Paul Bloom: The Psychology of Everything

Hi, I am Paul Bloom and I’m a Professor
of Psychology at Yale University.

And what I want to do today is talk about the field psychology, the science
of the human mind.

Now, I’m admittedly biased, but I think
psychology is the most interesting of all

fields.

It’s the most interesting because it’s
about us.

It’s about the most important and intimate
aspects of our lives.

It's about language and
perception. It's about our memory of things, it's about our dreams

Love, hate. It's about morality our sense of right and wrong.

It's about when things go wrong, as in depression or anxiety,

it's about happiness.

It's about everything that matters to us.

Psychology is a huge field and it breaks up into different sub fields.

Some psychologists study the brain, they study neuroscience,.

The question of how this physical lump of flesh we have

gives rise to our mental life.

Others, like me, are Developmental Psychologists.

We study how babies turn into children and how children turn into adults.

How does a baby or child think differently than an adult.

How much of it is hardwired?

How much of it do we have to learn?

Some psychologists study Social Psychology.

Which concerns the relationship of people to other people.

As with regard to question like prejudice or persuasion.

Others are Cognitive Psychologists.

Cognitive psychologist treats the brain like a complicated computer.

And asks questions like how do we solve computation problems

like understanding language or recognizing faces or remembering facts.

Some Psychologists approach this from an evolutionary perspective

Looking at the question of how the mind evolved.

and how the origin, the evolutionary origins of the mind

give us insight into how we think in the here and now.

Many people when they think of psychology they think of clinical psychology

they think of Dr. Phil and Freud and

people who are involved with mental illness.

and alot of psychologists do study this.

One huge and important field of psychology involves exploring the

diagnosis and the causes

and particularly the treatments mental illnesses.

Illnesses like schizophrenia, depression,

obsessive compulsive disorders, phobias.

and so many other things.

I'm going to talk about 3 separate case studies.

I'm going to talk about compassion.

racism, and sex.

And I'm going to use these case studies as a way

to introduce you to psychology.

The first case study is compassion.

what I mean by compassion
is concern for other people.

This is particularly interesting to me.

This is my own research program and my own
laboratory at Yale; we look at the emergence

of morality in babies and young children.

And we particularly focus on the emergence
of compassion.

At what point in development do babies care
about others?

At what point in development does feelings
of empathy and sympathy, sometimes anger,

guilt, other moral emotions.
How do they arise?

To what extent are they built in?

To what extent do they have to be learned?

As a starting point, I have here a picture
of a baby

and inside the baby’s head is
the baby’s brain.

The baby’s brain is an extraordinary computing
machine.

There are by some estimates

100 billion neurons in a babies brain.

Now neurons are basic cells

that process and transmit information.

And by one estimate, there’s about 1.8 million
connections between neurons that are created

per second.

To give you a feeling of the complexity of
the baby’s brain, I use an analogy from

Jeff Hawkins.

Imagine a football stadium.

Fill it up with cooked spaghetti, then shrink
it to the size of a soccer ball.

Then make it much, much, much denser.

And then you’ll have some understanding

of how much is going on inside a brain,

inside even a babies brain.

Now, that much we know for sure,

but where the real debate goes on

concerns the nature

of that computational structure.

There’s one of view that is held by many

philosophers and many psychologists which is that the

brain starts off as a blank slate, what the
philosopher, John Locke, called “a Tabula
Rasa.”

And what goes on in development, the point
of all those connections per second is learning,

is sucking up information from the environment.

The baby starts off knowing nothing and turns
into an adult, by virtue of absorbing information

at a tremendously powerful rate.

Many philosophers and many psychologists,
including me and my colleagues are more enamored

of another view.

We don’t deny that learning takes place,

but we would argue that in addition to that,

there is an extraordinary early understanding,
early specialization.

The brain could better be understood in terms
of what the psychologists, Leda Cosmides and

John Tooby, described as a Swiss Army knife,
has many different parts.

And each part is specialized for a different
function.

Now, so much of the action in psychology has
been a running debate over which view is right.

And this concerns morality.

Both moral judgements

right and wrong

but also moral feelings

including compassion.

Many people would argue that in that regard,
the baby starts off with nothing.

The idea is that children start off immoral,

monsters or if not monsters,

at least they know not from good and evil.

This is not the view which I think is supported
by the data.

I think there is now more and more data in
support of a different view of compassion.

