I and my colleagues Art Aron
and Lucy Brown and others,
have put 37 people who are madly in love
into a functional MRI brain scanner.
17 who were happily in love,
15 who had just been dumped,
and we're just starting
our third experiment:
studying people who report
that they're still in love
after 10 to 25 years of marriage.
So, this is the short story
of that research.
In the jungles of Guatemala,
in Tikal, stands a temple.
It was built by the grandest Sun King,
of the grandest city-state,
of the grandest civilization
of the Americas, the Mayas.
His name was Jasaw Chan K'awiil.
He stood over six feet tall.
He lived into his 80s,
and he was buried beneath
this monument in 720 AD.
And Mayan inscriptions proclaim
that he was deeply in love with his wife.
So, he built a temple
in her honor, facing his.
And every spring and autumn,
exactly at the equinox,
the sun rises behind his temple,
and perfectly bathes her temple
with his shadow.
And as the sun sets
behind her temple in the afternoon,
it perfectly bathes
his temple with her shadow.
After 1,300 years, these two lovers
still touch and kiss from their tomb.
Around the world, people love.
They sing for love, they dance for love,
they compose poems and stories about love.
They tell myths and legends about love.
They pine for love, they live for love,
they kill for love, and they die for love.
As Walt Whitman once said,
"O I would stake all for you."
Anthropologists have found evidence
of romantic love in 170 societies.
They've never found a society
that did not have it.
But love isn't always a happy experience.
In one study of college students,
they asked a lot of questions about love,
but the two that stood out
to me the most were:
"Have you ever been rejected
by somebody who you really loved?"
And the second question was:
"Have you ever dumped somebody
who really loved you?"
And almost 95 percent of both men
and women said yes to both.
Almost nobody gets out of love alive.
So, before I start telling you
about the brain,
I want to read for you
what I think is the most powerful
love poem on Earth.
There's other love poems that are,
of course, just as good,
but I don't think this one
can be surpassed.
It was told by an anonymous
Kwakiutl Indian of southern Alaska
to a missionary in 1896.
And here it is.
I've never had the opportunity
to say it before.
"Fire runs through my body
with the pain of loving you.
Pain runs through my body
with the fires of my love for you.
Pain like a boil about to burst
with my love for you,
consumed by fire with my love for you.
I remember what you said to me.
I am thinking of your love for me.
I am torn by your love for me.
Pain and more pain --
where are you going with my love?
I am told you will go from here.
I am told you will leave me here.
My body is numb with grief.
Remember what I said, my love.
Goodbye, my love, goodbye."
Emily Dickinson once wrote,
"Parting is all we need to know of hell."
How many people have suffered
in all the millions of years
of human evolution?
How many people around the world
are dancing with elation
at this very minute?
Romantic love is one of the most powerful
sensations on Earth.
So, several years ago,
I decided to look into the brain
and study this madness.
Our first study of people
who were happily in love
has been widely publicized,
so I'm only going to say
very little about it.
We found activity in a tiny,
little factory near the base of the brain
called the ventral tegmental area.
We found activity in some cells
called the A10 cells,
cells that actually make
dopamine, a natural stimulant,
and spray it to many brain regions.
Indeed, this part, the VTA,
is part of the brain's reward system.
It's way below your cognitive
thinking process.
It's below your emotions.
It's part of what we call
the reptilian core of the brain,
associated with wanting, with motivation,
with focus and with craving.
In fact, the same brain region
where we found activity
becomes active also
when you feel the rush of cocaine.
But romantic love is much more
than a cocaine high --
at least you come down from cocaine.
Romantic love is an obsession,
it possesses you.
You lose your sense of self.
You can't stop thinking
about another human being.
Somebody is camping in your head.
As an eighth-century Japanese poet said,
"My longing had no time when it ceases."
Wild is love.
And the obsession can get worse
when you've been rejected.
So, right now, Lucy Brown and I,
the neuroscientists on our project,
are looking at the data of the people
who were put into the machine
after they had just been dumped.
