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PROFESSOR: What stresses you?
You don't have to divulge
something deeply personal, but
in a general way stresses
people?
AUDIENCE: Lack of sleep
PROFESSOR: Yeah,
lack of sleep's
a pretty good stressor.
AUDIENCE: Exams.
PROFESSOR: Exams and
stuff like that,
grades stuff like that.
What else?
So let's make up some things.
Exams and grades if you're
student, right?
Deadlines of any kind throughout
your life will
stress you.
Traffic when you're trying to
get to the airport to make
that flight, or trying to get
to your job interview and
traffic is twice as bad
as you thought.
Somebody in front of you
seem to be driving
exceptionally slowly.
Sometimes family relationships,
I think even in
happy families, there's points
of stress in terms of a how
different views are
dealt with.
Maybe if you're a college
student, what the rest of your
life will be like, where it's
not four years all set out in
front of you approximately,
right?
But what the rest of your life
will be about and mean that
can be a stress if people talk
too much it to you about that.
What does not stress you
compared to what we might
imagine throughout evolution
was stressful for
mammals like us?
You're mostly not worrying about
being eaten or eating
another person for
dinner, right?
OK that's not an everyday stress
for you, but that's an
everyday stress for mammals
who're trying to survive
because they're the food of
another group, right?
And trying to get their
own food to live.
So the kinds of stressors we now
have in an industrialized
economy or post-industrial
economy is incredibly
different than the stressors
that occurred
for most of our evolution.
And I'm going to take a lot of
these points from a wonderful
book from a wonderful researcher
and writer, Robert
Sapolsky, Why Zebras
Don't Get Ulcers.
He asks in that sense what
stresses a zebra?
They're not worried about exams
and deadlines and MCATS
and things like this, right?
OK what are the forms of
stress that they face.
And they're things like serious
physical injury,
predators and starvation, very
fundamental things about
living and surviving.
Not careers, jobs, timetables,
the kind of world we mostly
live in, unless we have
a health threat.
And so what stress is, is
the psychological and
physiological response to a
stimulus, a stressor, that
alters the body's equilibrium.
And when we talk about stress we
can talk about two forms of
it-- acute, what's
instantaneous; and chronic
what's consistent and goes on.
So acute, physical stress would
be an injury, chronic
things are hunger or cancer,
long term problems.
An acute psychological stress
would be a deadline, a chronic
one would be chronic work
pressure if you have it
throughout the semester.
An acute stressor socially is
humiliation, a chronic one
might be isolation.
And we'll come back a little
bit actually to social
rejection as a stressor
later on.
So, Sapolsky's idea is this,
that for animals in the
wilderness, and for us maybe for
a long time in evolution,
stress is typically acute,
physical, and responsive.
Something happens, it's about
your bodily survival,
and then you act.
For people in the world we live
in, in this room, stress
is often chronic,
psychosocial--
it's not a physical threat
mostly that's happening to
you, it's something about your
sense of yourself in the
world, how you relate
to people, how you
relate to your goals--
and it's anticipatory--
we talked about it for
pleasure also, the
anticipation of reward turns on
your dopamine system once
you know what the reward will
be, not the reward itself.
But when it comes to fearful
things, we also know that we
can have dread.
We dread upcoming things for
quite some time before they
even get here if we think
they're going to be pretty
unpleasant.
And there's a neat study from
Greg Berns about the
neurobiology of dread
in people.
So it's an fMRI study, and in
a way that was approved by
human subjects.
They were waiting for a
cutaneous electrical
shock to the foot.
So it's a shock that's enough
to be unpleasant but not
enough to be dangerous.
And people signed up voluntarily
to do it, and at
each trial you sit
in the scanner.
You're told what's the voltage
level is going to be, compared
to the most unpleasant they use
in that experiment, and
how long until it comes.
So the voltage is how painful
it's going to be, the duration
of time, and something about how
long dread can develop in
anticipation of a painful
stimulus.
And at first you just got the
got the warning, and here
comes the pain.
After a while, you get a
choice and this is the
interesting thing.
Would you rather get, for
example you could think about
this, 90% voltage, that is,
9/10 as bad as the whole
experiment ever has it,
in three seconds--
so something pretty painful,
pretty fast--
or would you rather have 60%
voltage in 27 seconds.
So you can decide for yourself,
which would you
rather have?
And you can see the
trading-off in people's choices--
the actual physical pain, which
is greater than 90%
versus the period of dread, the
anticipation of something
miserable coming up in the case
where it's less pain but
a longer run up.
And what they found is that
people varied in interesting
ways, and they find
some [INAUDIBLE]
of this, but they found that
what they call the extreme
dreaders, that they would prefer
more voltage now than
to wait for any shock
later on.
Like, get it over with now, it's
more painful for me to
sit there and wait for something
even though there's
no painful stimulus than to
just get it over with now.
And maybe we all know the relief
that when we anticipate
something bad, having it happen
sometimes is almost a
relief to be past all that
miserable dread.
So, where in the brain does
some of this occur?
So, one area that we'll come
back to-- a couple different
areas-- one area I want to focus
on is this middle of the
brain, this area called
the cingulate.
And here, regardless of time and
in all subjects, the more
voltage you got, the bigger
the brain response.
OK, that's not very surprising,
it's in a part of
the brain-- we'll come to this
a little bit later-- that's
involved in the interpretation
of pain.
More voltage you get, it's easy
to interpret it as worse.
And then you say, what's the
difference in the people who
are the extreme dreaders, the
people who would say no matter
how bad the pain, I would rather
have it now than wait
for a lesser pain for
a few more seconds.
Give me the worst now, I have
to get it over with.
And what they found in the
brains of those individuals,
shown in red in this figure, is
that even before anything
was coming on in the same brain
areas that responded to
the pain, there was a rise in
activation as if the pain was
already happening.
The same areas that are involved
in responding to the
pain, especially in the people
who dreaded it the most, who
would take more pain now to
avoid the wait, those parts of
the brain are already showing
a pain-like response before
anything has arrived,
a physical
manifestation of dread.
So let's go back to mortality
for a moment.
So, in 1900, think about this,
what were the major causes of
death in the United States?
And they were mostly from
infectious disease and
childbirth.
Childbirth was extremely
dangerous in 1900.
So the most common causes
of death were pneumonia,
tuberculosis,--
if you know about this it won't
surprise you, but if you
haven't studied this in
history recently--
influenza, flu, in 1918 it
killed more Americans than
World War I, which was high at
that year it was killing many,
many people, and childbirth
and especially of course,
that's going to be
in young women.
How about a few years ago in
2007, which is roughly now,
how many people are dying
of these things?
Not so many in the United
States, they're dying of
diseases that are conceptualized
as cumulative
damage diseases, not an
infection but things like
heart disease, where over many
years a combination of
lifestyle and stress might
harm your heart function,
might promote the growth of
cancer, might promote a stroke
or cerebral-vascular disorders
including stroke.
And many of these diseases are
viewed as a combination of
long-term lifestyle things,
maybe exposure to toxins in
the environment, and some
mixtures of those.
Not a one-time, one-shot
infection or child delivery,
but long slow processes
that finally
culminate in mortality.