One way to make a baby cry

is to expose it to the cries of other babies.

There’s sort of contagiousness to the crying.

It’s not just crying.

We also know that if a baby sees another human
in silent pain, it will distress the baby.

It seems part of our very nature is to suffer
at the suffering of others.

We know that young babies,

as they become capable of moving voluntarily will share.

They will share food, for instance,

with their siblings and with kids that are around.

They will sooth.

If they see somebody else in pain, even the
youngest of toddlers will try to reach out

and pat the person.

Maybe hand over a toy.

There’s some lovely studies finding that
slightly older children are able to help others

when they see somebody who is unable to fulfill
a goal, they’ll seek out to come to their

aid.

So one elegant demonstration of this comes
from a recent set of experiments

Where they take a toddler

put him or her in a situation

where an adult is in some sort of

mild distress and see if the toddler

will voluntarily help

even without any prompting.

And they find that toddlers typically do.

There seems to be some sort of impulse in
us that’s altruistic, that’s kind, that’s

compassionate.

In all of these cases; however, the kindness
that we see seems to apply to people who are

close to us, who are either physically in

our proximity or who are our siblings or our

parents or our friends.

So the question arises, how broad does this
compassion extend?

Now some people would argue that we start
off with a very broad compassion, we would

extend it to all individuals, to all people.

But there’s evidence support a somewhat
different view, which is, there’s a moral

instinct in us, there’s a moral sense in
us, but it’s initially very narrow.

It’s only triggered by those close to us.

In fact, our natural default feelings towards
a stranger, far from being compassionate,

is actually some sort of mixture of fear and
hatred.

We see this in all sorts of different ways.

So in young children, we see it in what’s
called, “stranger anxiety.”

At around nine months of age, babies start
becoming panicked at the presence of strangers.

and it sees to capture a universal part

of development where the other is thought of as dangerous.

This sort of stranger anxiety fades in some
cultures.

If you were to find yourself in an airport

in a new city, you’re not likely to have

a panic attack because you’re surrounded

by people you don’t know. But in small scale

human societies, it might never go away.

In a situation when an individual is raised
with a few hundred other individuals around

them, that is their circle of compassion.

And their response to others is not positive.

This is an observation that’s been made

by many anthropologists who study small scale

societies.

So for instance, anthropologist, Jared Diamond,
talking about small scale societies in papua new guinea

writes, “To venture out of one’s
territory to meet other humans, even if they

lived only a few miles away, was equivalent
to suicide.

Many years before, Margaret Meade was talking
about the lifestyles of what were called at

the time, “primitive cultures.”

And she is famously a supporter of these lifestyles.

She argues that the Western world would be
much better if we were to adopt the customs

and thoughts and ideas, particularly in regard
to sexuality of these other societies.

But she was very honest and very blunt about
how members of these societies treat strangers.

She writes: “Most primitive tribes feel
that if you run across one of those sub humans

from a rival group in the forest, the most
appropriate thing to do is bludgeon them to

death.”

I’ve talked about fear and hatred, but there’s
a third sort of response that we often give
to strangers.

This is disgust.

Disgust is what Paul Rozin described as the
“body/soul emotion,” is a human universal.

Humans everywhere are disgusted by certain
things.

We are disgusted by feces, urine, blood, vomit,
rotten flesh, and most meat.

Disgust has a characteristic facial response

<<>>

and its easy part of our natures.

Now, if it was limited to food and cockroaches
and that sort of thing, it wouldn’t have

anything to do with my talk on compassion.

But what’s most interesting is that we’re
often disgusted by other people.

Particularly, we’re often disgusted by strange
people.

By definition

any category of human individuals

is something you either

belong to, or you don't.

It's either what psychologists call

an in group or an out group.

And we have laboratory research that explores

the relationship between feelings of disgust

and feelings towards out groups.

So we know for instance that people differ
in how easily disgusted they are.

You do a survey of people.

You ask them questions like, how badly would
this bother you.

So one of the questions might be, you have
to pick up a dead cat with your hands.

And there’s some people who say, “uh, whatever.”

Some people, “Oh my god!

I’d rather die”.

Or, you sit on a city bus seat

and it’s warm from the last person

who was on it.

And some people crack up, well why would that
bother me?

Other people say, “That’s very disturbing.”

People differ in how sensitive they are to
disgust.

It turns out that where you stand with regard
to disgust correlates with your feelings about

out groups.

