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PROFESSOR: In a way, I would
say most of this course up

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until today, or maybe the memory
lecture, was about how

00:00:34.920 --> 00:00:37.310
brilliant the human
mind and brain is.

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How the visual system is so
brilliant nobody can make a

00:00:40.520 --> 00:00:42.910
machine that sees so well.

00:00:42.910 --> 00:00:45.260
We didn't talk too much
about physical action.

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But how we move in the world,
how we act upon the world,

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there's no robot that can
compete with you.

00:00:50.320 --> 00:00:53.260
Language is far beyond computers
to be nearly as

00:00:53.260 --> 00:00:56.410
sophisticated as you are,
as a five-year-old is.

00:00:56.410 --> 00:01:00.400
So in all those domains, we
mostly think about in terms of

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psychology or brain function,
how is it that we're endowed

00:01:04.280 --> 00:01:06.680
with such amazing capacities?

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When it comes to thinking, one
of the highest forms of human

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activity, thinking, hard problem
solving, edges of

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creativity, that kinds of thing,
it's something we have

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a huge respect for, something we
wish for, something that we

00:01:20.690 --> 00:01:22.990
know is a very, very
valuable tool.

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But psychologists have
emphasized the

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traps we can fall in.

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I mean in a way what's easy
for us is what the brain

00:01:28.510 --> 00:01:30.010
empowers in us.

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It's easy for us to recognize
objects or faces

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or move in the world.

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When we feel something is hard,
like thinking hard, for

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problem sets or global warming
or other things that are hard

00:01:40.840 --> 00:01:44.960
to think about, then we know
that we're sort of leaving the

00:01:44.960 --> 00:01:47.830
apparatus that's easy for us
and we're entering into a

00:01:47.830 --> 00:01:51.980
hazardous, difficult form
of our mental lives.

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So, I'm going to show you
a video for a moment.

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Because the other fun thing is,
and maybe this is true of

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all of us in different ways, all
the time, we often don't

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recognize, we often don't
recognize when we're thinking

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not as well as we might.

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So this is a trap.

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So I'm going to show you, the
original punking TV show, this

00:02:12.590 --> 00:02:13.540
was called Candid Camera.

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It's pretty old.

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So this is a clip from there.

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And here's a couple people asked
to do a school problem,

00:02:19.090 --> 00:02:22.350
7/8 divided by 3/4 and
how many square

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feet in a square yard?

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And what's kind of funny about
it in my mind is, not only

00:02:26.940 --> 00:02:31.120
that the people are wrong, but
how wrong they are and how

00:02:31.120 --> 00:02:33.539
much they don't realize
sometimes how wrong they are.

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I mean what's impressive about
this is that not only are the

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people wrong, but they don't
say like, I forget.

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They just start to give answers,
throwing out numbers.

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And so how different are
all of us in that?

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So some of these again
are on the internet.

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And this is an MIT audience,
which is about the hardest

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audience to pull this off.

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And at Stanford, I could pull
this off much better.

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So some of these won't go as
easily as they might for other

00:03:08.440 --> 00:03:09.240
typical audiences.

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Here we go.

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Two train stations are a
hundred miles apart.

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At 2:00 PM one Saturday
afternoon, the two trains

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start toward each other,
one from each station.

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One travels at 60 miles
an hour, the other

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at 40 miles an hour.

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Just as the trains pulls out
of their stations, a bird

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springs into the air in front of
the first train, and flies

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ahead to the front
of the second.

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When the bird reaches the
second, it turns back, without

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losing any speed, and
flies directly

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toward the first step.

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Doesn't this remind you of all
the high school physics

00:03:30.630 --> 00:03:32.120
problems you had earlier?

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Where's the frictionless
pulley?

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The bird continues to fly back
and forth between the trains

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at 80 miles an hour.

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How many miles will the
bird have flown

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before the trains meet?

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It's a little bit of a trick.

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Because the answer is told to
you directly, pretty much.

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So 100 miles apart.

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How long will it take for the
trains to reach each other, if

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one is 60 miles an hour and
one is 40 miles an hour?

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AUDIENCE: Hour.

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PROFESSOR: Hour.

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So how many miles an hour
does the bird fly?

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AUDIENCE: 80.

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Easier than you think.

00:04:05.280 --> 00:04:08.020
So those are the kinds of ones I
just showed that people kind

00:04:08.020 --> 00:04:09.750
of get themselves into
their thinking cap.

00:04:09.750 --> 00:04:11.130
And it's a trick.

00:04:11.130 --> 00:04:12.900
Here we go.

00:04:12.900 --> 00:04:15.010
I need somebody who is willing
to, at their chair,

00:04:15.010 --> 00:04:16.260
just call out words.

00:04:22.120 --> 00:04:23.410
Thank you very much.

00:04:23.410 --> 00:04:23.990
Here we go.

00:04:23.990 --> 00:04:25.440
In English, many words are
pronounced somewhat

00:04:25.440 --> 00:04:27.170
differently depending on the
way they are spelled.

00:04:27.170 --> 00:04:28.330
But here we go.

00:04:28.330 --> 00:04:32.270
Can you give me a synonym for
people or family, a word that

00:04:32.270 --> 00:04:35.630
people would often
say for that?

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I'll give you one.

00:04:37.410 --> 00:04:39.590
Folk.

00:04:39.590 --> 00:04:40.810
Now, I know this is
a history quiz.

00:04:40.810 --> 00:04:42.020
But I'll help you.

00:04:42.020 --> 00:04:44.000
I wouldn't know the answer
to this, necessarily.

00:04:44.000 --> 00:04:45.940
Can you give me the name of an
American president at the time

00:04:45.940 --> 00:04:46.690
of the Mexican War?

00:04:46.690 --> 00:04:47.240
And I'll give you a hint.

00:04:47.240 --> 00:04:48.595
It rhymes with folk.

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AUDIENCE: Polk.

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PROFESSOR: Polk.

00:04:49.940 --> 00:04:51.020
Everybody can help.

00:04:51.020 --> 00:04:51.650
Everybody help.

00:04:51.650 --> 00:04:53.330
One, two, three.

00:04:53.330 --> 00:04:55.620
Can you give me the name of the
word that means egg white?

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AUDIENCE: Yolk.

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PROFESSOR: Aha.

00:04:58.520 --> 00:04:58.960
No.

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Is the yolk, the egg white?

00:05:03.050 --> 00:05:03.530
I know.

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It's a pretty hilarious course.

00:05:04.580 --> 00:05:06.240
Thank you.

00:05:06.240 --> 00:05:08.690
So this is an example
of what people

00:05:08.690 --> 00:05:10.880
call functional fixedness.

00:05:10.880 --> 00:05:12.990
Your mind is going
a certain way.

00:05:12.990 --> 00:05:14.470
And you're on a certain pace.

00:05:14.470 --> 00:05:16.280
And all of a sudden when you
need to put the mental break

00:05:16.280 --> 00:05:19.710
on, your habit of thought takes
you a slightly wrong

00:05:19.710 --> 00:05:21.190
direction, on a very
superficial test.

00:05:21.190 --> 00:05:24.110
Thank you very much.

00:05:24.110 --> 00:05:26.330
Here's an experiment.

00:05:26.330 --> 00:05:29.470
In 10 minutes, only about 39%
of people solve this.

00:05:29.470 --> 00:05:31.020
You go into a room like this.

00:05:31.020 --> 00:05:33.470
The strings are too far apart.

00:05:33.470 --> 00:05:34.810
You have stuff around here.

00:05:34.810 --> 00:05:36.670
And your job to tie the
strings together.

00:05:36.670 --> 00:05:37.920
What do you do?

00:05:40.870 --> 00:05:42.750
AUDIENCE: Stand on the chair?

00:05:42.750 --> 00:05:44.620
PROFESSOR: Standing on the chair
is an interesting one.

00:05:44.620 --> 00:05:46.830
Let's pretend it doesn't work.

00:05:46.830 --> 00:05:47.770
It wouldn't.

00:05:47.770 --> 00:05:50.020
It would get you up, but they'd
be far apart still.

00:05:50.020 --> 00:05:50.660
It could.

00:05:50.660 --> 00:05:53.400
Let's pretend it doesn't.

00:05:53.400 --> 00:05:54.660
You'd have to be there,
to be convinced.

00:05:54.660 --> 00:05:54.930
You know what I mean.

00:05:54.930 --> 00:05:56.180
It mean depends on the angle.

00:05:58.610 --> 00:05:59.790
AUDIENCE: [INAUDIBLE].

00:05:59.790 --> 00:06:00.115
PROFESSOR: Sorry?

00:06:00.115 --> 00:06:01.340
AUDIENCE: Tie it to the end.

00:06:01.340 --> 00:06:02.930
PROFESSOR: Ah.

00:06:02.930 --> 00:06:05.490
So you're one of the 39%.

00:06:05.490 --> 00:06:08.850
So the idea is, if you tie for
example, the pliers onto the

00:06:08.850 --> 00:06:12.680
thing and get it swinging, you
could catch it, right?

00:06:12.680 --> 00:06:17.770
So why don't people come up with
that answer very easily?

00:06:17.770 --> 00:06:21.390
PROFESSOR: Because what
are pliers for?

00:06:21.390 --> 00:06:23.180
Pliering.

00:06:23.180 --> 00:06:25.840
They're not for swinging
ropes.

00:06:25.840 --> 00:06:28.820
So again, the word they use
is functional fixedness.

00:06:28.820 --> 00:06:30.680
You know what a plier is for.

00:06:30.680 --> 00:06:35.390
It doesn't seem like a good
candidate to do this job.

00:06:35.390 --> 00:06:35.830
Here's another one.

00:06:35.830 --> 00:06:38.270
You walk into a room and there's
a door that's closed

00:06:38.270 --> 00:06:39.180
behind you.

00:06:39.180 --> 00:06:40.430
And you see these things
on a table.

00:06:40.430 --> 00:06:42.310
And you're asked, could
you support this

00:06:42.310 --> 00:06:45.290
candle on the door?

00:06:45.290 --> 00:06:49.780
About 23% of people
get this, in 1945.

00:06:49.780 --> 00:06:51.590
What do you do?

00:06:51.590 --> 00:06:54.220
This is just like all
the spy movies.

00:06:54.220 --> 00:06:55.944
Yes?

00:06:55.944 --> 00:06:57.194
AUDIENCE: [INAUDIBLE].

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PROFESSOR: Sorry?

00:06:59.875 --> 00:07:01.515
AUDIENCE: Put the tacks through
the width of the door.

00:07:01.515 --> 00:07:02.570
PROFESSOR: Yeah, through
the width of door

00:07:02.570 --> 00:07:03.790
would be pretty good.

00:07:03.790 --> 00:07:05.380
It's not really supporting
the candle, but it

00:07:05.380 --> 00:07:06.230
could get the job done.

00:07:06.230 --> 00:07:07.130
That's not a bad thought.

00:07:07.130 --> 00:07:08.350
These are all good thoughts.

00:07:08.350 --> 00:07:10.090
If it were me, I wouldn't
be close.

00:07:10.090 --> 00:07:11.300
So that's better than I do.

00:07:11.300 --> 00:07:11.980
Yeah?

00:07:11.980 --> 00:07:14.740
AUDIENCE: Take out the tacks
and then tack the base.

00:07:14.740 --> 00:07:16.300
PROFESSOR: Have you
see this before?

00:07:16.300 --> 00:07:16.690
No.

00:07:16.690 --> 00:07:17.410
Excellent.

00:07:17.410 --> 00:07:21.060
As I tell you, MIT's audience
is not an easy audience.

00:07:21.060 --> 00:07:25.230
The idea is that you dump the
tacks, and then stick the tack

00:07:25.230 --> 00:07:26.900
into the back of
the empty box.

00:07:26.900 --> 00:07:28.820
Nice platform for a candle.

00:07:28.820 --> 00:07:32.520
Why don't most people
think about that?

00:07:32.520 --> 00:07:36.650
Because what's the
job of the box?

00:07:36.650 --> 00:07:39.060
To hold the tacks.

00:07:39.060 --> 00:07:40.610
My job is to figure
out this problem.

00:07:40.610 --> 00:07:42.820
You hang on to the tacks.

00:07:42.820 --> 00:07:45.330
And in fact if they do the same
experiment, but just put

00:07:45.330 --> 00:07:48.070
the tacks next to the
box, a lot of people

00:07:48.070 --> 00:07:49.350
get it right away.

00:07:49.350 --> 00:07:52.650
Because now that box, it's
yearning to support something.

00:07:52.650 --> 00:07:53.570
It no longer has a job.

00:07:53.570 --> 00:07:56.360
It's an unemployed box that you
can stick onto the door

00:07:56.360 --> 00:07:57.530
and support this.

00:07:57.530 --> 00:08:01.140
Your mind just gets stuck with
thinking the box is a holder.

00:08:01.140 --> 00:08:02.390
It's not a platform.

00:08:04.870 --> 00:08:06.810
This is the original-- and
you've seen this so

00:08:06.810 --> 00:08:07.370
many times by now.

00:08:07.370 --> 00:08:09.860
This is one of the original,
thinking outside of the box

00:08:09.860 --> 00:08:12.500
things, where you're supposed to
connect the dots with four

00:08:12.500 --> 00:08:14.065
straight lines without
lifting a pencil.

00:08:21.440 --> 00:08:23.140
Some of you know this.

00:08:23.140 --> 00:08:24.430
Some of you are figuring
out on the spot.

00:08:24.430 --> 00:08:26.830
But I'll just show you.

00:08:26.830 --> 00:08:28.155
So there's an answer.

00:08:28.155 --> 00:08:30.840
The other ones are similar.

00:08:30.840 --> 00:08:33.140
Why do so many people
get stuck in this

00:08:33.140 --> 00:08:34.600
and not get it done?

00:08:34.600 --> 00:08:36.980
Because they don't
like this part.

00:08:36.980 --> 00:08:38.760
And they don't like this
part, because it's

00:08:38.760 --> 00:08:41.520
drawing outside the box.

00:08:41.520 --> 00:08:43.350
They're always looking for the
connections within the box.

00:08:43.350 --> 00:08:45.870
And it seems cheating in some
sense to draw outside the box.

00:08:45.870 --> 00:08:48.740
There's an intuition, like with
the box with the tacks,

00:08:48.740 --> 00:08:50.610
that you're supposed
to stay in there.

00:08:50.610 --> 00:08:54.450
So if they get no information
in this study, practically

00:08:54.450 --> 00:08:58.140
nobody solved it,
in a given time.

00:08:58.140 --> 00:08:59.830
If they get a hint, you
can draw outside the

00:08:59.830 --> 00:09:01.470
square, that helps.

00:09:01.470 --> 00:09:04.080
But then, outside the square
puts again, the first line.

00:09:04.080 --> 00:09:06.280
They're still only half
the time getting it.

00:09:06.280 --> 00:09:07.740
Because you've got to go
outside a second time.

00:09:07.740 --> 00:09:10.420
So it gets a lot of information
to get comfortable

00:09:10.420 --> 00:09:13.470
with finding a way to do this
that's completely within the

00:09:13.470 --> 00:09:16.410
rules, but not the way you
intuitively feel might be the

00:09:16.410 --> 00:09:17.840
right way to do it.

00:09:17.840 --> 00:09:21.170
So those are all examples of
functional fixedness, where

00:09:21.170 --> 00:09:23.620
you have a certain belief about
what's going on and it's

00:09:23.620 --> 00:09:27.670
hard to overcome that to solve
a problem in a novel way.

00:09:27.670 --> 00:09:29.950
Another thing that people think
about as the way to

00:09:29.950 --> 00:09:32.130
overcome some of these problems
of thinking about

00:09:32.130 --> 00:09:36.790
problems is different
representations that let you

00:09:36.790 --> 00:09:38.850
take a different look at
a problem to be solved.

00:09:38.850 --> 00:09:40.700
So picture a large
piece of paper, a

00:09:40.700 --> 00:09:42.050
hundredth of an inch thick.

00:09:42.050 --> 00:09:43.690
Now, in your imagination,
fold it once.

00:09:43.690 --> 00:09:44.770
You have two layers.

00:09:44.770 --> 00:09:46.620
Continue to fold it on
itself 50 times.

00:09:46.620 --> 00:09:48.120
It's true that's it's impossible
to fold it in

00:09:48.120 --> 00:09:50.270
place, such a piece of
paper, 50 times.

00:09:50.270 --> 00:09:52.350
But for the sake of the problem,
imagining that you

00:09:52.350 --> 00:09:55.712
can, about how thick would the
50-times-folded paper be?

00:09:55.712 --> 00:09:57.640
And everybody's first intuition
is, well, how thick

00:09:57.640 --> 00:09:58.430
can a piece of paper be?

00:09:58.430 --> 00:10:00.370
Of course, this is a
hypothetical problem, not an

00:10:00.370 --> 00:10:02.130
actual paper problem.

00:10:02.130 --> 00:10:03.660
But if you do the
math, it's big.

00:10:08.800 --> 00:10:10.150
So here's another one.

00:10:14.160 --> 00:10:16.620
One morning, exactly at sunrise,
a Buddhist monk began

00:10:16.620 --> 00:10:17.980
to climb a tall mountain.

