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PROFESSOR: So today I want to
talk with you about how it is
that we can do research of a
scientific kind for something
as complex as human behavior as
opposed to things that you
measure out in space or test
tubes or under microscopes.
People are complex
organisms, right?
And to do research on them, to
understand human nature, how
the mind works, how the
brain supports it, is
a challenging story.
So the usual thing
is an experiment.
You have a group of
participants.
And we'll talk about that.
But in the reading for today,
and I know it's the first time
we've done this so you may not
have read it, but if you have,
that'd be great, is a kind of
another thread of the kind of
way that people are studied,
which is dramatic individual
stories, case studies, single
stories that are illustrative
of something that we think
are broader principles.
And a lot of our biggest
discoveries-- and we'll come
to that later in the course--
have been made on very unusual
single individuals who turn out
to have a lesson that's
pretty broad, for example,
for the organization
of the human brain.
So in the Oliver Sacks book,
there's a story about Donald.
And what did Donald do that
got him in big trouble?
AUDIENCE: [INAUDIBLE].
PROFESSOR: Yeah, he murdered
his girlfriend
while he was on PCP.
He's in a psychiatric
hospital.
They try hypnosis to help
him remember it.
He says he doesn't
remember it.
Many of you may know that an
astounding number of criminals
under interrogation tell you
they don't remember anything
about the episode involved.
So people are suspicious, at
first, for many reasons.
Because the easiest thing
to say is I don't
remember what happened.
And then you can't catch
yourself in a lie or any
complexity, right?
Because you don't remember
what happened.
And sometimes you
don't remember.
And sometimes you do.
But in this case, they
tried hypnosis.
That doesn't help.
He's in there for four years.
And he knows conceptually that
he murdered his girlfriend.
And he says, I'm not
fit for society.
He knows it's a terrible
thing he did.
But it's kind of like an
intellectual knowledge, right?
It's not a feeling.
It's not a memory.
And then he goes biking and
something happens, which is he
gets hit by a car.
And so there's what appears to
be a drug-induced amnesia of
the original murderous
episode.
He gets hit by a car.
He has a severe head injury.
He's in a coma for two weeks.
He has left-sided weakness as
he comes out of it, which
means the biggest injury was
in the right side of his
brain, weakness and numbness.
And he has frontal
lobe contusions.
He has injury and bleeding
around the frontal lobes of
the cortex that sits in the
front of the brain.
But now a remarkable
thing happens.
It's as if two insults, two
wrongs, made a right, the
first wrong being the
PCP, the second
wrong being the accident.
And now what happens?
He remembers in vivid, in florid
detail the horror that
he actually committed
this murder.
It's as if two insults to the
brain, one drug-induced, one a
focal injury, repressed the
memory and then unrepressed
the memory.
And one of the first things they
have to do is discover
whether he really has his memory
or he just thinks he
has his memory.
And how do they figure out to
their satisfaction whether
it's a really recovered memory
or a fabrication of his mind?
AUDIENCE: [INAUDIBLE].
PROFESSOR: Right.
It's really important.
He remembers details of the
murder that are not publicly
available, that were not
in the information that
was given to him.
That's a really huge issue
in these kinds of memory.
So this is a really recovered
memory, not an inadvertently
fabricated memory.
And they discover he has deep
seizure activity in his limbic
structures, the parts of his
brain that are involved in
emotion, are having seizures.
In epilepsy, neurons are firing
for no good reason.
And that's part of
his disorder.
They give him medications
to help with that.
But here's the question
for you from a
moment to think about.
And it's now such a common
question because our society
is moving that way that
it's on many TV shows.
I see it like every couple of
weeks there's a Law & Order
episode that has something like
this, which is the more
you know about the biology that
underlies really criminal
terrible behavior, should
that be a cause for
understanding it or not?
So in this case, he
took the drugs.
He killed the person.
You think he's pretty
responsible.
But how about somebody who kills
somebody and it turns
out, and there's such a case, a
man with no history, a grown
man with no history of criminal
activity of any kind,
shoved his wife out of a high
window to her death in the
course of a standard argument.
Then they discover that he has
a big tumor growing in the
basal part of his
frontal cortex.
Now is the man responsible
for what he did?
It's a really interesting
question.
And the more we understand about
the neuroscience of our
brains, what makes us do things,
what lets us control
impulses, what makes
us murderous--
There's a guy, Kent Kiehl, the
University of Mexico, he's
driving around in a big van
with an MRI scanner.
And he goes from penitentiary
to penitentiary.
And he images the brains
of serial murderers, of
psychopathic murderers.
And he's getting things that
are pretty systematically
different about their brains.
And the question is, what
does that mean?
Does that mean those people
were prone to do it for
reasons of their early
environment or genes or some
incident that happened?
If that's the case, do you
forgive them differently?
Should we have a different moral
code or legal code as we
discover the brain basis for
some of these things?
Or is that irrelevant?
What counts is the action.
So this is the kind of thing
you can think about, maybe
discuss in your sections some.
The more we understand about
the human brain, the more
we'll understand
about behaviors
that we find terrible.
And what does that mean about
legal and moral decisions
about how to punish those
or think about those?
So that's coming in
your lifetime.
Because there's steady
progress on this.
And how to think about that
is really a big question.
So I'm going to talk with you
today about research in
psychology.
And a funny thing about
psychology, and I'll come back
to this, is everybody is an
amateur psychologist.
They have to be.
If you deal with people,
you're an amateur
psychologist.
Moreover, we live in a world
with Oprah Winfrey and Dr.
Phil, right?
So in case you're only an
amateur one, you hear all
kinds of stuff, newspaper,
internet, magazines.
Everywhere you go, friends
will tell you stuff about
psychologists have
found this or
psychologists have found that.
So you have your own intuitions
to deal with people
in everyday life.
And here's a kind of a sentence
from Time Magazine
that drives psychologists crazy
if you take it seriously.
So here's the literal
sentence.
"Almost half of children of
divorces enter adulthood as
worried, underachieving,
self-deprecating, and
sometimes angry young
men and women."
So that sounds kind of like a
psychological study of some
kind, kind of, right?
Somebody who wants to argue
about the importance of
divorce and breakdown
of the family, this
is the kind of thing.
So let's think about
this for a moment.
Almost half of children
of divorce enter
adulthood as worried.
Are you guys worried about
global warming?
A little.
Are you worried about peace in
the Middle East and how that
influences the Middle
East and the US?
A little.
Are you worried about an economy
that may not have jobs
waiting for you?
A little.
Who's not worried a little
bit of the time?
So it doesn't even tell you that
half of children in the
world, for example,
are who come from
families without divorce.
Because that's the only
relevant question.
It's not are people worried
about stuff.
Underachieving, compared
to what?
How would you prove somebody's
underachieving scientifically?
Most of you probably have
had days where you've
underachieved and days where
you've achieved pretty well.
But how would you measure
and prove that?
Self-deprecating, well,
sometimes I think that's
actually kind of nice if
a person's modest.
What's the difference between
modest and self-deprecation?
And I like this one, sometimes
angry young men and women.
Are you sometimes angry about
something or another?
And if you are, does that tell
us that society's breaking
down and your parents
did something
bad that you're sometimes?
Who as a human being is
not sometimes angry?
So here's a kind of
psychology-sounding sentence
on a serious topic, which is
what is consequences of
divorce in families?
Should we be thinking about
things that encourage
marriages to stay stable
and things like that?
But there's really no
information at all from a
research or science
perspective.
So I'm going to talk about a
little bit just reminding you
what science is, we're at a
university, obviously, that
thinks about science and does
science all the time, remind
you of what an experiment is,
a very brief history of
psychology experimentation, and
then walk you through a
few experiments that I find kind
of interesting, and then
some topics related
to psychology.
