Professor Paul Bloom:
Just to review,
here's where we left off.
The discussion from last
lecture and for about half of
this lecture is going to be
social psychology.
And so, we started off by
talking about certain
fundamental biases in how we see
ourselves.
We then turned to talk about a
bias and how we see other
people, the fundamental
attribution error.
And now we're talking a little
bit about some aspects of how we
see other people.
So, we quickly talked about
certain aspects of why we like
other people including
proximity,
similarity, and attractiveness,
and where we left off was a
discussion of the Matthew
effect,
which is basically that good
things tend to compound.
If you're rich you'll get a
better education,
if you're smart people will
like you more,
if you're attractive and so on.
Nobody bring up their papers at
this point.
They'll collect them at the end
of class.
What I want to talk to--
[laughter]
Okay, except for you.
Just hand me it now.
[laughter]
I'm going to ask the teaching
fellows to stop anybody from
approaching that area.
I want to begin by talking
about [laughter]
impression formation,
how we form impressions of
others,
and tell you a couple of
interesting things about
impression formation.
The first one is,
first impressions matter a lot.
They matter a lot for different
reasons.
They might matter a lot because
humans have, in general,
a confirmation bias such that
once you believe something other
information is then encoded
along the likes to support what
you believe.
So, the classic study here was
done by Kelley where a guest
speaker comes in and some of the
students received a bio
describing the speaker as very
warm,
the other as--do not bring your
paper up if you're coming in
late.
Just--at the end of class, yeah.
[laughter]
Others got a bio
saying--thanks,
Erik--the speaker was rather
cold and then it turned out
later on [laughter]
when they're asked for their
impressions of the speaker
people are very much biased by
what they first assumed.
If I'm described to you as a
vivacious and creative person
and you see me and I'm all kind
of bouncing around and
everything,
you could then confirm this as,
"Look how vivacious and
creative he is."
If I'm described as somebody
who drinks too much,
you might think he's an
alcoholic.
If he's described as somebody
who's insecure and nervous,
you could interpret my activity
as nervous twitches.
Your first impression sets a
framework from which you
interpret everything else.
This was the theme of an
excellent movie called Being
There starring Peter
Sellers.
And the running joke of the
movie "Being There" was that the
main character,
the character Chauncey Gardner,
somehow through accident had
the reputation for being a
genius but while,
in reality, he was actually
mildly retarded.
But he would go around and
people would ask him his
opinions on politics and he
would say things like "Well,
I like being in the garden."
And because of his reputation
as a genius people said,
"Wow.
That's very profound.
I wonder what he means."
And--or people would talk to
him and he'd just stare at them
and say--and people would
say--would be intimidated by his
bold and impetuous stare when
actually he just totally didn't
know anything.
So, first impressions can shape
subsequent impressions not just
when dealing with people.
A little while ago there was a
sniper, actually a pair of
snipers killing people in
Washington and the one thing
everybody knew about it was
there was a white van involved.
It turned out there was no
white van at all but in the
first incident somebody saw a
white van,
this was reported in all the
newspapers, then every other
incident people started seeing
the white van.
So, they started looking for
them and they started to
attending--attend to them.
So, first impressions matter
hugely when dealing with people
because it sets the stage for
how we interpret everything
else.
A second finding building on
the first is that we form
impressions very fast,
very quickly,
and this is a literature known
as "thin slices."
The idea is you don't have to
see much of a person to get an
impression of what they are.
The first studies done on this
were actually done on teachers,
on university professors.
So, university professors have
teaching evaluations and you
could use this as a rough and
ready approximation of what
students think of them.
So, what you do then is--the
question that these people were
interested in,
Rosenthal and Ambady,
two social psychologists,
were how long do you have to
look at a professor to guess how
popular a teacher he is?
So, they showed these clips for
a full class.
Do you have to see them for a
full class?
Do you have to see them for two
classes?
Do you have to see them for a
half hour?
How long do you have to be
around a person to see him,
to estimate how good a lecturer
that person is?
And the answer is five seconds.
So, after clips of five seconds
people are pretty good at
predicting what sort of
evaluations that person will
have.
Remember "The Big Five," how we
evaluate people on "The Big
Five?"
Well, you have a roommate and
your roommate you could evaluate
on "The Big Five."
You've had a lot of experience
with him or her.
How much time do you need to
evaluate somebody on the five
dimensions of personality?
The answer is,
again, not much time at all.
After very brief exposures to
people, people are very accurate
at identifying them on "The Big
Five."
One of the more surprising
findings is--concerns sexual
orientation or "gaydar."
That's not a scientific term
[laughter]
but the same psychologists were
interested in studying how
quickly you can--if at all how
long does it take to figure out
somebody's sexual orientation?
Now, what they did was--they
were clever psychologists so
they set it up in a study where
the people did not know sexual
orientation was at issue.
So, for instance,
they may be people like you who
filled in a form,
one question along a very long
form was your sexual
orientation,
and then you're sitting down
being interviewed by somebody
and your interview is being
filmed,
and then other people are
shown--who don't know you are
shown the film.
And the finding is that people
based on thin slices are quite
good at detecting sexual
orientation.
Everybody's good at it,
gay people are better at it
than straight people,
and, again, you don't need much
time.
You just need about a second.
You see somebody for about a
second, you could make a guess.
You're far from always right.
In fact, you're just a bit
better than chance but you are
better than chance at telling
sexual orientation.