00:10:17.980 --> 00:10:20.075
A narrow path no more than a
foot or two wide, spiraled

00:10:20.075 --> 00:10:21.430
around the mountain
to a glittering

00:10:21.430 --> 00:10:22.520
temple at the summit.

00:10:22.520 --> 00:10:24.690
The monk ascended at various
rates of speed, stopping many

00:10:24.690 --> 00:10:27.240
times along the way to rest
and eat dried fruit he

00:10:27.240 --> 00:10:27.710
carried with him.

00:10:27.710 --> 00:10:29.370
He reached the temple shortly
before sunset.

00:10:29.370 --> 00:10:31.350
After several days of fasting
and meditation, he began his

00:10:31.350 --> 00:10:33.920
journey back along the same
path, starting it at sunrise

00:10:33.920 --> 00:10:35.630
and again walking at variable
speeds, with many

00:10:35.630 --> 00:10:36.910
pauses along the way.

00:10:36.910 --> 00:10:38.710
His average speed descending
was, of course, greater than

00:10:38.710 --> 00:10:40.280
his average climbing speed.

00:10:40.280 --> 00:10:42.700
Show that there's a spot along
the path that the monk will

00:10:42.700 --> 00:10:44.320
occupy on both trips
at precisely the

00:10:44.320 --> 00:10:46.020
same time of day.

00:10:46.020 --> 00:10:48.050
So that sounds moderately
hard.

00:10:48.050 --> 00:10:50.610
But if you draw the
picture, so we

00:10:50.610 --> 00:10:51.630
went and get an equation.

00:10:51.630 --> 00:10:53.860
Now, we have a pictorial
representation.

00:10:53.860 --> 00:10:57.010
You can see there has to be some
moment of the ascending

00:10:57.010 --> 00:10:59.450
and descending path that
cross in time.

00:10:59.450 --> 00:11:00.820
You don't know what
it's going to be.

00:11:00.820 --> 00:11:02.600
But there has to be some
moment in time.

00:11:02.600 --> 00:11:03.700
And maybe that's obvious.

00:11:03.700 --> 00:11:05.840
But for a lot of people it seems
stunningly complicated

00:11:05.840 --> 00:11:07.025
that you could even
demonstrate that

00:11:07.025 --> 00:11:09.040
in any way at all.

00:11:09.040 --> 00:11:10.880
Here's one you could
think about.

00:11:10.880 --> 00:11:13.620
Suppose you are a doctor faced
with a patient who has a

00:11:13.620 --> 00:11:15.190
malignant tumor in
his stomach.

00:11:15.190 --> 00:11:17.340
It's impossible to operate on
the tumor, but unless the

00:11:17.340 --> 00:11:19.440
tumor is destroyed the
patient will die.

00:11:19.440 --> 00:11:21.660
There's a kind of ray that can
be used to destroy the tumor.

00:11:21.660 --> 00:11:24.860
If the rays reach the tumor all
at once, with sufficiently

00:11:24.860 --> 00:11:26.680
high intensity, the tumor
will be destroyed.

00:11:26.680 --> 00:11:30.350
Unfortunately, at this high
intensity the healthy tissue

00:11:30.350 --> 00:11:33.240
that the rays pass through,
will also be destroyed.

00:11:33.240 --> 00:11:35.860
At lower intensity, the rays
are harmless to healthy

00:11:35.860 --> 00:11:38.570
tissue, but they don't affect
the tumor either.

00:11:38.570 --> 00:11:40.860
What type of procedure might be
used to destroy the tumor

00:11:40.860 --> 00:11:43.910
with the rays, and at the same
time avoid destroying the

00:11:43.910 --> 00:11:44.820
healthy tissue?

00:11:44.820 --> 00:11:47.050
Now, if you know the answer to
this, don't jump right up.

00:11:47.050 --> 00:11:48.820
Give other people a few
moments to puzzle.

00:11:53.370 --> 00:11:57.760
About 10% of people solve this
in a small unit of time,

00:11:57.760 --> 00:11:59.010
before the Internet.

00:12:02.800 --> 00:12:06.180
And so, what's the answer
though, for those of you?

00:12:06.180 --> 00:12:07.950
Yeah, I see some
hands, I think.

00:12:07.950 --> 00:12:08.270
Go ahead.

00:12:08.270 --> 00:12:09.920
Did you want to say?

00:12:09.920 --> 00:12:10.410
AUDIENCE: [INAUDIBLE].

00:12:10.410 --> 00:12:10.530
PROFESSOR: No.

00:12:10.530 --> 00:12:11.385
Exactly at the spot, sir.

00:12:11.385 --> 00:12:12.780
AUDIENCE: [INAUDIBLE].

00:12:12.780 --> 00:12:13.430
PROFESSOR: Yeah.

00:12:13.430 --> 00:12:17.350
Have several weak ones aimed
to converge at the tumor.

00:12:17.350 --> 00:12:19.290
I saw your hands.

00:12:19.290 --> 00:12:21.170
So the idea is to have several
different rays, each of which

00:12:21.170 --> 00:12:22.740
are weak enough not to
destroy the tissue.

00:12:22.740 --> 00:12:24.930
But when they converge spatially
at the tumor, they

00:12:24.930 --> 00:12:27.400
would sum enough to
destroy the tumor.

00:12:27.400 --> 00:12:29.840
That's the problem-solving
answer to this.

00:12:29.840 --> 00:12:33.990
So knowing that, here's another
kind of a problem.

00:12:33.990 --> 00:12:36.390
A dictator ruled a small country
from a fortress.

00:12:36.390 --> 00:12:38.750
The fortress was situated in the
middle of the country and

00:12:38.750 --> 00:12:40.420
many roads radiated
outward from it,

00:12:40.420 --> 00:12:42.670
like spokes in a wheel.

00:12:42.670 --> 00:12:44.740
A great general vowed to capture
the fortress and free

00:12:44.740 --> 00:12:46.080
the country of the dictator.

00:12:46.080 --> 00:12:47.810
The general knew that if the
entire army could attack the

00:12:47.810 --> 00:12:49.320
fortress at once, it
could be captured.

00:12:49.320 --> 00:12:52.300
But a spy reported that the
dictator had planted mines on

00:12:52.300 --> 00:12:53.380
each of the roads.

00:12:53.380 --> 00:12:55.630
The mines were set so that small
bodies of men could pass

00:12:55.630 --> 00:12:58.180
over them safely, since dictator
needed to be able to

00:12:58.180 --> 00:13:00.000
move troops and workers about.

00:13:00.000 --> 00:13:02.610
However, any large force would
detonate the mines.

00:13:02.610 --> 00:13:04.320
Not only would this blow up
the road, but the dictator

00:13:04.320 --> 00:13:06.860
would destroy many villages
in retaliation.

00:13:06.860 --> 00:13:09.050
A full-scale, direct attack
on the fortress seemed

00:13:09.050 --> 00:13:11.250
impossible.

00:13:11.250 --> 00:13:13.270
Does this problem remind you of
the other problem, I mean

00:13:13.270 --> 00:13:15.190
back-to-back, like this?

00:13:15.190 --> 00:13:17.130
He divided his army up
into small groups.

00:13:17.130 --> 00:13:20.520
Now, they're small enough per
path into the castle.

00:13:20.520 --> 00:13:22.320
And they converge on the
castle, like the X-rays

00:13:22.320 --> 00:13:24.260
converged on the tumor.

00:13:24.260 --> 00:13:26.000
So this is reasoning
by analogy.

00:13:26.000 --> 00:13:27.170
We have problem solving
approach.

00:13:27.170 --> 00:13:29.000
Divide your resources
spatially.

00:13:29.000 --> 00:13:31.270
Have them meet at the same time,
and converge in a way

00:13:31.270 --> 00:13:32.310
that's effective.

00:13:32.310 --> 00:13:34.750
So what you might call the deep
structure of the problem

00:13:34.750 --> 00:13:36.760
is the same, with the surface
story being different.

00:13:36.760 --> 00:13:40.280
One is tumors and treatments.

00:13:40.280 --> 00:13:41.690
But there's a strict analogy.

00:13:41.690 --> 00:13:44.400
Capturing the castle is like
destroying the tumor.

00:13:44.400 --> 00:13:47.290
The fortress is like the tumor
that you want to get to.

00:13:47.290 --> 00:13:48.710
The army is like the
rays and the

00:13:48.710 --> 00:13:50.250
general is like the doctor.

00:13:50.250 --> 00:13:53.650
So if it is back-to-back like
this, where I just said,

00:13:53.650 --> 00:13:55.280
here's a problem.

00:13:55.280 --> 00:13:57.430
And here's a problem
just like that.

00:13:57.430 --> 00:14:01.300
Everybody says, well, send the
troops on the different paths

00:14:01.300 --> 00:14:03.660
and have them converge
at the same time.

00:14:03.660 --> 00:14:06.590
If you don't say that though, if
you don't tell people this

00:14:06.590 --> 00:14:08.010
is the same, use
the same rule.

00:14:08.010 --> 00:14:11.160
If you don't tell people that,
only about a third come up

00:14:11.160 --> 00:14:12.460
with it spontaneously.

00:14:12.460 --> 00:14:14.920
If you just make a little bit
of an effort not to make it

00:14:14.920 --> 00:14:17.610
completely obvious that
it's the same problem.

00:14:17.610 --> 00:14:18.860
You just wait a little bit.

00:14:20.990 --> 00:14:25.030
So the surface differences,
the war story versus the

00:14:25.030 --> 00:14:29.120
medical story, will mostly throw
people from recognizing

00:14:29.120 --> 00:14:30.220
the analogies.

00:14:30.220 --> 00:14:33.320
People recognize surface
analogies all the time.

00:14:33.320 --> 00:14:35.690
If we have war in the Middle
East now, from the US

00:14:35.690 --> 00:14:40.240
perspective there's analogies
to Vietnam, a war and a war.

00:14:40.240 --> 00:14:42.540
But other kinds of analogies
across situations, people have

00:14:42.540 --> 00:14:46.740
a hard time mapping, if the
surfaces look different.

00:14:46.740 --> 00:14:50.140
And here's an example where they
gave people two problems

00:14:50.140 --> 00:14:53.410
of a certain kind.

00:14:53.410 --> 00:14:55.720
And they said as part of the
experiment, and here's a

00:14:55.720 --> 00:14:56.800
classroom demonstration.

00:14:56.800 --> 00:14:59.620
If it's immediate, they
sort of get it.

00:14:59.620 --> 00:15:03.390
But if they wait just a little
bit, and they move from one

00:15:03.390 --> 00:15:07.640
room to another room, they don't
apply the rule at all.

00:15:07.640 --> 00:15:09.230
So it's very tricky.

00:15:09.230 --> 00:15:10.970
We would like to think well,
gee, we know all kinds of

00:15:10.970 --> 00:15:13.040
things about the world, that
we can bring in a mental

00:15:13.040 --> 00:15:16.380
toolkit to solve problems,
all kinds of ideas.

00:15:16.380 --> 00:15:19.690
But if the problem doesn't look
the same as the prior

00:15:19.690 --> 00:15:22.070
problem, people have a hard
time spontaneously saying,

00:15:22.070 --> 00:15:23.900
there's an answer I know, and
I can apply it to the

00:15:23.900 --> 00:15:26.520
situation, unless it's really,
really obvious.

00:15:26.520 --> 00:15:30.230
People don't transfer deep
solutions very easily across

00:15:30.230 --> 00:15:31.480
what looks like different
situations.

00:15:34.150 --> 00:15:35.020
Something different.

00:15:35.020 --> 00:15:37.530
The instructors in a flight
school adopted a policy of

00:15:37.530 --> 00:15:39.990
consistent, positive
reinforcement, recommended by

00:15:39.990 --> 00:15:40.780
psychologists.

00:15:40.780 --> 00:15:42.150
And we know we're very
suspicious about

00:15:42.150 --> 00:15:44.320
psychologists, right?

00:15:44.320 --> 00:15:47.580
But you have to imagine the
instructor went to some

00:15:47.580 --> 00:15:49.350
classroom and somebody said,
positive reinforcement

00:15:49.350 --> 00:15:50.800
is the way to go.

00:15:50.800 --> 00:15:53.480
They verbally reinforced each
successful execution of a

00:15:53.480 --> 00:15:54.820
flight maneuver.

00:15:54.820 --> 00:15:56.710
After some experience with this
training approach, the

00:15:56.710 --> 00:15:59.020
instructors claimed that
contrary to psychological

00:15:59.020 --> 00:16:03.980
doctrine, high praise for good
execution of complex maneuvers

00:16:03.980 --> 00:16:06.480
typically result in a decrement
of performance on

00:16:06.480 --> 00:16:07.880
the next try.

00:16:07.880 --> 00:16:09.920
Are they correct?

00:16:09.920 --> 00:16:12.360
So you understand, you have to
have in your mind all the

00:16:12.360 --> 00:16:13.550
military movies where
there's a really

00:16:13.550 --> 00:16:15.140
tough sergeant training.

00:16:15.140 --> 00:16:17.860
The other one that yells at
you to make you succeed.

00:16:17.860 --> 00:16:19.830
But for half the movie, you
don't know if the sergeant

00:16:19.830 --> 00:16:21.770
will break you or make you
into a better woman or a

00:16:21.770 --> 00:16:23.000
better man.

00:16:23.000 --> 00:16:23.970
So he's barking orders.

00:16:23.970 --> 00:16:25.940
And some psychologist says,
well, you should really think

00:16:25.940 --> 00:16:27.520
about saying nice things to
these people, because that's

00:16:27.520 --> 00:16:28.150
encouraging.

00:16:28.150 --> 00:16:29.760
Errgh.

00:16:29.760 --> 00:16:31.820
Somebody does a flight
maneuver and does

00:16:31.820 --> 00:16:32.427
a really good job.

00:16:32.427 --> 00:16:33.870
And he goes, that's awesome.

00:16:33.870 --> 00:16:35.400
And then the person goes
up and does worse.

00:16:35.400 --> 00:16:37.990
And he goes aargh, you're
all terrible.

00:16:37.990 --> 00:16:39.170
So what's happening?

00:16:39.170 --> 00:16:40.420
Yeah.

00:16:49.470 --> 00:16:53.110
AUDIENCE: It must-- the person
typically does really well.

00:16:53.110 --> 00:16:56.470
Doing really well one time isn't
indicative of really

00:16:56.470 --> 00:16:56.950
well the next time.

00:16:56.950 --> 00:16:58.100
PROFESSOR: It's even worse
than that, right.

00:16:58.100 --> 00:17:00.040
So all of us have in us a
range of performance.

00:17:00.040 --> 00:17:00.660
We know that.

00:17:00.660 --> 00:17:05.430
If you do sports, if you do
research, if you do anything,

00:17:05.430 --> 00:17:07.680
some days we're at
our average.

00:17:07.680 --> 00:17:08.920
Some days, we're not so good.

00:17:08.920 --> 00:17:11.480
Some days, we go wow, that
was pretty good.

00:17:11.480 --> 00:17:13.910
We all have a range of
performance that's possible,

00:17:13.910 --> 00:17:16.970
our average performance, our
best days, our worst days.

00:17:16.970 --> 00:17:19.700
So you just went up
and you did an

00:17:19.700 --> 00:17:21.700
awesome flight maneuver.

00:17:21.700 --> 00:17:24.919
Is that your average one or
is that a peak example?

00:17:28.530 --> 00:17:30.330
It's a peak example.

00:17:30.330 --> 00:17:32.070
Statistically, what's the
likelihood of your next one

00:17:32.070 --> 00:17:35.020
going to be, better or worse?

00:17:35.020 --> 00:17:36.270
Worse.

00:17:38.210 --> 00:17:40.930
You can't always be at your
best, because you'd sort of go

00:17:40.930 --> 00:17:43.440
into infinite excellence.

00:17:43.440 --> 00:17:44.840
You have a range
of performance.

00:17:48.500 --> 00:17:49.800
In the NBA, what's a
really good score?

00:17:49.800 --> 00:17:52.090
30 points is really good.

00:17:52.090 --> 00:17:53.700
That's the average though,
of the best players.

00:17:53.700 --> 00:17:55.530
They don't go out and go,
I got 30 tonight.

00:17:55.530 --> 00:17:56.600
And tomorrow, I'll get 32.

00:17:56.600 --> 00:17:58.770
And by the end of the season,
I have like 180

00:17:58.770 --> 00:18:01.320
points every game.

00:18:01.320 --> 00:18:02.690
Even if you're on the
Miami Heat, you have

00:18:02.690 --> 00:18:05.190
to do a good job.

00:18:05.190 --> 00:18:08.800
So do you understand?

00:18:08.800 --> 00:18:10.920
So here's another example.

00:18:10.920 --> 00:18:14.340
Parents of very famous,
successful kids, are they

00:18:14.340 --> 00:18:17.680
mostly super-famous and
super-successful?

00:18:17.680 --> 00:18:20.800
Or do we mostly read about them
and go whoa, that's a

00:18:20.800 --> 00:18:22.050
tough deal, what
happened there?

00:18:22.050 --> 00:18:23.365
What's your impression?