So let me start with this.
How do you know what is true?
How do you know what is true,
that you take to be true?
What is the answer?
Everybody's looking like
how do I know it.
Please tell me.
Well, when people try to analyze
this, and you can
think about it for
your own self,
one of them is authority.
Parents, teachers, textbooks,
scientists, professors, and
courses, we tell you
this is the truth.
And if you remember the truth
correctly, you get an A. So
authority is a huge
source, right?
It would be costly to go around
and kind of have your
own idea about everything.
12 inches in a foot?
I'm not taking that piece
of information without
skepticism, right?
You couldn't lead your life
without kind of believing a
lot of stuff.
But you don't want to believe
everything, right, just
because you hear it.
Repetition or tenacity, you hear
something often enough,
and people tend to
believe stuff.
A priori, what's reasonable?
You think things through.
Just by thought, what's
possible, rational, and so on?
Then maybe a fourth brand of
knowledge, too, something is
scientific analysis where we
have hypotheses and we test
them and some version of
experiments or at least
correlations among data.
Now, there's another view, which
is kind of whatever we
think makes something science
is what the scientific
community decides as a
community is true.
Roughly speaking that is the
mainstay of faculty of places
like MIT and Stanford and
Harvard and so on and around
the world at universities
tell you, this
is how science works.
You go, OK, that's how
science works.
I remember some years ago there
was a lot of excitement
about a satirical article
written by a scientist where
he said, oh, this is all just
societal authority.
The scientists tell you what's
true just because they believe
in it just like a sports
writer says the
Celtics are the best.
You don't really think that
the sportswriter know
scientifically the Celtics
are the best, right?
He wrote a paper saying that
gravity is simply a consensus
among scientists and a
particular view they're
foisting on society.
But none of us would want to
really go up there and jump
out the window going,
well, gravity is
one person's opinion.
And now here's my
opinion, right?
But it's kind of interesting.
Because for those of you who
go to medical school, for
example, you learn lots of
procedures and so on that the
medical committee believes
is true.
But there's not much scientific
evidence behind it.
But they have to use
it every day.
So you're used to hearing about
the scientific method.
It applies to psychology in many
ways just like it applies
to chemistry, physics,
or biology.
We have to test things
that are falsifiable.
We have to deal in probabilities
of outcomes in
terms of statistics
in some sense.
The kinds of data we can have
are descriptive or correlative
or experimental.
I'll talk about those
in a moment.
We are always trying to disprove
the null hypothesis
statistically as you know.
We can't prove that
something is true.
But we can prove that
it's not true.
And then finally, like all
fields of science, today's
most exciting breakthroughs
are tomorrow's things that
have to be apologized for
and rediscovered, right?
I mean what makes something
breaking science is not that
it's known with certainty.
What's known with certainty
is what's in your
textbook kind of.
What makes something breaking
science is it
moves the field forward.
So what's the difference between
the cutting edge and
the bleeding edge is
a very close call.
So here's a cartoon that says,
he's constantly proving his
experiments wrong.
And the guy's kind of
glum looking over.
He's proving the null hypothesis
to be correct.
Now, that's sort of funny
for scientists.
But it's sort of funny in the
sense that, no, we don't
really go around going, I hope
with all of my heart for this
research project I worked on for
the last five years that
it will prove the
null hypothesis.
There's no difference between
things I'm studying.
In fact, scientists, like all
humans, have agendas and hopes
like everybody else.
So they observe, hypothesize,
experiment.
So the data, it doesn't always
go perfectly, right?
And the last thing I want to say
is I'm going to emphasize
today a scientific approach to
the human mind and behavior.
But of course, there's many
other paths of knowledge for
important things in our life:
religion, philosophy,
arts, and so on.
There's many things that
science cannot address.
And I don't want to pretend
that it does.
That's not a problem
too much when
you think about chemistry.
It's kind of an interesting
problem when you think about
psychology.
Because when we think about
happiness or values or things
like that, those topics cut
across psychology and things
like religion, philosophy,
and topics like that.
So what makes something an
experiment is you have to have
sort of two things conceptually
especially, the
dependent variable, what you
measure, the outcome, and the
independent variable,
what you vary.
Once you have those things in an
experiment, you're kind of
an experiment in
a broad sense.
So in psychology, it
took a long time.
It wasn't until the 1800's that
people had kind of an
approach to doing experiments
in psychology and figuring
out, for example, how to use the
simple measurement of time
to measure how long a mental
operation lasts in your mind.
So that's pretty cool.
If you were to come to a fifth
grader and say, how would you
measure, not a brick or a stone,
but how long a thought
takes, you would say, well,
that would be pretty hard.
But it turns out it's not
as hard in a simple way.
So Wilhelm Wundt, big figure in
psychology, first textbook
in psychology, first laboratory
in psychology, did
the following test of mental
chronometry, simply measuring
how long it takes you
to do things.
So he would show you a light.
And you'd simply press
the button.
And that would take about
1/5 of a second.
And then he would say,
instead, you do this.
If the light turns on and it's
red, you push one button.
And if it's green,
you push another.
So his idea was the motor system
to push the button is
about the same.
The time to observe the light
is about the same.
But the difference between these
two is how long it takes
to make a choice, how long it
takes to make a choice.
And that difference, when he
subtracts them, took about
1/10 of a the second by
that measurement.
So all of sudden you could
start to measure, in an
objective sense, how long
a mental operation
takes in your mind.
Then psychology went a lot
of different directions.
A famous one from Titchener,
who worked with Wundt,
developed a psychology
department at Cornell, was
introspection, look
inside yourself
and think very carefully.
When you think about a topic,
how do I think about it?
That lost its way as a
scientific method.
The trouble is one person
thinks one way.
And one person thinks
another way.
And you can't really
settle it, right?
So introspection about your
thoughts is a private process.
It's not a public measure that
you can exchange among
scientists, like time
or measurements.
But we still introspect a
lot when we think about
psychology, whether it feels
right to us, what are the
questions to ask.
But still just being human, you
can't help but introspect
about psychology topics.
In the US, there was a sort
of a huge response to
introspection as being
too loosey goosey.
One famous name in this
is John Watson.
He said the mind is
unobservable.
So we can only study behavior,
things that people do,
actions they take.
Their mouth moves.
Their hand presses.
And then we identify what in
the environment influences
those behaviors.
The principles of the mind
should be similar between
animals and humans.
And that the only thing a
responsible experimental
scientist can do is relate
environmental factors to actions.
And so there's a stimulus.
And you can control the stimulus
as a scientist.
There's a response.
You measure the response.
And that's your psychology
experiment.
And then the 1980's became
the cognitive revolution.
Partly this path lead to not,
after a while, to not very
interesting science.
That was the biggest problem.
And people said, no, we can make
inferences about the mind
as it translates what it hears
or sees into what a person
does so representations or
knowledge in the mind or in
the brain later on and how that
translates what's out
there and how you act upon it.
So I'll remind you of a
couple more things.
And then we'll get
to specifics.
So correlations you can only get
in an experiment, right,
where you have an independent
variable.
Sorry.
Correlations you can look
at all the time.
Experiments only allows
us to infer causation.
So let's pick an example when
I read that struck me as
slightly relevant so age
of parent and risk for
disease in a child.
So most of you are young enough
that you're not too
worried about this yet.
And you have no reason to be.
But for those of us who are
in my generation and some
generations back, many people
are postponing childbirth as
they do their careers and
complete different tasks.
And parents are getting older.
They don't only seem old.
They are old.
It's the case statistically
that, the older the mother is,
the higher the risk of
Down's Syndrome.