It was very difficult actually,
putting these people in the machine,
because they were in such bad shape.
(Laughter)
So anyway, we found activity
in three brain regions.
We found activity in the brain region,
in exactly the same brain region
associated with intense romantic love.
What a bad deal.
You know, when you've been dumped,
the one thing you love to do
is just forget about this human being,
and then go on with your life --
but no, you just love them harder.
As the poet Terence,
the Roman poet once said,
he said, "The less my hope,
the hotter my love."
And indeed, we now know why.
Two thousand years later,
we can explain this in the brain.
That brain system -- the reward system
for wanting, for motivation,
for craving, for focus --
becomes more active
when you can't get what you want.
In this case, life's greatest prize:
an appropriate mating partner.
We found activity
in other brain regions also --
in a brain region associated
with calculating gains and losses.
You're lying there,
you're looking at the picture,
and you're in this machine,
and you're calculating what went wrong.
What have I lost?
As a matter of fact, Lucy and I
have a little joke about this.
It comes from a David Mamet play,
and there's two con artists in the play,
and the woman is conning the man,
and the man looks at the woman and says,
"Oh, you're a bad pony,
I'm not going to bet on you."
And indeed, it's this part of the brain,
the core of the nucleus accumbens,
that is becoming active
as you're measuring your gains and losses.
It's also the brain region
that becomes active
when you're willing to take enormous risks
for huge gains and huge losses.
Last but not least,
we found activity in a brain region
associated with deep attachment
to another individual.
No wonder people suffer around the world,
and we have so many crimes of passion.
When you've been rejected in love,
not only are you engulfed
with feelings of romantic love,
but you're feeling deep
attachment to this individual.
Moreover, this brain circuit
for reward is working,
and you're feeling intense energy,
intense focus, intense motivation
and the willingness to risk it all,
to win life's greatest prize.
So, what have I learned
from this experiment
that I would like to tell the world?
Foremost, I have come to think
that romantic love is a drive,
a basic mating drive.
Not the sex drive --
the sex drive gets you looking
for a whole range of partners.
Romantic love enables you
to focus your mating energy
on just one at a time,
conserve your mating energy,
and start the mating process
with this single individual.
I think of all the poetry
that I've read about romantic love,
what sums it up best
is something that is said by Plato
over 2,000 years ago.
He said, "The god of love
lives in a state of need.
It is a need, it is an urge,
it is a homeostatic imbalance.
Like hunger and thirst,
it's almost impossible to stamp out."
I've also come to believe
that romantic love is an addiction:
a perfectly wonderful addiction
when it's going well,
and a perfectly horrible addiction
when it's going poorly.
And indeed, it has all
of the characteristics of addiction.
You focus on the person,
you obsessively think about them,
you crave them, you distort reality,
your willingness to take enormous
risks to win this person.
And it's got the three main
characteristics of addiction:
tolerance, you need to see them
more, and more, and more;
withdrawals;
and last: relapse.
I've got a girlfriend who's just
getting over a terrible love affair.
It's been about eight months,
she's beginning to feel better.
And she was driving along
in her car the other day,
and suddenly she heard a song
on the car radio
that reminded her of this man.
Not only did the instant
craving come back,
but she had to pull over
from the side of the road and cry.
So, one thing I would like
the medical community,
and the legal community,
and even the college community,
to see if they can understand,
that indeed, romantic love
is one of the most addictive
substances on Earth.
I would also like to tell the world
that animals love.
There's not an animal on this planet
that will copulate with anything
that comes along.
Too old, too young, too scruffy,
too stupid, and they won't do it.
Unless you're stuck
in a laboratory cage --
and you know, if you spend
your entire life in a little box,
you're not going to be as picky
about who you have sex with,
but I've looked in a hundred species,
and everywhere in the wild,
animals have favorites.
As a matter of fact,
ethologists know this.
There are over eight words
for what they call "animal favoritism:"
selective proceptivity, mate choice,
female choice, sexual choice.