00:18:27.200 --> 00:18:28.630
Let's ask this question--

00:18:28.630 --> 00:18:30.950
and if you are facing
these burdens.

00:18:30.950 --> 00:18:34.155
If your parent wins a Nobel
Prize, what's the odds that

00:18:34.155 --> 00:18:36.450
you win a Nobel Prize.

00:18:36.450 --> 00:18:36.785
Small.

00:18:36.785 --> 00:18:39.530
And they go oh, the
underachieving kid.

00:18:39.530 --> 00:18:42.110
All the pressure from the parent
to do really well, with

00:18:42.110 --> 00:18:43.710
a Nobel Laureate
as your parent.

00:18:43.710 --> 00:18:44.960
Well, maybe.

00:18:44.960 --> 00:18:47.360
Maybe your parent is berating
from kindergarten on saying,

00:18:47.360 --> 00:18:49.820
if you don't eat your peas and
carrots, you won't win a Nobel

00:18:49.820 --> 00:18:51.380
Prize, like I. That's
a possibility.

00:18:51.380 --> 00:18:53.180
We can't rule it out.

00:18:53.180 --> 00:18:55.490
But if somebody in your family
wins a Nobel Prize, what's the

00:18:55.490 --> 00:18:58.630
odds that other people in your
family will win that.

00:18:58.630 --> 00:18:58.950
PROFESSOR: Yeah.

00:18:58.950 --> 00:19:01.320
So we call that regression
to the mean.

00:19:01.320 --> 00:19:04.380
If you have an outstanding
example, a person who wins a

00:19:04.380 --> 00:19:09.210
Nobel Prize, everybody around
them is not likely to win.

00:19:09.210 --> 00:19:12.870
If you have an outstanding day
at what you do, like a really

00:19:12.870 --> 00:19:17.120
good day, the next day is
likely to be worse, just

00:19:17.120 --> 00:19:18.080
statistically.

00:19:18.080 --> 00:19:20.000
So what's happening with
this flight instructor?

00:19:20.000 --> 00:19:22.160
This is a very powerful and
important idea, that

00:19:22.160 --> 00:19:23.830
intuitively often, what's
happening with the flight

00:19:23.830 --> 00:19:24.440
instructor?

00:19:24.440 --> 00:19:27.050
Of course if the guy does
awesome, he's going to do

00:19:27.050 --> 00:19:30.700
worse the next time, every
single time, practically,

00:19:30.700 --> 00:19:31.620
statistically.

00:19:31.620 --> 00:19:35.200
So we can think about this,
regression to the mean.

00:19:35.200 --> 00:19:35.770
Here's a standard

00:19:35.770 --> 00:19:37.640
distribution, bell-shaped curve.

00:19:37.640 --> 00:19:39.560
Here's the mean of whatever
you do, how well you shoot

00:19:39.560 --> 00:19:41.785
baskets, how well you study for
a test, how well you wrote

00:19:41.785 --> 00:19:45.680
a paper, how well you helped a
friend who needed consoling.

00:19:45.680 --> 00:19:47.930
You pick your thing.

00:19:47.930 --> 00:19:49.610
Some days you do a medium job.

00:19:49.610 --> 00:19:50.540
You're average.

00:19:50.540 --> 00:19:54.150
Some days you really impress
yourself with how you did.

00:19:54.150 --> 00:19:57.270
And some days, you're pretty
shocked at what a miserable

00:19:57.270 --> 00:19:58.630
day you had.

00:19:58.630 --> 00:19:59.710
Does that makes sense?

00:19:59.710 --> 00:20:02.230
So if you had an awesome outing,
by average, the next

00:20:02.230 --> 00:20:06.220
outing is going to be less good,
regression to the mean.

00:20:08.790 --> 00:20:12.570
So one place that this has been
done over and over and

00:20:12.570 --> 00:20:14.290
over again, and somebody
help me out here.

00:20:14.290 --> 00:20:15.570
This could happen
in any sport.

00:20:15.570 --> 00:20:19.270
But especially in basketball,
people talk about a hot hand.

00:20:19.270 --> 00:20:21.050
So some of you are sports
enthusiasts.

00:20:21.050 --> 00:20:22.130
Probably some of you are not.

00:20:22.130 --> 00:20:25.250
So a sports enthusiast, will
you please help me describe

00:20:25.250 --> 00:20:30.410
what a hot hand is
in basketball?

00:20:30.410 --> 00:20:31.320
Help the rest of the class.

00:20:31.320 --> 00:20:31.812
Oh, thanks.

00:20:31.812 --> 00:20:34.887
AUDIENCE: You think you're on a
hot streak just because you

00:20:34.887 --> 00:20:36.240
made a couple baskets in row.

00:20:36.240 --> 00:20:38.536
But they do the statistics and
then it ends up being that

00:20:38.536 --> 00:20:41.652
they're just overconfident in
their shots, since they are

00:20:41.652 --> 00:20:45.550
shooting more shots
in the end.

00:20:45.550 --> 00:20:45.641
PROFESSOR: So people
have a saying --

00:20:45.641 --> 00:20:47.920
If you watch a basketball game,
it's incredibly how

00:20:47.920 --> 00:20:50.790
often the announcer will
say, oh, player x, he

00:20:50.790 --> 00:20:53.370
or she is on a tear.

00:20:53.370 --> 00:20:54.350
They're so hot.

00:20:54.350 --> 00:20:55.570
Pass that ball to that person.

00:20:55.570 --> 00:20:56.600
They're so hot.

00:20:56.600 --> 00:20:57.510
They shoot a three-pointer.

00:20:57.510 --> 00:20:58.540
And they come down and they
shoot a three-pointer.

00:20:58.540 --> 00:20:59.970
And they say, why are
you passing the

00:20:59.970 --> 00:21:00.620
ball to that person?

00:21:00.620 --> 00:21:03.100
They're so hot.

00:21:03.100 --> 00:21:06.610
And some players are known as
streaky players, who go out

00:21:06.610 --> 00:21:09.160
and have just awesome nights.

00:21:09.160 --> 00:21:10.650
You hear this in the sports
all the time.

00:21:10.650 --> 00:21:12.790
I can't tell you, the end of
a close March Madness game,

00:21:12.790 --> 00:21:14.400
they're always saying,
pass it to this guy.

00:21:14.400 --> 00:21:17.580
Because this guy is on a
streak in this game.

00:21:20.180 --> 00:21:21.550
So they can do the statistics.

00:21:21.550 --> 00:21:23.020
How would you do the
statistic to know

00:21:23.020 --> 00:21:24.700
whether streaks actually--

00:21:24.700 --> 00:21:27.170
streaks exist.

00:21:27.170 --> 00:21:29.610
Sometimes you do two baskets
in a row or five.

00:21:29.610 --> 00:21:30.870
Or you miss five in a row.

00:21:30.870 --> 00:21:33.520
There are runs, like
heads and tails.

00:21:33.520 --> 00:21:36.380
But the question we're asking
is, if you made a shot, does

00:21:36.380 --> 00:21:39.460
that an increase in any short
run, the probability that

00:21:39.460 --> 00:21:40.870
you'll make the next shot?

00:21:40.870 --> 00:21:41.660
That would be the streak.

00:21:41.660 --> 00:21:42.780
That would be the hot shooter.

00:21:42.780 --> 00:21:44.180
So you can go do statistics.

00:21:44.180 --> 00:21:44.930
And they did it.

00:21:44.930 --> 00:21:47.540
Psychologists have done it on
many teams, in many leagues.

00:21:47.540 --> 00:21:50.440
They did every single shot of a
Cornell basketball team, the

00:21:50.440 --> 00:21:51.070
entire season.

00:21:51.070 --> 00:21:52.500
But they've done it on
many other teams.

00:21:52.500 --> 00:21:54.670
There is no such thing
as a hot streak.

00:21:54.670 --> 00:21:55.920
There is no such thing
as a hot streak.

00:21:55.920 --> 00:21:59.090
Of course, you have small runs,
where people have a lot

00:21:59.090 --> 00:22:00.500
of good shots.

00:22:00.500 --> 00:22:02.280
Another day, they'll have
a lot of bad shots.

00:22:02.280 --> 00:22:04.740
But the probability of making
any one shot is no higher or

00:22:04.740 --> 00:22:07.140
lower, given the probability
that you made the prior shot.

00:22:07.140 --> 00:22:08.850
They're completely
independent.

00:22:08.850 --> 00:22:11.430
And nobody can find statistical
support for any

00:22:11.430 --> 00:22:13.900
kind of streaks in sports,
except of course you have huge

00:22:13.900 --> 00:22:14.420
distributions.

00:22:14.420 --> 00:22:15.910
So sometimes a person
will have an

00:22:15.910 --> 00:22:17.775
exceptionally good or bad night.

00:22:20.570 --> 00:22:21.910
So this is kind of like that.

00:22:21.910 --> 00:22:23.140
And you will get this.

00:22:23.140 --> 00:22:25.290
Suppose that you have a normal
penny with a head and a tail.

00:22:25.290 --> 00:22:26.130
You toss it six times.

00:22:26.130 --> 00:22:27.460
Which is these outcomes
is most likely?

00:22:30.860 --> 00:22:32.690
All the same.

00:22:32.690 --> 00:22:34.350
You're absolutely right.

00:22:34.350 --> 00:22:42.980
But why do people tend not to
like a), mostly, who haven't

00:22:42.980 --> 00:22:45.280
studied probability much?

00:22:45.280 --> 00:22:45.950
They don't like a).

00:22:45.950 --> 00:22:47.200
Why don't they like a)?

00:22:49.400 --> 00:22:52.500
Most people, most of the time,
as a random thing?

00:22:52.500 --> 00:22:52.980
Yeah?

00:22:52.980 --> 00:22:53.960
AUDIENCE: It doesn't
look random.

00:22:53.960 --> 00:22:56.360
PROFESSOR: It doesn't
look random, man.

00:22:56.360 --> 00:22:57.540
A) can't be random, right?

00:22:57.540 --> 00:22:59.610
But we know that we have
short runs of anything.

00:22:59.610 --> 00:23:01.010
And each of these are
independent outcomes.

00:23:01.010 --> 00:23:02.260
That's exactly what you got.

00:23:04.690 --> 00:23:05.850
We did this example before.

00:23:05.850 --> 00:23:07.650
But there are 30 people
in the group.

00:23:07.650 --> 00:23:09.470
You get the month and date of
each person's birthday.

00:23:09.470 --> 00:23:11.330
What is the approximate
probability that two people

00:23:11.330 --> 00:23:12.670
have the exact same birthday?

00:23:12.670 --> 00:23:15.490
And most people will say, oh, I
haven't met that many people

00:23:15.490 --> 00:23:16.020
on my birthday.

00:23:16.020 --> 00:23:17.090
Not that high.

00:23:17.090 --> 00:23:19.290
But it's actually 70%.

00:23:19.290 --> 00:23:20.420
Because it's any two
in the group.

00:23:20.420 --> 00:23:21.580
It's not you.

00:23:21.580 --> 00:23:22.650
It's any two in the group.

00:23:22.650 --> 00:23:26.080
And that increases it to 70%.

00:23:26.080 --> 00:23:27.010
Here's one we haven't done.

00:23:27.010 --> 00:23:28.997
Imagine a college in which the
average height of men is 175

00:23:28.997 --> 00:23:30.040
centimeters.

00:23:30.040 --> 00:23:31.980
You randomly measure the
height of three men.

00:23:31.980 --> 00:23:33.620
Which of these two outcomes
is more likely?

00:23:33.620 --> 00:23:36.540
And I'll let you think about
this for a moment.

00:23:36.540 --> 00:23:40.610
John at 178, Mike at 170, and
Bob at 176; or John at 177,

00:23:40.610 --> 00:23:43.400
Mike at 177, and Bob at 177?

00:23:43.400 --> 00:23:46.174
Which is more likely,
or can't tell?

00:23:46.174 --> 00:23:47.424
AUDIENCE: [INAUDIBLE].

00:23:52.820 --> 00:24:01.510
PROFESSOR: I heard a
B. Is it obvious?

00:24:01.510 --> 00:24:02.045
Let me tell you.

00:24:02.045 --> 00:24:04.160
It's the same concept we've
been talking about, about

00:24:04.160 --> 00:24:05.810
distributions and means.

00:24:05.810 --> 00:24:10.610
So here's the average, which
you are given as 175.

00:24:10.610 --> 00:24:14.000
So these guys are closer
to the average.

00:24:14.000 --> 00:24:17.550
Height is distributed
in a normalized way.

00:24:17.550 --> 00:24:21.320
So here's the three people, who
are red dots, the equal

00:24:21.320 --> 00:24:23.680
heights, 177, and
177, and 177.

00:24:23.680 --> 00:24:25.150
Here are the heights
of the blue.

00:24:25.150 --> 00:24:26.940
There's more people in this
part of the distribution.

00:24:26.940 --> 00:24:30.100
So it's actually more likely to
get this than this, about

00:24:30.100 --> 00:24:31.480
40% more likely.

00:24:31.480 --> 00:24:34.140
Because you're sampling from
closer to the mean.

00:24:34.140 --> 00:24:36.820
And there are more people
near the mean.

00:24:36.820 --> 00:24:38.420
Does that make sense?

00:24:38.420 --> 00:24:39.530
But people don't like that.

00:24:39.530 --> 00:24:42.380
Overwhelmingly, if you ask
people, they like the top

00:24:42.380 --> 00:24:45.160
answer, because it just doesn't
feel right to get

00:24:45.160 --> 00:24:48.430
three people of equal height,
in a random way.

00:24:48.430 --> 00:24:51.990
And you could say, what do you
mean it doesn't feel right?

00:24:51.990 --> 00:24:54.490
We can do the math or we can
show you the picture.

00:24:54.490 --> 00:24:57.390
And we can all agree, I think,
that that's correct.

00:24:57.390 --> 00:24:59.660
What do you mean it doesn't
feel right?

00:24:59.660 --> 00:25:02.540
And that's what people mean
by the difference between

00:25:02.540 --> 00:25:04.220
algorithms and heuristics.

00:25:04.220 --> 00:25:06.230
This is work from Kahneman and
Tversky, that won a Noble

00:25:06.230 --> 00:25:07.410
Prize for Danny Kahneman.

00:25:07.410 --> 00:25:08.690
Tversky passed away.

00:25:08.690 --> 00:25:11.370
Which is that humans could
figure out many things

00:25:11.370 --> 00:25:12.330
algorithmically.

00:25:12.330 --> 00:25:14.060
You can do the probability.

00:25:14.060 --> 00:25:17.440
But as an intuition, for many,
many, many people, even

00:25:17.440 --> 00:25:20.280
educated people who know a
lot about probability.

00:25:20.280 --> 00:25:22.590
There's an intuition that we
have about things, heuristics,

00:25:22.590 --> 00:25:24.700
a feeling we have
about things.

00:25:24.700 --> 00:25:28.370
Like the odds of this
are almost nil.

00:25:28.370 --> 00:25:30.590
And we go by that feeling,
instead of by being the

00:25:30.590 --> 00:25:36.790
rational analyst that
we might be.

00:25:36.790 --> 00:25:37.160
Here's one.

00:25:37.160 --> 00:25:38.240
You'll get this one, I think.

00:25:38.240 --> 00:25:40.220
A nearby town is served
by two hospitals.

00:25:40.220 --> 00:25:42.910
About 45 babies are born each
day in the larger, about 15 in

00:25:42.910 --> 00:25:43.910
the smaller.

00:25:43.910 --> 00:25:46.010
Approximately half of
the babies are boys.

00:25:46.010 --> 00:25:47.600
However, the exact percentage
varies day to

00:25:47.600 --> 00:25:48.610
day, of boys and girls.

00:25:48.610 --> 00:25:50.120
Some days, it's higher
than 50%.

00:25:50.120 --> 00:25:51.350
Some days, lower.

00:25:51.350 --> 00:25:53.490
For a period of a year, both
the larger and the smaller

00:25:53.490 --> 00:25:56.350
hospital recorded the number of
days in which more than 60%

00:25:56.350 --> 00:25:57.850
of the babies were boys.

00:25:57.850 --> 00:25:59.860
So a disproportionate
number were boys.

00:25:59.860 --> 00:26:01.870
Which hospital do you think
recorded more such days?

00:26:10.360 --> 00:26:16.090
The answer is about the same.

00:26:16.090 --> 00:26:18.040
The most common answer
is about the same.

00:26:18.040 --> 00:26:21.003
But because of the law of small
numbers, you're going to

00:26:21.003 --> 00:26:23.115
get more weird samples in
the smaller hospital.

00:26:25.930 --> 00:26:27.070
Because it'll be a less
of a distribution.

00:26:27.070 --> 00:26:29.970
You'll get more weird stuff.

00:26:29.970 --> 00:26:31.130
Here's one.

00:26:31.130 --> 00:26:34.040
It's a little dated, in terms
of the language used.

00:26:34.040 --> 00:26:35.460
But they would give people
an example of this.

00:26:35.460 --> 00:26:36.860
Linda is a 31-year-old, single,

00:26:36.860 --> 00:26:37.840
outspoken, very bright.