So, many of our current ideas
about stress come from a
researcher named Hans Selye And
in the 1930's, it turns
out, he's one of the main people
thinking about stress
as an important thing in our
life, but he was infamously
not good for his handling of
rats in the laboratory.
Now have any of you
handled rats in a
laboratory by your hands?
I see one hand going up
there, any others?
OK, how easy is it
to handle them ?
When you pick them up and do
stuff, are they like thank you
very much, I knew it was time
for injection or time for
feeding or whatever
you do with them?
No?
Are they kind of squirreling
around a lot and wiggling and
not very happy when you pick
them up, on the whole?
About as happy as we would be
if a giant picked us up and
shook us, and injected us with
the stuff for the day?
I was only involved in one rat
experiment ever and I can't
claim to be a great success like
Selye , but I can claim
to be as bad as he was
with handling rats.
Because it was kind of scary,
they were really mean and want
to get out of your hand.
Of course, from their
perspective they're just
trying to live the life they
were meant to lead and you're
fighting with them and you're
forcing them into this thing
that thing to get injected, and
they're squirreling around.
So, he was doing an experiment
where they had extracted
ovarian chemical, and they were
trying to figure out what
it does at the time.
He injected the rats daily.
And he was pretty bad, by his
own admission, he would drop
them on the floor and they would
scurry behind tables.
He would hunt them down
and drag them out.
And he would do this day in,
day out for months because
they were on a daily
experimental schedule.
And what he found, after
months of this sort of
inadvertent nonstop stressing of
the rats, because of course
the better thing to do if you're
skilled is to just pick
them up with authority,
inject them, and
put them back, right?
All the fighting and stuff from
the poor handling is not
making them any happier.
What he found in them is peptic
ulcers, ulcers in their
eating system, enlarged adrenal
glands, shrunken
immune tissue, but it wasn't
about the ovarian chemical, it
was also in his control rats.
Basically he was giving all
of them stress-induced
physiological changes.
And what he was impressed by,
and many other people too, is
that you can expose rats to a
whole huge range of stressors,
different things you do in their
environment, and they
all seem to converge on these
ulcers, these enlarged adrenal
glands, and shrunken
immune tissue.
A lot of different things that
can stress you seem to
converge upon a common
biological pathway and
consequences for the animal.
So stress response is similar in
a broad array of stressors,
and if they go on for too long,
people get sick, the
chronic stress.
So, you remember from your
introductory biology courses
and so on, that when we talk
about the autonomic nervous
system in people, there's
a sympathetic and
parasympathetic branch.
The sympathetic goes from the
brain to the spine to organs
to blood vessels to sweat glands
to muscles and hairs,
that's why you get goosebumps
when you're scared.
That's the nerves innervating,
that's when your
hair stands on end.
It turns on for emergency
situations, arousal,
activation--
the famous joke that it's
related to the four F's,
flight fright, and sex.
I was so afraid I'd mess
it up, I couldn't
read the four word--
flight, fright fight, and sex.
And it releases epinephrine
and norepinephrine.
Epinephrine and norepinephrine
is the same thing as
adrenaline and noradrenaline,
one's English-American, and
one's American-American,
same thing.
The parasympathetic is your
zen, couch-potato system.
It operates highly when you're
asleep or you're eating or
you're relaxing.
And so you can talk about
different organs and how
they're responding to the two
kinds of systems when one is
up and one is down they're in
mutual opposition or balance.
So in the heart, when you're
sympathetic, when you have to
activate a run from being
attacked and your heart rate
speeds up, your parasympathetic
system will
turn it down.
For the blood it's seceded to
muscles, and when you're in
sympathetic action and when
you're in parasympathetic
relaxation it's drawn from the
muscles to other organs.
Part of that response too is
the hypothalamus, which
releases corticotropin releasing
hormone to the
anterior pituitary.
In about 15 seconds that
releases ACTH into the blood,
that reaches the kidney and
a few minutes later that
produces glucocorticoids, or
steroids, or cortisol, that's
often used as a marker for
stress response, a brain to
hypothalamus to pituitary
to kidney circuit.
And then we can talk about how
what can be adaptive response
in an acute emergency can become
maladaptive if it's
chronic and happens over
and over again.
So mobilization of energy good
when you're escaping danger,
but if you have it all the time
maybe it leads to muscle
weakness, myopathy, fatigue
or diabetes.
Increased cardiovascular tone
good for escaping danger,
stress-induced hypertension
not good.
Suppression of digestion, you
don't want to start to spend
energy on digestion when you're
running for your life
but if you suppress it too
much it's associated with
ulceration and colitis.
Suppression of growth-- we'll
come to that-- if you're in a
growth period of your life,
that's metabolically expensive
to do, growth.
You turn off growth mechanisms
briefly when you're in
sympathetic action.
Reproduction is turned off or
down, too much of that may
lead to impotency
loss of libido.
Suppression of the immune
system, again you're turning
down energy spent on immune
processes temporarily for
emergency, too much of that
you could have increased
disease risk.
Sharpening of cognition,
you want to be as smart
as you can be, right?
Under danger circumstances,
having your system in high
gear all the time can lead to
neuronal death, and I'll show
you an example of hippocampal
shrinkage that occurs with
stress in that way.
So everything that can be
adaptive in one hand, can be
related to stress-related
disorders on the other hand in
the heart or in the arteries.
And here's a picture
of a stomach ulcer.
We'll come back to that because
the ulcer is one of
the great interesting stories of
the second half of the last
century, is the complete
re-interpretation of why
people get ulcers.
So, let's talk about that now.
So, the adaptive response when
you're in an emergency is to
suppress digestion,
that's part of
the sympathetic response.
And stress has long been
associated with getting ulcers
which are holes in the
walls of your organ.
Now, for many, many, many
years, physicians and
scientists thought that getting
ulcers in adults was
associated with a combination
of stress and diet.
And people who had ulcers were
told try to have less stress
in your life and eat
more bland food.
And then Robert Warren and Barry
Marshall won the Nobel
Prize in 2005.
But this is one of those stories
in science where
everybody literally ridiculed
these people in conferences
and papers they were literally
ridiculed by the entire
orthodox scientific field,
because they put forth the
idea, which had been around a
little bit but they really
pushed it, that this was due not
to the combination of diet
and stress but it was due to an
actual specific bacterium.
And people thought that's
ridiculous because our
stomachs are so acidic that no
bacterium would survive in the
acidic environment of our
stomachs long enough to do any
harm in this sort
of chronic way.
And part of the way, as they
struggled to get data, they
did these kind of funny
experiments where Marshall
went and took the bacterium they
suspected and actually
swallowed it to see what
would happen, OK?
This kind of weird, heroic
self medical experiment.
And he thought, like in 10 years
I'll see if I have an
ulcer, but what happened is
within a couple of days he was
having severe gastritis, severe
disturbance of the
stomach, and that was
the first piece of
evidence they could do.
He couldn't find out if he would
have an ulcer in the
long run because his wife made
him take medications right
away after that.
But still, that built up the
case that it's a bacterium
that's swallowed that
causes the gastritis
that leads to ulcers.
And that if you get people
antibiotic treatments that
will treat the bacterium,
they improve a lot.
So, a complete re-understanding
of what
caused the disorder and
how to treat it.
So, some people say, well it was
never about stress, it was
always about the bacterium,
that's it, it's a simple
biological story.