It correlates with your feelings about immigrants;
it correlates with your feelings about sexual

minorities, in particular male homosexuals.

The more easily disgusted you are, the more
aversion you find to these others.

We also know this experimentally.

We know that by making people be disgusted,

we can make them meaner. I’ll give you an example of this.

This is from a study I was involved with,
with David Pizarro at Cornell University as

the lead investigator.

What we did was we brought people into the
lab… into a lab at Cornell.

And we asked him all sorts of questions regarding
their feelings towards different groups and

different policies.

What do you think of African-Americans?

What do you think of gay men?

What do you think of welfare?
What do you think of immigration?

And so on and so forth.

Half the people just filled it out and went
home.

The other half of the subjects went into the
room, got the same survey.

But the difference was, before they entered
the room

we sprayed the room with a fart spray.

That’s the first experiment I’ve ever
been involved with that used a fart spray.

People would be kind of grossed out.

And it would make them meaner.

Not towards everything, but it would make

them particularly meaner towards out groups,

like male homosexuals.

And this supports the idea that there’s
a connection in our minds between a visceral

emotion of disgust and our feelings towards
others.

So what I’ve argued is, we do have a natural compassion,

but it’s limited. It does not naturally extend to others.

But that raises a puzzle

because you and me and everyone else we know

can extend our compassion to strangers.

To put it in the language that the philosopher Peter Singer has used,

“Our moral circle has expanded.”

It might be that our ancestors, it might be the people in small scale societies only

cared about their family and friends.

But we have a broader circle of compassion.

We think about we care about people in other countries.

We care about people from other races.

We care about people we’ve never seen before
and we never will see.

When some sort of disaster strikes like a
tsunami or a hurricane, many

of us give our resources, even our blood,
to help out people we’ve never met before.

And that poses a neat psychological puzzle.

What forces take our narrow moral circle,
our narrow scope of compassion and

bigger and expand it to care for these others?

Now I think that there are a lot of different
answers to that question.

Robert Wright, for instance, has argued that
one force in expanding the moral circle has

been human interconnections in commerce, in
international travel and so on.

The more people you know, the more people
you have contact with, the more we are interconnected

in the world, the more you might care about
them in a sort of self-interested altruism

where you care about them because they’re
fates are intertwined with yours.

And I think that there’s a lot of value
in that insight.

But I want to focus on a more

psychological more individual based mechanism.

for expanding our the moral circle.

A mechanism that happens to individuals

as they get older

part of devleopment.

which is, their sympathies expand because of a certain

sort of persuasion.

I want to suggest that there is psychological
evidence that supports the idea that we can

expand our compassion, our moral circle to

far away strangers by being made to think

of them as if they are individual people.

We think of them as if they’re our friends and family.

We think of them as if they are right in front
of us.

Joseph Stalin famously said, “A single death
is a tragedy, a million deaths is a statistic.”

And Mother Theresa presented a similar sentiment
when she said, “If I look at the mass, I

will never act.

If I look at the one, I will.”

Psychologists like Paul Slovic has explored this in the lab.

So for instance, they would do a study where

they would have an appeal for a charity.

And in fact, they would take the money they
got and send it to the charity.

And they would, for one group of subjects,
describe the problem in terms of statistics,

in terms of numbers, in terms of the millions
of people suffering, a sort of suffering a

proportion of the population who is in desperate
need.

And they found that people would give say,
roughly a dollar.

For the other group, they didn’t bother
with statistics at all.

They didn’t bother trying to impress them
with the huge number of people suffering.

They told them a story about a single individual.

They had a picture of that individual, they
gave her a name.

And when you do that, you find that people
are far more generous.

It’s a far more powerful effect on their
compassion.

They will give, roughly, twice as much.

Charities, when they try to appeal for people’s

help, won’t throw numbers at you.

They typically won’t because they know that

doesn’t work.

The way to extend people’s compassion, the
way to motivate altruistic action is to appeal

to some very natural, very hardwired systems
within us that respond to individual people.

I think it’s a tremendously
persuasive way for a charity to work.

And I think more generally, as part of the
story for how our compassion can get bigger

and bigger.

People talk about moral progress.

People have argued that through our history,

our moral circles have been expanding.

We now live in a world where people believe
we have moral obligations to other races,

other nationalities that sexism and racism
are immoral.

Consider the end of slavery in the United States.