So the statistics are, if a
mother is age 20 to 24, it's
very rare to have
Down's Syndrome.
And the number goes up
dramatically if the mother is
over age 42.
So this is simple observation
and measurement.
But it's something a lot of
women giving birth in their
30s and 40s are thinking about
and worrying about.
And it's a thing
on their mind.
Up until relatively recently men
said, oh, it's too bad for
those women.
But no problem for us.
So you have the movie star,
right, who's 90 years old and
marries a 20-year-old actress,
right, that kind of model that
you see all the time.
Because it doesn't matter
how old the guy is.
Well, it turns out
it does matter.
And here's some data for that.
So here's the probability of
developing schizophrenia, a
disease that's typically
diagnosed in a person's late
adolescence or 20s depending
on the age of the father.
And you can see if the father
is less than 25,
it's one out of 141.
If the father is in his 50s,
it becomes one out of 50, a
dramatic growth in the
likelihood of an offspring
child having schizophrenia
depending on
the age of the father.
Now, there's a correlation
between age and whether a
child expresses schizophrenia.
So let's guess about the
possible causes of that.
I can tell you, it's unknown.
But let's even begin
to guess about it.
Let me ask you to
guess about it.
Yeah?
AUDIENCE: Maybe the gametes
become damaged by age.
PROFESSOR: Yeah, bad sperm,
right, for some reason, in
some way, and sperm that leads
more likely to be risk for
schizophrenia.
That's your first intuition.
And that may turn out to be
right, something problematic
about the sperm from the male.
Here's another one, though.
And this shows you the
challenges with correlational
research on something even so
important as this, which is
how about an alternative,
which is who
marries later in life?
Maybe the desirable men are
plucked off the market on
average in large statistics
by age 30 or something.
And a bunch of us-- and
I'm a late marrier--
limp to find some woman around
the world who will accept us.
And finally, out of pity, some
woman says, OK, drag yourself
into your 50s and
I'll take you.
Because it's not random
probably.
We're averaging over
many people.
But it's not random probably who
marries at 25 in a given
society and who marries at 50.
It's not random.
It could be big differences
among the--
and how can we tell
that difference?
Maybe it's nothing to
do with the sperm.
Maybe it's something about the
genes and environment that
goes with being a parent in your
50s versus being a parent
in your 20s.
Completely different
explanations, someday maybe
we'll know.
But we don't know now.
So this is the limits
of correlations.
And both could be
true, neither.
It could be a third
story altogether.
So that was about me, my
becoming a parent late in life
and marrying late in life.
Let's talk about you.
So let's talk about the level
of stress you have and how
empathetic you are on average,
your college generation
relative to ones five or
10 or 20 years ago.
So let's ask that question.
Why would people want to
know such a thing?
Well, you might want to
understand what pressures are
we putting young people under
as they go through grade
school and high school
and college.
What's the world like?
Is it pretty much the same?
Is it pretty much changing?
Now, how would we figure that?
How would we begin
to measure that?
It's a very simple question.
Are you more stressed than
people 10 years ago at MIT on
average across the country?
And are you more or
less empathetic
towards other people?
How might one answer that
kind of a question?
Yeah?
AUDIENCE: [INAUDIBLE]
we know a little bit about
hormones to the extent
[INAUDIBLE].
PROFESSOR: That would be a
very interesting path.
It's a tough research path.
But you're right.
If we had some biological
signature of stress, that
would be a good one.
But let's ask this question.
Let's say I measured everybody
in here and got your average
stress hormone or something
like that.
Now what's my answer about
whether 10 years ago people
were more or less stressed?
Yeah?
AUDIENCE: We could look
at suicide rates.
PROFESSOR: That would
be an outcome of it.
Yeah, that would be sadly
an extreme outcome
of stress of a kind.
But there's a lot of things
that are going--
So you have to worry
about two things.
One thing we know is-- let
me ask another one.
You could compare your level of
stress to people who are 10
years older than you or 20
years older than you.
What do you think about that?
Yeah?
Yeah?
AUDIENCE: It would actually be
more accurate if you measured,
if you want to know for college
students specifically,
you'd have to be the baseline
of yourself from somewhere
[INAUDIBLE].
PROFESSOR: Yeah, because maybe
people who are 30 or 40 are
more stressed for other reasons
because they have more
bills and mortgages to pay or
less stressed for other
reasons or whatever, right?
Maybe it's not about the
generation you're in.
Maybe it's about being
a person with more
responsibilities at 40, right?
So for some things you
get some luck.
And you have it in your hands.
So here's an emotional health
questionnaire where students
across the country for the last
25 years have been given
the identical questionnaire.
It's a questionnaire, it's not a
biology measure, about their
self-reported measure
of stress.
And this was on the New York
Times just a few weeks ago.
It's you guys on average across
the country, US college
students, are at an all
time high level of
self-reported stress.
Sorry about that.
It's not the perfect measurement
in every way.
But it's the same questionnaire
to college
students year in and year out.
By self-report, people say,
I feel more stressed.
You can also see that
there's a difference
between men and women.
Women, on average, report
feeling more stressed.
And it may be relevant that on
average, for example, there's
a higher rate of depression
among women than men.
There's a much higher rate of
autism among men than women.
So being one sex or the other
is not a gift certificate of
avoiding mental health
challenges.
So you're more stressed
than ever.
Good luck.
We'll try to do the best we
can in this course to not
worry that way worse.
But it's something
to think about.
I got a call the other day from
somebody who said there's
a lot of curiosity about whether
the shift from book
learning and book reading to
internet worlds and Twitter
and Facebook worlds are
fundamentally changing how
people think.
And that sounds kind
of possible.
And there are people who give
amazingly entertaining
lectures about these things.
Scientifically, it's
unbelievably hard to imagine
how we would ever answer that.
So when I get occasional phone
calls like what do
neuroscientists know about
that, what could
they know about it?
Is that even an answerable
question?
If I take you now and say, well,
you've probably done
more Facebook than a 50-year-old
and compare you to
a 50-year-old on some other
thing, is that going to answer
the question of how you think
about ideas given the world
you live in versus the world
the 50-year-old lived in?
No.
So there's just a lot of huge
deep things about changes in
the world that we can't
even begin to get at.
Sometimes we get lucky.
And people have been giving
some particular
measure for some time.
Empathy, by self-report--
and now I wouldn't
fill it out now.
But you can take a look
just to get a
feeling at your leisure.
This is the questionnaire
they used for
self-reported empathy.
It's self-report, 40% lower
today than 20 years ago.
So on average you guys,
literally, on average by these
measures, are more
stressed and less
empathetic towards others.
Sorry.
This is not an individual.
This is an average, right?
So the levels that society
operates, things are going on
and moving for some reason.
By the way, I can tell you that,
when I'm stressed, I
have less room to
be empathetic.
So maybe these things
are related.
If you're feeling stressed, your
first thought is not how
can I help others but how can
I just get through the day?
So these things might
be related.
So let's turn a little bit to
experimentation and some of
the challenges of relating
psychology to real world
policies that are meant to make
the world better or safer
in some way.
So there's a famous broken
window theory from the
political scientist James Wilson
and the criminologist
George Kelling.
And their idea was this that,
especially in neighborhoods
that are not immaculately kept
or to say it the other way
where there's a lot of damage
around you, things like broken
windows is the phrase they used,
that this promotes in
people who live in that
community or work around that
community to sense that
the rules don't count.
Anybody can do anything.
And then it fosters the growth
of petty crimes.
And once you do a petty crime,
you're more vulnerable or
willing to do a major crime,
a slippery slope.
And in fact, Rudy Giuliani and
Commissioner Bill Bratton
employed this.