But there's two ways in which
probably stress is relevant.
One of them, the milder one,
is that out 15% of cases of
ulcer don't have any measurable
bacterium, they
don't seem to have that, OK?
So who knows about that 15%.
But here's the more
amazing piece--
many, many, many of us have
this bacterium, it's
incredibly common widespread
bacterium.
But only 10% of the people
who have the
bacterium have ulcers.
OK, so it seems like it's not
just about having the
bacterium, but it's interaction
perhaps, between
the bacterium and the stressors
of your environment.
There's not many stories about
suppression of growth, but
there's one historically
interesting one, so this is at
the edge of science, this
is an anecdote.
I'll show a clinical case, you
can't do many experiments
about this, about what's called
psychogenic dwarfism,
an inability to get to standard
height that's thought
to be based on psychological
principles.
So this is a story of a British
Victorian family,
their favorite son was
killed at age 13, a
tragic loss of a son.
The bereaved mother takes to her
bed for years, she doesn't
leave her room or bad, and
she ignores her surviving
six-year-old son, constantly
idealizing the boy who passed
away, having almost no interest
in the surviving son.
And when he would come into the
room, bringing her food to
her room as she lay in her bed
in severe depression, she
would say to him David--
that's the boy who
passed away--
oh David is that you?
Oh, it's only you, she would
say to the surviving son.
So, depressed and discounting
her surviving son.
David was always perfect,
the surviving son was an
irritating reminder.
He grew to only 5 feet as an
adult, and he's famous for
writing the play Peter Pan.
So the next time you see the
play, or see the movie, think
about what childhood means to a
person who had this kind of
childhood, and grew to
a very short stature.
It was interpreted as a
psychological response to a
long period of stress,
the lack of
attachment from his mother.
And here's a clinical case of
a child who went into a
hospital, you can see this
picture of this child growing,
he was in obviously a
non-supportive environment.
He enters a hospital and his
growth hormone level is 5.9,
it's very low.
He takes to a nurse, and 100
days later it goes to 13, it
more than doubles.
He's gaining height
considerably.
The nurse goes on vacation, he
goes back to his low levels of
growth hormone and growth.
She returns and he goes back to
typical growth of height.
So, very psychological
relationship between his
physical growth and his
relationship to the nurse.
And so we understand this to be
extreme cases of emotional
neglect or something like that
in the homes, these are not
small spats with your parents.
But again, a relationship
between a very chronic stress,
an emotional one, and then
physical growth.
Now this is a famous chair, and
the story goes like this.
In the mid-1950's Meyer Friedman
and Ray Rosenman were
cardiologists on the West
coast, and they had a
cardiology practice.
And they had a chair, and this
is the chair, that sat in
their waiting room.
And they had a guy who came, in
his name is lost to history
although everybody agrees he
gets credit for beginning this
idea, and his job was to
re-upholster the chairs.
And he told these two
physicians, I go to a lot of
places and I work in a lot of
offices, and nowhere do I go
do I have to re upholster chairs
as often as I do in
your office.
And this triggered a thought in
these two people, because,
don't forget that for many
physicians, understandably,
and maybe less so now,
cardiology is like real
biology and psychological stuff
is kind of peripheral
and edgy, may not
really matter.
OK so to Friedman and Rosenman's
credit they say
what is going on?
Why does our chairs
look like this?
Now, sometimes you might have
that experience yourself, have
you ever stood in line in a
way that's unbelievably
irritating because you have
somewhere to go, and there's
somebody really slow in front of
you or somebody working the
line who's really slow?
And you're going come on, I've
got like minutes to go here,
can't I get my coffee or
my tea or whatever.
Have you ever seen people jump
from line to line in grocery
stores because they cannot bear,
they dread that moment
when they get somebody who
gets into the line where
you're supposed to have
10 and they have 12?
Have you seen that?
None of us think that's quite
fair play, but some of us say
OK, wish they had 10 items,
and some people are really
mad, right?
OK, so that's type A personality
and we'll talk
about that in a moment.
And what they began to say is
the patients are sitting in
the office, fidgeting,
fidgeting, fidgeting, where's
the doctor?
Where's the doctor?
I have important things to do.
And they're wearing down the
arms and the chair because
they're so fidgety waiting for
that appointment to happen.
Not just for one moment but for
a long time and they're
literally wearing
down the chair.
And they're showing up at a
high rate to a cardiology
practice of people with
heart problems.
And that's developed this idea
that a huge threat--
and I'll qualify this
in a moment
with subsequent studies--
but in the 1960's, that type A
personality, you've heard that
phrase perhaps, type A
personalities, this is where
that began.
It's become a widespread term.
These are people who are
immensely competitive,
over-achieving, time-pressured,
impatient,
hostile, and they have
increased risk of
cardiovascular disease.
And in the first analyses, the
risk if you had this kind of
personality was equal to
smoking or very high
cholesterol.
I mean, there's a very high
risk and that's why these
chairs were being worn down by
the type A personalities
showing up with cardiac problems
because they were
stressing themselves all the
time by everyday life events.
And this picture sort of--
they had anecdotal things,
they had a early morning
group, a patient support group
for type A individuals with
cardiovascular disease to get
together and say, OK when I'm
really stressed out, I'm
going to count to
5 and relax, right?
It was a support group.
So, here is your car.
So, now when you go park your
car sometimes, there's some
people depending on the
situation who park forward
into their spots.
But if you know you have to get
away super fast and you
don't have a minute to waste,
how do you park?
You park backwards, right?
So when you jump into your car
you can hit that accelerator
and you're out in two seconds.
So all of the type A people are
all lined up here, ready
to race away out after
the session.
And here's the middle of the day
mixed parking, some people
front-end in, some people
rear-end in.
These are anecdotal, but this is
the kind of thing they were
noticing, that led
to these ideas.
So it turns out, in subsequent
studies, that a lot of the
effect wasn't as broad as they
thought, but it does apply to
people who are relatively young
with cardiovascular
problems, and the key
psychological aspect is not
the impatience and
aggressiveness.
Although if you work for
somebody like that, you don't
enjoy that, probably.
But the key thing is whether the
person feels in themselves
hostility, not impatience but
hostility, and especially when
they suppress it.
Like, they go, I'm so mad, I'm
so mad, I'm so mad but I can't
really hit the person in
front of the line.
And that person brewing with
hostility and suppressing that
rage is actually pushing
up their risk of
cardiovascular disorders.
So again we talked about to
adaptive stress-responses and
for practically every one of
them, what can be understood
to be a stress-related disease
when that form of stress
continues chronically
and unabated.
And here's a picture of a neuron
in a healthy animal
with lots of dendrites and
arborization, and the
whithered neuron in a
hippocampal animal given lots
of stress in laboratory
experiments.
So you can see it at the
neuronal level, you can see it
at the behavioral level, you
can see it at the disease
level, chronic stress is
toxic in many ways.
So one form of stress that
occurs after really terrible
experiences is post-traumatic
stress disorder.
And you may have heard--
where do you hear it these
days most of all, about
post-traumatic stress
disorder?
AUDIENCE: The wars.
PROFESSOR: The wars, right.
The unabated wars in the Middle
East, for American
soldiers going over there under
many tours of duty,
under constant fear
of explosion.
For the civilian populations
in those parts of the world
under nonstop war threat
for many, many years.