There are a lot of different factors that
led to the end of slavery, but many historians

would argue that one of the forces that led
many white Americans to believe slavery was

wrong was persuasion, in particular, it was
the work of the author Harriett Beecher Stowe

in her book, Uncle Tom’s Cabin.

In this book, she didn’t make logical arguments;
she didn’t make theological points or philosophical

proposals.

Rather, she got her readers to extend their
sympathies.

And this had a profound effect.

It had a profound effect persuading them that

slavery was wrong

so part of morality, part of right and wrong

is intimately connected with compassion over our feelings towards others.

Some scholars like David Hume,

argue that a sense of empathy, a sense of compassion

is aptly central to becoming a fully moral being.

And certainly notions of right and wrong

come up in the domain of race.

Cause the very question of forming stereotypes

and forming attitudes towards human groups is morally fraught.

The second case study I want to talk about
is racism.

And I want to begin by making a connection
to a branch of cognitive psychology.

In particular the branch of cognitive psychology
that deals with how we make sense of the world.

How we naturally form categories of the things
we see and the things we interact with.

Cognitive psychologists have pointed out that in order to survive in the world, we have to make generalizations.

You probably have never seen those three pictures
I have up here, but you immediately know that

one is a dog and one is an apple and one is
a chair.

You will also have intuitions about these
things… you’ll make generalizations.

You’ll believe the dog can bark, the apple
is something you can eat, a chair is something

you can sit on.

Now, you probably also realize that there
are exceptions to this.

Some dogs are silent, some apples are poisonous,
some chairs will collapse if you sit on them,

but still if you couldn’t make those generalizations,
if you didn’t recognize that some properties

tend to co-occur with some objects, you would
be helpless in the world.

You wouldn’t know what to eat, you wouldn’t
know how anything would react; you wouldn’t

survive.

Part of being a successful human, in fact,
part of being any successful animal is being

able to learn.

And a good part of what learning is is to
make statistical generalizations on the basis

of limited experience.

You eat a thousand apples, they all taste
pretty good, you conclude, I can eat apples,

apples taste good.

And when you’re hungry, you reach for the apple.

This is adaptive, it is rational, it is reasonable.

But now there’s a twist.

The twist is that some of the categories that
we form are categories of people.

We form categories on the basis of sex, of age, of

race, profession, religion, sexual orientation,
nationality, and where the person lives.

When we form categories of people, we often call these stereotypes.

Now, stereotype may sound like a bad word,
but there’s nothing bad about it.

For one thing, stereotypes are often accurate.

We’re reasonably good statistical learners,
and so we tend to be reasonably accurate.

Also, stereotypes are often positive, particularly
of groups that we ourselves belong to.

Some of the statistical generalizations may
be correct and may be positive as some groups

have reputations for being smart, for being
loyal, for being brave, for all sorts of things

that are not at all negative.

And so there’s nothing inherently wrong
about stereotypes.

On the other hand there are several problems with stereotypes.

For one thing, they’re reliable insofar
as they’re based on a sample, an unbiased

sample, of the population.

But a lot of the information we get about
human groups is through biased sources like

how they’re represented in the media.

And if these sources don’t give you an accurate
rendition, you’re a stereotype won’t be

accurate.

For example, many Italian-Americans were upset
at the depiction of Italian-Americans in a

television show, “The Sopranos.”

This is because, if you are in an area where
the only Italian-Americans you meet are those

you see on TV and those you see on “The
Sopranos,” you’re going to think they’re

all mobsters.

Many Jews historically have been troubled
by Shakespeare’s depiction of Shylock.

If the only Jew you know is Shakespeare’s
Shylock, again, it’s going to be a very

bad impression.

And so one problem with stereotypes is while
we have accurate statistical mechanisms for

taking in information and drawing conclusions
from them, often our information isn’t reliable

and often this can lead to the formation of
stereotypes that aren’t right.

A second problem is that stereotypes regardless
of whether or not they’re accurate can have

a negative effect on the people that they apply to.

And this is what the psychologist, Claude
Steele, described as stereotype threat.

So he has a vivid example of this.

Here’s how to make African-Americans do
worse on a math test.

You have the test and you put on the test
that they have to identify their race.

The very act of acknowledging that their African-American
when given a test ignites in them thoughts

of their own stereotype, which isn’t positive,
which is negative regarding academics and

that makes them do worse.

Want to know how to make a woman do worse
on a math test?

Same thing, get her to write down her sex.