00:26:37.840 --> 00:26:39.580
She majored in philosophy
as a student.

00:26:39.580 --> 00:26:41.165
She was deeply concerned with
the issue of discrimination

00:26:41.165 --> 00:26:43.690
and social justice and also
participated in antinuclear

00:26:43.690 --> 00:26:44.420
demonstrations.

00:26:44.420 --> 00:26:46.690
And then rank the options in
terms of their likelihood.

00:26:46.690 --> 00:26:48.840
In describing Linda, I'll give
a ranking of 1 to the most

00:26:48.840 --> 00:26:51.660
likely option and a ranking of
8 to the least likely option.

00:26:51.660 --> 00:26:53.350
So people go through this.

00:26:53.350 --> 00:26:54.980
I mean you're sort of just
making up stuff.

00:26:54.980 --> 00:26:58.090
Having said this, I think people
go around all the time

00:26:58.090 --> 00:27:00.280
having impressions of people in
their head, what are they

00:27:00.280 --> 00:27:01.930
really like, what are
they really about.

00:27:01.930 --> 00:27:03.280
But they do this
kind of thing.

00:27:03.280 --> 00:27:06.770
And here's the interesting
element to the result.

00:27:06.770 --> 00:27:09.320
People on average, are more
likely to endorse the

00:27:09.320 --> 00:27:11.990
statement, Linda is a bank
teller and active in the

00:27:11.990 --> 00:27:15.060
feminist movement, than Linda
is a bank teller.

00:27:15.060 --> 00:27:21.060
Now, why logically is that a bad
idea, as you're guessing

00:27:21.060 --> 00:27:22.790
about Linda and what
you might do?

00:27:22.790 --> 00:27:25.890
Why is it logically a bad idea
to pick h, more than f?

00:27:25.890 --> 00:27:26.940
AUDIENCE: [INAUDIBLE].

00:27:26.940 --> 00:27:28.360
PROFESSOR: Right.

00:27:28.360 --> 00:27:28.630
Yeah.

00:27:28.630 --> 00:27:29.860
Yeah.

00:27:29.860 --> 00:27:33.500
Just logically, heuristically,
algorithmically, right, sorry,

00:27:33.500 --> 00:27:35.253
it's more likely you'd
be correct saying

00:27:35.253 --> 00:27:35.430
she's a bank teller.

00:27:35.430 --> 00:27:36.970
She's a bank teller and shes--

00:27:36.970 --> 00:27:38.660
But why do you think more
people pick this one?

00:27:42.790 --> 00:27:43.570
Because of your intuition.

00:27:43.570 --> 00:27:45.000
So people think, well
this is a person who

00:27:45.000 --> 00:27:46.330
might be like this?

00:27:46.330 --> 00:27:48.310
So they go for the bigger
description.

00:27:48.310 --> 00:27:51.020
And not just unsuspecting
undergraduates, but also

00:27:51.020 --> 00:27:52.960
first-year grad students in
stats courses, and also

00:27:52.960 --> 00:27:54.630
doctoral students in decision
science programs

00:27:54.630 --> 00:27:55.840
and business school.

00:27:55.840 --> 00:27:59.460
It's not, with more training
you can avert these errors.

00:27:59.460 --> 00:28:04.060
But everybody has it in them
pretty easily to be seduced by

00:28:04.060 --> 00:28:06.940
intuitive heuristics of
reasoning, rather than

00:28:06.940 --> 00:28:10.380
algorithmic analyses.

00:28:10.380 --> 00:28:11.560
Availability is kind of fun.

00:28:11.560 --> 00:28:13.030
So this is a slow one.

00:28:15.930 --> 00:28:18.460
This example is a little
work, for an example.

00:28:18.460 --> 00:28:20.040
Some experts studied the
frequency of appearance of

00:28:20.040 --> 00:28:21.440
various letters in the
English language.

00:28:21.440 --> 00:28:23.360
They studied a typical passage
in English and recorded the

00:28:23.360 --> 00:28:25.250
relative frequency with which
various letters of the

00:28:25.250 --> 00:28:26.840
alphabet appeared in the
first and the third

00:28:26.840 --> 00:28:27.400
positions of words.

00:28:27.400 --> 00:28:28.840
For example, in the word
"language," appears "L"

00:28:28.840 --> 00:28:31.990
appears in the first position
and "N" appears in the third.

00:28:31.990 --> 00:28:33.530
In this study, words with
less than three

00:28:33.530 --> 00:28:34.310
letters were not examined.

00:28:34.310 --> 00:28:36.730
Consider the letter "K." Do you
think that the K is more

00:28:36.730 --> 00:28:38.210
likely to appear in
the first position

00:28:38.210 --> 00:28:39.480
or the third position?

00:28:39.480 --> 00:28:42.310
Now estimate the ratio for the
number of times it appears in

00:28:42.310 --> 00:28:45.490
the first versus the third.

00:28:45.490 --> 00:28:49.010
So it could be even, 1:1; it
could be more often in the

00:28:49.010 --> 00:28:51.840
third position, like 1:2; or it
could twice as often in the

00:28:51.840 --> 00:28:54.160
first position.

00:28:54.160 --> 00:28:55.410
Any feelings?

00:28:58.190 --> 00:29:01.110
Just for fun, who thinks K
appears more often in the

00:29:01.110 --> 00:29:03.700
first word than the third?

00:29:03.700 --> 00:29:03.980
Just for fun.

00:29:03.980 --> 00:29:05.080
Help me out here.

00:29:05.080 --> 00:29:05.430
Hands up.

00:29:05.430 --> 00:29:06.520
If you have to pick
one or the other.

00:29:06.520 --> 00:29:08.180
You have to pick one
or the other.

00:29:08.180 --> 00:29:10.920
How many people like in
the third position?

00:29:10.920 --> 00:29:14.265
Anyway, so here's what
happens mostly.

00:29:14.265 --> 00:29:16.660
Not your estimate, but
the estimate of

00:29:16.660 --> 00:29:17.950
students in larger samples.

00:29:17.950 --> 00:29:20.090
2:1, they like K in the
first position.

00:29:20.090 --> 00:29:22.140
It's really 1:2 in
the dictionary.

00:29:22.140 --> 00:29:24.760
Why do you think on average,
people tend to go for K in the

00:29:24.760 --> 00:29:26.220
first position?

00:29:26.220 --> 00:29:29.710
So now we need somebody who's
willing to say something, give

00:29:29.710 --> 00:29:30.740
some answers out there.

00:29:30.740 --> 00:29:32.050
Yeah?

00:29:32.050 --> 00:29:34.504
AUDIENCE: Because it's easier
to think of words that start

00:29:34.504 --> 00:29:35.380
with K than it is--

00:29:35.380 --> 00:29:36.560
PROFESSOR: Yes.

00:29:36.560 --> 00:29:37.250
So help me out.

00:29:37.250 --> 00:29:39.040
Let's do this for one second.

00:29:39.040 --> 00:29:40.540
Somebody call out a
K word, any word?

00:29:40.540 --> 00:29:41.360
AUDIENCE: Knight.

00:29:41.360 --> 00:29:41.820
PROFESSOR: Knight.

00:29:41.820 --> 00:29:42.770
Another word?

00:29:42.770 --> 00:29:43.570
AUDIENCE: Kind.

00:29:43.570 --> 00:29:44.400
PROFESSOR: Kind.

00:29:44.400 --> 00:29:46.000
Another word?

00:29:46.000 --> 00:29:46.910
AUDIENCE: Kangaroo.

00:29:46.910 --> 00:29:47.080
PROFESSOR: Kangaroo.

00:29:47.080 --> 00:29:47.780
Excellent.

00:29:47.780 --> 00:29:48.510
OK, very good.

00:29:48.510 --> 00:29:50.305
OK, quick, a K in the
third position?

00:29:50.305 --> 00:29:51.460
AUDIENCE: [INAUDIBLE].

00:29:51.460 --> 00:29:52.710
PROFESSOR: Oh, you guys are--

00:29:55.090 --> 00:29:58.350
I should have done
it differently.

00:29:58.350 --> 00:30:01.340
So now we're talking about the
heuristic of availability,

00:30:01.340 --> 00:30:05.450
that we sort of think that how
common something is and then

00:30:05.450 --> 00:30:08.650
in some ways, how important
something is, by the ease with

00:30:08.650 --> 00:30:09.520
which it comes to mind.

00:30:09.520 --> 00:30:12.510
It's easier really to think of
words beginning with K, then

00:30:12.510 --> 00:30:14.100
having K in the third
position.

00:30:14.100 --> 00:30:16.420
Here's a question.

00:30:16.420 --> 00:30:18.720
How much more likely are you,
and I don't know the answer to

00:30:18.720 --> 00:30:20.405
this, but you can figure it out,
to drown in the bathtub

00:30:20.405 --> 00:30:22.510
than to die from a terrorist
attack in the United States?

00:30:22.510 --> 00:30:25.980
Obviously since 9/11, terrorism
has been a a huge

00:30:25.980 --> 00:30:28.490
issue in our county,
a huge issue.

00:30:28.490 --> 00:30:31.820
But in the US, what
do you think?

00:30:31.820 --> 00:30:36.730
Much more likely for people to
die drowning in a bathtub than

00:30:36.730 --> 00:30:39.880
terrorist attacks, including
9/11, for the 2000s.

00:30:39.880 --> 00:30:43.600
So why is it, why is it that you
have constant discussion

00:30:43.600 --> 00:30:44.990
about terrorism?

00:30:44.990 --> 00:30:48.430
Why is it that you take off your
shoes and can't take much

00:30:48.430 --> 00:30:50.220
of your toothpaste
on the airplane?

00:30:50.220 --> 00:30:54.280
And yet nobody is talking to
you, saying, please exercise

00:30:54.280 --> 00:30:55.580
caution when you go
into the bathroom.

00:30:55.580 --> 00:30:57.930
And please have those things,
those sticky things that make

00:30:57.930 --> 00:30:59.740
it less likely to slip.

00:30:59.740 --> 00:31:01.540
Do you get much of that?

00:31:01.540 --> 00:31:04.050
Do you go to the airport and
they say, those shoes look a

00:31:04.050 --> 00:31:07.440
little slippery, in case
you go into a shower.

00:31:07.440 --> 00:31:09.950
So think about this, which is
the real danger, just in a

00:31:09.950 --> 00:31:13.500
practical way, and why do people
worry so much, and not

00:31:13.500 --> 00:31:15.520
for bad reasons, about
terrorism?

00:31:15.520 --> 00:31:18.830
What's the difference
between them?

00:31:18.830 --> 00:31:21.410
And you can think of
more than one.

00:31:21.410 --> 00:31:21.900
Yeah?

00:31:21.900 --> 00:31:24.104
AUDIENCE: You hear about
terrorism on the news, but you

00:31:24.104 --> 00:31:25.830
don't hear about anyone drowning
in the bathtub.

00:31:25.830 --> 00:31:26.280
PROFESSOR: That's huge.

00:31:26.280 --> 00:31:27.930
Availability is huge.

00:31:27.930 --> 00:31:31.400
The news is a very powerful way
in which we think that's

00:31:31.400 --> 00:31:33.560
what the world is full of,
terrorism in the US.

00:31:33.560 --> 00:31:35.770
We hear about terror groups that
are found, terror cells

00:31:35.770 --> 00:31:37.750
that are found.

00:31:37.750 --> 00:31:42.330
We'll hear about homicides a
little bit, in the local news.

00:31:42.330 --> 00:31:44.370
But you just never hear about,
unless it unfortunately

00:31:44.370 --> 00:31:46.600
happens to somebody you know
personally, somebody slipping

00:31:46.600 --> 00:31:47.690
and dying in the bathtub.

00:31:47.690 --> 00:31:48.730
And it does happen.

00:31:48.730 --> 00:31:49.990
But you don't hear
about it much.

00:31:49.990 --> 00:31:50.720
It's not available to you.

00:31:50.720 --> 00:31:51.080
Yeah?

00:31:51.080 --> 00:31:53.972
AUDIENCE: We're most scared of
things that are foreign to us

00:31:53.972 --> 00:31:54.936
even if they are
less dangerous.

00:31:54.936 --> 00:31:58.068
Like we'd be more likely to
drink a clear fluid that was

00:31:58.068 --> 00:32:00.250
more dangerous than something
that looks scary.

00:32:00.250 --> 00:32:02.080
PROFESSOR: Part of it is, what
you're saying, there's a sense

00:32:02.080 --> 00:32:04.420
of foreignness to the terrorism
that we don't

00:32:04.420 --> 00:32:04.940
understand.

00:32:04.940 --> 00:32:06.440
Maybe there's a sense
of passivity.

00:32:06.440 --> 00:32:08.430
We feel like we could do
something about the bathroom.

00:32:08.430 --> 00:32:10.470
We can't do something about
an airplane being

00:32:10.470 --> 00:32:11.860
driven into a building.

00:32:11.860 --> 00:32:12.960
These things are complicated.

00:32:12.960 --> 00:32:17.450
But it's fascinating what people
think is scary versus

00:32:17.450 --> 00:32:19.750
what by any rational analysis,
is dangerous.

00:32:22.480 --> 00:32:26.640
Here's another kind of way that
people easily struggle

00:32:26.640 --> 00:32:27.900
with numbers and thinking
about what's

00:32:27.900 --> 00:32:29.030
dangerous and not.

00:32:29.030 --> 00:32:31.100
So imagine you're a physician
and you're presented with this

00:32:31.100 --> 00:32:31.380
information.

00:32:31.380 --> 00:32:34.090
And let's hypothesize
that it's true.

00:32:34.090 --> 00:32:35.230
Somebody comes in
with dizziness.

00:32:35.230 --> 00:32:37.390
And they say, I'm worried
about a brain tumor.

00:32:37.390 --> 00:32:38.700
They go to your neurologist.

00:32:38.700 --> 00:32:40.630
And the neurologist says well,
here we have some statistics

00:32:40.630 --> 00:32:43.360
over the last two years, whether
somebody turned out to

00:32:43.360 --> 00:32:46.300
have a brain tumor or not,
present or absent; and whether

00:32:46.300 --> 00:32:47.990
they were dizzy or not,
present or absent.

00:32:47.990 --> 00:32:52.320
So you can make a 2 x 2 cell,
about they had a tumor and

00:32:52.320 --> 00:32:56.040
they reported dizziness; they
reported dizziness, but it

00:32:56.040 --> 00:32:58.280
turns out they had the
tumor; and so on.

00:32:58.280 --> 00:33:00.330
So here's the question
for you.

00:33:00.330 --> 00:33:03.760
Is being dizzy something
to worry about in

00:33:03.760 --> 00:33:05.480
terms of having a tumor?

00:33:05.480 --> 00:33:07.680
Should you be worried if you're
dizzy, that you might

00:33:07.680 --> 00:33:11.870
have a brain tumor,
by these numbers?

00:33:11.870 --> 00:33:14.020
So what do you think
most people think?

00:33:14.020 --> 00:33:16.900
You have to make
a quick answer.

00:33:16.900 --> 00:33:19.170
You're one of those doctors on
House, who's going to get

00:33:19.170 --> 00:33:21.320
berated in a moment.

00:33:21.320 --> 00:33:27.620
And you go, whoa, 160, bad.

00:33:27.620 --> 00:33:29.240
That's what a lot
of people feel.

00:33:29.240 --> 00:33:32.270
And by the way, there's a lot
of concern in medicine about

00:33:32.270 --> 00:33:36.140
how doctors convey risk to
patients, as patients pick

00:33:36.140 --> 00:33:37.740
what kind of treatment
they want.

00:33:37.740 --> 00:33:39.510
Because it's exactly what
we're talking about now.

00:33:39.510 --> 00:33:42.790
It's the exact way that you
convey to a patient, the risk

00:33:42.790 --> 00:33:45.540
they're facing or their family
member is facing among

00:33:45.540 --> 00:33:48.250
different treatment options.

00:33:48.250 --> 00:33:49.740
So is dizziness associated
with a brain tumor?

00:33:49.740 --> 00:33:53.820
And the answer is no, because
if you do the probabilities,

00:33:53.820 --> 00:33:56.170
so the probability of
a tumor is 4:1.

00:33:56.170 --> 00:34:00.680
So here's whether you have
the tumor, brain tumor.

00:34:00.680 --> 00:34:03.450
And it's one out of four, and
it's one out of four.

00:34:03.450 --> 00:34:04.980
The odds are identical.

00:34:04.980 --> 00:34:07.460
But you're impressed by this
absolute, big number.

00:34:07.460 --> 00:34:12.440
Intuitively, almost everybody
is, almost all the time.

00:34:12.440 --> 00:34:13.739
Here's another one that's
a bit more subtle.

00:34:13.739 --> 00:34:15.489
It comes up all the time
in medical testing.

00:34:15.489 --> 00:34:18.150
It's come up in things like
discussions about how often we

00:34:18.150 --> 00:34:21.940
should test for, if you're a
male, for prostate cancer when

00:34:21.940 --> 00:34:26.060
you get older; if you're a
female, for breast cancer.