They asked the police to write
lots of tickets and make lots
of sort of minor arrests for
things where people weren't
upkeeping the environment to
where they were littering or
things like that.
And this is a huge debate.
Because in a police department
you can only do so much.
So if they have a person working
on jaywalking and
littering, that's a person not
working on major crime rings
so to try to make a choice where
they think they can make
community safer in the
most effective way.
And the crimes went way
down in New York.
In most cities now, you don't
hear crime discussed as a big
topic nationally.
In some local areas, like
in Boston, some
specific areas, you do.
I don't think in the State of
the Union there was a word
about crime that I can
remember a week ago.
It's not a big national topic.
In some local places, it is a
big topic, but not nationally.
So you don't know some years ago
when people said New York
City was this horrible place
to go because there was so
much crime that you'd walk out
from your airplane and get
mugged before you made
it to your taxi.
It was like the whole country
was saying big cities were
just crime-ridden
and dangerous.
They do this policy.
Things get better.
So everybody says, hmm, that
sounds pretty good.
But of course, it's
not an experiment.
It's a real life policy.
And then people had these kind
of incredibly clever
reinterpretations of why
crime went down.
So the wildest one was in
Freakononimics was discussed
in that, which said,
well, abortion was
legalized in 1973.
That gave women who didn't have
access to legal abortions
the ability to have them, that
the children, on average, in
these communities that had at
least access to safe and legal
abortions would be poor,
unstable, addiction-ridden
communities statistically.
And so that if you imagined the
reduced abortion rate in
poor areas could, when you
count out the number of
possible criminals in those
areas, account for the
reduction in crime all by
itself, a completely different
interpretation that has nothing
to do with the policy.
It just said we can have a
demographic shift, which will
have a weird unexpected
consequence of lowering the
crime rate because it's the
finding that young men, in
particular, are most likely to
engage in violent criminal
activities.
It's not an all rule but
a statistical average.
Or there was a big crack
epidemic that reduced.
Or lots of states put in laws
that put people into jail for
much higher, longer periods,
much more severe penalties
with new drug laws.
So it's very hard to know if the
policy that was initiated
really worked or whether
completely other things were
happening that moved
the crime rate.
And here's some very sort
of perverse or other
explanations.
So that left the question,
is broken
windows even a good idea?
Just because Harvard--
and we know Harvard
is always right--
but just because a Harvard
psychologist says pretty
interestingly, that sounds right
to me, is that even a
right idea?
So let's take a step back.
Can we test that
experimentally?
So here's the experiment.
And the idea is, again, that,
when people observe that
others violate a social norm or
legitimate rule, are they
more likely to violate it?
If you see people around you
breaking rules, are you more
likely to do it?
And you could say, it
seems like it is.
But let's do the science.
So here's an independent
measure.
I'll show you the environment.
The dependent measure is
the number of people
who perform a violation.
Now, you can't go getting people
murdering each other
and stuff for an experiment.
But you can do this.
You can have two conditions.
So on the top condition, do you
ever go back to your car
or bike, usually it's cars, I
think, and they put leaflets
in your car?
And now what are you
going to do?
You're running away.
They'll leave the leaflet on
your windshield wiper.
So they put it out.
And they either had a wall like
this, which was clean.
There's a sign that
says no graffiti.
And they put on those
white pieces of
paper onto the bikes.
Or they put a lot of graffiti
on the wall.
And people came out from
their classes.
They parked their bike.
They ran into class.
They came out.
And they got all these
white leaflets.
And what they did is watched.
And they said, how many people
put the leaflet away?
And how many people crumpled
it up and threw it right on
the ground?
So we don't know what they're
going to do with the leaflet
after they put it away.
But we could hope they're
going to throw it out.
But the one thing we know for
sure, if you crumple it up and
throw it on the ground, it's
littering and not a good
social norm.
And sure enough, 1/3 of the
people littered if the wall
had no graffiti.
But it more than doubled if
the wall had graffiti.
So that's a small thing.
That's not a broken down,
complicated neighborhood.
But just at that moment, as you
roar out of class, you get
that piece of paper
on your bike.
And you see like, wow, this
is a pretty crummy place.
People are breaking the rules
all the time, twice as likely
to throw a piece of paper
on the ground.
So that shows that people very
easily are influenced by very
mild perceptions of whether
people are following rules or
not and will be their better
selves or their worse selves
depending on that sense
of are all rules on or
are all rules off.
And there's a pretty good
bet they're not
thinking about it, right?
They're not sitting there
thinking, OK, here's
littering, not as bad
as killing somebody.
Here's the wall.
Well, there's 30% graffiti.
I mean nobody does that.
They have an emotion
quick response.
But the environment makes a
difference in that regard.
So an important thing about
studies like this, so let me
tell you about this one.
Here's a study to look at a
drug that was supposed to
lower mortality from coronary
artery disease.
So those who took the drug, 80%
or more, because people
follow whether you take the
drug, if you don't take the
drug, of course, the drug
won't work, had a 15%
mortality rate within
five years.
Those who took the drug less
than 80% had a 25% mortality.
So you'd say, well, 10% better
chance of living for five
years, that's worth it.
The nice thing is they
had a placebo.
And there was no difference
whatsoever between those who
took the active drug and those
who took the placebo.
The difference was those who
followed the instructions to
take the pill and those
who didn't.
So what does that mean?
How do you interpret that?
It's not the drug.
Yeah?
AUDIENCE: It could be the stress
of not following the
directions, meaning
it's not working.
PROFESSOR: It could be that.
It could be the stress.
It could be that.
But let me make a guess.
There's no scientific
answer to this.
People who tend not to follow
instructions, are they mostly
stressed by not following
instructions?
The intuition is they're
blowing it off.
They're like, yeah, that's
the instructions.
But I got things to do
and places to go.
But you could be right.
So anyway, the idea is, what you
pick up is, are people who
tried to take care
of themselves.
They have a health condition.
And the people who are following
the pill instruction
are probably also doing the
best they can in terms of
exercise and diet, all the
things they could do to
maximize their health, right?
And they're taking
their placebo.
Or they're taking the drug.
They don't know.
But they're doing everything
they can.
And the people who blowing off
stuff, they're the ones who
are doing all the things that
aren't healthy, including not
even taking your pills.
I mean, if you don't even
take your pills, right--
Exercise is work.
Diet is work.
Popping a pill that's been
handed to you that you're told
might help you is probably
not that much work.
It's what's called
self-selection bias, that you
stand out if you tend to take
care of yourself or not.
So when we run experiments at
universities that involve
people, a huge issue for us is
the idea is this, that we
randomly recruit people.
And we'll come back to
this in a moment.
Then we randomly assign them to
one condition or another,
for example, the placebo
condition or the drug condition.
We randomly assign them to the
messy wall or the clean wall.
We discover something.
And then we try to generalize it
as far as we can to people
as a whole.
We've discovered something
fundamental about how humans
work, generalizable principles
of human mind or behavior.
So what really happens
in the world?
And you're in between sort of
the best possible world and
the world we actually live in.
So is it really random who
participates in research
studies in psychology
departments where a lot of the
research gets done.
Is it really random?
No.
So who volunteers?
Have any of you volunteered
to be a subject in
an experiment anywhere?
Yeah.
So it's not random.
Some people, they either need
to make a few bucks.
Or they're very curious
about psychology.
Or they have a friend
who's in psychology.
It's not random.
And in fact, population-wide,
people have said that
psychology could be described
as WEIRD research for the
following reason, that the vast
majority of the findings
you'll read about everywhere,
including in your textbook,
but everywhere are from nations
that are westernized,
educated, industrialized, and
relatively rich democracies.
The vast majority are
between 17 and 25.
They're undergraduates or
graduate students who
participate in research.