One recent study found a sort of clever twist
on this.

The study involved testing Asian-American
women.

Turns out, when Asian-American women are given
a test and they’re asked to mark down their

race, they do better than they would otherwise
do.

They’re reminded of the stereotype, but
as a positive stereotype and it bumps them

up.

You ask them, on the other hand, to mark down
their sex, they do worse because they’re

women and that’s a negative stereotype towards
women.

That’s an example of how stereotypes have
a potentially damaging effect on people.

A third problem with stereotypes is, in some
way, our stereotypes of human groups are like

our categories of dogs and apples and chairs.

But there’s a way in which they aren’t.

We’re not dogs and apples and chairs.

But we are members of human groups.

And this fact of how you connect with the
category has an effect on how you think of

the category.

There’s a lot of evidence suggesting that
when you’re a member of the category, you

boost it.

You give it higher qualities.

People in your group are smarter or nicer,
they’re more deserving and so on.

On the other hand, if it’s an out group,
if it’s another category, particularly if

it’s a category that you’re in some way
competing against, the category gets denigrated.

We see some vivid historical example of this.

In one study in 1942, Americans were asked
to describe the top two features of Russians.

And they described them as brave and hard-working.

In 1948, they were asked the same question.

They described them as cruel and conceited.

The Russians didn’t change, what changed
was our relationship to them over the intervening

years; they went from being part of a group
that we were a part of to the out group.

The final problem with stereotypes is a moral
one.

Even if stereotypes are perfectly accurate,
even if they’re accurate summaries of the

statistics of a group, there are many cases
where we believe that it’s morally wrong

to judge somebody based on their group membership.

We should judge them as individuals.

For all of these reasons, and maybe mostly
for the last one,

there’s an interesting tension in how we think about other groups.

On the one hand, we want to be consciously
egalitarian, consciously non-racist, consciously

thinking of individuals as individuals and
not letting stereotypes, particularly ugly

stereotypes affect our judgments.

And there’s some evidence that we succeed
at this.

You look at the statistics, for instance,
what you see in this graph, is there are a

portion of Americans who say they would vote
for a qualified African-American to be President.

And what you could see is, at a certain point
by the mid-nineties, just about everybody

says, that they would.

And the election of Barrack Obama shows that
this wasn’t just people lying when asked

questions, it really reflects an honest to god consciously egalitarian viewpoint.

On the other hand, we also have an unconscious
system.

And an unconscious system is more statistics
driven, more biased and less sensitive to

moral concerns.

So you get a tension between the conscious
egalitarian system and the unconscious system,

which is often driven by bias.

This conscious, this unconscious system is
data-driven

and it is a lot less sensitive to our
moral concerns than the conscious system.

One striking example of unconscious biases involves

being shown these two faces.

And asked who is more American?

Well at some level this is a ridiculous question.

You would laugh when they hear it.

Barack Obama is more American cause he's like American.

Tony Blair is British.

But unconsciously you can ask the same question.

You can see how quickly it takes to associate

these faces with words like American or not American.

And it turns out based on this sort of implicit unconscious test

people are often more willing and quicker to

associate the face of Tony Blair as American

than the face of Barack Obama.

Of course because Tony Blair has a white face

and Barack Obama has a dark face.

Now, one response to these sorts of studies,
one perfectly legitimate response I think

is say, who cares.

Consciously, we’re egalitarian, consciously
we’re non-prejudice, we have these weird,

quirky unconscious biases that drive our behavior

when pressing buttons and responding fast.

What difference does it make?

But there’s evidence it does make a difference.

There’s evidence that these unconscious
biases play a role in things that matter very

much in the real world.

So consider some studies by Jack Dovidio and
his colleagues.

They first did this study in 1989, and what
it involved is, you give people resumes of

candidates and these resumes have pictures.

And what the subjects and experiment don’t
know is they were always given the same resume,

but half of them got it with a white person,
half of them a black person.

And then they were asked, how strongly would
you recommend this person for a job?

Now, if these candidates had strong qualifications,
they both would be recommended.

In fact, perhaps the black is a bit more likely
to be recommended than the white one.

But when they had moderate qualifications,
when it’s a judgment call, the white candidate

was statistically more like to be recommended
for a job than the black candidate.

Not because these people said, I’m a racist,
I’m going to do it this way,

but rather they are swayed by this factor that they might
not have been conscious of.

As I said, this was done in 1989.