So, these two facts taken
together, thin slices and the
power of first impressions,
means that just by a brief
exposure to somebody it shapes
so much of how you're going to
think about them in the future.
Now, we can look at this from
the other direction.
We're talking about the
perceptions of other people,
how we perceive other people,
but social psychologists are
also interested in the question
of what happens to other people
as a result of being perceived
in a certain way.
So, one question is,
"What would cause me to
perceive somebody as intelligent
or stupid, gay or straight,
anxious or level-headed?"
A second question is,
"What are the effects of being
judged that way?"
And psychologists have coined a
term, talk about self-fulfilling
prophesies,
and the claim here more
specifically is what's known as
"the Pygmalion effect."
And the Pygmalion effect is if
I believe you have a certain
characteristic this might cause
you to behave as if you have
that characteristic.
The name comes from the play by
George Bernard Shaw
Pygmalion,
and the quote here is "The
difference between a lady and a
flower girl is not how she
behaves but how she's treated.
I shall always be a flower girl
to Professor Higgins because he
always treats me as a flower
girl and always will,"
made into a better known movie,
My Fair Lady.
But I think that the same theme
is better exemplified in a far
better movie,
La Femme Nikita,
where a cold-blooded killer is
treated with respect and
affection and then she becomes a
much more warm and accessible
person,
and then she kills a lot of
people but that--[laughter]
but still it illustrates the
point.
And this point has tons of
empirical validity.
The classic experiment was by
Rosenthal and Jackson where they
told teachers that some of their
kids were really smart and other
kids were less--were not really
smart,
they weren't expected to show a
huge jump or spurt in their IQ,
and this was of course
trickery.
The children were chosen at
random but the children who were
described as showing--as
expected to show a jump in IQ,
in fact, did show a jump in
their IQ scores and this isn't
magic.
It's basically--if I am told
that you're a genius and your
genius is about to be in
full-flower throughout this
class and it's a small class as
these classes were,
I'll focus more on you,
I'll give you more of my
attention.
If I'm told "not so much for
you," you'll suffer relative to
him.
And so the Pygmalion effect
shows how our expectations can
really matter.
This brings us to the
final--the issue of expectations
and how we judge people is a
story that could be told about
individuals but it's also a
story that could be told about
groups.
And this is where I want to end
this section on social
psychology by talking about
groups.
A lot of social psychology is
concerned with the question of
how we think about human groups
and we've already discussed this
in the lecture on morality when
we talked about the human
dynamic pushing us to think in
terms of "us" versus "them" as
shown in the Robber's Cave study
and also shown in the minimal
group research by Tajfel showing
that from a motivational,
emotional standpoint it's not
difficult for us to think in
terms of "my group" versus "your
group."
And this way of thinking has
real consequences for our
emotional life,
our affective life,
and how we choose to distribute
resources.
What I want to talk about here
though is a different aspect of
how we think about human groups.
I want to talk a little bit
about stereotypes.
Now, "stereotypes" in English
often just is a bad word.
To have a stereotype is to
be--is to have something wrong
with you.
You might say it's not good to
have stereotypes.
Psychologists tend to use the
term in a broader sense.
We tend to use the term to
refer to information we have
about categories and intuitions
we have about the typicality,
our frequency of certain
features of categories.
And it turns out that
collecting information about
categories is essential to our
survival.
We see novel things all the
time and if we were not capable
of learning and making guesses,
educated guesses,
about these novel things we
would not be able to survive.
So, when you see this object
over here you categorize it as a
chair and you recognize that you
could probably sit on it.
This apple is probably edible,
this dog probably barks and has
a tail and eat me--eats me and
doesn't speak English.
These are all stereotypes about
chairs and about apples and
about dogs.
It doesn't mean they're
logically true.
This could be a vegetarian dog,
a poison apple,
an explosive chair,
but [laughter]
they're typically true.
And if you were suddenly
stripped of your ability to make
generalizations,
you'd be at a loss.
You wouldn't know what to eat,
how to interact.
So, some sort of ability to
record information and make
generalizations is absolutely
essential to making it through
life.
What's interesting though is we
also categorize types of people.
So, we have stereotypes in our
heads about men and women,
about children,
adolescents or adults,
whites, blacks,
Asians and so on.
Now, this is not essentially a
bad thing for a couple of
reasons.
First, some of these
stereotypes are positive.
You might have positive
stereotypes about certain
groups.
You might believe some groups
are unusually creative or
intelligent.
You might have a particularly
positive stereotype about your
own group even if your own group
is Yale students or your own
group is people from France or
your own group is people from
such and so college.
You might have positive
stereotypes.
More importantly,
we collect stereotypes about
groups of people through much
the same way we collect
stereotypes about categories
like chairs and apples and dogs.
And so they're pretty often
accurate.
When there are studies which
ask people who is more likely to
be a lawyer, someone who's
Jewish or someone who is
Hispanic,
who is likely to be taller,
somebody from Japan or somebody
from Sweden, people can answer
these things.
They have their stereotypes
that guide their answers,
and the answers are not
arbitrary or random.
Their answers are often correct
and often possessing stereotypes
lets us make reasonable and
correct generalizations about
the world.
That's the sort of good news
about stereotypes but there's
also bad news.
One problem is that they're not
always accurate and there's a
couple of factors that could
lead them away from accuracy.
One is what we talked about
before regarding first
impressions, which is a
confirmation bias.
