
He's been promoted since.
And it turns out, I discovered in this article,
that Barack Obama knows about this research.
I was like, wow!
And so, it turns out that Barack Obama has actually taken in this research
and thought about how it applies to his day.
And so, what he does... I mean, he makes, as you know,
a lot of really important decisions about the economy, about society,
about the war against terrorism... A lot of really important stuff.
So, it turns out, though, what he does
--he also makes decisions about unimportant things--
is, he consciously saves his mental energy for those important things.
He doesn't sweat the little things, so he only has blue suits or grey suits.
He doesn't have to waste time on which colour.
Not just waste time, waste mental energy.
He doesn't... He eats the same breakfast, right?
He doesn't waste time figuring out what he's gonna have, which is...
You know, he is, after all, a guy that has a personal chef,
so he could have anything he wants.
And so, I think there's a lot of wisdow to this
and I'd like to actually share this quote from him and I'd like us all to read this together,
and he says the following:
"You need to focus your decision-making energy. You need to routinize yourself.
You can't be going through the day distracted by trivia."
There's a lot of wisdom to this in the light of this sort of mental gas tank idea,
which is: don't waste your time on decisions that are not important.
Not... You know, not everything is worth your effort.
Save your mental capacity for those decisions that are really important to you
and for your loved ones.
And so, does that mean it's gonna prevent this experience of decision fatigue
from your day to day life? Not necessarily.
But it's gonna help. It's gonna help a lot.
Sometimes, though, you're gonna be faced with complicated sequential decisions
and you're gonna hit that point where you start feeling like mental sweat. Right?
Where this is getting to be a lot.
And so, in those situations, don't hesitate to take a second,
take a break and go have a sandwich.
Thank you very much.
(Applause)