But they did the same study in 1999 and got
the same result.

And they did the same study in 2005, and got
the same result.

So, we’re at war with ourselves.

We have on the one hand these conscious beliefs
about how we think we should think, how we

think we should behave.

On the other hand, we have this unconscious
system that makes all these sorts of decisions

and affects us in ways that we might not know
about, we might not be aware of.

The good news is we’re also smart.

And part of being smart means that we can
structure our world so that we can make it

that unconscious biases matter less.

To give you an example of this, I’ll turn not to race, but to gender.

Not too long ago, women were deeply underrepresented
in symphony orchestras.

And the reason for this, it was argued is
because they don’t play as well.

In a fair and biased fashion
they’d been judged and they just don’t

sound as good.

But in part, based on these sorts of discoveries,
symphony orchestras began to hold blind auditions.

What they would do is they would have the
person play behind a screen.

The judges won’t know if they are listening to a man or to a woman.

Once this was put into place, the representation
of women in symphony orchestras shot up.

It wasn’t that originally these were just sexist, to say,

I don’t like women; I’m going to count against them.

Rather, these were perhaps good, non-sexist
people, who couldn’t help hearing the woman

differently from the man.

And I like this example because it shows how
first, social psychology and psychology in

general can shape policy in a good way.

But second, it shows how we’re smart enough
to manipulate the world so that our better

selves get to make the decisions.

The third case study I want to talk about
is sex.

And when it comes to sex, considerations of
evolution become incredibly relevant.

I think the question of how we evolve and
the question of how our minds are now shaped

in response to evolution pressure is something
that pertains to all of psychology.

It pertains to, certainly, for how we think
about human groups, certainly for compassion

and morality, and all sorts of other topics
I haven’t discussed, like perception and

language and memory.

But it’s screamingly obvious in the domain
of sex.

As soon as you start thinking about
our bodies and our brains, you’re faced

with a puzzle.

And it’s the sort of a puzzle that can only
be resolved in terms of evolution.

And here’s what the puzzle is.

What’s the difference between males and
females?

Well, there’s a general answer to this that
doesn’t pertain to any particular species

that goes across every creature on earth.

The males are the ones with the small sex
cells.

To be a male is to have a sperm, which contains
genetic material, and that’s basically it.

The females have the large sex cells.

The female sex cell, the egg, also contains
genetic material but it contains a cover,

it contains food, it contains all the apparatus
needed to get an organism growing.

So here’s the puzzle.

You look around most animals, not all animals,
but most animals.

And the male is bigger and more aggressive.

So why would the animal with the smaller sex
cell tend to grow up to be the bigger animal.

And this has been a mystery for a very long
time until an evolutionary biologist named

Robert Trivers, solved it.

And he solved it by making reference to the
idea of parental investment.

Trivers defines parental investment as any
investment by the parent in an individual

offspring that increases the offspring’s
chances of surviving at the cost of the parent’s

ability to invest in other offspring.

Given the different size in the sex cells

it means that males typicaly have less investment than females.

Because in most, though not in all species

the offspring grows inside the females body.

And while that offspring is growing inside the females body

the male is free to have other offspring, but the female is not.

for humans for instance a man can ejaculate

then moments later or hours later

or however much later can ejaculate again.

And there's virtually no practical limit

to how many different offspring a man can have.

For a woman when she get's pregnant

she can't have more kids during that period.

In fact it is difficult for her to have kids even later on when she is breastfeeding.

So there is a fairly small number of offspring

a female human can have.

This makes a difference,

it makes a difference. It makes a difference in the

sort of economic game theoretic structure.

of human sexuality.

What follows from this from an economic point of view

is that males compete with on another

for access to females.

Both males and females want offspring, that’s
the genetic imperative, but males can be more

into number while females can be more into
quality.

This leads to competition between males.

And the competition is of two different sorts.

There’s competition male against male, which
leads to the evolution of aggressive trades.

It even leads to the evolution of some species
with special organs, like the giant horns

of some animals that exist for males and not
females because they’ve evolved according

to this reproductive logic based on the lower
parental investment.

It also leads males to evolve certain traits
to attract the attention of females.

Females are the scarce resource here.

Females as a rule are more choosey

when it comes to short term sexual partners than males.

And so males compete with one another to attract
females.

The most striking biological example of this

is the elaborate, glorious plumage of the peacock.