If you believe that homosexuals
are effeminate,
that gay men are effeminate,
then this is going to shape how
you see future gay men.
If you see an effeminate gay
man, you'll probably say,
"Ah, more evidence for my
theory."
If you see a man who is not
effeminate, you might ignore it
or say maybe he's not really gay
after all.
If you believe black men are
criminals, then when you see a
black man who is a criminal
you'll chalk it down as support
but you'll pay less attention to
evidence that white men are
criminals and some black men are
not criminals.
You won't look at this as a
scientist objectively scanning
data.
Rather, you'll be biased in
certain ways.
You'll be biased to put extra
weight on the cases that support
your theory and diminish cases
that refute it.
Furthermore,
our data is not always
reliable.
So--oh, and this is actually an
example of this at work.
It turns out in the world of
classical music there's a
stereotype of women being simply
less proficient than men:
they play smaller than men,
they don't have the same force
and they have smaller
techniques, they're more
temperamental and so on.
If you asked somebody who was a
judge, the judge would say,
"Look.
This is just the way things are.
I'm not being biased at all."
The test of this then is to
have blind auditions where
people do their auditions behind
a screen so you can't tell
whether they're man or a woman,
or for that matter,
white or black or Asian or
whatever.
It turns out when you do that
women get hired far more
suggesting that the stereotype
is A,
incorrect and B,
has a real negative and unfair
effect on people getting hired.
A second problem is – what I
was talking about immediately
before this – is some of our
data are misleading so we get a
lot of the information about the
world from the media.
The media would include
television and movies but would
also include plays and books and
stories.
And to the extent these portray
an unrealistic or unfair or
biased perception of the world
we could construct stereotypes
that are faithful to the data
we're getting but the data is
not representative.
And so people,
for instance,
object to the fact that when
there's Italian Americans on TV
they're often members of the
Sopranos, a mobster family.
Throughout history Jews have
been upset at the portrayal of
Shylock in "Merchant of Venice,"
not a very nice guy.
And often in response people
who want to foster more positive
views will often try to--will
often put in representatives
from other groups in unusual
ways to make that point.
Anybody here ever see the
television show Battlestar
Galactica?
Okay.
Who's that?
He's the star of "Battlestar
Galactica."
You don't know because you're
too young.
In the original
"Battlestar"--[laughter]
and I hate you.
[laughter]
In the original "Battlestar
Galactica," this was the star.
This was the main character
known as "Starbuck," who got
transformed into a woman in the
more recent one,
a sort of example of how
portrayals are shifting in
interesting ways.
There's also,
of course, moral problems over
stereotypes.
So, it's fine to judge chairs
and apples and dogs based on the
stereotypes.
It's even fine to judge breeds
of dogs.
If I told you that I decided to
buy a greyhound instead of a pit
bull because I wanted a dog of a
gentle temperament,
nobody would scream that I'm a
dog racist [laughter]
involving--and--but honestly,
it's a stereotype.
Greyhounds are supposed to be
more passive and gentle than pit
bulls.
I think it's a true stereotype
but it's a stereotype
nonetheless.
But we have no problems when it
comes to things like breeds of
dogs with stereotypes.
We have serious problems
judging people this way.
So, for instance,
it's a moral principle that
some of us would hold to that
even if stereotypes are correct
it is still immoral to apply
them in day to day life.
The term for this would be
"profiling."
Now, it gets complicated
because there are some cases
where we do allow stereotypes to
play a role.
When you all go and get
driver's licenses or when you
did get driver's licenses you
have to pay higher auto
insurance premiums than I do.
I think this is perfectly fair
because young people like you
get into a lot more accidents
with your reefer and your
alcohol [laughter]
and so it is--now,
some of you are saying "that's
a stereotype."
And it is a stereotype but it's
a statistically robust one and
nobody lines up to protest this.
It's an acceptable stereotype
to make a generalization from.
On the other hand,
what if insurance companies
determined that people from Asia
got into more accidents than
people from Europe?
Would people be equally
comfortable charging people from
Asia higher rates of insurance?
Almost certainly not.
So, the issues are complicated
as to what sort of
generalizations we're--are
reasonable to make and what
aren't.
There's also a second problem.
Stereotypes have all sorts of
effects.
Now, some of them are obvious
effects.
If people--for instance,
if people pull you over while
you're driving because you're
black,
this could have a huge effect
on how you feel welcome in this
society on race relations and so
on.
But some of the effects are
more subtle and more interesting
and you might not expect this.
And this is some work done by
the psychologist Claude Steele
and his colleagues at Stanford.
And the issue is called
"stereotype threat."
Imagine you have a math test
and this is the front of the
math test.
Claude Steele made an
interesting discovery.
Here is how to make black
people do worse on this math
test.
It's very simple.
The finding is that if your
race or your group has a
negative stereotype associated
with it in any particular
domain,
being reminded of it serves as
a stereotype threat and hence
damages your performance in all
sorts of domains.
If the stereotype is "your
group doesn't do good in this,"
if I remind you that you're a
member of that group immediately
before doing it,
your performance will drop.
Now, you know how to make women
do worse on math tests too,
like that, and this has a
demonstrative effect.
So, stereotypes are complicated
and morally fraught things.
When people study stereotypes
they often make certain
distinctions between three
levels of stereotypes and this
is nicely summarized here.
There's "public."
If I asked you:
One of the people running for
the Democratic nominee for
president is black,
another one is female--if I
asked people to raise their
hands for who thinks that
because being black or because
being female they should be
automatically disqualified for
being president,
few of you would raise your
hands.