So, if you did a brutal, vicious
experiment of people
under constant threat for their
life, unfortunately you
couldn't create a more perfect
one than the Middle East, for
both soldiers and civilians for
the last decade, right?
Constant threat and
danger for people,
everywhere, all the time.
I was reading a story about
one soldier, for example,
civilians as well, who was
standing in line to get his
toothpaste, IED blows up
and he loses his leg.
That's what the life is like
for those soldiers.
And as you know, because in
the US we have a volunteer
army, soldiers are sent again
and again for years
altogether.
And the civilians living there
all the time, that's the world
they're in, brutal
stress induction.
Just a few months ago, the
number of American soldiers
who died from suicide is now, on
a monthly basis, exceeding
those who die from
war injuries.
Think about that.
The number of active American
soldier who die from suicide
is equal to or higher in many
months nowadays than the
number who died from war
consequences of bombs and
things like that.
So, there's a lot of interest
in PTSD from the war, from
civilians having been exposed
to the war, and then from
individuals who have brutal
episodes in their lives,
tragically, of assault
or rape.
It's a severe anxiety disorder
that can develop after
exposure to any event
which results in
psychological trauma.
People re-experience the
original trauma through
flashbacks, dreams, increased
arousal, hyper-vigilance.
And it's very common for anybody
who goes through an
emotionally brutal experience
and it persists strongly in
what's estimated about 20%
of people who go through
something like that.
So people have tried to
understand, what is the brain
basis of PTSD, who is at risk
for it, and how does it happen
in the brain in a way that
treatment might become more
effective to help people.
So one thing that was observed,
and not everybody
guessed this finding, is that
individuals with smaller
volumes of the hippocampus--
when they look at soldiers with
PTSD they tend to smaller
hippocampal volumes.
So, let's ask the question, how
could this be a cause or
how could this be a consequence
of a severely
traumatic experience you have,
like serving in a particularly
brutal and nasty war--
or being a civilian in one.
But these are soldier studies,
so we'll focus on that.
How can you tell?
They come back from the war,
they have PTSD they have
smaller hippocampi.
Was that a risk factor for
becoming somebody with PTSD
into a high-stress situation, or
was it the way that the war
situation made you have PTSD?
Is it the cause, or
the consequence?
Does that make sense?
OK, so here's an approach
that people have taken.
They did a twin study--
I'll show you the graph
in a moment--
where one twin, this was for
Vietnam now, went to serve in
Vietnam, and one twin did not
serve in the military at all.
And these are identical twins.
And then they asked is the
hippocampus smaller in the
twin who never went?
And the logic was--
it's not a complete
certainty--
but the logic is, if the twin
who stays home in the US also
has a smaller hippocampus, that
suggests that it's a risk
factor for PTSD, rather
than the way that PTSD
develops in the brain.
Does that make sense?
It might also play a role in
that, but it's present even
before that.
And that's exactly
what they found--
these graphs, I really have to
get the projector fixed-- but
there's two steep lines here
on your notes you'll see.
They're both pretty steep.
The top one is the correlation
between severity of PTSD in
the soldiers who went and
hippocampal volume.
And the bottom is hippocampal
volume in the twins who didn't
go, and they look incredibly
similar.
That is, the larger hippocampus
of either the twin
who went to war or the twin who
stayed home, the larger of
either one correlated
with the PTSD in the
twin who went to war.
Does that make sense?
OK.
So it's as if the genetic
influence, or the early
environmental influence
at home, or both--
if you have a smaller
hippocampus, you're at high
risk for PTSD.
Now, if you're not sent
into war, you won't
necessarily get PTSD.
But if you're sent into war,
then you're at high risk for
getting PTSD.
Is that OK?
So, more recently people have
begun to do pre/post studies,
and this is one done in the
Israeli military, 50 recruits
before and after they did
military service as
paramedics.
And what they found was that
there was increased stress
associated with a greater
amygdala and hippocampal
response fMRI to stress-related
content.
But the amygdala reactivity
before stress-related contact
predicted how many stress
symptoms you have, and the
hippocampus change over time
correlated with stress symptoms.
So now this goes a little bit
differently, it says the
amygdala function predicts who's
at risk for having PTSD,
and the hippocampal changes
over time before and after
your initial service go with
the degree to which you
exhibit the PTSD.
I'll just say that.
So, there's been a lot of work
on understanding what can
positively modify stress.
What can you do, given stress
you can't avoid, to do better
and cope better with that?
What can be the sources
of resilience?
And I'm going to give you
examples, but I'm going to
tell you the following, these
are the categories that have
come up in pretty
well-controlled studies.
Outlets for frustration, if
you have a good outlet for
frustration, that diminishes the
toxic effects of stress.
If you can predict bad things
and feel you have control,
even if you have bad things
happen, you can cope with the
consequences better.
We talked about that in learned
helplessness before,
this was our theme before.
If things seem to be getting
better, even if they're pretty
bad, if they seem to be getting
better, that's a huge
source of resilience.
And social support
is very powerful.
So let me show you
the empirical
evidence for these things.
So, here's a study where
rats received shocks.
They had a prolonged stress
response, because they were in
a situation of getting shocks
and shocks and shocks.
Heart rate goes up,
glucocorticoid cortical
secretion goes up, high
rate of ulcers.
Now you have other rats getting
a similar thing, but
they can gnaw on a wooden
bar, or eat or
drink, or run on a wheel.
So, they have outlets
for frustration.
It doesn't prevent the shocks,
it's just after they get a
shock they'll go for a quick
angry run on the wheel, OK, or
they'll bite on something, OK?
And they have fewer ulcers.
So, just having an outlet
for frustration
reduces the toxic effects.
Even another rat in the
cage that they can go
and bite helps, OK?
Now that's not a nice thing for
the other rats, but it's
just like this common thing
that we have, it's not the
best human trait, this is an
example of a rat trait as an
example, but if somebody is as
miserable as you, you feel
better about things, OK?
And baboons will attack
bystanders
after losing a fight.
So, baboons, depending on
where they are in the
hierarchy, alpha male and so
on, they lose a fight, they
get themselves healthier in
terms of glucocorticoids if
after they lose a fight
they go beat up a
lower-ranking baboon.
we're not recommending that as
a nice way to behave, we're
just saying, weirdly enough,
these kinds of actions some
outlet for frustration--
some are more constructive
than others--
result in resilience
in these animals.
Fewer ulcers, lowering
of glucocorticoids.
So, some kind of outlet
for stress.
How about predictability
and control?
So if rats hear a warning before
a shock, even though
they get an equal number
of shocks,
they have fewer ulcers.
So, as long as they can know the
shock is coming, they have
all the dread of that too, but
they feel like I know what's
going on, and that literally
results in fewer ulcers.
If food is delivered to a rat at
intermittent intervals they
can predict versus random
delivery, they're more
stressed with the
random delivery.
Again, prediction--
equal amount of food, but if
they can predict it, they feel
like they know what's
going on.
Rats are given a lever to avoid
the shock, even if the
lever is disconnected
to the shocks, the
stress response is reduced.
So, it's kind of an outlet too,
like here's a lever I'm
pushing, it doesn't do
anything, but they
feel like, who knows?
I feel like I have
some control.