There’s a carton I enjoy here because the
peahens are saying to the peacock,

“Cut the crap and show us your willy.”

Which I like because it sounds sort of British,
but I also like because it nicely captures

the evolutionary logic behind what all of
this is for.

Finally, you get to relative choosiness.

Females are, as a rule, more choosy when it
comes to short-term sexual partners than males.

And this shows up in a couple of ways, it
shows up in prostitution.

So, prostitution is a huge industry in the
world.

And with very few exceptions, prostitutes
cater to male customers.

Then there’s pornography.

Now, pornography may appeal to different sexes,
some people have argued that romance novels

are sort of the equivalent to pornography
for women.

But what appeals to men is often sort of images
of sexually receptive women.

This isn’t the same as sort of a one-night
stand, but is a psychologically vicarious

one-night stand, where this image is enough
to lead to arousal.

The only thing interesting I have to say about
this is a recent study that suggests this

is not exclusively a human vice.

So recent study involved showing pornography
to Rhesus Macaques, these are a type of monkey.

The question was, would these monkeys pay to see porn?

And so you didn’t have a financial system
for these monkeys, so they set up a nice apparatus

where at a certain point, the
monkey had a choice, he could either stare

at a picture or turn and sip sweet orange
juice; monkeys love orange juice.

So the question is, what sort of pictures
would they pay, would they give up on this

orange juice in order to see?

And there were two sorts of pictures that
they would pay to see.

They would pay to see the behinds of female
Rhesus monkeys and they would pay to see the

faces of high status male Rhesus monkeys.

Sort of like the equivalent of a Playboy Magazine
and People Magazine, suggesting that two of

the major human vices, pornography and celebrity
worship are in fact not uniquely human.

Now, you can go on about the differences between
males and females in terms of sexual interest

and sexual hues and so on, but I want to focus
for the rest of this case study on certain

things we have in common.

And one thing that we have in common is an
attraction to what we would call beauty.

Certain things are beautiful, certain things
appeal to us universally.

Some studies find in the first tenth of a
second after looking at a face, you have computed

how beautiful it is.

Cultures differ tremendously, different times,
different places

in what counts as beautiful, what counts as sexually attractive.

And that is entirely true; there are interesting
and powerful differences.

But at the same time, there are also universals.

There are certain things that people everywhere
find attractive.

And we can use evolutionary theory to makes
sense of the sort of things people find as

beautiful.

So to some extent, beauty equates to youth.

Hues like round eyes, full lips, smooth tight
skin.

Most likely it is because they are cues the person is young,

is able to have kids, has many years ahead of them.

And so on.

Beauty also equates to health.

We are drawn to features like

absence of deformities, clear eyes, unblemished skin

intact teeth, and average faces.

And you might think, average faces?

That’s strange thing to put in beautiful,
as a category of beautiful.

But it turns out average faces actually look
really good.

So what an average face does is it gets rid
of all of the things that are unusual and

people tend to find it quite attractive.

Now one accusation that always comes up in
these situations is,

who did you get this data from?

And in fact, psychologists are often guilty
of collecting data from 24 university freshmen

and then saying that these conclusions apply
to all of humanity, but not in this case.

In this case, studies of human attractiveness
have been done cross-culturally and you get

pretty much the same findings wherever you
go.

Again, there’s some interesting differences,
but these universals seem to always be attractive.

The work that’s most exciting to me along
these lines is actually done with babies.

So adults can rank faces as attractive or
unattractive, but you can also see what babies

think about faces.

And it turns out, using babies looking time
as a measure for what they like to see.

So how long will they look at a face?

It turns out that babies preference for attractive
faces match pretty well adults preferences

for attractive faces.

So for instance, in some wonderful work by
Languar[ph] and her colleagues, she would

show different degrees of averageness across
faces, composites of more and more people.

You can see this in these faces are not the
faces of real people, these faces are computer

composites of multiple people and they are
not bad looking, but you can get better than

average for both males and females.

For females, many people will judge a face
better than average if it’s feminized.

If you take the features that define a face
as female and you exaggerate them, as in the

picture on the right, it tends to look a little
bit better than your average female face.

For men, you could do the same thing.

you can take faces and

take your average male face and turn it into
testosterone man, which is the face that you’re

looking at on the left.

It turns out that women’s responses to testosterone
man differ according to whether or not they’re

ovulating.

So if a woman is ovulating, she is more likely
to find this manliest of man face attractive,

while if not, she tends to go back to just
find average man more attractive.