It's been estimated that, if
you're a US college student,
you're 4,000 times more likely
to show up in a scientifically
reported experiment than if
you're a person anywhere else
on the planet, 4,000 times.
Because why?
Because it's changing a little
bit but for many, many years
the huge amount of research
happened in the US at
universities, pretty much at
better universities, pretty
much at highly selected
students.
And then we never
publish that.
We never say MIT students
did the following thing.
Because people will say,
yeah, MIT students.
Because then we have a different
report from Stanford
or from UMass or from
Michigan or Texas.
We say, no, humans did
an experiment.
And humans are like this.
And it's just something to think
about as you see studies
and stuff like that.
And people are more and more
sensitized to that.
As more and more of the world
gets somewhat industrializes,
there's more and more research
around the world.
But still the vast majority
of findings are you guys.
Now, that's just to start with
who's in the subject pool or
the participant pool.
How normal are you when
you do an experiment?
Are you like yourself?
Or are you doing weird stuff?
And people use this idea that
you're really weird when you
do an experiment in
another sense.
Because you don't know
what's going on.
You're following instructions.
So they do experiments to show
how ridiculously people behave
when they're doing an experiment
like they would
never do it.
So they ask them to come in.
And they say, will you fill out
200 sheets of paper filled
with random digits,
add them pairwise?
And I'll come back
in a few hours.
Now, if a friend asked you to do
that, add random digits for
a couple hours, you would
go no, thank you.
I've got about eight million
better things to
do than that, right?
I could multiply random digits
just to start with.
But people will do
it for hours.
Because they're in this weird
like that's the instruction.
And that's what my mission is.
Or even more ridiculous,
they pick up a
card after each page.
They've added all these numbers
for no good reason.
And the instruction tells them,
when you've done the
page, tear the page
up into 32 pieces.
And here's the next page
and the next page.
It's obviously fruitless and
pointless, ridiculously so.
But because you're in an
experiment and somebody told
you do that, you just keep
barreling forward.
How much are we who we are when
we do experiments versus
people following weird
instructions?
And we'll come back to that
in some serious context.
That's the subjects.
How about experimenters?
Experimenters are
never objective.
We try to be as scientists
as objective as we can.
We're never, we believe
certain hypotheses.
We have certain goals.
We recognize results that
would be super exciting.
We recognize results that
would be boring.
We're humans, too.
We want to do stuff
that matters.
We want to do stuff that
people reward us for.
I mean it's just human.
So here's a lowest case example
of how, once you're an
experimenter, you produce
your own results.
And believe me, it's much more
when your result matters for
things like your career
advancement or your
status in the field.
So students were told that rats
were either maze-bright
or maze-dull.
They were told that these rats
were bred to be smart learners
or not so smart.
The rats were all just
random rats.
It's a fake story to
undergraduates.
Then they had them
test on a maze.
And they said for your
laboratory exercise write down
how quickly the rat
runs the maze.
And amazingly, the smart
rats did way better
than the dull rats.
Now, these are not students
trying to become famous or
have a career.
They're handing in
an assignment.
And how did that happen?
Well, they went back.
And it wasn't that anyone
faked data or
anything like that.
But when they looked at films or
discussed stuff with kids,
students in the course, every
little thing that the students
did that moved the data in tiny,
tiny ways always favored
finding the maze-bright rats
being brilliant maze runners.
So for example, they would put
the rat-- if you've ever run a
rat in a maze, has anyone
run a rat in a maze?
Yeah?
Is it easy?
Have you picked them up and
put them in the maze?
It's more automated now.
Is it physically easy?
Are rats like, please, show
me the starting line?
I'm ready to go.
No.
What are they like?
Help me out here for you guys
who have done this.
Are they kind of really--
AUDIENCE: [INAUDIBLE].
PROFESSOR: And they
don't like to be
handled that much really.
And they're fighting.
And these are undergraduates
who've hardly
ever touched a rat.
They're like, please, don't
attack me or something.
So they're holding up.
And the rat's fighting back.
And because it's really
uncomfortable, the rat's
really unhappy.
And the student's
like really--
So what happens is--
and then they plunk
the rat down.
And they go, oh, my gosh, it's
facing the wrong direction.
And it's a smart one.
Wait, stop the clock.
Let's get him--
But if it's a dull one facing
the wrong direction, it's OK.
It's a dull one.
Let the maze-- so lots
of little things.
Are you sure you wrote
this down.
Was it 12 seconds or 11?
I guess it was 11.
Oh, because it's a smart one.
So completely innocently,
completely innocently as far
as we understand, they made the
result to match up with
what the expectation was.
And it's not just that.
And if you know this example,
cognitive psychologists have
studied a phenomenon
like this.
So try this at your desk.
Each card is a letter on
one side and a number
on the other side.
Your job is to figure out what's
the smallest number of
cards you have to pick
up to discover if
this rule is right.
If a card has a vowel on one
side, then it has an even
number on the other side.
So think about this
for a moment.
If a card has a vowel on one
side, then it has to have an
even number on the other side.
What's the smallest number of
cards you can pick up to test
that hypothesis?
So here's what people
have found.
The correct answer
is E and seven.
And about 10% of people on
average come up with that.
Many, many more people pick
E alone or E and six.
Why?
Well, everybody gets that you
have to look at E. Because if
it's an even number, so
you flipped E over.
And if that one turns out to
have, it's a vowel, if it has
an odd number, the hypothesis
is wrong, right?
Everybody gets that you should
check E. Pretty much everybody
gets that J is irrelevant.
Because it's a consonant.
Now comes the interesting
six and seven.
Because the sentence is talking
about a vowel and an
even number, sometimes people
feel like I got to check the
even number.
But it doesn't say anything
about even numbers couldn't go
with consonants.
It doesn't tell you anything.
That's not part of
the hypothesis.
But if you flipped over number
seven and you discovered a
vowel, you'd violate the rule.
So what happens is they're
tempted to go for things that
feel like they confirm
the question.
And it feels like
E confirms it.
And it feels like
six confirms it.
It's what is called confirmatory
bias that when
you look at stuff, if you see
what you think confirms it,
then you tend to go for that,
even when there's evidence in
front if you that could
contradict your expectation.
So now I'm going to give you a
practical suggestion for how
to win somebody over if you
have a brewing romantic
interest in that person.
So finally we get practical,
right?
Everything was like, I look at
you, I'm not running rats.
And I think it's very
interesting.
Because when we think about how
people make decisions in
their lives, we tend to think
intuitively about big decisions.
What's my career going to be?
Where do I go to college?
We think those are the
big decisions.
But a huge amount of
life is little
decisions, moment to moment.
If somebody asks you
for something, did
you say yes or no?
Somebody walks up to
you at a party.
They want to talk with you.
Do you feel like talking or
not feel like talking?
Maybe you talk with them and
it's a lifetime friend or
romantic partner or whatever.
So I think we make constantly
little decisions that turn out
to big effects in our lives.
So here's some evidence about
things like that that
influence that.
And this is worked on at Yale.
So we describe people as warm.
Or we can define them as
cold or aloof, right?
And we could think those words
are kind of arbitrary.
And most of us, if you met
somebody at a party, would you
rather hang out with somebody
who's warm or cold?
Warm, OK, just checking.
Now sometimes there's an idea
of embodied cognition.
And here's what it is.
We can't really know how warm or
cold that person is or even
that's an abstract idea.
But we know we're comfortable
when we're kind of warm.
And we know we're not
comfortable physically inside
us when we're kind of cold.
So there's an idea that when we
think about other people's
feelings, other people's
thoughts or abstract things in
the world, we base them on
physical experiences that we
have inside, that there's a more
direct link between what
we know inside us.
And we use that to interpret
the world out there.