00:34:26.060 --> 00:34:28.340
So these kinds of things come
up all the time in decisions

00:34:28.340 --> 00:34:30.820
about should you get the tests
or not, and so on.

00:34:30.820 --> 00:34:33.130
So imagine now, a hypothetical
syndrome, is a serious

00:34:33.130 --> 00:34:35.889
condition that affects
one person in 1,000.

00:34:35.889 --> 00:34:38.760
Imagine also that the test to
diagnose the disease always

00:34:38.760 --> 00:34:41.170
indicates correctly that
a person who has it,

00:34:41.170 --> 00:34:42.899
actually has it.

00:34:42.899 --> 00:34:46.300
So if you actually have the
disorder and you get a yes,

00:34:46.300 --> 00:34:47.580
you will always be identified.

00:34:47.580 --> 00:34:49.630
So that's a good test
in that way.

00:34:49.630 --> 00:34:51.880
Finally, suppose the test
occasionally misidentifies a

00:34:51.880 --> 00:34:54.620
healthy individual as having
that disorder.

00:34:54.620 --> 00:34:56.370
So that's a false positive.

00:34:56.370 --> 00:34:58.340
The test is a false positive
at a rate of 5%.

00:34:58.340 --> 00:35:00.670
Meaning the test wrongly
indicates that the virus is

00:35:00.670 --> 00:35:02.640
present in 5% of cases
where the person does

00:35:02.640 --> 00:35:04.380
not have the virus.

00:35:04.380 --> 00:35:07.280
So if you have it, it's
always correct.

00:35:07.280 --> 00:35:10.040
But 5% of healthy people will
be misidentified on the

00:35:10.040 --> 00:35:11.470
initial test.

00:35:11.470 --> 00:35:15.170
Choose a person at random,
administer the test, and the

00:35:15.170 --> 00:35:17.950
person tests positive
for that syndrome.

00:35:17.950 --> 00:35:21.630
What is the probability the
person really has that?

00:35:21.630 --> 00:35:24.760
This is the kind of medical
testing topic that goes on all

00:35:24.760 --> 00:35:26.050
the time, all the time.

00:35:30.840 --> 00:35:32.200
What do you think most people
are going to say?

00:35:35.984 --> 00:35:36.930
AUDIENCE: 95%.

00:35:36.930 --> 00:35:38.515
PROFESSOR: Yeah, 95% exactly.

00:35:38.515 --> 00:35:40.950
Because he said well, 5%
of the time it's wrong.

00:35:40.950 --> 00:35:42.840
But that ignores the base
rate of this order.

00:35:42.840 --> 00:35:46.110
Because if there's 1/1000,
then if the other 999 are

00:35:46.110 --> 00:35:51.140
tested, then you have
about 0.5 times 999.

00:35:51.140 --> 00:35:53.580
That means for every 51 who are
tested, only one has it.

00:35:53.580 --> 00:35:55.610
So the answer is
only about 2%.

00:35:55.610 --> 00:35:58.070
Because the odds, the prior
odds, that you have

00:35:58.070 --> 00:36:00.890
it are so, so low.

00:36:00.890 --> 00:36:03.470
So that comes into the
likelihood that it's an

00:36:03.470 --> 00:36:05.710
accurate test and the
false positive rate.

00:36:05.710 --> 00:36:07.840
So again, people's intuition
when they hear, their

00:36:07.840 --> 00:36:11.560
intuition is there's a 95%
probability that the person

00:36:11.560 --> 00:36:12.780
has the disorder.

00:36:12.780 --> 00:36:18.400
It's really only about 2%, given
the low known base rate.

00:36:18.400 --> 00:36:20.650
And if all this is whizzing by
you a bit, I know I'm going

00:36:20.650 --> 00:36:22.050
through it pretty fast.

00:36:22.050 --> 00:36:23.730
But you can think in two ways.

00:36:23.730 --> 00:36:25.970
You can also think you're a
patient being told this.

00:36:25.970 --> 00:36:27.420
You're not going to get an
hour long lecture on

00:36:27.420 --> 00:36:28.730
probabilities either.

00:36:28.730 --> 00:36:31.790
So how this is communicated to
physicians, for example in the

00:36:31.790 --> 00:36:36.120
medical area and families, is
a really big challenge.

00:36:36.120 --> 00:36:38.500
So we talked about two
heuristics, that people liked

00:36:38.500 --> 00:36:42.850
things to look random, that we
tend to go for what we often

00:36:42.850 --> 00:36:44.970
hear about and imagine that's
how frequent or dangerous

00:36:44.970 --> 00:36:48.920
something is, in a very
broad, intuitive way.

00:36:48.920 --> 00:36:50.880
Anchoring and adjustment,
here's a fun one.

00:36:50.880 --> 00:36:52.080
So here's the experiment
they did.

00:36:52.080 --> 00:36:54.926
They went to people, like in
courtyards around things that

00:36:54.926 --> 00:36:56.970
are around Stanford,
actually mostly.

00:36:56.970 --> 00:36:58.230
And they had them do
the following.

00:36:58.230 --> 00:37:02.850
They gave them either this
problem or this problem.

00:37:02.850 --> 00:37:05.230
And here's what happened.

00:37:05.230 --> 00:37:07.270
If they got this problem, and
they quickly had to guess the

00:37:07.270 --> 00:37:10.220
answer, they came up
with this many.

00:37:10.220 --> 00:37:12.130
This was their average estimate
and this was the

00:37:12.130 --> 00:37:13.090
average estimate.

00:37:13.090 --> 00:37:14.990
So the first thing we can agree
upon, regardless of the

00:37:14.990 --> 00:37:17.070
fact that everybody is
completely underestimating the

00:37:17.070 --> 00:37:18.530
actual answer--

00:37:18.530 --> 00:37:21.020
that's almost not the point--

00:37:21.020 --> 00:37:23.810
regardless of that, look
at this estimate.

00:37:23.810 --> 00:37:26.840
This rapid estimate is four
times greater than that.

00:37:26.840 --> 00:37:29.260
Why is that happening?

00:37:29.260 --> 00:37:30.890
You're only getting
one or the other.

00:37:30.890 --> 00:37:32.700
But why is that happening?

00:37:32.700 --> 00:37:35.960
This is the heuristic of
anchoring, how people come to

00:37:35.960 --> 00:37:37.210
quick decisions.

00:37:41.000 --> 00:37:44.540
If we go, 8, that's a
pretty big number.

00:37:44.540 --> 00:37:47.000
8, we're talking some big
numbers here, right now.

00:37:47.000 --> 00:37:50.300
They don't even get that they're
going to get to here.

00:37:50.300 --> 00:37:51.890
They start with 1 and 2.

00:37:51.890 --> 00:37:54.340
They go, we're talking about
a pretty small thing.

00:37:54.340 --> 00:37:56.630
But I can't quite calculate it
out, because it's too hard to

00:37:56.630 --> 00:37:58.930
calculate it out
for most of us.

00:37:58.930 --> 00:38:01.110
This is going to be pretty small
by the time-- so they

00:38:01.110 --> 00:38:02.180
are already thinking small.

00:38:02.180 --> 00:38:04.860
They are already thinking big.

00:38:04.860 --> 00:38:08.600
So now you know why, when you
go negotiate for your salary

00:38:08.600 --> 00:38:11.490
somewhere in the future, if
you have any negotiating

00:38:11.490 --> 00:38:13.680
power, start with
a big number.

00:38:16.400 --> 00:38:18.250
And the person who is
negotiating with you knows

00:38:18.250 --> 00:38:20.800
that too, and in fact is often
more practiced than you are.

00:38:20.800 --> 00:38:22.080
So here's a practical clue.

00:38:22.080 --> 00:38:23.470
Start with a big number.

00:38:23.470 --> 00:38:24.960
Because that's the number where
people's minds are.

00:38:24.960 --> 00:38:26.520
And I'll show you several
more examples of how

00:38:26.520 --> 00:38:27.780
ridiculous this is.

00:38:27.780 --> 00:38:30.250
But when there's no true, exact
number that you can

00:38:30.250 --> 00:38:32.590
quickly come up with, what's
the fair salary for you to

00:38:32.590 --> 00:38:35.770
get, the first year out of MIT
in a job or something?

00:38:35.770 --> 00:38:39.100
First number out there,
has a lot of power.

00:38:39.100 --> 00:38:41.540
So here they made
it ridiculous.

00:38:41.540 --> 00:38:44.630
This anchoring, that my mind
start somewhere and I kind of

00:38:44.630 --> 00:38:45.810
stay in that neighborhood.

00:38:45.810 --> 00:38:47.750
I don't recalibrate myself.

00:38:47.750 --> 00:38:50.420
So they took a wheel of fortune,
a spinning wheel of

00:38:50.420 --> 00:38:52.100
fortune, with the numbers
1 to 100.

00:38:52.100 --> 00:38:53.590
It's clearly random.

00:38:53.590 --> 00:38:56.120
Can't make it more obviously
random than that.

00:38:56.120 --> 00:38:57.070
It stops somewhere.

00:38:57.070 --> 00:38:59.270
And they say, we want you to
estimate the number of African

00:38:59.270 --> 00:39:00.130
nations in the UN?

00:39:00.130 --> 00:39:01.320
And most people don't
really know.

00:39:01.320 --> 00:39:03.520
And there's some vague sense
that it's more than a couple.

00:39:03.520 --> 00:39:06.170
But who knows how big
it is exactly.

00:39:06.170 --> 00:39:08.210
So the number stops somewhere.

00:39:08.210 --> 00:39:10.400
And here's the kind of
thing that happens.

00:39:10.400 --> 00:39:12.880
First you say, is it more or
less than the number it

00:39:12.880 --> 00:39:13.780
randomly stopped at?

00:39:13.780 --> 00:39:16.170
Let's pretend it
stopped at 65.

00:39:16.170 --> 00:39:20.190
Then average estimate was
45 African nations.

00:39:20.190 --> 00:39:22.110
Let's say it randomly
stopped at 10.

00:39:22.110 --> 00:39:26.170
Then the average estimate
was 25 nations.

00:39:26.170 --> 00:39:27.100
What's happening?

00:39:27.100 --> 00:39:28.390
Anchoring.

00:39:28.390 --> 00:39:29.890
You say well, it's
more than 10.

00:39:29.890 --> 00:39:33.280
But 10, I'm going to
go way up from 10.

00:39:33.280 --> 00:39:34.820
Because that's way too low.

00:39:34.820 --> 00:39:36.250
And I'll split--

00:39:36.250 --> 00:39:38.980
going beyond 25 seems
hazardous.

00:39:38.980 --> 00:39:39.810
You start at 65.

00:39:39.810 --> 00:39:41.650
You go, whoa, that's
way too many.

00:39:41.650 --> 00:39:42.900
But you're anchored.

00:39:42.900 --> 00:39:45.310
And then you use don't
go down that much.

00:39:45.310 --> 00:39:47.870
So that first number, when you
don't really know what the

00:39:47.870 --> 00:39:50.970
right answer is, has an
incredible power over how far

00:39:50.970 --> 00:39:54.300
you range from that, for
your best estimate.

00:39:54.300 --> 00:39:55.450
Same idea.

00:39:55.450 --> 00:39:57.340
Is the Mississippi
River longer or

00:39:57.340 --> 00:39:58.610
shorter than 500 miles?

00:39:58.610 --> 00:40:00.120
So they're giving
you the anchor.

00:40:00.120 --> 00:40:01.910
How long is it actually
do you think?

00:40:01.910 --> 00:40:04.290
Or another person is asked, is
it longer or shorter than

00:40:04.290 --> 00:40:05.550
5,000 miles?

00:40:05.550 --> 00:40:06.520
There's the anchor.

00:40:06.520 --> 00:40:07.750
How long is it, do you think?

00:40:07.750 --> 00:40:09.440
And here's the estimates.

00:40:09.440 --> 00:40:11.100
They're both underestimating.

00:40:11.100 --> 00:40:13.600
But they're moving towards
that number that was

00:40:13.600 --> 00:40:15.260
completely randomly thrown in.

00:40:15.260 --> 00:40:17.360
But it's not random
to the human mind.

00:40:17.360 --> 00:40:19.280
We don't know what the right
number is, but we're going to

00:40:19.280 --> 00:40:22.240
start in the neighborhood that
we first have any number

00:40:22.240 --> 00:40:24.470
presented to us.

00:40:24.470 --> 00:40:25.110
Framing.

00:40:25.110 --> 00:40:28.900
Framing is arguably, together
with availability, maybe the

00:40:28.900 --> 00:40:30.910
one that's the most interesting
in terms of how

00:40:30.910 --> 00:40:34.715
powerful it is and how often
people use it to convince you

00:40:34.715 --> 00:40:37.550
that their political position,
their corporate position,

00:40:37.550 --> 00:40:40.540
their anything, is
the way to go.

00:40:40.540 --> 00:40:43.300
And once you know framing,
you're empowered a bit to

00:40:43.300 --> 00:40:45.560
think about that, because you
hear arguments made to you

00:40:45.560 --> 00:40:47.460
about what to believe in
or what to support.

00:40:47.460 --> 00:40:48.970
So here comes the framing.

00:40:48.970 --> 00:40:50.955
Imagining the United States is
preparing for the outbreak of

00:40:50.955 --> 00:40:53.230
an unusual South American
disease, which is expected to

00:40:53.230 --> 00:40:54.870
kill 600 people.

00:40:54.870 --> 00:40:56.330
Two alternative programs
to combat the

00:40:56.330 --> 00:40:57.960
disease have been proposed.

00:40:57.960 --> 00:41:00.290
Assume that the exact scientific
estimate of the

00:41:00.290 --> 00:41:01.960
consequences of the programs
were as follows.

00:41:01.960 --> 00:41:04.580
If Program A is adopted, 200
people will be saved.

00:41:04.580 --> 00:41:06.690
If Program B is adopted,
there's a one-third

00:41:06.690 --> 00:41:09.300
probability the 600 people will
be saved and a two-thirds

00:41:09.300 --> 00:41:10.590
probability that no people
will be saved.

00:41:10.590 --> 00:41:12.640
Which program do you favor?

00:41:12.640 --> 00:41:14.590
So B is pretty complicated.

00:41:14.590 --> 00:41:17.200
But A is pretty simple,
200 people might be

00:41:17.200 --> 00:41:19.740
saved, will be saved.

00:41:19.740 --> 00:41:26.140
So here's the exact same
scenario by lives and deaths,

00:41:26.140 --> 00:41:30.600
given to a second group of
research participants.

00:41:30.600 --> 00:41:33.190
If Program A is adopted,
400 people will die.

00:41:33.190 --> 00:41:36.460
Do you see that if A is adopted,
200 people are saved,

00:41:36.460 --> 00:41:40.110
equals 400 people will die.

00:41:40.110 --> 00:41:40.680
It's the same thing.

00:41:40.680 --> 00:41:43.040
There's 600.

00:41:43.040 --> 00:41:46.300
You're really saying
the same outcome.

00:41:46.300 --> 00:41:50.450
But that numerical identity
is treated by humans as

00:41:50.450 --> 00:41:53.370
incredibly different information
on which to base

00:41:53.370 --> 00:41:54.220
your decision.

00:41:54.220 --> 00:41:55.740
And here's what happens.

00:41:55.740 --> 00:41:58.000
If people are given this
scenario, which is explained

00:41:58.000 --> 00:42:01.665
in terms of lives saved, 200
lives saved out of 600, 3/4 of

00:42:01.665 --> 00:42:02.875
the time they pick it.

00:42:02.875 --> 00:42:06.560
If people are given this
scenario, 3/4 of the time they

00:42:06.560 --> 00:42:07.420
don't pick it.

00:42:07.420 --> 00:42:11.190
It's the exact same choice.

00:42:11.190 --> 00:42:16.220
But to be human, is to gravitate
towards something

00:42:16.220 --> 00:42:18.650
where you save lives
and avoid something

00:42:18.650 --> 00:42:20.460
where you lose lives.

00:42:20.460 --> 00:42:23.510
Even though numerically, it's
the exact same outcome.

00:42:23.510 --> 00:42:26.130
But people radically switch
which one they think is the

00:42:26.130 --> 00:42:27.670
correct one, by the
framing of it.

00:42:27.670 --> 00:42:29.610
By simply the way it's
described in

00:42:29.610 --> 00:42:31.880
this most simple sense.

00:42:31.880 --> 00:42:33.760
So does that makes sense?

00:42:33.760 --> 00:42:34.745
I mean it's very powerful.

00:42:34.745 --> 00:42:37.200
When people present to you
stuff, how do they present it?

00:42:37.200 --> 00:42:40.700
Lives saved, lives lost; jobs
made, jobs lost; whatever you

00:42:40.700 --> 00:42:43.690
want, money made, money lost.

00:42:43.690 --> 00:42:45.060
We don't treat them
as two bits of

00:42:45.060 --> 00:42:46.260
information that are equal.

00:42:46.260 --> 00:42:47.280
We should.

00:42:47.280 --> 00:42:51.390
That's the algorithm,
out of 600 people,

00:42:51.390 --> 00:42:53.430
200 people make it.

00:42:53.430 --> 00:42:55.680
But that's not how we
psychologically interpret it.

