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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.