And indeed, there are now
three academic articles
in which they've looked
at this attraction,
which may only last for a second,
but it's a definite attraction,
and either this same brain region,
this reward system,
or the chemicals of that reward
system are involved.
In fact, I think animal attraction
can be instant --
you can see an elephant
instantly go for another elephant.
And I think that this is really the origin
of what you and I call
"love at first sight."
People have often asked me
whether what I know about love
has spoiled it for me.
And I just simply say, "Hardly."
You can know every single ingredient
in a piece of chocolate cake,
and then when you sit down
and eat that cake,
you can still feel that joy.
And certainly, I make all the same
mistakes that everybody else does too,
but it's really deepened my understanding
and compassion, really,
for all human life.
As a matter of fact, in New York,
I often catch myself
looking in baby carriages
and feeling a little sorry for the tot.
And in fact, sometimes
I feel a little sorry
for the chicken on my dinner plate,
when I think of how intense
this brain system is.
Our newest experiment has been hatched
by my colleague, Art Aron --
putting people who are reporting
that they are still in love,
in a long-term relationship,
into the functional MRI.
We've put five people in so far,
and indeed, we found exactly
the same thing.
They're not lying.
The brain areas associated
with intense romantic love
still become active, 25 years later.
There are still many questions
to be answered
and asked about romantic love.
The question that I'm working on
right this minute --
and I'm only going to say it
for a second, and then end --
is, why do you fall in love
with one person, rather than another?
I never would have
even thought to think of this,
but Match.com, the Internet dating site,
came to me three years ago
and asked me that question.
And I said, I don't know.
I know what happens in the brain,
when you do become in love,
but I don't know why you fall in love
with one person rather than another.
And so, I've spent
the last three years on this.
And there are many reasons
that you fall in love with one person
rather than another,
that psychologists can tell you.
And we tend to fall in love with somebody
from the same socioeconomic background,
the same general level of intelligence,
of good looks, the same religious values.
Your childhood certainly plays a role,
but nobody knows how.
And that's about it, that's all they know.
No, they've never found
the way two personalities
fit together to make a good relationship.
So, it began to occur to me
that maybe your biology pulls you
towards some people rather than another.
And I have concocted a questionnaire
to see to what degree
you express dopamine, serotonin,
estrogen and testosterone.
I think we've evolved four
very broad personality types
associated with the ratios
of these four chemicals in the brain.
And on this dating site
that I have created, called Chemistry.com,
I ask you first a series of questions
to see to what degree
you express these chemicals,
and I'm watching who chooses who to love.
And 3.7 million people have taken
the questionnaire in America.
About 600,000 people have taken it
in 33 other countries.
I'm putting the data together now,
and at some point --
there will always be magic to love,
but I think I will come closer
to understanding
why it is you can walk into a room
and everybody is from your background,
your same general level
of intelligence, good looks,
and you don't feel
pulled towards all of them.
I think there's biology to that.
I think we're going to end up,
in the next few years,
to understand all kinds
of brain mechanisms
that pull us to one person
rather than another.
So, I will close with this.
These are my older people.
Faulkner said, "The past is not dead,
it's not even past."
Indeed, we carry a lot of luggage
from our yesteryear in the human brain.
And so, there's one thing that makes me
pursue my understanding of human nature,
and this reminds me of it.
These are two women.
Women tend to get intimacy
differently than men do.
Women get intimacy
from face-to-face talking.
We swivel towards each other,
we do what we call
the "anchoring gaze" and we talk.
This is intimacy to women.
I think it comes from millions of years
of holding that baby
in front of your face,
cajoling it, reprimanding it,
educating it with words.
Men tend to get intimacy
from side-by-side doing.
As soon as one guy looks up,
the other guy will look away.
(Laughter)
I think it comes from millions of years
sitting behind the bush,
looking straight ahead, trying to hit
that buffalo on the head with a rock.
I think, for millions of years,
men faced their enemies,
they sat side-by-side with friends.
So my final statement is: love is in us.
It's deeply embedded in the brain.
Our challenge is to understand each other.
Thank you.
(Applause)