00:42:55.680 --> 00:42:57.940
We go tremendously
by, we're drawn--

00:42:57.940 --> 00:43:01.210
any answer that uses the word
"saves", is a positive thing.

00:43:01.210 --> 00:43:04.560
And we're averse from any answer
that talks about bad

00:43:04.560 --> 00:43:06.090
things, how many people
will die.

00:43:06.090 --> 00:43:07.730
Even though they're
identical in the

00:43:07.730 --> 00:43:09.310
consequence of life and death.

00:43:09.310 --> 00:43:11.200
Is that clear?

00:43:11.200 --> 00:43:13.040
Very powerful.

00:43:13.040 --> 00:43:14.790
Here's another version of
it now, moving to money.

00:43:14.790 --> 00:43:16.480
And it gives you another
feeling of this.

00:43:16.480 --> 00:43:18.650
So you could think about
the top one.

00:43:18.650 --> 00:43:21.040
Would you rather have
a sure gain of $75.

00:43:21.040 --> 00:43:22.680
Somebody said, I'll give
you $75 right now.

00:43:22.680 --> 00:43:25.690
Or you can have a lottery where
you have a 75% chance of

00:43:25.690 --> 00:43:29.430
winning $100, so that's even
more, or a 25% chance of

00:43:29.430 --> 00:43:30.680
winning nothing at all.

00:43:33.970 --> 00:43:35.630
Another group of people
get this question.

00:43:35.630 --> 00:43:37.540
We're going to take
from you $75.

00:43:37.540 --> 00:43:40.781
It's a rough experiment
to sign up for.

00:43:40.781 --> 00:43:44.220
Or you're going to be in a
lottery with a 75% chance of

00:43:44.220 --> 00:43:48.060
losing $100, which is even a
worse loss, and 25% chance of

00:43:48.060 --> 00:43:49.460
losing nothing at all.

00:43:49.460 --> 00:43:52.260
So these are meant to be kind
of symmetric stories.

00:43:52.260 --> 00:43:56.370
But one is expressed all in
terms of gain and one all in

00:43:56.370 --> 00:43:57.590
terms of losses.

00:43:57.590 --> 00:44:02.380
And when people are thinking
about gains,

00:44:02.380 --> 00:44:03.890
they're risk averse.

00:44:03.890 --> 00:44:06.590
I'm not going to give up
what's in my hands.

00:44:06.590 --> 00:44:10.520
So 84% of the time,
they take that.

00:44:10.520 --> 00:44:13.110
Even though this is sort of
formally similar because it's

00:44:13.110 --> 00:44:17.350
a loss, now when it's losses,
people are risk taking.

00:44:17.350 --> 00:44:19.470
Humans are very asymmetric.

00:44:19.470 --> 00:44:21.750
If things are expressed in
gains, we're risk averse.

00:44:21.750 --> 00:44:22.970
Let's do the safe thing.

00:44:22.970 --> 00:44:25.740
I'm going to hang on to what's
already in my grasp.

00:44:25.740 --> 00:44:28.730
If it's in terms of loss, it's
like, let's bet the house,

00:44:28.730 --> 00:44:30.670
let's do any crazy,
wild thing.

00:44:30.670 --> 00:44:33.910
Because losses are so bad
that I'll take any

00:44:33.910 --> 00:44:35.900
chance to avoid a loss.

00:44:35.900 --> 00:44:38.980
Even though rationally, the
choices should be about the

00:44:38.980 --> 00:44:42.460
same, if we were machines
making choices.

00:44:42.460 --> 00:44:44.060
Very big difference.

00:44:44.060 --> 00:44:45.820
I mean when I first
heard about these

00:44:45.820 --> 00:44:46.730
things, I was stunned.

00:44:46.730 --> 00:44:48.650
Because it's huge.

00:44:48.650 --> 00:44:51.120
Everything that we vote for,
everything that we support,

00:44:51.120 --> 00:44:54.730
every decision we make about
careers, and policies that we

00:44:54.730 --> 00:44:57.960
are for or against, are always
being expressed to us in a

00:44:57.960 --> 00:44:59.350
framework like this.

00:44:59.350 --> 00:45:01.920
Things that we can gain or lose
in our own lives, in the

00:45:01.920 --> 00:45:03.870
world, in societies.

00:45:03.870 --> 00:45:07.790
And you spin around so easily
by how they're framed.

00:45:07.790 --> 00:45:08.980
Although now you
know something.

00:45:08.980 --> 00:45:10.230
And you can think about them.

00:45:12.570 --> 00:45:14.830
Here's just two odds and ends
things, that I thought were

00:45:14.830 --> 00:45:17.470
kind of fun.

00:45:17.470 --> 00:45:19.800
Other things that people find
kind of challenging to think

00:45:19.800 --> 00:45:22.320
their way through, just because
of the way our minds

00:45:22.320 --> 00:45:22.920
are constructed.

00:45:22.920 --> 00:45:24.390
So here's a problem.

00:45:24.390 --> 00:45:27.480
Jack is looking at Anne, but
Anne is looking at George.

00:45:27.480 --> 00:45:31.260
Jack is married, but
George is not.

00:45:31.260 --> 00:45:32.750
Here's your problem
to think about.

00:45:32.750 --> 00:45:39.040
Is a married person looking at
an unmarried person, yes, no,

00:45:39.040 --> 00:45:40.290
or cannot be determined?

00:45:46.970 --> 00:45:48.560
The only reason I know the
answers to these is because I

00:45:48.560 --> 00:45:49.830
have the answers to these.

00:45:49.830 --> 00:45:52.480
The first time I see these,
I'm like, oh no.

00:45:52.480 --> 00:45:57.500
So just for fun.

00:45:57.500 --> 00:45:59.970
You can go by intuition and
maybe you worked it out or you

00:45:59.970 --> 00:46:01.170
looked ahead.

00:46:01.170 --> 00:46:05.420
How many people who haven't
looked ahead, say yes?

00:46:05.420 --> 00:46:07.360
OK, there's some hands, 10.

00:46:07.360 --> 00:46:09.360
How many say no?

00:46:09.360 --> 00:46:09.580
Nobody.

00:46:09.580 --> 00:46:11.750
How many say, cannot
be determined?

00:46:11.750 --> 00:46:14.680
The answer is, that's good.

00:46:14.680 --> 00:46:18.046
Most answer, 80% say cannot
be determined.

00:46:18.046 --> 00:46:20.800
But the answer is this.

00:46:20.800 --> 00:46:21.390
Think about this.

00:46:21.390 --> 00:46:22.160
The answer is yes.

00:46:22.160 --> 00:46:23.340
And here's why.

00:46:23.340 --> 00:46:24.510
We don't know Anne's
marital status.

00:46:24.510 --> 00:46:25.200
The other two are given.

00:46:25.200 --> 00:46:27.230
So we have to figure out
Anne's situation.

00:46:27.230 --> 00:46:28.860
Let's say she's married.

00:46:28.860 --> 00:46:31.150
Then she's looking at
unmarried George.

00:46:31.150 --> 00:46:31.960
Let's say she's not married.

00:46:31.960 --> 00:46:33.070
Then Jack is looking
at unmarried Anne.

00:46:33.070 --> 00:46:34.420
Is that OK?

00:46:34.420 --> 00:46:36.560
This is what people in logic,
call fully disjunctive

00:46:36.560 --> 00:46:40.610
reasoning, where if you work
your way through the

00:46:40.610 --> 00:46:43.140
possibilities, you see
it has to work out.

00:46:43.140 --> 00:46:46.930
But that's not our intuitions.

00:46:46.930 --> 00:46:51.250
I mean you're a very
smart group.

00:46:51.250 --> 00:46:54.620
So if it's hard for you, imagine
the rest of the world

00:46:54.620 --> 00:46:57.250
is not as suspicious about how
to figure their problems out.

00:46:57.250 --> 00:47:00.010
So it's just fantastically
interesting how the human mind

00:47:00.010 --> 00:47:01.410
is brilliant at some things.

00:47:01.410 --> 00:47:05.850
And for other things, it could
solve, it could solve,

00:47:05.850 --> 00:47:07.970
intuitively, it's not often
going to happen.

00:47:07.970 --> 00:47:10.450
We go by these shortcuts where
either we don't get the answer

00:47:10.450 --> 00:47:12.690
at all or we come up with a
completely wrong one, because

00:47:12.690 --> 00:47:15.450
of availability or framing.

00:47:15.450 --> 00:47:15.970
Here's a quick one.

00:47:15.970 --> 00:47:17.100
You'll get this fast.

00:47:17.100 --> 00:47:17.740
It's fun.

00:47:17.740 --> 00:47:20.810
A ball and a bat cost
$1.10 in total.

00:47:20.810 --> 00:47:22.100
The bat cost a dollar
more than the ball.

00:47:22.100 --> 00:47:25.330
How much did the ball cost?

00:47:25.330 --> 00:47:26.780
All right, you guys are now,
you're very suspicious.

00:47:26.780 --> 00:47:28.150
You're thinking it through.

00:47:28.150 --> 00:47:30.330
Most people love $0.10.

00:47:30.330 --> 00:47:33.330
But you can tell that's
not going to work?

00:47:33.330 --> 00:47:35.520
Because then the bat would have
to cost $1.10 and the

00:47:35.520 --> 00:47:38.700
total would be $1.20.

00:47:38.700 --> 00:47:44.230
But a lot you were pulled to,
most of us to, having a $1.10,

00:47:44.230 --> 00:47:45.490
because we don't quite
think it through.

00:47:45.490 --> 00:47:46.030
There's $1.00.

00:47:46.030 --> 00:47:47.060
There's $0.10.

00:47:47.060 --> 00:47:49.400
And we do these shortcuts, these
heuristics, instead of

00:47:49.400 --> 00:47:52.250
logically working
our way through.

00:47:52.250 --> 00:47:54.390
One more example of this
kind of thing.

00:47:54.390 --> 00:47:55.950
Because now we're going
to add one more

00:47:55.950 --> 00:47:56.940
element just for this.

00:47:56.940 --> 00:47:58.950
Imagine that the US Department
of Transportation has found

00:47:58.950 --> 00:48:00.860
that a particular German car
is eight times more likely

00:48:00.860 --> 00:48:03.370
than a typical family car to
kill occupants of another car

00:48:03.370 --> 00:48:04.500
in a crash.

00:48:04.500 --> 00:48:06.260
The federal government is
considering restricting sale

00:48:06.260 --> 00:48:07.230
and use of this German car.

00:48:07.230 --> 00:48:09.090
Do you think sales of the German
car should be banned in

00:48:09.090 --> 00:48:12.300
the US or do you think the
German car should be banned

00:48:12.300 --> 00:48:13.670
from being driven on
the US streets?

00:48:13.670 --> 00:48:18.860
So here's one, given in this
study to US participants.

00:48:18.860 --> 00:48:20.600
Or to do exactly the same
thing, but it's

00:48:20.600 --> 00:48:21.690
not a German car.

00:48:21.690 --> 00:48:22.940
It's a Ford Explorer.

00:48:25.960 --> 00:48:29.600
So American participants, if
it's a German car, 73%, get

00:48:29.600 --> 00:48:31.610
that car off the road.

00:48:31.610 --> 00:48:35.230
If it's a Ford Explorer,
sorry.

00:48:35.230 --> 00:48:37.300
If a German car, off the
streets, you get 73%, If it's

00:48:37.300 --> 00:48:40.110
the American car, and Germany
is making the decision, only

00:48:40.110 --> 00:48:43.560
40% of the people think that
Germany should do that.

00:48:43.560 --> 00:48:45.400
Now, that's not purely logic.

00:48:45.400 --> 00:48:47.280
What is that?

00:48:47.280 --> 00:48:48.130
That's bias, right?

00:48:48.130 --> 00:48:51.140
That's like, yeah, on my
streets, we don't want these

00:48:51.140 --> 00:48:53.720
threatening machines
from overseas.

00:48:53.720 --> 00:48:55.730
Germany, we've got to keep
that economy going.

00:48:55.730 --> 00:48:58.310
Those Ford workers are really
doing a good job.

00:48:58.310 --> 00:49:02.340
So of course most decisions
aren't hyperrational in the

00:49:02.340 --> 00:49:03.860
way we've been talking about,
unknown people.

00:49:03.860 --> 00:49:06.800
Of course they involve things
in the world that we already

00:49:06.800 --> 00:49:07.650
have feelings about.

00:49:07.650 --> 00:49:10.500
So you add that in and you can
see that making a truly

00:49:10.500 --> 00:49:13.690
logical judgment is shockingly
hard, if anything is a little

00:49:13.690 --> 00:49:15.750
complicated.

00:49:15.750 --> 00:49:19.370
So let me turn for the last
little bit to what we think of

00:49:19.370 --> 00:49:22.260
as some of the core parts of
the brain for higher level

00:49:22.260 --> 00:49:25.770
thought, the struggle we have
between the best we have in

00:49:25.770 --> 00:49:28.730
our mind and the traps
we can fall into.

00:49:28.730 --> 00:49:32.650
And when we talk about that,
we tend to focus on sort of

00:49:32.650 --> 00:49:33.820
three areas of the
frontal lobe.

00:49:33.820 --> 00:49:36.380
So let me just remind
you of this.

00:49:36.380 --> 00:49:39.370
So here's the frontal lobes.

00:49:39.370 --> 00:49:41.210
And you could think of the
frontal lobe I think as the

00:49:41.210 --> 00:49:43.210
business end of the brain.

00:49:43.210 --> 00:49:45.510
Here comes visual information
coming in, auditory

00:49:45.510 --> 00:49:47.800
information coming in,
touch coming in.

00:49:47.800 --> 00:49:51.760
Somewhere back here,
would be taste.

00:49:51.760 --> 00:49:54.750
So that's getting stuck in and
figuring out what's out there.

00:49:54.750 --> 00:49:57.350
So the front half is the
business end of the brain,

00:49:57.350 --> 00:49:58.360
acting upon the world.

00:49:58.360 --> 00:50:01.020
Moving your hands, moving your
body, making decisions about

00:50:01.020 --> 00:50:02.580
what you do.

00:50:02.580 --> 00:50:06.100
Motor cortex, premotor cortex,
a guy's motor cortex.

00:50:06.100 --> 00:50:08.340
This so-called lateral
prefrontal cortex, that's

00:50:08.340 --> 00:50:10.030
higher levels of thought.

00:50:10.030 --> 00:50:12.900
And this bottom part of
ventromedial or orbitofrontal

00:50:12.900 --> 00:50:15.920
cortex, that we talked about
with Phineas Gage.

00:50:15.920 --> 00:50:20.260
So Oliver Sacks, in Chapter 13,
talks about one example of

00:50:20.260 --> 00:50:25.330
a woman who has a large tumor
in this ventromedial area.

00:50:25.330 --> 00:50:29.610
So sometimes I think there's a
Roman philosopher who said

00:50:29.610 --> 00:50:33.130
that life is composed of desires
and decisions, desires

00:50:33.130 --> 00:50:34.070
and decisions.

00:50:34.070 --> 00:50:36.400
So this part of the brain is
involved in desires and this

00:50:36.400 --> 00:50:37.210
part in decisions.

00:50:37.210 --> 00:50:39.210
And I'll show that,
roughly speaking.

00:50:39.210 --> 00:50:42.620
So here's a woman who is a
former research chemist.

00:50:42.620 --> 00:50:44.830
And she has a rapid personality
change, becoming

00:50:44.830 --> 00:50:47.450
facetious, impulsive,
superficial.

00:50:47.450 --> 00:50:49.430
And she a cerebral
tumor in this

00:50:49.430 --> 00:50:51.540
ventromedial part of the brain.

00:50:51.540 --> 00:50:53.540
When I see her, she's full
of quips and cracks,

00:50:53.540 --> 00:50:55.020
often clever and funny.

00:50:55.020 --> 00:50:57.425
Yes, father, she says to me on
one occasion; yes, sister, on

00:50:57.425 --> 00:50:59.230
another; yes, doctor,
on a third.

00:50:59.230 --> 00:50:59.960
What am I?

00:50:59.960 --> 00:51:01.620
And then she make some jokes.

00:51:01.620 --> 00:51:03.260
So she's constantly joking.

00:51:03.260 --> 00:51:08.030
And she says, everything
means nothing.

00:51:08.030 --> 00:51:10.090
Nothing at all, she says with
a bright smile and a tone of

00:51:10.090 --> 00:51:13.020
one who makes a joke, wins an
argument, or wins at poker.

00:51:13.020 --> 00:51:17.090
So she just finds that sort of
there are facts of the world,

00:51:17.090 --> 00:51:20.010
but they just don't feel like
they mean anything.

00:51:20.010 --> 00:51:22.460
Because a tumor is influencing
a part of the brain that we

00:51:22.460 --> 00:51:26.450
understand to organize the
relationship between thoughts

00:51:26.450 --> 00:51:28.450
and feelings, between thoughts
and feelings.

00:51:28.450 --> 00:51:31.150
And that's a huge way about
how we go about the world,

00:51:31.150 --> 00:51:32.650
what we think, what we feel.

00:51:32.650 --> 00:51:34.360
We've put it into a formula
of some sense.