Embodied cognition, your
body is the vehicle for
understanding things
out there.
So here's the experiments.
It's really clever.
There's two temperature
conditions.
So what happens is you
go into a building.
And the examiner, an
undergraduate usually or a
graduate student, meets a
subject in the lobby.
And she's carrying or he's
carrying a cup of coffee,
sometimes it's hot coffee,
sometimes it's cold coffee, a
clipboard, two textbooks.
So you can imagine.
It's a set-up, right?
The person's walking.
They're juggling with
the coffee, the
textbook, oh, the clipboard.
And he says, on the elevator he
says, could you just hold
my cup while I write down your
name on my list of subjects in
the experiment?
It's very innocent, right,
on the elevator.
And so you hold the cup of
coffee, which half the people
get a hot cup, half the
people get a cold cup.
Then you read a description
of a person.
It's just a paragraph.
And you have to rate whether you
find the person described
as warm or cold.
And if you had the warm cup of
coffee, you're more likely to
describe that person as a
warm kind of a person.
Now, these subjects
have no idea.
They held a cup of coffee.
They probably didn't
even think whether
it was warm or cold.
But something in their body
that got warmed up to the
least degree possible,
that thought is
still in their head.
So when they read a description
of something, you
go, oh, this seems like
a warm person.
Of if it was a cold cup of
coffee, they say, oh, this
seems like a cold, aloof kind
of person as far as I can
tell, that little bit
of difference.
So here's the lesson
just so you got it.
If you want to take somebody
because you have a possible
friendship or romantic interest
in that person, are
you better off going out for a
warm cup of coffee or giving
them a cold glass of beer?
For that first impression,
scientific research shows it's
something warm will
work it out.
It's not that powerful.
You're not going to be able
to control the world.
But what it says is when we are
in ambiguous situations,
ambiguous situations, we
first meet somebody.
We don't really know them.
Little things can start
us off on one path.
Or it can start us
off another path,
surprisingly little things.
Now, then they have to worry
about a confound.
Can you imagine a
confound here?
Think of the rats.
Who knows if the cup is cold
or hot besides the person
holding it?
The examiner, right?
Now, maybe the examiner doesn't
try to do this, but
maybe the examiner, no matter
what, says, oh, we're in the
warm condition.
And I'm smiling because this
is going to be nice.
I'm helping this person
feel good.
Here's the aloof condition
I'm giving.
We're all going to
be miserable.
And the examiner knows it.
Because they know if they have
a hot or cold cup of coffee.
So maybe the person's not
vibing to the coffee.
They're vibing to the expression
or feeling or
sentiment of the examiner who
understands what's going on.
So they do one more experiment
where they give-- have you
seen these hot and icy
therapeutic packs that you can
make hot or cold?
Now somebody else makes
it hot or cold.
The experimenter has no idea
whether it was hot or cold.
So it's what we call
double blind.
A person doesn't know it's
relevant, the experimenter.
They rate the pad.
And now, this moves it a little
bit, they either get,
after this thing's over, they're
told it's a product
evaluation of the pad.
But they either got a hot
pad or a cold pad.
And they can either choose one
of two rewards, a Snapple
beverage or a $1 gift
certificate, whichever you
like better.
You had two little things
you could do.
But here's the big decision.
Do you get it for yourself?
Or we can send it for
you to a friend.
We can send them the Snapple
or the certificate.
If the people got a cold pad,
75% of the times they say,
please, give it to
me right now.
I'll take it.
If they had a warm pad, the
majority of the time they
actually send it to
their friend.
That pad difference moved
quite substantially the
likelihood that you take it for
yourself or you give it
away, quite substantially.
If you're a charity trying to
get people to donate or you
want to get help from somebody,
25% success rate is
a lot worse than a 54%, right?
It's a doubling, a doubling,
of whether you keep it for
yourself or you're generous
to your friend, just that
therapeutic pad.
I'm going to give you two
more and then go to--
How about money?
When you think about money, I
don't mean traumatic things
about money, just a little bit
about money, how does that
influence how you relate
to other people?
OK, here's the experiment.
The idea is that money, on
average, when you just think a
little bit about it-- and I'll
show you how ridiculously
little they think about it--
their hypothesis is that money
makes you think about
self-reliance, you earn your
money, your bank account,
compared to situations
where you're not
thinking about money.
So here's what they did.
They have people come in
in three conditions.
And they had to unscramble
sentences.
You have no idea what's
going on.
You got a sentence like, cold it
desk outside is, which you
would make into a good sentence,
or high a salary
desk paying.
So you just make those, you
scramble those words around.
But the money condition has
a word like salary in it.
Or you get the neutral
sentences that
have no money reference.
And you see Monopoly money in
the corner of the room.
So we're not talking like people
just sent you your
tuition bill or whatever.
Or you just found out that
something terrible happened
financially or you
won the lottery.
It's Monopoly money.
It's just like the
idea of money.
And then they give
you a task to do.
And the experimenter, as he or
she leaves the room, they say,
it's a pretty hard task.
You may want some help.
So just come and get me.
I'm glad to help you,
not a problem.
So what happens?
Here's the probability
of getting help.
And it's incredibly more for the
control group that did the
sentences without money and
way less not only for the
people who unscrambled the
sentence with the word salary
but also way less if they saw
Monopoly money in the corner.
The mere idea of money, not
money given to you, not
financial trauma or financial
gain, the mere idea of money
makes you less willing to
get up and get help.
So the positive it makes
you more self-reliant.
The negative is people were less
willing to help somebody.
So now at the end as the
examiner comes and says, I'm
an undergraduate like you.
I've got huge pressure
to get this paper in.
Can you help me code?
Can you help me score
up a few sheets?
People were twice as much
willing to help if they just
did the neutral things than if
they unscrambled the money
sentences or saw the Monopoly
money in the
corner of the room.
Because just that thought about
money goes like, man,
self-reliance, we're all
in it for ourselves.
I've got my money.
You've got your money.
Good luck.
Self-reliance can
be a good thing.
But it doesn't actually
go with helping
people very much also.
Yeah?
AUDIENCE: [INAUDIBLE]
because the Monopoly money and
he's suspicious of why this
money's over there, that's why
you're not going to help.
PROFESSOR: It could be.
Yeah, the Monopoly money,
I agree with you.
Maybe that's why they also had
the one where you just get the
scrambled sentences.
I agree with you.
You could think there's many,
many ways to think about this.
The last example of this kind
that I want show you is dating
behavior and the way, again,
an experiment can challenge
various ideas.
And this is specifically about
dating between men and women.
The story, to the extent it's
been studied, would be a
little bit different if you're
dating within a sex.
So if we're dating between men
and women, who is more
selective in their dating
choices do you think?
Who's more willing to date
widely or a lot or less?
What's your thought if you have
to generalize about men
and women on average in your--
AUDIENCE: Men.
PROFESSOR: Thank you.
And evolutionary psychologists,
and I love
evolutionary psychology.
But it drives me crazy, too.
Evolutionary psychologists
will go, well, because by
evolutionary theory men have
to go and make as many
offspring as they can to
keep their genes going.
Women have to be
more selective.
It takes nine months
to bear a baby.
It takes nine seconds
to do the male
part, right, estimated.
So this might or might
not be true.
It's kind of fun.
We all laugh about it.
All of us find it kind
of amusing to
sort of think about.
But how would we actually
know if this is
vaguely true on average?
How would we actually know if
men for dating behavior?
How would we even,
is that true?
Is that a bad myth, bad
rap, or whatever?
Yeah?
AUDIENCE: Dating websites?
PROFESSOR: Yeah, thank
you very much.
