GUY RAZ, HOST:
It's the TED Radio Hour from NPR. I'm Guy Raz. Today's show - ideas around how we love. And the thing about love is that for at least a century, scientists have been getting closer to the mystery of how it works.
HELEN FISHER: You know, the elation, the giddiness, the euphoria, the energy, the possessiveness, the craving, the obsession.
RAZ: This is Helen Fisher. She teaches at Rutgers.
FISHER: I'm a biological anthropologist, and I study love, romance and personality. I'm also chief scientific advisor to Match.com, the dating service.
RAZ: That's cool. That's actually - the academic stuff - eh. It's the Match.com that's cool.
FISHER: Well, thank you.
RAZ: Helen looks at the science behind love. And her research is based on one big idea - that our brains are actually wired to fall in love, that there's actually a drive, a brain circuitry that developed millions of years ago that's devoted entirely to romantic love.
FISHER: People have resisted thinking that romantic love actually is a brain system. They're scared that it will break the magic. They want romantic love to be part of the supernatural.
RAZ: But why can't that brain chemistry be kind of supernatural?
FISHER: Well, on some level, I mean - I don't know. I'm a scientist. I put people in brain scanners.
FISHER: But, you know, when it actually happens to you, it can feel supernatural. I mean, why isn't it supernatural? 'Cause it's housed in the brain. Why do we want to feel that it's supernatural? 'Cause it feels so good.
RAZ: OK, so this brain system, it's kind of like a...
FISHER: Sleeping cat. It can be awakened at any time.
RAZ: Any time, any place. And it's partly because...
FISHER: As you grow up, you begin to build what I call an unconscious list of what you're looking for in a partner, which I call your love map.
RAZ: For example, when you walk into a party and...
FISHER: Boom, you look up at her. She fits within that love map. It triggers that brain circuitry and boom. You're off to the races.
RAZ: And all of a sudden, your brain starts flying through this very subjective list of criteria.
FISHER: Too tall, too short, too fat, too thin, too old, too young, too scruffy - they're out. Wrong accent - they're out. They smile at you, they don't have any teeth - they're out.
RAZ: And if that person makes the cut, your brain...
FISHER: Is becoming active, is giving you that pleasing sensation, is pumping out the dopamine to make you feel more optimistic, energetic. You feel that intense rush.
RAZ: And it happens in a flash. And you're not really sure what's going on, but you know something is going on. So what's happening? Well, Helen explains the science behind it on the TED stage.
(SOUNDBITE OF TED TALK)
FISHER: I and my colleagues, Art Aron and Lucy Brown and others, have put 37 people who were 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 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 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.
RAZ: OK, but, I mean - but, like, what makes you get that rush for one person, right, over somebody else?
FISHER: Well, I wondered about that, and of course this is what interested me so much with Match.com. They asked me, why do you fall in love with one person rather than another?
(SOUNDBITE OF TED TALK)
FISHER: And so I've spent the last three years on this. And psychologists can tell you, we tend to fall in love with somebody from the same socioeconomic background, the same general level of intelligence, the same general level of good looks. And that's about it. That's all they know. They have 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've 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.
RAZ: Helen calls the series of questions the Fisher Temperament Inventory - 56 questions that can gauge whether you have higher or lower levels of certain brain chemicals. And the questions include things like, do you change your mind easily? Or is it important to you to respect authority? And do you prefer interesting friends or loyal friends?
FISHER: And over 13 million people have now have taken that questionnaire. About 30,000 take it every month on Chemistry.com. So, you know, it's big data. I mean, Match.com enabled me to really collect a lot of big data.
RAZ: So what did you find out?
FISHER: As it turns out, people who are very high on the dopamine system - curious, creative, spontaneous, energetic - they go for people like themselves. People who are traditional - the serotonin system - they also go for people like themselves. In the other two cases, opposites attract. People with the traits linked with the testosterone system - the analytical, logical, direct, decisive, tough-minded - they go for their opposite. People who are very expressive of the estrogen system - imaginative, intuitive, good verbal skills, good people skills - they also go for their opposite.
RAZ: So when this happens and you meet your perfect neurochemical match, your brain is in love. You are literally addicted to that person. And then you get dumped.
FISHER: People who've been rejected in love show activity in brain regions linked with pain. In fact, one of the brain regions is a brain region that also becomes active when you feel tooth pain. So it's a really powerfully, painful - literally painful experience when you've been rejected in love.
(SOUNDBITE OF TED TALK)
FISHER: Lucy Brown and I, the neuroscientist 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 not a - it was very difficult actually, putting these people in the machine 'cause they were in such bad shape.
FISHER: So anyway, we found activity in exactly the same brain region associated with intense romantic love. You know, when you've been dumped, the one thing you'd love to do is just forget about this human being and then go on with your life. But no, you just love them harder. 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.
RAZ: I mean, there is, like, a human need for companionship.
RAZ: I mean, we need that, like - I mean, what is it about that? Like, why?
FISHER: Because millions of years ago, the trees began to disappear, and we had to get out. And we began to climb on down, and they would rush out onto the grasslands and stand up on two feet, collect what they could to eat and race back to a place where they were protected. With the beginning of standing came walking.
And with that, women had to begin to carry their babies in their arms instead of on their back. So females began to need a partner to help them rear their baby, and we evolved, in the human animal, the brain circuitry for romantic love and for deep, profound attachment to another individual - the very hallmarks of humanity.
(SOUNDBITE OF TED TALK)
FISHER: So what have I learned from this experiment that I would like to tell the world? Foremost, I've come to think that romantic love is a drive - a basic mating drive, not the sex drive. The sex drive gets you out there 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 a single individual.
What sums it up best is something that is said by Plato over 2000 years ago. He said the God of love lives in the 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. 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.
RAZ: Helen Fisher. She wrote about her ground-breaking research in the book "Why We Love." She's given several other TED talks. Check out all of them at TED.com.
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