00:51:34.360 --> 00:51:36.590
And that's how we act upon the
world, whether we help

00:51:36.590 --> 00:51:38.390
somebody, or don't help
somebody, like somebody, or

00:51:38.390 --> 00:51:39.350
don't like somebody.

00:51:39.350 --> 00:51:40.860
All those sorts of things.

00:51:40.860 --> 00:51:47.690
So when we think about behavior,
we normally think of

00:51:47.690 --> 00:51:49.830
the challenge of getting
it going.

00:51:49.830 --> 00:51:52.020
You get in your car and you
turn on and you accelerate

00:51:52.020 --> 00:51:53.190
from 0 to 60.

00:51:53.190 --> 00:51:55.680
But a really interesting thing
about the human brain is that

00:51:55.680 --> 00:51:59.030
we have lots of habits, things
we acquire about how to deal

00:51:59.030 --> 00:51:59.640
with the world.

00:51:59.640 --> 00:52:03.540
So just as big a problem for
our brains is stopping the

00:52:03.540 --> 00:52:07.490
course of action that's
no longer relevant.

00:52:07.490 --> 00:52:10.520
So the frontal cortex both has
the job of initiating things,

00:52:10.520 --> 00:52:11.870
but also stopping things.

00:52:11.870 --> 00:52:14.280
And you can see it in a couple
of ways, I'll show you.

00:52:14.280 --> 00:52:15.860
So here's an example
of a patient with a

00:52:15.860 --> 00:52:17.880
frontal lobe injury.

00:52:17.880 --> 00:52:21.090
They're drawn this scratchily,
by a physician.

00:52:21.090 --> 00:52:22.480
And here's their exact copy.

00:52:22.480 --> 00:52:24.950
Do you see they can't stop?

00:52:24.950 --> 00:52:26.590
Here's again the model,

00:52:26.590 --> 00:52:27.750
scratched out by the physician.

00:52:27.750 --> 00:52:28.460
Look at the patient.

00:52:28.460 --> 00:52:30.360
The patient can't stop.

00:52:30.360 --> 00:52:32.000
So the problem's not starting.

00:52:32.000 --> 00:52:35.060
The problem is stopping the
mental operation once it's

00:52:35.060 --> 00:52:36.550
going and repeating.

00:52:36.550 --> 00:52:39.250
And it's hard to put on
the mental breaks.

00:52:39.250 --> 00:52:42.860
Here's an example of a
behavioral test of that kind.

00:52:42.860 --> 00:52:45.650
And I remember this, when I was
testing patients in E17

00:52:45.650 --> 00:52:48.170
and E18 here, I did
this a fair bit.

00:52:48.170 --> 00:52:50.770
It's called the Wisconsin
Card Sorting Test.

00:52:50.770 --> 00:52:54.330
And what happens is, you put
on four cards like these.

00:52:54.330 --> 00:52:54.930
These are the key cards.

00:52:54.930 --> 00:52:56.310
It's very mysterious when
you give the test.

00:52:56.310 --> 00:52:58.400
You just put them down.

00:52:58.400 --> 00:53:00.860
And you have a pile of
cards over here.

00:53:00.860 --> 00:53:03.410
And you tell the person, your
job is to pick a card from

00:53:03.410 --> 00:53:07.090
this pile and put it below
one of these cards.

00:53:07.090 --> 00:53:10.370
And I'll tell you if you're
right or wrong.

00:53:10.370 --> 00:53:12.120
And then use that information
to know where to

00:53:12.120 --> 00:53:13.840
put the next card.

00:53:13.840 --> 00:53:15.800
So imagine you are doing this
experiment, and if you're

00:53:15.800 --> 00:53:17.440
color blind, there's
an extra issue.

00:53:17.440 --> 00:53:17.960
I'll just warn you.

00:53:17.960 --> 00:53:20.610
But you get this first card.

00:53:20.610 --> 00:53:21.960
Where would you put it below?

00:53:21.960 --> 00:53:23.516
Where could you put it below?

00:53:23.516 --> 00:53:25.500
AUDIENCE: [INAUDIBLE].

00:53:25.500 --> 00:53:26.140
PROFESSOR: OK.

00:53:26.140 --> 00:53:27.090
That has an equal number.

00:53:27.090 --> 00:53:27.840
That's one possibility.

00:53:27.840 --> 00:53:30.430
What's another possibility, as
the rule by which you might

00:53:30.430 --> 00:53:31.510
sort the card?

00:53:31.510 --> 00:53:31.980
AUDIENCE: Color.

00:53:31.980 --> 00:53:32.510
PROFESSOR: Color.

00:53:32.510 --> 00:53:33.110
Yeah, that's green.

00:53:33.110 --> 00:53:33.650
That goes with that.

00:53:33.650 --> 00:53:35.340
What's another possibility
that you can see?

00:53:35.340 --> 00:53:35.635
Shape.

00:53:35.635 --> 00:53:37.320
You can say that's a plus sign,
that's a plus sign.

00:53:37.320 --> 00:53:38.770
They all seem reasonable.

00:53:38.770 --> 00:53:40.915
So people usually pick
one of those three.

00:53:40.915 --> 00:53:44.510
And if they happen to pick the
one that I as a tester know

00:53:44.510 --> 00:53:47.070
from my instruction sheet,
it's my job to reinforce.

00:53:47.070 --> 00:53:49.770
Let's pretend it starts
with color.

00:53:49.770 --> 00:53:51.920
If they do this, I go wrong.

00:53:51.920 --> 00:53:54.020
I go, hmm.

00:53:54.020 --> 00:53:55.930
And they pick another card and
they try something else.

00:53:55.930 --> 00:53:58.160
They pick another card and
they try something else.

00:53:58.160 --> 00:54:00.200
And after three or four
cards, people pretty

00:54:00.200 --> 00:54:02.830
much get the color.

00:54:02.830 --> 00:54:04.240
And then you go get
another card out.

00:54:04.240 --> 00:54:07.840
You go right, right, right,
right right, wrong.

00:54:07.840 --> 00:54:10.980
And when I did this, I was
approximately your age.

00:54:10.980 --> 00:54:12.430
And most of the patients
I tested were older.

00:54:12.430 --> 00:54:15.180
And they go like, sonny, look
back on your score sheet

00:54:15.180 --> 00:54:16.140
because it's correct.

00:54:16.140 --> 00:54:17.580
And I go no ma'am, no sir.

00:54:17.580 --> 00:54:18.170
I'm sorry about that.

00:54:18.170 --> 00:54:19.520
But it's wrong.

00:54:19.520 --> 00:54:22.050
Because what you do is after
10 consecutive correct

00:54:22.050 --> 00:54:26.910
responses, you switch the rule
from color to shape.

00:54:26.910 --> 00:54:29.510
After 10 correct shape,
you switch to number.

00:54:29.510 --> 00:54:30.360
And then you do that again.

00:54:30.360 --> 00:54:32.400
So you switch the
rule after 10.

00:54:32.400 --> 00:54:35.500
So it's a test of mental
flexibility, in a fairly

00:54:35.500 --> 00:54:36.090
simple way.

00:54:36.090 --> 00:54:37.300
Does that make sense?

00:54:37.300 --> 00:54:39.040
They have to figure out
what the answer is.

00:54:39.040 --> 00:54:39.960
Then they're zooming along.

00:54:39.960 --> 00:54:41.806
And you go, no stop.

00:54:41.806 --> 00:54:44.160
And you have to come up
with the next answer.

00:54:44.160 --> 00:54:47.790
So here's what happens for
patients with frontal lobe

00:54:47.790 --> 00:54:50.490
lesions, they make a huge
amount of what's called

00:54:50.490 --> 00:54:52.260
perseverative errors.

00:54:52.260 --> 00:54:55.550
So this is now the intellectual
analog of the too

00:54:55.550 --> 00:54:57.320
many squiggles.

00:54:57.320 --> 00:55:01.870
Once they get that first rule,
they can't stop that rule.

00:55:01.870 --> 00:55:04.150
So they go color, color,
color, color, color.

00:55:04.150 --> 00:55:05.740
They get about 10.

00:55:05.740 --> 00:55:06.640
So you switch.

00:55:06.640 --> 00:55:07.730
And they just keep doing it.

00:55:07.730 --> 00:55:11.150
You go no, wrong, wrong,
wrong, wrong, wrong.

00:55:11.150 --> 00:55:14.310
But they can't stop the rule
that worked in the first

00:55:14.310 --> 00:55:17.950
place, without the prefrontal
cortex being intact.

00:55:17.950 --> 00:55:20.800
So our mental flexibility seems
to depend tremendously

00:55:20.800 --> 00:55:22.470
on prefrontal cortex.

00:55:22.470 --> 00:55:24.510
And you can do the same kind of
thing in imaging, just to

00:55:24.510 --> 00:55:25.740
make sure it's not just
a patient thing.

00:55:25.740 --> 00:55:29.090
And again, when you have to do
this very same kind of task,

00:55:29.090 --> 00:55:32.410
typical people activate
prefrontal cortex to do the

00:55:32.410 --> 00:55:36.490
mental manipulation of the
simple problem solving task.

00:55:36.490 --> 00:55:38.640
So we talked about
perserveration and its hard to

00:55:38.640 --> 00:55:41.000
stop and mental flexibility.

00:55:41.000 --> 00:55:43.240
With ventromedial lesions, you
get some weird things.

00:55:43.240 --> 00:55:44.960
You get what they call
utilization behaviors.

00:55:44.960 --> 00:55:47.720
So again, we're having this
idea what's the good thing

00:55:47.720 --> 00:55:49.820
about having very
powerful habits?

00:55:53.400 --> 00:55:55.980
Is it very good to have very
powerful habits, and we use a

00:55:55.980 --> 00:55:59.470
different word for this,
when you read?

00:55:59.470 --> 00:55:59.930
Yeah.

00:55:59.930 --> 00:56:00.820
Because that's how you're
a fast reader.

00:56:00.820 --> 00:56:02.990
You know how to read
words really fast.

00:56:02.990 --> 00:56:07.126
Is it good to have very powerful
habits when you walk?

00:56:07.126 --> 00:56:07.710
Yeah.

00:56:07.710 --> 00:56:10.050
You don't want to go like, OK,
I'm moving the leg now.

00:56:10.050 --> 00:56:10.860
Everybody get ready.

00:56:10.860 --> 00:56:11.780
We're moving the other leg.

00:56:11.780 --> 00:56:13.540
Because you could never get
out of the room very

00:56:13.540 --> 00:56:14.340
efficiently.

00:56:14.340 --> 00:56:17.090
So for many, many things, having
very powerful habits

00:56:17.090 --> 00:56:17.840
are very strong.

00:56:17.840 --> 00:56:21.650
But for other things, they're
not as good and you have to

00:56:21.650 --> 00:56:22.270
put the brakes on.

00:56:22.270 --> 00:56:24.480
So Lhermitte described patients
with ventromedial

00:56:24.480 --> 00:56:27.150
lesions who came in,
saw in his office.

00:56:27.150 --> 00:56:28.300
This was not a set-up
experiment.

00:56:28.300 --> 00:56:29.440
He didn't expect this.

00:56:29.440 --> 00:56:30.694
There was a hammer, a
nail, and a picture.

00:56:30.694 --> 00:56:32.550
And the patient just
goes over, up.

00:56:32.550 --> 00:56:34.770
And you could imagine, if you
go into the doctor's office

00:56:34.770 --> 00:56:37.710
and you see a hammer, a nail,
and a picture, would you go

00:56:37.710 --> 00:56:39.630
over and put up the picture?

00:56:39.630 --> 00:56:40.740
No.

00:56:40.740 --> 00:56:42.610
I mean you know that's what
you do with that stuff.

00:56:42.610 --> 00:56:44.140
You know that's what's
going on.

00:56:44.140 --> 00:56:45.730
But you go, that's not my place
to do it, even though

00:56:45.730 --> 00:56:46.750
it's attempted to do it.

00:56:46.750 --> 00:56:48.450
The patient could not help
himself but go do that,

00:56:48.450 --> 00:56:49.740
literally go do that.

00:56:49.740 --> 00:56:52.090
The most dramatic example was,
the patient walks in and sees

00:56:52.090 --> 00:56:54.080
a hypodermic needle, pulls down
his pants, and injects

00:56:54.080 --> 00:56:56.810
himself in the derriere.

00:56:56.810 --> 00:56:59.740
So again, he knew that
was going to happen.

00:56:59.740 --> 00:57:01.060
He knew that's the habit.

00:57:01.060 --> 00:57:02.950
But you wouldn't go into a
doctor's office and start

00:57:02.950 --> 00:57:05.160
using their stuff and
perform on yourself.

00:57:05.160 --> 00:57:05.680
You understand.

00:57:05.680 --> 00:57:08.330
The habits are completely
running the show.

00:57:08.330 --> 00:57:11.010
And any kind of frontal cortical
control of those

00:57:11.010 --> 00:57:14.030
habits has been eliminated
in these patients.

00:57:14.030 --> 00:57:15.115
And here's a couple
more things that

00:57:15.115 --> 00:57:16.920
are along that line.

00:57:16.920 --> 00:57:20.550
So I need a volunteer, in your
seats, to try something with

00:57:20.550 --> 00:57:21.800
me for a minute.

00:57:23.730 --> 00:57:25.080
It's not bad.

00:57:25.080 --> 00:57:27.420
I think I've traumatized
you in these examples.

00:57:27.420 --> 00:57:29.250
OK, thank you.

00:57:29.250 --> 00:57:30.970
If you had to answer this
question, and there's no

00:57:30.970 --> 00:57:31.530
correct answer.

00:57:31.530 --> 00:57:33.110
But let's just talk about
how you might do it.

00:57:33.110 --> 00:57:35.577
How long is a man's
spine, on average?

00:57:35.577 --> 00:57:37.020
AUDIENCE: About two feet?

00:57:37.020 --> 00:57:38.220
PROFESSOR: And how did you
kind of come to that?

00:57:38.220 --> 00:57:39.548
And that might be
right or not.

00:57:39.548 --> 00:57:42.416
AUDIENCE: My back is roughly
two feet long.

00:57:42.416 --> 00:57:45.290
My spine is--

00:57:45.290 --> 00:57:45.660
PROFESSOR: Yeah.

00:57:45.660 --> 00:57:47.280
It's got to be less
seven feet.

00:57:47.280 --> 00:57:49.750
Because that's like the tallest
basketball players.

00:57:49.750 --> 00:57:51.950
On average, it's got to be
more than a couple feet.

00:57:51.950 --> 00:57:52.890
Something in that range.

00:57:52.890 --> 00:57:54.680
OK, you just guessed
which it was.

00:57:54.680 --> 00:57:56.860
Or how fast does a horse
in a race gallop?

00:57:56.860 --> 00:57:59.720
Or what's the largest object
normally found in the house?

00:57:59.720 --> 00:58:01.854
What do you think
that might be?

00:58:01.854 --> 00:58:02.730
AUDIENCE: Fridge?

00:58:02.730 --> 00:58:03.500
PROFESSOR: Help me out here.

00:58:03.500 --> 00:58:03.830
AUDIENCE: A refrigerator.

00:58:03.830 --> 00:58:04.970
PROFESSOR: A refrigerator
is a good one.

00:58:04.970 --> 00:58:06.052
Anybody else?

00:58:06.052 --> 00:58:07.290
AUDIENCE: [INAUDIBLE].

00:58:07.290 --> 00:58:08.110
PROFESSOR: All those are good.

00:58:08.110 --> 00:58:09.600
Is toaster a good answer?

00:58:09.600 --> 00:58:11.310
No.

00:58:11.310 --> 00:58:11.880
One more person.

00:58:11.880 --> 00:58:12.650
Who's going to help
me out here?

00:58:12.650 --> 00:58:13.900
One more example.

00:58:21.160 --> 00:58:21.780
Come on.

00:58:21.780 --> 00:58:22.100
One more example.

00:58:22.100 --> 00:58:22.340
It's easy.

00:58:22.340 --> 00:58:23.580
OK, thank you, Rich.

00:58:23.580 --> 00:58:26.090
How many camels are there
in the Netherlands?

00:58:26.090 --> 00:58:27.310
Now, nobody knows.

00:58:27.310 --> 00:58:30.010
But tell me a thought process
roughly, so you would come up

00:58:30.010 --> 00:58:31.063
with an estimate.

00:58:31.063 --> 00:58:32.050
AUDIENCE: 100.

00:58:32.050 --> 00:58:32.600
PROFESSOR: Yeah.

00:58:32.600 --> 00:58:34.830
Because are you going to figure
there's a lot in the

00:58:34.830 --> 00:58:35.785
Netherlands?

00:58:35.785 --> 00:58:36.140
No.

00:58:36.140 --> 00:58:37.850
Because there's no
desert, right?

00:58:37.850 --> 00:58:40.410
Where might you find a few?

00:58:40.410 --> 00:58:42.610
AUDIENCE: [INAUDIBLE]

00:58:42.610 --> 00:58:43.976
PROFESSOR: On a ranch.

00:58:43.976 --> 00:58:46.660
I haven't been to Amsterdam
for a while, so perhaps

00:58:46.660 --> 00:58:50.395
there's a few loping around
in the canals.