Those are your public
presentations of stereotypes.
Even if I was to ask you on a
sheet of paper,
you might deny it because you
might be afraid that it's not
anonymous.
Then there is private.
Private is what you really
think but you don't tell people.
Some of you--some of the
population of the United States
are not going to vote for
somebody because he or she is
black but they won't tell you
but they know it to be true.
That's common sense.
What's more interesting is
below even that there may be
unconscious associations that
work that people don't actually
know about but affects their
thoughts about race,
gender and other social groups.
So, here are some data about
what people publicly say.
This is the proportion of
people who say they will
vote--they would vote for an
African American president.
What's interesting is
when--around when I was born the
answer in the United States was
about half.
Now, it is as close to one
hundred percent as you can get
it.
Here is another one.
This is also public stereotypes
of blacks, proportion of white
respondents endorsing each
trait.
Now, it's infinitesimal.
These numbers are so low they
could be dismissed as people
filling in the wrong things or
making jokes or just being
confused compared to [laughter]
stunningly superstitious high
rankings.
And so, there's been a profound
change in public presentations,
public views,
on race but what about implicit
views?
This gets more complicated.
Here is a simple study.
This is the sort of study that
you might do here at Yale.
What you might do,
for instance,
is be sitting at a computer
screen and you'll be given
incomplete words to fill out
like "hos-" and you have to fill
out this word.
What you don't know is that
pictures of black faces or
pictures of white faces are
being flashed on the screen but
they're being flashed on the
screen subliminally so fast you
don't even know you're seeing
them.
Still this has an effect.
When you see black faces
subjects are more likely to fill
this with words like "hostile"
while whites more likely to fill
it with words like "hospital."
I will now welcome you to
participate in an experiment on
implicit attitudes.
This was developed by Mahzarin
Banaji who used to be at Yale
and now is in an inferior
university in Boston [laughter]
and it's called implicit
attitudes test and it's the
biggest psychology experiment
ever done in terms of people.
I don't know.
A million people have
participated in this and you
could just go online,
implicit.harvard.edu and then
you could do it yourself.
But we'll do it now as a group.
If you did it in the lab or on
your computer screen,
you would do it by pushing
buttons.
We'll do it by speaking.
And it's very simple.
You're going to see things over
here and they're either going to
be words or they're going to be
pictures.
If it's an African American or
a bad word, a negative word,
I want you to shout out
"right," this side,
"right."
If it's a white American or a
good word, I want you to shout
out "left."
People ready.
Try to do it as fast as
possible without making any
mistakes.
[laughter]
Because of the very loud wrong
person we're going to try that
again.
[laughter] Are you ready?
[audience response] Good.
That is "congruent," congruent
according to a theory that says
that people, both African
Americans and white Americans,
have biases to favor white
Americans over African
Americans.
How do we know by this?
Well, we compare it.
That's "congruent."
Now, it's different.
If it's a white American or a
bad word, say "right."
If it's an African American or
a good word, say "left."
Okay.
For all I could tell,
people did equally well but
this experiment has been done
tens of thousands of times and
you could do it yourself on a
computer screen.
And this is one way of doing it
but they'll alternate and
they'll give you different ones
to shift around and everything.
And it turns out that this
version people are slower at
than the other version
suggesting that their
associations run one way and not
the other.
And this work has been extended
for all sorts of ways looking at
for example at gender,
looking at the connection
between women and English and
men and math,
looking at age,
attitudes towards people who
are obese versus people who are
thin, attitudes towards people
who are straight versus people
who are gay,
and you could go online and do
these studies and it'll give you
some feeling for the sort of
implicit attitudes that we have
within us.
Well, a legitimate question is
"Who cares?"
I mean, if you do the--If you
look at the results for the
study, it turns out that there
is an association as bias to
view white Americans as positive
and African Americans as
negative but it shows up in half
a second difference.
Who cares?
Well, there's two answers to
this.
One answer is there are times
in your life where half a second
can matter a lot.
So, studies with police
officers using reaction time in
split-second choices on who to
shoot find that your
stereotypical attitudes play a
huge role in who you're likely
to shoot when they're holding an
object in their hand that's
unclear.
Also, more generally,
it could be that these implicit
attitudes play a role in
judgment calls.
In cases where you have a hard
decision to make,
you know you're not racist.
You have no explicit racist
attitudes, honestly you really
don't, but the argument is that
these stereotypes can affect
your behavior in all sorts of
subtle ways.
Here is one example.
What they do is they do an
experiment where somebody is in
trouble.
You hear a scream from outside
either from a black person or a
white person.
In one condition you're the
only person around.
In another condition there's
other people around you.
Now, we know from the work in
the Bystander effect that in
general which one are we more
likely to help in,
when we're the only person or
multiple?
"Only," exactly.
And in fact,
when it's the only person just
about everybody helps regardless
of the color of the person in
trouble but when you're with
other people there's a big
difference.
Now, again this isn't--these
things are not done with members
of the KKK.
They're done with the standard
university undergraduates like
you and these--and if you were
in this group you wouldn't say,
"Oh.
I didn't want to help because
the person's black."
Rather, what you would say is,
"Well, I didn't think it was
worth helping.
There were other people around.
Someone else would help," but
we know by looking at it that
this difference makes a real
difference.