Same thing with people, they
did experiments where they
give obnoxious noises,
and one person has a
button to stop the noise.
They're less hypertensive
whether the button
is pressed or not.
So they don't even have to
press, but if they feel like,
they feel like they might have
control that's already a
protective measure for stress.
And there's famous studies
looking at occupational
stress, because some
jobs have very high
demand and low control.
The most famous one that I
know of is from pilots in
World War II in the
British Air Force.
And they compared the pilot, who
sat up front and rode the
plane, versus the gunner--
and if you think of those
airplanes from books or movies
there's a little turret down and
there's a gunner shooting
at the other planes and they're
shooting back at him--
does he feel like he
has any control?
No.
Wherever the pilot's going he's
like, no don't go there,
don't go there they're all
just shooting at him.
So, and then they look at the
life expectancy and health of
the people and the pilots did a
lot better than the gunners
after the war.
Because the gunners just went
out day-in, day-out and they
just went wherever the pilot
took them and the shots were
coming out.
So everybody was at risk, but
the pilots felt they had
control and the gunners felt
they had no control.
So, many different examples.
Here's a very famous one, and
I read somewhere they're
making a movie of this, I don't
know exactly how they'll
make compelling,
but here we go.
So this is a study from Judy
Rodin and Ellen Langer where
they looked at the sense
of predictability
in a nursing home.
And they took people at randomly
assigned, from
randomly selected different
floors.
And group A, in the nursing
home, got to make many
decisions for themselves.
They got to decide where to
receive their visitors, when
to watch a movie, what house
plant to take care of-- they
all took care of
a house plant.
These are sort of minor things
but people in a nursing home
don't have a huge
range of things
they can control anyway.
But they took these things they
could put under their
control, and group B got no
instructions to make decisions.
They got a plant, but the staff
took care of the plants.
So everybody gets a plant, but
one group, they're saying make
the decisions you can
for yourself.
And the other group, the nurses
and doctors made all
the decisions they could
for those individuals.
They look at what happened
one and a half
years later after this.
Not only the group A, the
people who are making
decisions for themselves in
the nursing home, report
themselves to be more cheerful,
more active, and alert.
They were also objectively
healthier and, kind of
amazingly, only half as many
had died, literally died.
So it's an extremely
compelling--
I've shown you so many sources
of evidence, from controlled
animal things to anecdotal
things to kind of a controlled
experiment with humans with
random assignment here, where
the sense that a person has
control is incredibly powerful
not only for their happiness,
but it literally seems to
fight off stress-related
diseases in their body, in
their hearts and their
life expectancy.
Now the psychological modifiers
of the stress
response are going to vary
depending on who you are and
the culture you're in.
I'm going to show you one
experiment about that, we'll
talk a little bit later about
different cultures.
But here's one about what counts
as predictably and
control, it'll vary
by culture.
So, we'll talk more about this
in social psychology, but
social psychologists like
to talk about one giant
distinction around the world
as a simplified way of
organizing a huge complexity
of cultures--
individualist cultures and
collectivist cultures.
Individualist cultures tend to
emphasize the individual--
be yourself, be all that
you can be, OK?
You're the one, you're
the special person.
That's thought to be common
as a cultural mode in
the US and in Europe.
Over time, just in the last
decade, people decided the US
is like way, way out of control,
different than the
rest of the world in this.
The US would send this message
to everybody, the way to be
happy and successful is to
be super individualistic.
Europe, a little less so.
And other cultures, Japan South
Korea, China received a
lot of attention--
and East Asia--
tend to be more like we're
in this together.
Now this is super simplifying
over many people, many
situations.
But cultures do send messages.
Where you grow up, everything
from your household to your
town you're in, the school
you're in, the
country you're in.
They send you messages
of ways to be.
I mean, we live in them.
And here's an example, an
experiment that shows,
depending on the cultural
influences, roughly speaking,
averaging out across people and
families, you can view one
thing or another as a better,
healthier, happier control.
So here's the experiment--
and there's a bunch these,
but this is one.
In an elementary school, I think
it was in San Francisco,
7 to 9 year olds who are either
from Asian-American
families or Anglo-American
families.
So that's the cultural thing,
trying to look at this
cultural versus individualist.
Parenthetically, Asian-American
families in the
US are probably somewhere
in-between Asian families in
Asia and Anglo-American families
in the US, right?
Probably somewhere in between.
So they did an experiment with
Ms. Smith, the teacher, and
she has six markers and six
piles of anagrams, and
somebody got to pick which
anagrams you would work on to
do your best and solve, OK?
So, typical school little
exercise, you try to do well.
And they divided all these
children into three groups.
In one group the children chose
which anagrams they
would you do.
In one group, the teacher
chose it.
And one, they said we've
communicated with your mother
and she says this is the
anagram set for you.
OK, so you could think
in your own life.
If you arrive to class tomorrow
at MIT and people
told you, here's
a problem set.
You pick the problems, I pick
the problems, or I emailed
your mother and she said you
should really try those
problems, OK?
Well you're older
you wouldn't--
you'd be weirded out, right?
But 7 to 9 year olds.
They sort of take that, right?
Alright, here's the
interesting thing.
So we're going to talk about
performance on the anagrams.
So this is actual performance,
what seems like a
self-controlled thing.
For the children who are from
Anglo-American families, they
performed best when they picked
the anagrams set.
The anagram sets were all
equal difficulty.
Just like, I picked it I know
what I'm doing, OK?
Four times better than the
teacher and two and a half
times better than when
the mother picked.
That is, there's something about
picking that set that
makes them feel like that's the
right set for them, and
they perform best.
For the children from
Asian-American families, on
average they perform best when
the mother had selected the
anagram set.
30% better than themselves,
and twice
as well as the teacher.
So all this is saying is,
culture influences all of us
in various ways, in
complicated ways.
This is one of the easiest
things to identify, is this
kind of a cultural difference.
But the important thing is, it's
psychological what you
perceive as a source
of control, right?
So the way we interpret this
is, for children who are
exposed heavily to an
Anglo-American emphasis on
independent selfness.
You're the one, you believe you
do best the most control
is exerted, when you choose.
And, apparently, for these
Asian-American children, they
feel the best control has been
exerted when their mother had
selected for them the
anagram they're most
likely to succeed on.
And the performance goes
with that belief for
both groups of children.
I always worry about these
things, and we're going to
talk a little more about
stereotypes, because you
sometimes feel like you're
supporting stereotypes, but
these are real studies and
they didn't have to
play out that way.
And it's obviously this
doesn't say every
Anglo-American is this
way, and every
Asian-American is that way.
But cultures do influence us,
otherwise the other choice is
cultures don't influence us.
And all the data says that
culture matters.
The world we grow up in, the
values we're exposed to.
OK here's another kind of brutal
experiment about sense
of control from 1957.
This is truly life and death.
So, they were interested in
understanding really about
survival for animals for water
temperature and endurance.
And they put the rats in a jar,
and they asked, brutally,
how long does a rat swim
before drowns?
OK, this is a brutal experiment,
as you can--
And the goal there was more
to understand things about
temperature, and whether people
could survive different
temperatures.
It wasn't just to be
mean to rats, OK?
The science goal was to
understand thermal survival
for people, in the long run.