So there's an entire research
enterprise out there now that
uses online dating sites, which,
of course, it's only in
the last 20 years or something
that they've existed, I think.
So it wasn't before.
And the other one that's been
a treasure trove of data is
speed dating environments where
you can observe things
and measure things.
And those studies have shown,
for example, that online
dating on average men are 1.5
times more likely to send
email offerings dates to a
woman than the other way
around compared to women.
And in speed dating, too, men
are more likely to indicate
they would be happy to date a
person they met than women.
So there's objective evidence
that this is true on average
in this society at this time.
And so everybody, oh, yeah, this
shows the evolutionary
psychology.
Evolutionary psychology
drives you crazy.
Because, on the one hand, it's
certainly the case that our
minds and brains evolved
through evolution.
So there's something about the
history we went through as a
species that matters
for who we are now.
That's got to be the case.
On the other hand, it was
a different world before
internet dating and speed
dating, right?
It's hard to know how those
things line up exactly.
So here's the fun thing.
It turns out that on average
in speed dating a typical
speed dating event will have
four minutes, right?
So you typically have women
sitting at desks.
Almost always they set
it up that way.
And the men are sitting in
chairs in front of the desk.
And they meet.
And they talk for
four minutes.
The bell rings.
The men jump up.
And they shift over
one station.
And then what happens is, for
each time you meet a person,
you fill out a card that says
yes or no I'd be willing to
have a date with the person.
And if you have two yeses from
the man and the woman, the
speed dating organizer exchanges
the information so
they can make direct contact.
Does that sound OK?
And men make more
yes responses.
And it turns out, it doesn't
have to be this way, but
almost, from my reading, that
almost every speed dating
thing has the men rotating
around and the women sitting
there waiting for the men
to rotate around.
So let's just ask
this question.
What happens if the women
rotate, which
almost never happens?
But they did this
experimentally.
They said for half of the speed
dating sessions the men
will be sitting at the table.
And the women will stand up and
move a chair over every
four minutes.
The bell rings.
So the women are moving
and rotating.
And here's the results.
Basically, what's showing on
the left are when the men
rotate, the standard
condition.
First, it's romantic desire.
Men feel more romantic desire,
on average, for the partner
they sit with.
They feel that more chemistry
is happening with the person
they sit with.
And on the bottom left corner,
they also are more likely to
give a yes response, I would
like a date with this person.
But reverse the roles, have the
women rotating, and look
at these bars.
There's no difference at all.
You completely wipe out the
male female difference and
self-reported romantic desire
per person, self-reported
chemistry they think is
happening, and the yes no
responses that I would
have a date.
You completely eliminate it when
the women are rotating.
It's flat even.
So that's the result.
What does this suggest?
What happened to the
evolutionary psychology?
It disappeared just by
having the women
rotate around the room.
It suggests, and we don't know
this with certainty.
But people are following this up
who are interested in this.
It suggests that there's
something about getting up and
approaching that person, your
body going here I come, I'm
not sitting in my chair hanging
out, it's like here I
come, that makes a person
energized, feel more romantic,
feel more chemistry is
happening, and more likely to
ask on a date.
And it doesn't matter
whether you're a man
or a woman at all.
It's the getting up and that
physical approach.
You're more invested.
You're more out there.
Who knows what it is, completely
eliminates what
everybody had said is an
ancient, inevitable,
evolutionary difference
between men and women.
And this isn't to say there
might not be some of those
streaks in us.
Who knows.
But speed dating is
not showing that.
All you got to do is have
the women rotate.
And you completely eliminate
what's thought to be some
hard-wired biological difference
on this dimension.
Now, talking about that, when
we do experiments like this
that look at sort of fun things
like dating around a
thing or age difference between
a five-year-old and a
20-year-old or a 20-year-old and
a 80-year-old, cultures,
there's lots of experiments
that compare say Western
cultures verses Eastern Asian
cultures, we'll talk about
that later in the course in
terms of behaviors, genes,
whether you have one gene or
another, all those things, are
those independent variables?
No.
We can't assign you randomly to
be a man or a woman, young
or old, to come from the United
States or Japan or
China, or to have this
gene or that gene.
It's not that we couldn't do
stuff in some monstrous world
but not ethically.
And it's never going
to happen, right?
So whenever you have science
that talks about differences
between men and women or young
and old or cultures or genes,
it's not really a completely
independent manipulation.
We can't assign you randomly.
And so it means everything in
the world about what it means
to be a man or a woman, a
20-year-old or an 80-year old,
come from this continent or that
continent, have this gene
or that gene, those are not
things we can freely
manipulate.
And we have to be extra cautious
in interpreting those
kinds of studies.
Because we can't randomly assign
you to conditions.
We just can't.
And I didn't talk about the
fact that, up until this
moment, we've made every
conclusion a complete
generality about human nature.
And people are different one
from the other, individual
differences.
We'll talk about that later
in the course, too.
So for the last couple minutes
I want to talk about this,
folk psychology.
Everybody has ideas
about psychology.
So if you have this piece of
paper, if you would zoom
through it, ideas about people
in psychology and just where
there is some scientific
evidence, if you just zoom
down and mark yes or no--
On average, do opposites
attract?
On average, does familiarity
breed contempt?
On average, more people present
in an emergency, are
you more likely to
get some help?
On average, are there such
things as visual learners and
verbal learners, and if they
got the right kind of
instruction that would
help them in school?
Is hypnosis baloney?
Does subliminal advertising
work?
When things are presented so
you don't see them below
consciousness, does it help
you buy something?
Does playing Mozart to
an infant boost their
intelligence, Mozart effect?
Is old age, on average,
associated with
dissatisfaction?
If you're unsure of your answer
when taking a test, I'm
going to tell you the
science about this.
It's best to stick with
your first hunch.
Practically every website
tells you that.
Have you heard that
many times?
I'm going to tell you what the
actual evidence is about that
and how they get that
in a moment.
Ulcers are caused primarily
by stress.
A positive attitude can
stave off cancer.
Raising children similarly leads
to similarities in their
adult personalities.
Low self-esteem is
a major cause of
psychological problems.
People's responses on the ink
blot test tells us a lot about
their personalities.
Interviews help identify those
most likely to succeed in
medical school.
OK?
I'll give you a minute.
A bunch of these we'll come
back to in the course.
But the answer for all
these is this.
And there's evidence
to it all.
So I'm going to tell you about
four of them for 10 minutes.
One of the ones you might want
to know most about is the
changing your initial
hunch answer.
How do you know that?
So the people have gone back
over test scores and looked
where people crossed out an
answer or erased an answer.
That's the best source
of evidence they
have in large samples.
And people are twice as likely
to give a better, the correct
answer, than to move
to a wrong answer.
That's the empirical evidence.
So it's a fantastically
interesting disconnect that
you see so many places.
In teachers' advice, you go
with your first hunch when
you're unsure.
The empirical evidence is you're
much more likely to be
correct when you go with
your best final answer.
I mean, of course,
you're not sure.
So you're going to
miss a fair bit.
But you're twice as likely to
come out with the correct
answer when you go with your
best possible answer.
So that people who crossed out
their answers or erased their
answers, they were twice as
likely to move to a good
answer than leave behind
a good answer.
Yeah?
AUDIENCE: Do you know that
maybe it's they picked an
answer and then they switched
their answer and then picking
their best and going
back later--
PROFESSOR: Yeah, that's
an excellent question.
We don't know.
They've kind of gone like five
times back and forth.
The assumption has been, on
average, that people will go
once back and forth.
But you're right.
But ask yourself the other
question, too.
What's the evidence ever that
going with your hunches?
And nobody's been able
to show that.
So where there's evidence,
it's all in
favor of best answer.
And nobody's shown evidence that
hunch is the best way to
go empirically.