A final study,
and this was done by my
colleague who just got hired
here, Jack Dovidio,
who's done some wonderful work,
looked at how people judge to
hire somebody based on their
recommendations.
This is a little bit of a
confusing thing.
The green bars are the African
Americans.
The blue bars are the white
Americans.
And in some cases these people
have strong recommendations.
When they have strong
recommendations in 1989 you're
willing to hire everybody,
and this is not a difference at
all.
But when their recommendations
are so-so, when it's a judgment
call, the subjects are
significantly more likely to
hire the white American than the
African American.
Nineteen eighty-nine was a long
time ago but the same results
showed up in 1999.
The same results also showed up
about a year and a half ago.
And again, this doesn't show
that people are explicit
terrible racists.
It does show that people
possess these stereotypes that
make a difference in their
real-world behavior.
A way to put this all together
is in Trish Devine's
automaticity theory,
which goes something like this.
The idea is that everybody
holds stereotypes.
These are automatically
activated when we come into
contact with individuals.
In order to not act in a
stereotyped fashion,
we have to consciously push
them down,
we have to consciously override
them, and that's possible,
but it takes work.
It takes work both at the
individual level and it takes
work at the group level.
Any questions or thoughts about
this?
Yes.
Student: [inaudible]
Professor Paul Bloom:
It's a good question.
These results are surprising
and disturbing and I said there
is work to be done at an
individual and group level and
this young man challenged me to
be more explicit about that.
Here is one case.
We have job searches and
sometimes job--senior job
searches involve the faculty
sitting in--around in a room and
tossing out names and we use
these names as a basis for
further discussion.
"Hey, I wonder--What about that
person?
That person does great work."
What we do now in the
psychology department is we make
a special point of trying to get
names from disadvantaged groups,
not with an eye towards an
affirmative action policy but
rather because there's a lot of
evidence suggesting that people
who are just as qualified don't
come to mind unless you make
some sort of procedure to do it.
Here's another example.
A lot of journals do blind
reviewing now because of the
evidence I talked about before
regarding sexual stereotypes,
that whether it has a male name
or a female name makes a
difference.
So those are not--those are
group level in that they're not
saying, "You get rid of your
prejudices by trying harder."
It's rather,
"Let's set up a system so that
your prejudices can't work," the
blind auditions,
for instance,
being a beautiful example of
that.
At an individual level,
your question's a harder one
and I'm not exactly sure what we
could do but I think what we
should do is be conscious of
these things and know that it's
not enough to say,
"Well, I'm explicitly not
racist so I'll give everybody a
fair shake," but to recognize we
might have biases and to work
hard to overcome them,
not by overcorrecting in some
random way but trying to--if
you're interested for instance
in qualifications setting up
some system that these
qualifications can be observed
absent knowledge of race or sex.
Yeah, in back.
Student: [inaudible]
Professor Paul Bloom:
Yes.
The question's a good one.
How much of this is due to
stereotypes and how much of this
is due to an own-group bias?
So, the fact that--so,
the experiments as I have
described them are to some
extent ambiguous.
The fact that white Americans
favor white Americans over black
Americans might be because of
stereotypes but they also might
be of in-group favoritism.
I think the answer is that both
play a role but some of the
effects are due to stereotypes
above and beyond in-group
favoritism.
And one reason why we know that
is in studies like the IAT,
the Implicit Attitudes Test.
African Americans show much the
same effect as white Americans.
So, African Americans also are
biased against African Americans
and in favor of white Americans,
showing it doesn't reduce to
group favoritism though that
probably plays a big role.
Okay.
I'm going to shift and spend
the rest of this class on a
couple of mysteries.
Here's a summary.
The first one is a minor
mystery.
I think we have some progress
in explaining it.
The second one is a total
mystery.
The first one's sleep.
Sleep is a motivation.
It is a motivation like food or
drink.
It is a form of torture.
I won't get into definitions of
what torture is but it would
cause somebody tremendous pain
and anguish to keep them from
sleeping.
When you're really tired sleep
is what you want to do like when
you're really hungry you want to
eat.
How many people here on
average--from the beginning of
the semester until now get on
average more than eight hours of
sleep a night?
That's good.
Good.
There is a sort of school of
sleep macho.
A sleep macho used to be "I
only get forty-two minutes of
sleep a night."
Now sleep macho is "I sleep
eleven hours."
[laughter]
Who gets on average more than
seven?
On average more than six?
Who here has been making it
since the beginning of the
semester on under six hours a
night?
Okay.
Anybody of you that has been
getting under five hours a
night?
Okay.
There is big individual
differences in how much sleep
people need and sleep itself is
what we spend a lot of our life
on but it's very hard to study
and we didn't used to know much
of it because you can't ask
people what's happening during
it because they're sleeping so
you need sort of clever methods.
One such clever method is an
EEG.
You bring somebody in the sleep
lab, you put electrodes on their
scalp and you see what
these--what sort of electrical
activities you get in the brain.
Right now many of you are
showing irregular beta waves
suggesting intense comprehension
and great intellectual focus.
[laughter]
Some of you are awake but non
attentive and your brain's
giving you these large,
regular alpha waves.
Some of you are sound asleep,
deep in delta.
[laughter]
When you sleep you get the
following stages.
You start off with a transition
period when you're falling
asleep.
We call that stage I.
Then you get successively
deeper, II through IV,
slow, irregular,
high amplitude delta waves,
and then once you reach stage
IV you start going up again,
up through stage III and II.