But one thing they noticed
was this--
some rats gave up in about 15
minutes, others would struggle
as long as possible, and
would go for an hour
before they gave up.
Some would surrender quickly,
and some would fight as long
as a rat can possibly
flight, OK?
Now what's the difference
between those
rats who give up early--
Yeah?
AUDIENCE: Did they give up after
60 minutes or 60 hours?
PROFESSOR: 60 hours, I'm
sorry, it is 60 hours.
OK?
Yeah it is fantastic,
I'm sorry.
Yes, you're right, I mis-said
that because--
yes that's correct.
But it's huge, OK,
and yes 60 hours.
There we go, it is hours.
OK, thank you.
Is that unbelievable?
AUDIENCE: [INAUDIBLE]
PROFESSOR: But for life and
death you might do that.
For life and death?
AUDIENCE: [INAUDIBLE]
PROFESSOR: But you can't
do anything else.
I know, it's kind of amazing.
What's amazing to them is not
necessarily the 60 hours,
which is pretty impressive
itself, it's that some just
gave up really fast and some
just went as long as you could
go before you would expire,
no matter what.
And I think what it is, they did
an experiment-- this is a
little bit like the Seyle
experiment, but on purpose.
But before they put the rats
into here, they picked up the
rats they let them wiggle
around, and they would put
them in and out of the water,
and then they would put them
in this fatal final
experiment.
And then practically all
of the rest went for
the 60 hours of effort.
Why?
You can't really know, you
can't ask the rat, right?
But the interpretation is they
went in and out, they went in
and out, they struggle--
they had hope.
Literally, as far as we can
understand, they had hope.
Because before they were
taken out, OK?
And if you have hope,
you struggle for
a long, long time.
And if you're hopeless for some
reason if you don't have
hope, you give up fast.
So it's very compelling that
this sense of self control,
including hope, makes a
tremendous difference in
performance.
And it's very psychologically
malleable in people, what
counts, for them, as sources
of hope and control.
How about social support?
So in primates, after a stress
response, among strangers,
they're worse.
If they're among animals they
know, they're better.
And this is measured by
glucocorticoids, an objective
measure in monkeys.
That they're better if they're
among monkeys they know.
So, you could think in your
own life, family, friends.
Intuitively are they
sources of support?
Yes.
So, they do stressor experiments
with people.
A really good one is to tell
somebody they're about to do
public speaking task, that turns
out to scare people, or
a difficult math task, or
they're about to argue with a
stranger about a controversial
topic.
They have less cardiovascular
response if they're with a
supportive friend present when
they get the instruction, OK?
So if you're told you're going
to do something, like have a
really unpleasant argument with
somebody, but there's
somebody you know with you, who
you know, you have less of
a physiological response for the
dread, if you want, or the
stress of the upcoming event.
And then, so those
are controlled
experiment with people.
And there's epidemiological
observation that people with
spouses and close friends live
longer, that when spouses die,
the risk of dying increases for
the surviving spouse, that
parents of children killed in
war have a higher risk of
disease and mortality but only
if they're divorced and
widowed, that patients with
severe coronary disease had
three times the death rate over
five years if they lack
social support.
So these are all correlation
studies, all of them would
have alternative
interpretations, but they are
all consistent with these
experimental studies that
social support is an incredibly
powerful buffer for
resilience for stress
and threat.
Here's another one, perception
of life improving.
So, rats getting shocks.
Rat number one got 10 hours
a day, rat number
two got 50 per hour.
And day two, all rats
get 25 per hour.
So rat number one, life
is getting worse.
Rat number two, life
is getting better.
And it's the group that goes
from 10 to 25 that gets
hypertensive, OK?
So if you think things are
getting better things can
still be pretty bad.
But if they feel like they're
better, then you're going to
be happier.
As a side note--
I should have put this in as a
note but-- there's a work from
Danny Kahneman on perception
of pain.
So he talked about people who
went in to dentists, which can
be sometimes unpleasant, and
had them rate the pain
periodically.
And what he found is that, when
you look back in your
memory of how bad your
experience was, he could
predict it largely
by two numbers--
the peak pain response you
report and the change near the
end if it's getting better.
So what he discovers, weirdly
enough, is this--
if you have peak pain responses
that are similar
with the dentist, if you add
more pain but it's getting
lower, people will feel like
they had less pain overall,
even though you added pain.
Because if you just stop,
it just stops.
But now you've got a little bit
of pain, and it's getting
better and better and better.
So you're adding pain, but the
perception is, at the end it
was getting better.
Does that make sense?
OK, you're adding pain,
but it's getting less
and less and less.
But it's still an add, because
you're adding it.
People, in their mind,
they'll say it was
less painful overall.
Because, what counts for
them at the end is the
getting-betterness.
Getting better, even if it's
bad, is a hugely powerful way
the people view things
in terms of how
miserable life can be.
So here's a graph that
summarizes, here's risk of
ulcer in rats.
If there's another rat present,
if they get a warning
signal for control, a lever for
responsive, if things seem
to be getting better, if
they have friends.
All these things change the
physiological consequence of
very rough structures
in the laboratory.
And, as far as we could measure,
it seems to happen in
people as well.
So it's kind of a dual
story, right?
There's fantastic stressors that
we have in daily life in
the world we live in that are
chronic and unabating in many
ways, but quite well-identified
things they
can help us manage those
much, much better.
Or become victims of them,
much, much more likely.
OK, I'm going to talk a bit
about a couple studies about
pain and romance.
So, and this goes back to an
idea we talked about before,
but let me just remind you.
This idea of embodied
cognition.
That the nature of the human
mind largely determined by the
form of the human body.
That bottom-up physiology has
a bigger role in our mental
life than we might think.
And I'm going to talk about
emotional pain.
And two things that are very
painful emotionally--
and if you've gone through
, you know this-- they're
shockingly painful sometimes.
If you haven't had it recently,
they're social
rejection or romantic
rejection, right?
It's a sad thing, but it's true
that I think those are
shockingly painful for many
people, even if you didn't
think it was going
to be that bad.
The shock of being rejected
socially or romantically is a
pretty brutal experience
emotionally.
I'm going to show you guys from
pretty strong evidence
that it's because, when you
have that kind of pain it
literally turns on the same pain
system as heat or shocks.
OK?
Literally the same one gets
turned on as far as we can
measure it.
So, here's a thing just remind
you that pain has is comprised
of having two part.
A sensory one that's the
objective response to the
pain, and what people call
affective, that is, how much
you suffer from that pain.
So we could measure the
objective one and the
subjective one.
And a bunch of studies have
suggested that, for example
somatosensory cortex, this the
cortex that represents your
body, if you get physical pain
like a shock or heat gun,
responds to the amount
of that.
Whereas something like the
anterior sineal, this part of
the brain viewed from the top,
or this part viewed from the
side, interprets that pain.
So we know that people can
withstand pain sometimes, we
think this doesn't
care about that.
This is a part of your mind, or
a component of your mind,
supported by this part of the
brain, that tells you how much
you suffer subjectively from
an objective thing.
And part of reason they
think that is the
study, a hypnosis study.
So we talked before, is
hypnosis real or not?
This is one of the things
that should convince
you a little bit.
I was as skeptical as anybody
but this is me apart
So these are individuals who
are highly hypnotic, only
those are in this kind of
a study, who get pain.