And there's different theories of precisely why this is so.

It does suggest that our sexual psychologies
connect with our reproductive preferences

in all sorts of interesting ways.

But there’s a lot more to looking
good than how you look.

It turns out, how attractive you find a face

is critically dependent on how much you like the person.

The more you like somebody, the better they look to you.

This is why spouses and happy marraiges

will honestly find their husband or wife

far more attractive than anyone else finds them.

This is true more generally.

In a classic study, David Bus,

tested people from 37 different cultures around the world

and asked who is your perfect mate?

He was largely looking for sex differences in theses studies

and he found them, he found all sorts of differences

in what men were looking for and in what women were looking for.

But he also found one similarity, one thing

one way in which women and men were alike.

And this is that for both, the number one quality

people were looking for in a mate

was kindness.

All of this in the domain of sex

supports a moral from Shakespeare

which is "love looks not with the eyes, but with the mind".

What I have done is I have very briefly talked about

three case studies in the domain of psychology.

I talked about compassion,

I talked about racism,

and I have talked about sex.

In the course of this I've tried to illustrate

certain themes in the study of psychology, in general.

And in fact I started by listing six domains of psychology.

Neuroscience, I started by talking about the babies brain

and gave that as a starting point

for the question of the development of compassion

the development of these other traits.

but every domain of psychology every

aspect of our mental life

is caused by our physical brains.

And in fact, in all of these domains I’ve
talked about, compassion and moral psychology

and more general, race and stereotyping and
thinking about groups, and sex and sexuality,

people have used the methods of neuroscience

to better understand how the mind works in
these domains.

I’ve talked about development and I focused
mostly in development on the first case study

of compassion, but of course there’s a huge
amount of very interesting research on the

development of our understanding of groups
asking the question, for instance, are young

children racist?

Do young children have complicit biases?

And of course in the development of romance
and sexuality, how does the mind of a child

before puberty differ and how much is it like
the mind of an adult after puberty and how

did these differs take place?

These are extraordinarily interesting developmental
questions.

All three domains connect to social psychology and cognitive psychology in clear ways.

They are all questions about social psychology,
they are all questions about dealing with

other people; how we deal with and make sense
out of other people.

And they all connect to questions of cognitive
psychology, like the perception of faces,

the formation of categories, the comprehension
of stories; those are all central parts of

cognitive psychology and central to understanding
the domains we’ve talked about here.

We’ve talked about evolution, particularly
again, in the case of sexuality.

But of course, the evolutionary psychology
of morality and compassion is a fascinating

issues connecting it with research done with
other primates, our evolutionary relatives

like chimpanzees and monkeys.

I’ve said the least about clinical psychology.

Clinical psychology is extraordinarily interesting
and also connects to each of the domains that

I’ve talked about.

People are interested in the psychopathology
related to sexuality.

They’re particularly interested in the psychopathology
in mental illness in the domain of morality

because this connects to one of the most troubling
and one of the most interesting questions

in clinical psychology, which concerns the
psychopath.

There are some of us, apparently, who don’t
have consciences, who don’t feel compassion,

who will destroy other people’s lives out
of malice or self-interest or simple boredom.

And the question of where psychopaths come
from, what’s the precise nature of what’s

going wrong with them.

Most of all, what can be done about them are
issues of extraordinary interest.

Psychology is the perfect liberal arts major

because it connects across all these interesting disciplines

and gives you intellectual tools, tools that we share

with philosophers and we share with chemists

and we share with people who study english literature.

It brings them all together in the project of studying the mind.

Every interesting question in psychology is also an

interesting question for scholars outside psychology.

We've made huge progress over the last many years

in understanding mental life.

And I think there's no reason to expect this progress to stop.

I think that in the end

the most important and intimate aspects of ourselves,

how we understand people, our emotions, our motivations

our desires, our sense of right and wrong.

can be understood through the methods of scientific
psychology

through constructing and testing hypotheses.

Through bringing to bear considerations

based on evolution.

and computation and neuroscience.

Now, some people might find this a scary prospect.

I know that there are some people that worry
that a scientific perspective of the mind

takes away from us somehow.

It diminishes us.

It makes us less than what we are.

I don’t agree.

I have the opposite reaction, which is that
as the more you understand the mind from a

serious scientific point of view; the more
you come to appreciate its complexity, its

uniqueness and its beauty.

Thank you.