Then REM sleep emerges,
rapid eye movement sleep.
REM sleep is neat because your
brain looks like it's wide awake
but – and I'm going to talk a
little bit more in detail about
this later – you're relaxed,
your rapid eye movements occur;
that's where your--the name
comes from and dreams occur and
then on a good night's sleep
you've got four to five sleep
cycles and it looks like this.
You start off and you go down,
down, down, and then you come
up, then you get your first REM
cycle,
again, again,
again, again,
again, and then you wake up.
So, the general takeaway
message here is that there's two
types of sleep.
There is slow-wave sleep or
"quiet sleep."
Your eyes drift separately and
slowly you're hard to wake up.
Then there is REM sleep.
Your brain is active as if you
were awake, your EEGs are
similar to waking,
paralyzed except for the eyes,
oh, men get erections and you
have dreams.
One sleep researcher joked that
these two are connected because
what happens is dreams fly
around through the ether and
then their erections serve as
antennas so you pick them up.
[laughter]
Don't write that down.
[laughter]
Why do we sleep and why don't
we--why aren't we always awake?
There's a couple of answers to
this.
Probably the best answer is our
body is worn out during the day
and sleep is necessary to put it
back into shape.
So, when you sleep growth
producing hormone goes through
the body, your brain and other
organs get restored,
there are--you need less food,
your immune system seems to be
hard at work,
and in fact,
one answer--people always
wonder what happens if you'd
stop sleeping and the answer is
not one discovered in the
laboratory but it's been
recorded in different cases.
If you stop sleeping you die.
You don't die in some dramatic
way.
You get sick and then you die,
suggesting that sleeping is
good to keep you healthy.
And an analogy I like to think
about is that your--when you
bring your car in to repair
it--for repairs,
when you're repairing your car,
the first thing you do is you
stomp it and shut off the
engine.
You make it stable and at rest
so you can then work on repair.
A related view is that sleep
emerged to preserve energy and
keep you out of trouble at
night.
And these views are of course
not incompatible.
This explains why we sleep at
all and this probably explains
why we sleep at night.
There are sleep disorders.
I won't go through them.
I just list a few of them here.
They're sort of bad things that
could happen to you when you're
asleep.
One particularly trendy sleep
disorder that's been discovered
recently are side effects of
sleeping pills such as Ambien.
So, one of the bizarre side
effects is some people with
Ambien while sleeping go
downstairs, open up their
refrigerator and eat huge
amounts of food.
[laughter]
A more recent side effect of
Ambien that's quite serious is
some people become--have the
compulsion while they're
sleeping to go driving,
which is not good.
[laughter]
What we're really interested in
though when it comes to sleep is
dreams.
So, remember Hamlet.
People--you've all studied
Hamlet, "to be or not to be."
That's all I know but basically
[laughter]
he was deciding--he--I wrote
this down though.
He was deciding whether or not
to kill himself and so he made
up two lists.
The lists of reasons to kill
himself were "the slings and
arrows of outrageous fortune,"
"a sea of troubles," and "the
heartache in the thousand
natural shocks that flesh is
heir to."
He only had one argument not to
kill himself:
Nightmares.
"To sleep, perchance to dream,
for in that sleep of death what
dreams may come when we have
shuffled off this mortal coil
might give us pause."
He was worried about nightmares.
Now, dreams have always
fascinated people and
philosophers.
If you take a philosophy
course, there'll be a couple of
questions about dreams that you
will wonder about.
One is "Are you dreaming right
now?"
So, Rene Descartes famously
wondered whether the real world
doesn't exist.
Maybe right now it's just a
dream.
See also "The Matrix."
And can you be immoral in a
dream?
We do all sorts of things in
dreams that are bad.
Are these sins?
And the great theologians and
philosophers like Augustine
wondered about this,
can you sin in a dream?
I will answer both questions.
You are not dreaming right now,
unless you're asleep but if
you're--and you can't usually be
immoral in a dream.
The exceptions are lucid dreams
where you choose what to dream
about, and then possibly you
could be immoral if you
encourage bad habits of thought.
What do we know about dreams?
Well, first there's a
distinction, a distinction
between real dreams versus sleep
thought.
So, real dreams are you're in a
submarine wrestling a chicken
while your grandmother looks
disapprovingly on.
Those are real dreams.
"Sleep thought" is the sort of
thing you get typically before
you fall asleep and it's like
"did I take the garbage out,
where is the garbage,
did I take the garbage out?"
And so it's really just this
kind of rumination and you could
do this while you're sleeping.
So, if you're woken up during
slow-wave sleep you're going to
be thinking "Did I take
the--yes,
while I was dreaming I was
thinking about the garbage," but
if you're woken up during REM,
"But a monkey was eating my
grandmother," and that sort of
thing.
[laughter]
So, there is a distinction.
What do people dream about?
Well, we know some facts about
dreams.
Everybody dreams.
Not everybody remembers their
dreams.
If you want to remember your
dream by the way keep your
dreams--keep a dream diary,
very useful,
but everybody dreams three to
four times a night.
That depends on how much sleep
you get but dreams leave fragile
memories.
They fade quickly.
This is why a dream diary or
writing up--writing your dreams
as soon as you wake up turns out
to be useful.
What do people dream about?
Well, basically,
the way to find that out is you
ask people and people
have--psychologists and
sociologists have collected
dream reports.