And they're told to
imagine that the
pain is always identical.
it's always identical, but
they're hypnotically suggested
that it's high or low.
So in this primary response to
pain in the somatosensory
cortex, not much difference.
But in the interior cingulate in
the interpretation of pain,
a big difference.
Here's how much it is when they
think it's a low pain by
hypnotic suggestion, here's the
response when they think
it's high pain.
So this change in brain
response is
purely hypnotic effect.
The painful stimulus
is always constant.
Right?
But that supports of you that
this part is brain response is
an interpretation rather than a
simple objective response to
the pain itself.
There's many sources of
evidence for that.
So here's a study from Matt
Lieberman at UCLA, where you
come into a scanner and you're
playing a game with somebody.
Sometimes they tell you
there's a person
playing with you.
It's very simple and it just
shows you that even as adults
we retain some of our childhood
feelings, which is a
game very simple computerized
catch.
And sometimes a person who's
supposedly playing with you
outside the room throws
the ball back to you.
And sometimes the person is
really mean and they exclude
you from playing catch
on the computer.
So, this is about as silly a
version as you can get for
young adults participants for
pain, but hey we don't like
being left out even when it's
some weird experiment.
And set up a little bit so you
really believe the other
people in the experiment have
left you out of the ball
tossing game.
And here's what turns on, right
in the middle of this
pain region, the interior
cingulate for this pain of
social rejection under such
a mild circumstance, OK?
And, by the way, they do the
same experiment and they tell
you it's a computer who's
deciding whether to toss you
the ball, you don't
have a problem.
It's only when you believe it's
a person who's choosing
to exclude you.
OK?
So this was published in Science
because they said,
look being left out of a group
is as painful as if we had
given you a shock
or thermal gun.
And it could sound ridiculous,
but look it's the same system
that's responding.
OK so just recently a paper was
published where they said,
let's go all the way, this is
just a little laboratory
experiment.
Let's grab people who recently
self report a very unhappy
romantic breakup, OK, where
somebody left them.
So they gave them both physical
pain and they looked
at its relation to
romantic pain.
So participants felt intensely
rejected as a result of
recently experiencing
an unwanted romantic
relationship breakup.
What's the word we use for
that when somebody--
isn't there a word?
Help me out here.
AUDIENCE: [INAUDIBLE]
PROFESSOR: Dumped.
Yeah, this is when somebody
dumps you.
Oh my god, I'm really hurt.
And what's wrong with me?
It's easy to laugh about
years later.
I could tell, I have a story
or two, but I won't
drag you into my--
but almost everybody lives
through a version of this some
time in their lives.
So it's surprisingly intense.
So what they did, this is
a tough experiment.
They had them view pictures
of ex-partners, the
person who left them.
OK?
I don't even know how they're
going to-- please bring us all
the pictures that are
now covered with
tears and stuff, right?
And you view those pictures,
they also had you bring in
pictures of other friends,
people you knew.
And you and either thought about
the ex-partners and how
you were rejected, or you
viewed pictures of your
friends and you thought
about good
things about your friends.
So they controlled for
looking at a face.
And here's where they find.
Here's physical pain
and social pain in
the anterior cingulate.
Pretty much turning on the
same part of the brain.
When you see the person who
dumped you and when you get a
heat gun applied to you that
exerts physical pain.
And in brain region after
brain region that which
responds to physical pain is
also turned on with the pain
of looking at somebody who
dumped you recently and you
still feel that feeling
of rejection.
So now all of this is social
rejection is very painful.
Romantic rejection is very
painful, painful literally.
OK?
It's not a metaphor,
it's not a story.
It's literally the same system
in your brain that feels
physical pain, feels
this emotion pain.
Emotional pain is
very powerful.
And here's an amazing
follow up with this.
And this is the kind of study--
it'd be interesting to
see this replicated--
but it kind of makes sense.
So they randomly assign people
to 2000 milligrams a pain
medication like Tylenol,
Excedrin for three weeks or
they got placebos.
So you don't know what you've
got, a double blind study.
They provide daily reports
of how their day was.
By day 15, they reported less
painful responses to rejection
in their daily lives.
And they also had less brain
response to social rejection,
by taking drugs that
work on pain.
And they don't even know it's
a double blind comparison.
Now there's all kinds
of issues--
for those of you, I've just
got to tell you this-- to
chronically take these
drugs, you get ulcers
and things like this.
so don't do that.
But it just pushes the point
that there's some incredibly
interesting relationship between
emotional pain and
physical pain that's
very striking.
OK now I'm going to go on for
the last few minutes to
another topic.
And again it's one of these
topics about racial relations
in the US that's always
a very difficult
topic in our culture.
And I hope I communicate it
correctly, and appropriately.
So we talked before about
stereotyped threat, and this
is a threat that a
person feels--
this is another form
of stress--
that others' judgments or one's
own actions will confirm
a negative stereotype
about one's group.
And that, for example, in
multiple studies that
African-Americans when a test
framed about a kind of a test
of people might think
African-Americans won't do
well, do less well, when they
just take the test they do
perfectly well.
And then we talked about that
whatever stereotype might
apply to you, when it's invoked
people under-perform
in that area.
And we interpret that as a sort
of a stress that's not
letting people perform
at their best.
So I'm going to talk about that
stress element, but we're
going to do an exercise.
And I need you to be sensitive
on this, and
hopefully I'll do it.
This is the most common way
that psychologists measure
attitude something about the
stereotypes that inhabit the
minds of people who live
in this country.
So we're going to do it as an
exercise if you're willing to
do, you just tap with one
hand or the other.
And we'll just try it
you don't have to do
this at your desk.
I read about this kind of
research for a number of years
before I ever did it as a
demonstration when I was at a
conference.
And somebody works in this field
did it and i it was kind
of striking when it happened.
So it's up to you anyway.
So think about whether you want
to do this, but here's
what we're going to do.
So the experiment has two kinds
of stimuli, basically.
One of them are adjectives
that are pleasant or
unpleasant.
everybody agrees that murderer
or sicknesses is unpleasant,
everybody agrees cheer and
peace are pleasant.
The second category or stimuli
that are relevant are names
that are selected in these
experiments to be usually
thought of-- and of course
it's a generalization--
to be found for people who are
European-Americans and more
likely to be associated with
African-Americans.
OK?
All right, I mean you'll see,
the experiment has to work
this way but I'll talk with you
about other versions of it
that don't depend
on exactly this.
OK?
it doesn't really matter.
you can think about things and
ask questions in a minute.
So what I'm going to ask you
to do, This you're going to
see a list like this
of adjectives.
Go from top to bottom if it's
an unpleasant word you tap
with your left on your desk, it
it's a pleasant word with
the right hand.
From top to bottom.
And I'll just read
you the times
as we go, on a stopwatch.
Ready?
So left hand if it's unpleasant,
right hand if it's
pleasant, OK?
Here we go 9 seconds, 10
seconds, or 11 seconds, 13
seconds, 14.
OK all right, there's
some practice effect
and all that stuff.
OK now you're going
to have the names.
Tap with you left hand if it's
a name that's more typical of
an African-American, your
right hand if it's more
typical of a European-American.
Ready?
Go.
5,6,7,9,10,11,12,13 OK.