That doesn't mean that sometimes
it doesn't happen.
But on average, that's
the way the ends go.
But your point's excellent.
How about Rorschach tests?
Every psychology program,
clinical psychologist in the
country, is required to learn
how to administer and evaluate
a Rorschach.
You know this?
So this obviously shows,
obviously it shows, some sort
of horrible sex act
between animals.
You know these kinds of tests.
You're supposed to read it.
And then the examiner
listens to you.
And they figure out
something, right?
There's been about 10,000
publications about this.
There's no evidence that there's
anything predictive or
correct about this test,
none, zero, none.
People argue it.
People give it.
People have to learn how
to give this test.
So this is a disconnect that
happens a lot between clinical
stuff and experimental work.
I mean researchers can't grasp
why people still give this.
Medical school interviews, those
of you who will apply to
medical school will
get interviews.
You'll get interviews
for jobs.
You'll get interviews for all
kinds of things in your life.
What's the evidence that
interviews are
any good for anything?
How could you know whether
interviews
are good for anything?
A company interviews you.
A university interviews you.
How would you even
decide whether?
So I can tell you this.
Social psychologists have
shown repeatedly that
interviews are cesspools
for discrimination.
Because people tend to like
people who are like them.
Oh, you went to MIT?
Yeah, course nine.
Then you go, oh, man, this is
going to be good, right?
I went to CalTech.
We didn't like MIT people.
We thought they were a little
bit snobby or something.
And you go that's not
going to be so good.
Social psychologists have shown
that, if you just vary
information in practice
interviews, people tend to
like people who are like
them, by background, by
appearance, and so on.
On average, they try not to.
They try to be fair.
So we know that.
So here's what they did.
Yale compared students who were
accepted or rejected on
the basis of an interview.
So they all had scores that
got them to the interview.
And then they looked at them
where they went in pairs or
larger than pairs to other
medical schools.
So let's say you got
accepted by Yale.
And you were accepted or
rejected on the interview.
But you ended up as two students
at Penn or two
students at Michigan.
You're sitting next
to each other.
One of you was accepted
by interview at Yale.
One of you was not.
Who does better at
that other place?
They're dead even.
The interview added nothing
for predicting grade point
average or completion
of medical school.
Here's one more example,
University of Texas enlarged
in the midst of their, at
Houston, in the midst of their
interviews, it enlarged from
150 to 200 students.
They had interviewed 800.
The 150 who came were among
their top ones.
They interviewed them.
They liked them.
They came.
And then all of a sudden because
the state legislation
said, by law, mandating that you
take 50 more, they took 50
more who didn't do so well
in the interview.
Those 50 more performed
identically to the ones who
got in with the successful
interview.
They couldn't find a difference
between them.
Now, there's at least one thing
you might think the
interview might have done.
But we don't know.
What do you think it
might have done?
So the outcome was your grades
in medical school and your
likelihood of completing
medical school.
What else could an interview
have been relevant for?
Maybe, maybe, maybe something
about bedside manner or how
you relate to people, maybe,
maybe, maybe, but there's no
evidence that that's true.
Now you're starting to
grasp at straws.
So there's no evidence that
interview processes make any
difference anywhere.
But everybody does interviews
all the ways.
Because we always think we're
kind of good judges of human
nature or something.
So interviews, it's very
hard to tell that
they ever do anything.
So here's my last thing.
Self-esteem, you cannot watch
Oprah or Dr. Phil without some
discussion of self-esteem
at some moment.
And it sounds good
to everybody.
I mean nobody would wish for you
as a parent or friend for
you to have low self-esteem.
And in fact, higher self-esteem
is correlated with
higher initiative and
persistence, happiness and
emotional resilience, and also,
unfortunately, with
people who are narcissistic
and bullies.
And how they measure it, just so
you know, because this is a
problem, too, how do
you measure it?
There's several scales.
But the most widely used scale
is this Rosenberg scale.
So you have that, too,
if you want to
try it out on yourself.
Self-report, and when they
reviewed 15,000 studies some
years ago, they could find
no evidence that higher
self-esteem leads to
better things.
It all seemed the other way
around that doing better at
things led to higher
self-esteem.
They could never find
that pushing your
self-esteem up doesn't.
Having said that, I can tell you
as a parent of two young
kids or if you have friends and
you care about them and
you know this, we like to praise
people to build up
their self-esteem.
We tell you you're awesome.
Someday you'll go to MIT.
I know you will.
You're a wonderful person.
And you're smart.
And you're beautiful.
Parents want their children and
teachers, too, to grow up
and thrive and build up
that self-esteem.
And the easiest way to do that
is praise, right, just telling
your kid how awesome he or she
is or your younger sibling how
awesome her or she is.
Get their self-esteem up.
So the last thing I'm going to
tell you and then we'll be
done in about three minutes is
work from Carol Dweck that
shows you how dangerous it is
and counterproductive it is to
have praise where you
don't think through
its relation to people.
And in one sense we'll talk
about, are you going to
succeed in life by your
effort or your talent?
What's a bigger question
than that?
Wherever you get to in your
life, it's going to be based
on your effort or your
talent or both.
I'll just have a sentence
about that now.
So here's the experiments she
did with fifth graders.
She had them perform
a pretty hard task.
And afterwards, randomly, they
were either praised for their
intelligence.
So a person said to
them, you, fifth
grader, you are so smart.
I can't believe how great you
did on that, fifth grader.
Or they were praised for
their hard work.
This shows a lot of hard
work, different kids.
And some kids got no praise
at all in this experiment.
Then they get a task that's
even a little bit harder.
How does the different kind of
praise influence things?
And here was the finding.
If you were praised for your
intelligence, you did worse on
the second test.
If you were praised for your
hard work, you did better.
If nobody said anything, your
performance didn't change.
And the idea is this.
You understand, praised for
your intelligence, you did
worse on a hard task.
Praised for your effort,
you did better.
And here's the idea that, if
we praise people for their
intelligence to build up their
self-esteem, they start to
care more about how their
performance reflects on them
than the performance itself.
Because you're trying
to prove that you're
an intelligent person.
The students who get that
kind of praise for their
intelligence, they persist
less in a difficult task.
They say they don't
enjoy challenges.
Why?
They just want to ace everything
to keep proving
they're smart.
The kids who got praised for
effort, they're kind of like,
OK, I'm going to make
some mistakes.
But I'm just going
to keep going.
Because with effort I can
do things sometimes.
And it turns out that it makes
a remarkable thing.
And so Dweck, and we'll come
back to this, talks about you
can imbue your intelligence as
a trait, I have only so much,
or as a growth, the harder I
work, the smarter I get.
But I have to do the hard
work to get there.
And we live in a society that
often goes by fixed traits.
American Idol, the harder the
work, the better you sing or
who has the talent
is discovered?
Who has the talent is
discovered, right?
Because the idea is
you have a certain
amount of musical talent.
And now the judges show.
And you break into the world.
And you're a famous
singer, right?
So ask yourself this.
When you are good at what you
do, is it because something in
your genes and environment made
you good at it or is it
because you try really hard?
So Malcolm Gladwell has this
statement that's floating
around, gets a lot of attention,
that anybody can
become great at anything
if they work on
it for 10,000 hours.
So how much of your success in
the past, currently, and in
the future is going be
based on your effort?
And how much is it going to
be based on your talents?
And how would we know that?
And we're a very talent-oriented
society.
And it seems like, the more we
encourage effort, maybe the
more people might flourish.
So we talked about how
psychology and science,
experiments, brief history of
psychology experimentation,
some issues in experimentation,
and some
psychological topics, and some
practical information for
being generous and kind and
winning friends rapidly.
OK, thanks very much.