If you go to dreambank.net,
a guy named Hill collected
50,000 dream reports;
you could make some
generalizations.
Most dreams are bad.
They're not bad,
bad, they're not nightmares,
but most dreams are from a
scale of one to ten with five
and a half in the middle they're
on the negative side.
They report misfortunes.
People in tribal societies have
dreams with more physical
aggression than people in
industrialized societies.
Men have more aggressive dreams
than women.
Americans have more aggressive
dreams than Europeans.
Yeah.
[laughter]
What do people want to dream
about?
Well, psychologist--the
findings were totally not going
to surprise you.
Women want to dream about
romance and adventure.
Men want to dream about sex
with strangers.
[laughter]
Turns out that once you get
past the hormonal blast of
adolescence about 10% of dreams
have explicit sexual content.
What's the most common dream?
Guesses.
Falling.
That's a good guess.
Falling is among the top dreams
but falling is not the winner.
Somebody else.
Flying?
Also close.
Public speaking?
Good phobic dream but not it.
Naked in public, not it.
[laughter] Excellent.
Being chased.
Evolutionary psychologists and
cognitive neuroscientists have
puzzled over this one.
It seems to be sort of a primal
dream but the dream about being
chased is a biggie.
Has anybody here ever dreamt of
being chased that you could
remember?
Yeah.
Being chased is the big one.
Naked in public?
[laughter]
Grandmother killed by a monkey?
[laughter] No.
So, what are dreams for?
There are Freudian theories
that dreams are disguised with
fulfillment and other things.
There is not much support for
these.
One theory which is popular is
that dreams are a side effect of
memory consolidation so your
body,
sort of below the neck,
rebuilds itself while you're
sleeping but also what happens
while you're sleeping is your
memories get played over and
over again to consolidate them
into different parts of the
brain.
Almost--the best analogy here
is backing up a computer.
Your brain backs itself up.
In the course of backing itself
up, there are sort of random
events flash to consciousness
and get put together in a
coherent story.
From this perspective,
dreams serve no adaptive
function at all but rather
they're epiphenomena.
They are the byproducts of
another system.
Final topic is laughter and
this is a true mystery.
I got interested in this--well,
I got interested in this as a
developmental psychologist
watching my own children laugh
and trying to figure out what it
is that made them laugh.
This is my son,
Zachary, pretty young but
[laughter]
this is not the youngest record
of laughing.
I found this on the web.
[laughter] It's a huge puzzle.
From an evolutionary point of
view, people's pursuit of sex
and food and drink and sleep are
not these huge mysteries,
our abilities to understand
language and make sense of the
visual world and cohere in
groups,
but the fact that we make this
weird noise at bizarre
circumstances is a huge puzzle
and typical--typically
psychologists have failed to
explain this puzzle.
So, here's something;
here's a first guess I read in
a neuroscience textbook.
"We laugh when there is
incongruity between what we
expect and what we
actually--what actually happens
unless the outcome is
frightening."
[laughter]
Now, this is a fair effort.
It is about as wrong as
anything can be wrong in any
possible way.
[laughter]
The first thing is it doesn't
really explain "why?"
So, why should a
non-frightening incongruity
cause people to make a
distinctive loud noise consisted
of staccato segments of one
fifteenth of a second each
separated by a fifth of a
second?
It doesn't explain why we make
that loud noise when dealing
with incongruity.
It's not the case that
incongruity causes laughter.
If there was a bowl of fruit up
there as you walked in,
it'd be incongruous but people
wouldn't shriek with laughter
and point to the fruit.
[laughter]
It's also--a lot of laughter
isn't caused by incongruity so a
lot of times when we laugh
there's nothing incongruous in
any deep sense about it.
So, laughter is kind of a
puzzle.
We don't know why we laugh.
We don't know what makes us
laugh.
Over the last five,
ten years there's been some
work done on this.
A lot of the work is done by
Robert Provine who summarizes
this in his excellent book
Laughter. And Provine
decided to do something that
nobody in the history of the
world has done.
He decided to send himself and
his students to different places
including shopping malls and
observe when people laughed and
write down what made them laugh.
And this is the first
descriptive step to developing a
theory of laughter.
And his big finding is that you
could separate people--you could
separate the question of
laughter from the question of a
joke or the question of humor.
Most of what people--what made
people laugh wasn't in any sense
a joke or humorous.
So, he had over a thousand
laughter-initiated situations
and here are some typical
comments that initiated
laughter,
sometimes uproarious laughter,
on the parts of people.
"I'll see you guys later."
"Look.
It's Andre."
[laughter] "Are you sure?"
"I know."
"How are you?"
"I try to lead a normal life."
It's sort of funny.
[laughter]
It was anyway in a context
where it wasn't particularly
amusing.
"It wasn't you."
"We can handle this."
Only ten percent of the
comments were--could be re-coded
later on as people--as actually
humorous in any sense.
And these included "Poor boy
looks just like his father,"
[laughter]
"You smell like you've had a
good workout,"
[laughter]
"Did you find that in your
nose?", [laughter]
a reference to dormitory food,
[laughter], "He has a job
pulling back skin in the
operating room."
[laughter]
So, Provine suggests we
separate the question of
laughter and jokes and then ask
what do we know about laughter?
Well, here are some basic facts
that--remember we're trying to
think like evolutionary
biologists here.
Humans have this universal
trait.
There's no society without
laughter.
It's early emerging as we saw
in those clips.
So, what's it for?
What does it do?