00:58:50.395 --> 00:58:54.130
And some zoo, some kids' petting
thing, who knows?

00:58:54.130 --> 00:58:56.030
So, yeah, 100 sounds
good to me.

00:58:56.030 --> 00:58:58.860
But frontal patients will
give really bad answers,

00:58:58.860 --> 00:59:00.620
thousands or zero.

00:59:00.620 --> 00:59:02.560
Or 12 feet for a spinal cord.

00:59:02.560 --> 00:59:03.600
Or just something that
you go like, where

00:59:03.600 --> 00:59:05.250
did you come up that?

00:59:05.250 --> 00:59:06.760
You can do the Price Is
Right game with them.

00:59:06.760 --> 00:59:08.920
They'll come up with more
ridiculous answers.

00:59:08.920 --> 00:59:09.950
Here's just a graph.

00:59:09.950 --> 00:59:12.770
These are bad answers for how
expensive something is, just

00:59:12.770 --> 00:59:14.280
unreasonable answers
within these sort

00:59:14.280 --> 00:59:15.760
of open-ended questions.

00:59:15.760 --> 00:59:18.330
Or you can do more
formal problems.

00:59:18.330 --> 00:59:20.640
The kind of problem
where you're given

00:59:20.640 --> 00:59:21.380
a puzzle like this.

00:59:21.380 --> 00:59:24.900
And your job is to move these
into a target state.

00:59:24.900 --> 00:59:27.730
And so to get over to here,
you've got to move the blue

00:59:27.730 --> 00:59:32.160
guy over here and whatever, in
a different number of moves.

00:59:32.160 --> 00:59:34.310
That's planning ahead
and problem solving.

00:59:34.310 --> 00:59:36.790
Patients with frontal lobe
lesions make many mistakes on

00:59:36.790 --> 00:59:39.470
these kinds of tasks.

00:59:39.470 --> 00:59:41.210
So the last thing I want to
talk is a little bit about

00:59:41.210 --> 00:59:44.390
Phineas Gage kind of lesions.

00:59:44.390 --> 00:59:49.120
And we'll get in a moment to a
comment about serial killers.

00:59:49.120 --> 00:59:51.120
So Phineas Gage had
this huge injury.

00:59:51.120 --> 00:59:52.320
We talked about him
already in the

00:59:52.320 --> 00:59:55.730
ventromedial prefrontal cortex.

00:59:55.730 --> 00:59:58.090
There's some other patients
who have orbitofrontal

00:59:58.090 --> 00:59:59.030
lesions, who have
been studied.

00:59:59.030 --> 01:00:00.210
And let me tell you
a little bit about

01:00:00.210 --> 01:00:02.050
what's known about them.

01:00:02.050 --> 01:00:03.590
And I can tell you this is the
part of the brain that's been

01:00:03.590 --> 01:00:07.180
most implicated in psychopaths,
some of whom turn

01:00:07.180 --> 01:00:10.110
out to be these serial
killers.

01:00:10.110 --> 01:00:12.360
One measure they've used in
these experiments is galvanic

01:00:12.360 --> 01:00:13.250
skin response.

01:00:13.250 --> 01:00:14.360
That's the kind of
stuff they use in

01:00:14.360 --> 01:00:15.730
polygraphs, lie detectors.

01:00:15.730 --> 01:00:19.220
They put them on your skin and
what they measure is responses

01:00:19.220 --> 01:00:22.190
that are related to
sweat glands.

01:00:22.190 --> 01:00:26.430
So it's a measure of emotional
reactivity, basically.

01:00:26.430 --> 01:00:28.020
Here's a really interesting
thing.

01:00:28.020 --> 01:00:30.820
If we measure your galvanic skin
response and we show you

01:00:30.820 --> 01:00:33.320
faces of people you know, family
members, friends, and

01:00:33.320 --> 01:00:36.730
so on, versus people you don't
know, you get a galvanic skin

01:00:36.730 --> 01:00:38.510
response for the people
you know, because

01:00:38.510 --> 01:00:39.780
they matter to you.

01:00:39.780 --> 01:00:44.030
It's an emotional response,
versus faces you don't know.

01:00:44.030 --> 01:00:46.350
You even get that kind of
strikingly in several studies

01:00:46.350 --> 01:00:47.850
in patients with
prosopagnosia.

01:00:47.850 --> 01:00:50.280
So we talked about those
patients who can't recognize

01:00:50.280 --> 01:00:51.890
people by their faces.

01:00:51.890 --> 01:00:54.620
But something in them still
recognizes who's

01:00:54.620 --> 01:00:57.120
familiar and who's not.

01:00:57.120 --> 01:01:00.030
Even if they can't tell you,
that's my mother or that's my

01:01:00.030 --> 01:01:02.980
father or that's my brother,
their galvanic skin response

01:01:02.980 --> 01:01:06.210
is a pretty good response.

01:01:06.210 --> 01:01:07.520
Patients with orbitofrontal
lesions

01:01:07.520 --> 01:01:09.140
are exactly the opposite.

01:01:09.140 --> 01:01:11.830
When they're shown pictures of
family members and friends,

01:01:11.830 --> 01:01:15.280
they have no more of a response
in the sweat glands,

01:01:15.280 --> 01:01:17.300
in the autonomic nervous system,
than they do for

01:01:17.300 --> 01:01:19.120
absolute strangers.

01:01:19.120 --> 01:01:22.220
And you might intuitively
imagine that it's pretty easy

01:01:22.220 --> 01:01:25.730
to lie and deceive your friends
and family, if they

01:01:25.730 --> 01:01:27.420
don't mean to you anything more

01:01:27.420 --> 01:01:28.670
than an absolute stranger.

01:01:30.890 --> 01:01:32.640
No galvanic response
to emotional

01:01:32.640 --> 01:01:33.990
versus neutral pictures.

01:01:33.990 --> 01:01:36.420
And so these patients seem to
have this disconnection

01:01:36.420 --> 01:01:37.660
between thought and emotion.

01:01:37.660 --> 01:01:39.160
They know who the person is.

01:01:39.160 --> 01:01:41.620
But they don't have an emotional
response of any kind

01:01:41.620 --> 01:01:43.460
to that person.

01:01:43.460 --> 01:01:46.020
And here's one clever experiment
that shows some of

01:01:46.020 --> 01:01:47.560
the consequence of that.

01:01:47.560 --> 01:01:49.780
So this is work from Damasio
and his colleagues.

01:01:49.780 --> 01:01:51.670
So they took a couple
of these patients.

01:01:51.670 --> 01:01:53.020
There's not that many of them.

01:01:53.020 --> 01:01:55.160
And they put them into an
experiment where you could

01:01:55.160 --> 01:01:56.410
pick from two decks.

01:01:56.410 --> 01:01:58.100
One deck has a low immediate
reward, but

01:01:58.100 --> 01:01:59.860
positive long-term rewards.

01:01:59.860 --> 01:02:02.410
It's a little bit like studying
a lot, and hoping it

01:02:02.410 --> 01:02:03.930
all pays off.

01:02:03.930 --> 01:02:06.490
And another one is high
immediate rewards, but higher

01:02:06.490 --> 01:02:07.270
long-term losses.

01:02:07.270 --> 01:02:10.860
Like not studying has some
unpleasant consequences.

01:02:10.860 --> 01:02:12.040
So two decks of cards.

01:02:12.040 --> 01:02:15.570
And you don't know this, but you
just quickly discover that

01:02:15.570 --> 01:02:21.120
Pile A, you get the occasional
$50, but you often lose $100.

01:02:21.120 --> 01:02:25.460
But Pile B, you get the thrill
of the $100 loss, but you

01:02:25.460 --> 01:02:27.730
often lose $1,000.

01:02:27.730 --> 01:02:30.310
So they're kind of pitting
against each other, the thrill

01:02:30.310 --> 01:02:36.500
of the $100 win, versus the
certain doom of the quick

01:02:36.500 --> 01:02:38.450
thrill pile.

01:02:38.450 --> 01:02:41.510
You get the quick thrill,
but it will doom you.

01:02:41.510 --> 01:02:43.270
So what do typical people do?

01:02:43.270 --> 01:02:45.480
After a little while, they
figure out well, Pile B is

01:02:45.480 --> 01:02:46.680
pretty fun when I
get the $100.

01:02:46.680 --> 01:02:49.270
But it beats me up a lot in the
long term, so they go for

01:02:49.270 --> 01:02:50.180
Pile A.

01:02:50.180 --> 01:02:51.650
Orbitofrontal patients don't.

01:02:51.650 --> 01:02:54.470
They go for that one-time
thrill, over any long-term

01:02:54.470 --> 01:02:56.720
consequences.

01:02:56.720 --> 01:02:59.830
As interesting as that, if you
measure the galvanic skin

01:02:59.830 --> 01:03:05.650
response, for control people,
typical people, when they go

01:03:05.650 --> 01:03:10.040
for the risky pile, their heart
is pounding, their hands

01:03:10.040 --> 01:03:10.230
are sweating.

01:03:10.230 --> 01:03:13.390
And they go, I'm going to
walk on the wild side.

01:03:13.390 --> 01:03:15.320
Back to the save file, mostly.

01:03:15.320 --> 01:03:17.340
No galvanic skin response
for the patients with

01:03:17.340 --> 01:03:17.690
orbitofrontal lesions.

01:03:17.690 --> 01:03:18.117
Yeah?

01:03:18.117 --> 01:03:20.370
AUDIENCE: Do people
get the lesions

01:03:20.370 --> 01:03:22.930
after reaching adulthood?

01:03:22.930 --> 01:03:23.640
PROFESSOR: So this
is interesting.

01:03:23.640 --> 01:03:26.620
I'm going to come to
this in a moment.

01:03:26.620 --> 01:03:29.330
Actually literally, absolutely
right now.

01:03:29.330 --> 01:03:31.680
Same pattern for people who
have these injuries at 15

01:03:31.680 --> 01:03:34.500
months or three months, as
happens in adulthood.

01:03:34.500 --> 01:03:36.590
Now, we don't know if
that's everybody.

01:03:36.590 --> 01:03:39.290
But these are patients who
came forth with problems.

01:03:39.290 --> 01:03:40.800
So this is a little bit like,
we don't know if there are a

01:03:40.800 --> 01:03:42.860
lot of people with damage there,
who are not doing this.

01:03:42.860 --> 01:03:47.160
But these two patients who
they studied, had that.

01:03:47.160 --> 01:03:48.380
And they got in lots
of trouble in

01:03:48.380 --> 01:03:49.220
school, all the time.

01:03:49.220 --> 01:03:51.770
They did all the things
you might imagine a

01:03:51.770 --> 01:03:53.660
three-year-old, and for
the rest of us, like

01:03:53.660 --> 01:03:55.700
Phineas Gage would do.

01:03:55.700 --> 01:03:57.890
So that raises the question
about whether the kinds of

01:03:57.890 --> 01:04:02.020
people who behave in this most
disturbing, psychopathic,

01:04:02.020 --> 01:04:06.540
serial killer fashion have
either an injury or something

01:04:06.540 --> 01:04:11.310
like that, that makes them
predisposed to being very

01:04:11.310 --> 01:04:12.810
inhumane in the way they
think about people.

01:04:15.480 --> 01:04:18.010
And just in case you, as careful
MIT scientists, worry

01:04:18.010 --> 01:04:20.210
about well, maybe they're not
having a GSR that works at

01:04:20.210 --> 01:04:22.220
all, what does that mean?

01:04:22.220 --> 01:04:25.720
If these patients who had the
damage early in childhood just

01:04:25.720 --> 01:04:30.780
get a loud tone, a big boat
horn, like ooh, there's a

01:04:30.780 --> 01:04:32.620
galvanic skin response that
looks pretty good.

01:04:32.620 --> 01:04:35.880
So it's not their autonomic
system won't respond to

01:04:35.880 --> 01:04:38.430
emotionally provocative things,
like a big sound.

01:04:38.430 --> 01:04:40.980
It just doesn't respond to
emotionally provocative things

01:04:40.980 --> 01:04:44.600
like risk and people you
should care about.

01:04:48.250 --> 01:04:49.810
And I'll just end in
this one minute.

01:04:49.810 --> 01:04:54.650
So this is an area where a
guy, Kent Khiel, at the

01:04:54.650 --> 01:04:55.350
University of New Mexico.

01:04:55.350 --> 01:04:56.150
You can go look this up.

01:04:56.150 --> 01:04:57.850
It's an amazing story.

01:04:57.850 --> 01:05:01.830
He's very interested in these
brain differences in

01:05:01.830 --> 01:05:02.640
psychopaths in prison.

01:05:02.640 --> 01:05:05.280
Many are in prison because
they're scary people.

01:05:05.280 --> 01:05:07.150
So you can't get them out to
do research very easily.

01:05:07.150 --> 01:05:09.070
So he has a truck with
an MR scanner.

01:05:09.070 --> 01:05:12.030
And he drives from penitentiary
to penitentiary

01:05:12.030 --> 01:05:14.240
and does brain scanning
with these people.

01:05:14.240 --> 01:05:16.650
And is getting on average,
some differences

01:05:16.650 --> 01:05:18.480
in this brain region.

01:05:18.480 --> 01:05:22.600
So I have a question for you,
just for one minute.

01:05:22.600 --> 01:05:24.935
Do you think that should be
introduced in a court case for

01:05:24.935 --> 01:05:26.185
a serial killer?

01:05:30.840 --> 01:05:34.510
If he gets up there and shows
you brain pictures, should a

01:05:34.510 --> 01:05:38.550
jury hear about that or should
they not hear about that, for

01:05:38.550 --> 01:05:41.416
somebody who's done an
awful murder or an

01:05:41.416 --> 01:05:42.060
awful string murders?

01:05:42.060 --> 01:05:43.330
AUDIENCE: I'd say no.

01:05:43.330 --> 01:05:44.430
PROFESSOR: Sorry.

01:05:44.430 --> 01:05:45.000
You say no.

01:05:45.000 --> 01:05:45.695
Because what?

01:05:45.695 --> 01:05:49.102
AUDIENCE: I think that the risk
is too great that you

01:05:49.102 --> 01:05:51.587
will have innocent
people be shown.

01:05:51.587 --> 01:05:54.072
And the science is not fully
resolved yet in that respect.

01:05:54.072 --> 01:05:56.805
There are also a lot of
salient factors and

01:05:56.805 --> 01:05:59.539
environmental factors that
have been constrained by

01:05:59.539 --> 01:06:03.515
genetics, and say, oh, if you
have this huge issue, this

01:06:03.515 --> 01:06:07.550
condition of the brain, you're
automatically [INAUDIBLE].

01:06:07.550 --> 01:06:08.260
PROFESSOR: OK.

01:06:08.260 --> 01:06:09.330
Let me tell one sentence.

01:06:09.330 --> 01:06:10.230
Yeah, go ahead.

01:06:10.230 --> 01:06:13.530
AUDIENCE: You know the
correlation in one direction--

01:06:13.530 --> 01:06:15.780
PROFESSOR: We don't know.

01:06:15.780 --> 01:06:16.430
These are good points.

01:06:16.430 --> 01:06:18.480
Let me just say, so here's where
we stand now, because

01:06:18.480 --> 01:06:20.320
this will be your lives in
the future, in a lot

01:06:20.320 --> 01:06:21.940
of different ways.

01:06:21.940 --> 01:06:25.580
Where we stand now is, for the
first time ever, brain imaging

01:06:25.580 --> 01:06:29.180
evidence was introduced in the
court case about a year ago of

01:06:29.180 --> 01:06:31.300
a serial killer.

01:06:31.300 --> 01:06:33.120
They were only allowed
to do it--

01:06:33.120 --> 01:06:34.820
court cases like this go
through two phases.

01:06:34.820 --> 01:06:36.520
You see these in TV
shows or movies.

01:06:36.520 --> 01:06:38.300
There's the initial trial.

01:06:38.300 --> 01:06:40.440
And if the person is found
guilty, there's a second phase

01:06:40.440 --> 01:06:42.280
where they decide what the
appropriate penalty is.

01:06:42.280 --> 01:06:46.520
The judge said they could only
be reported in the penalty

01:06:46.520 --> 01:06:48.350
phase, when people were thinking
about what's the

01:06:48.350 --> 01:06:51.610
right punishment for a person,
not before the conviction.

01:06:51.610 --> 01:06:54.640
And they said they couldn't
show any color pictures of

01:06:54.640 --> 01:06:55.660
brain stuff, because that would

01:06:55.660 --> 01:06:58.510
over-influence the jurors.

01:06:58.510 --> 01:07:00.330
And so you could only talk
about this stuff.

01:07:00.330 --> 01:07:02.040
Because if you showed a brain
picture, sort of like you

01:07:02.040 --> 01:07:04.600
said, it would look so
scientific that they were

01:07:04.600 --> 01:07:08.330
afraid it overwhelm the
jurors' judgment.

01:07:08.330 --> 01:07:11.690
So this is all coming up, about
what the brain maybe do

01:07:11.690 --> 01:07:12.570
in your lifetimes.

01:07:12.570 --> 01:07:13.820
Thanks.