OK, tap with your left hand if
the adjective is an unpleasant
adjective or the name of an
African-American, your right
hand if it's pleasant
or the name of a
typical white American.
OK so now it's a mixed list.
Ready?
Go 5 10 12,13,14,15.
OK, so by about 15 we got
pretty much everybody.
OK, we'll do this now, left
for a name typically
associated in this kind of
experiment for a white
American, right for
a black American.
Ready?
Go.
8, 9, 10, 11, 12,13,14 OK.
Now this is the last
one coming up.
So now it's going to be left
hand if it's a unpleasant
adjective or a white American
name, on the right if it's a
pleasant or a black
American name.
Ready?
Go.
8 9, 10, 11, 12,13, 14,15
,16, 17,18,19, 20, 21,
Still tapping, right?
All right, so this is
a shock, right?
I mean if you don't know this
lecture, it's a shock.
And it's a shock because this
effect, which you heard
yourself, happens in
undergraduates across this country.
People who are very convinced
that racism is wrong, they
hold no stereotypes themselves
and with racism is wrong,
they're definitely
right about that.
Definitely don't foster
a stereotype, I
mean you don't either.
But in experiment after
experiment in a country, and
there's literally hundreds of
these published, people on
average are faster when they
have to do unpleasant and
black or unpleasant white as if
it were easier to associate
these two concepts.
And we just did now you are the
easy condition you were
all done in about 15 seconds.
In the more difficult condition,
the unpleasant or
white condition, there was still
tapping occurring at 20
could have gone to 25 or 30.
OK so you had that
experience, too.
I heard you going I think
giggling, I think
just because of shock.
Because you say, if you're like
me, you say I harbor no
prejudices, how did
this happen to me?
So this experiment, and you
could look up a lot of
information about this from
Mazarin Banaji at Harvard,
who's sort of the leader of
this, with Tony Greenwald.
They have a huge amount of
evidence about this.
So one thing you kind of laughed
at, because it was so
silly almost, the way
we set up here,
were the names, right?
Because it was kind of a
funny list of names.
I could tell you the experiment
work identically,
just about, if you
show pictures of
white or black people.
So the names is not an issue
in that case, OK?
So it's a shocking thing.
And where does it come from
that people are faster for
white and pleasant than
black and pleasant?
That occurs in 75% or people who
are white and about 50% of
people who are black.
So it's not as if black people
reverse that pattern, it's
just they're even.
And on average for white people
they find just easier
to associate white things with
pleasant things than black
names or faces with
pleasant things.
Yeah?
AUDIENCE: Was the experiment
ever done any other way, where
you would tap first
or [INAUDIBLE]?
PROFESSOR: Yes, yes.
So you are absolutely correct
that in the demonstration now,
I slightly loaded up
the order of these
things to make it work.
But why I give you this website
is to tell you that in
hundreds of experiments where
that's all controlled for by
reversing the order, half
the time and stuff,
it all plays out.
OK?
It's a demonstration today,
slightly loaded it that way
but there's hundreds of
experiments where
it all plays out.
In these numbers are first the
actual experiments where it
all plays out.
People worry about whether the
frequency of the names, that a
name like Chip might be more
frequent, common than a name
that's an African American name,
just by shear number.
So therefore the pictures get
it out of the equation.
People have worried about lots
of things about this.
I think almost everybody agrees
the basic phenomenon
holds up under well-controlled
experimental designs.
That's an excellent question.
Any other questions
about this?
It's a very disturbing thing,
partly it shows you that
stereotypes are out there,
unfortunately, to this day.
Even with an African American
president, stereotypes are out
there, in people's heads.
They used to call it
a test of implicit
attitudes because it--
but now is this really an
attitude to the person has in
their head?
Or is it really they
know about a
stereotype that's out there?
It's still problematic to have
the stereotypes out there,
even if it's not the
one you believe in,
subscribe to, or live by.
Yeah?
AUDIENCE: [INAUDIBLE] actually
[INAUDIBLE] for the
experiment.
And whether they found that it
was more associated with your
own proof--
PROFESSOR: So with African
Americans it's about 50-50 on
average, across them.
It not reverse.
It's not like, my group is
awesome, all other groups are
not so awesome as my group
because I'm in my group.
It could be that, and that also
would be problematic as
much as anything.
But it doesn't seem to
play out that way.
It seems to play out a little
bit to what you might call--
and then this will change, my
guess is-- to what is the
dominant group in a society.
And now the US is changing
in this regard, OK?
But it's not changed yet.
And you get these kinds of
things in lots of domains,
we've talked about that
before it's not just
about black and white.
But the last thing
I'll show you--
we'll be done in five minutes,
it's just two slides.
It's sort of a follow
up on this.
So here's an experiment that
was done at Dartmouth.
And they had white participants
complete this
task that you just did under
better control circumstances.
So for each person they could
measure by how quickly they
responded in the computer the
difference between responding
to black and white names in
relation to pleasantness.
So some person might be 10
milliseconds, different
somebody might be 200
milliseconds different.
People vary.
But then they had them go
to a different room--
and this is the critical thing--
to interact with
either a black or white
experimenter.
All the participants in this
experiment were white.
Then they were told the reason
we're doing this is, we want
to videotape you making comments
about the college
fraternity system and racial
profiling after 9/11.
That's kind of a cover story,
although the racial word was
probably meant for them to think
a little bit about the
test they did.
They go into a room they
interact with a black or white
experiment then they go back to
the original room and they
perform a cognitively demanding
task, the Stroop
task where you have to name
colors that are in the wrong
color, which you've
seen many times in
this course you already.
And here's what they find.
if you're a white person and you
had a white experimenter,
this is the performance
on the Stroop task.
It's unrelated to how you
did on the IAT test.
This is the IAT test, the people
who are more along here
had a bigger gap between
black and white, OK?
So they varied.
But look at the people who went
and took the IAT test
like you just did, again under
more controlled circumstances.
Now they go and do the Stroop
and look at the more their
score reflected knowledge of the
stereotype, the more the
knowledge of that stereotype
influenced in some way their
performance--
that's along this axis--
the worse they did on the sort
of cognitively demanding task.
As if the stress that harms
performance is occurring on
both sides of racial
groups, right?
We already said that stereotype
threat can diminish
performance for people when
they're working in the area
where there's a stereotypes
that they're not
supposed to do well.
Just thinking about that
diminishes their performance.
And now for the other group for
the white participants,
just thinking about
the stereotyping--
and you may have that too.
Just thinking like, what I do?
Why was I slower for that?
I'm not a prejudiced person,
how did I do that?
The more their performance
looked like that, the worse
they did on this task.
As if again, now they were
having a part of their mind in
the wrong place or
over-aroused and
under-performing.
So everybody's falling victim,
on both sides of this
prospective, to these
racial stereotypes.
Whether you're black or white,
it's disturbing to have that
thought and it diminishes your
ability think clearly.
So in that sense stereotypes
makes you stupider on
performance in a cognitively
demanding task.
there's so many forms of stress
and the one good thing
is, psychologists are getting
better and better at
discovering sources
of resilience.
And we talked earlier in the
course, it includes resilience
from stereotyped threat.
We'd like to just get rid of
stereotypes today, but pending
that we've talked about things
like essays and so on that
work surprisingly risk
effectively sometimes.
OK thanks very much.