If it's an accident,
what's it an accident from?
What properties does it have?
And there are some properties
that are important to know.
It's social and communicative.
Why do we know that?
Because it's loud.
Laughter is not like hunger.
Hunger can be silent.
Hunger is not essentially a
message to other people but when
humans – when it involves a
loud noise – the reason why
we've evolved loud noises is to
communicate with other people.
Laughter could be viewed as a
form of involuntary noisemaking
and it's contagious.
That's another interesting
thing about it.
One of the great discoveries in
television and movies was the
invention of the laugh track.
The laugh track makes things a
lot funnier because people laugh
a lot more when they're in
groups.
The rim shot after a comic
remark is an attempt to
simulate--sort of a
pre-technological attempt to
simulate the sound of laughter.
Children are particularly
influenced by the contagiousness
of laughter, but just in
general,
if you hear somebody laughing,
like the kids you saw before,
it's the sort of thing that
could easily make you laugh.
Other primates do it to some
extent and then it's interesting
when they do it.
Monkeys laugh when they attack.
When monkeys get together to
kill and eat somebody they make
a kind of a laughing noise and
chimpanzees laugh when they
tickle each other.
And then you'll see--And what's
tickling?
Well, a fair definition of
tickling is touching parts of
the body in a mock attack.
You sort of attack somebody and
they're laughing but if
it's--but if somebody's trying
to mug you you're not "Ah,
this is so funny."
[laughter]
You have to realize that this
is a mock attack;
you're simulating attack.
So one theory is--is a signal
of mock aggression and
collective aggression.
It's basically--it's like a
sound of some sort of mob
attack.
It's mock aggression in the
sense that when people laugh
they're often teasing,
kidding around.
They're throwing out insults,
maybe they're tickling each
other, maybe they're making fun
of each other,
maybe they're making fun of
themselves, and there's some
aggression to it.
Most laughter is inspired by
some degree of aggression,
but it's attenuated and it's
not real.
And the laughter is a signal
this isn't real.
And collective aggression--a
lot of mob assaults,
executions, lynchings,
rapes are accompanied with the
sound of laughter.
When you're in a group doing
something terribly aggressive
and you are not--you don't feel
like you're at risk you might
laugh and laughter is a signal
to other members of your group
as a signal of solidarity and
what you're doing together.
A different way of putting
it--and none of this is going to
come in with a sharp,
decisive theory.
These are sort of flailing away
at different ideas but another
way of doing--an older way is
proposed by Plato,
who viewed laughter as a form
of bonding against a common
enemy.
It's a sound of group cohesion
against the common enemy.
Comedians have not missed the
aggressive nature of laughter.
Dave Barry writes: 
The most important humor
truth of all is that to really
see the humor in a situation you
have to have perspective.
Perspective is derived from two
ancient Greek words,
‘pers' meaning something bad
that happens to someone else and
‘ective' meaning ideally
somebody like Donald
Trump.
[laughter]
And the idea is that it's
something bad happening but not
to you or to somebody you love.
Mel Brooks puts it in somewhat
sharper terms,
distinguishing between comedy
and tragedy: "Tragedy is when I
cut my finger.
Comedy is when you fall in an
open sewer and die."
[laughter]
To sum up, ingredients of humor
is there has to be a target who
experiences some harm.
It could be an enemy.
It could be a friend.
It could be yourself.
The harm shouldn't be so
serious that it elicits strong
negative emotions like fear,
grief or pity.
So, if a stranger slips on a
banana peel and lands on his
butt, I might laugh because I'm
not overcome by compassion.
If he splits his head open and
there's blood everywhere,
I'm less likely to laugh unless
I don't like him or something.
[laughter]
And this is why the humor--why
the damage is often a certain
sort of damage involving things
like embarrassment,
sex, scatology,
a banana peel,
pie in the face,
your pants fall down or
something,
where there's no real harm.
So, empathy,
caring, sympathy don't kick in,
but instead there's the
aggression unleashed at somebody
and there has to be some level
of surprise.
This is what--this is where the
humor for that baby comes in,
which is you couldn't predict
when the sound was coming and
some aspect of that was what
made it so funny then,
what elicited the laughter.
This is--what elicited the
laughter for Zachary was
watching the classic film
Winnie the Pooh and the
Blustery Day where Rabbit
climbed on a high bunch of
shelves and it all came crashing
down on him.
But he didn't--he wasn't dead.
He was just kind of stunned.
[laughter]
Final question for anybody
interested in laughter is,
"Why can't we tickle
ourselves?"
Now, I've talked about laughter
on two separate occasions and on
each of the occasions when I
talked in front of a large group
like this somebody came up to me
afterwards and said,
"But I can."
[laughter]
And [laughter]
I don't--and they seemed
sincere but if people say,
"I can tickle myself," how many
people here will own up to being
able to tickle themselves?
One?
[laughter]
It's a fascinating question why
some people can.
The general story of why we
can't in general is because
there's no surprise,
there's no mock aggression,
and also there may be a general
deadening of self-stimulation.
I'm going to end with the final
reading response.
Think of an interesting
testable idea about either
dreams or laughter.
You could go into as much
detail as you want.
If you want your thing could be
one sentence long but it could
be longer.
I will ask the teaching fellows
to each send me their one or two
most interesting remarks.
I will then judge and then the
winner will win some small
prize, either of a literary or a
food nature.
Okay.
I'll see you all on Wednesday.
 
