TED日本語 - ヘレン・フィッシャー: 人が恋する理由

I'd like to talk today about the two biggest social trends in the coming century, and perhaps in the next 10,000 years. But I want to start with my work on romantic love, because that's my most recent work. What I and my colleagues did was put 32 people, who were madly in love, into a functional MRI brain scanner. 17 who were madly in love and their love was accepted; and 15 who were madly in love and they had just been dumped. And so I want to tell you about that first, and then go on into where I think love is going.

"What 't is to love?" Shakespeare said. I think our ancestors -- I think human beings have been wondering about this question since they sat around their campfires or lay and watched the stars a million years ago. I started out by trying to figure out what romantic love was by looking at the last 45 years of research on -- just the psychological research -- and as it turns out, there's a very specific group of things that happen when you fall in love. The first thing that happens is what I call -- a person begins to take on what I call, "special meaning." As a truck driver once said to me, he said, "The world had a new center, and that center was Mary Anne."

George Bernard Shaw said it a little differently. He said, "Love consists of overestimating the differences between one woman and another." And indeed, that's what we do. (Laughter) And then you just focus on this person. You can list what you don't like about them, but then you sweep that aside and focus on what you do. As Chaucer said, "Love is blind."

In trying to understand romantic love, I decided I would read poetry from all over the world, and I just want to give you one very short poem from eighth-century China, because it's an almost perfect example of a man who is focused totally on a particular woman. It's a little bit like when you are madly in love with somebody and you walk into a parking lot -- their car is different from every other car in the parking lot. Their wine glass at dinner is different from every other wine glass at the dinner party. And in this case, a man got hooked on a bamboo sleeping mat.

And it goes like this. It's by a guy called Yuan Chen: "I can not bear to put away the bamboo sleeping mat. The night I brought you home, I watched you roll it out." He became hooked on a sleeping mat, probably because of elevated activity of dopamine in his brain, just like with you and me.

But anyway, not only does this person take on special meaning, you focus your attention on them. You aggrandize them. But you have intense energy. As one Polynesian said, he said, "I felt like jumping in the sky." You're up all night. You're walking till dawn. You feel intense elation when things are going well; mood swings into horrible despair when things are going poorly. Real dependence on this person. As one businessman in New York said to me, he said, "Anything she liked, I liked." Simple. Romantic love is very simple.

You become extremely sexually possessive. You know, if you're just sleeping with somebody casually, you don't really care if they're sleeping with somebody else. But the moment you fall in love, you become extremely sexually possessive of them. I think that that is a Darwinian -- there's a Darwinian purpose to this. The whole point of this is to pull two people together strongly enough to begin to rear babies as a team.

But the main characteristics of romantic love are craving: an intense craving to be with a particular person, not just sexually, but emotionally. You'd much rather -- it would be nice to go to bed with them, but you want them to call you on the telephone, to invite you out, etc., to tell you that they love you. The other main characteristic is motivation. The motor in your brain begins to crank, and you want this person.

And last but not least, it is an obsession. When I put these people in the machine, before I put them in the MRI machine, I would ask them all kinds of questions. But my most important question was always the same. It was: "What percentage of the day and night do you think about this person?" And indeed, they would say, "All day. All night. I can never stop thinking about him or her."

And then, the very last question I would ask them -- I would always have to work myself up to this question, because I am not a psychologist. I don't work with people in any kind of traumatic situation. And my final question was always the same. I would say, "Would you die for him or her?" And, indeed, these people would say "Yes!" as if I had asked them to pass the salt. I was just staggered by it.

So we scanned their brains, looking at a photograph of their sweetheart and looking at a neutral photograph, with a distraction task in between. So we could look at the same brain when it was in that heightened state and when it was in a resting state. And we found activity in a lot of brain regions. In fact,one of the most important was a brain region that becomes active when you feel the rush of cocaine. And indeed, that's exactly what happens.

I began to realize that romantic love is not an emotion. In fact, I had always thought it was a series of emotions, from very high to very low. But actually, it's a drive. It comes from the motor of the mind, the wanting part of the mind, the craving part of the mind. The kind of mind -- part of the mind -- when you're reaching for that piece of chocolate, when you want to win that promotion at work. The motor of the brain. It's a drive.

And in fact, I think it's more powerful than the sex drive. You know, if you ask somebody to go to bed with you, and they say, "No, thank you," you certainly don't kill yourself or slip into a clinical depression. But certainly, around the world, people who are rejected in love will kill for it. People live for love. They kill for love. They die for love. They have songs, poems, novels, sculptures, paintings, myths, legends. In over 175 societies, people have left their evidence of this powerful brain system. I have come to think it's one of the most powerful brain systems on earth for both great joy and great sorrow.

And I've also come to think that it's one of three basically different brain systems that evolved from mating and reproduction. One is the sex drive: the craving for sexual gratification. W.H. Auden called it an "intolerable neural itch," and indeed, that's what it is. It keeps bothering you a little bit, like being hungry. The second of these three brain systems is romantic love: that elation, obsession of early love. And the third brain system is attachment: that sense of calm and security you can feel for a long-term partner.

And I think that the sex drive evolved to get you out there, looking for a whole range of partners. You know, you can feel it when you're just driving along in your car. It can be focused on nobody. I think romantic love evolved to enable you to focus your mating energy on just one individual at a time, thereby conserving mating time and energy. And I think that attachment, the third brain system, evolved to enable you to tolerate this human being -- (Laughter) -- at least long enough to raise a child together as a team.

So with that preamble, I want to go into discussing the two most profound social trends. One of the last 10,000 years and the other, certainly of the last 25 years, that are going to have an impact on these three different brain systems: lust, romantic love and deep attachment to a partner.

The first is women working, moving into the workforce. I've looked at 130 societies through the demographic yearbooks of the United Nations. And everywhere in the world,129 out of 130 of them, women are not only moving into the job market -- sometimes very, very slowly, but they are moving into the job market -- and they are very slowly closing that gap between men and women in terms of economic power, health and education. It's very slow.

For every trend on this planet, there's a counter-trend. We all know of them, but nevertheless -- the Arabs say, "The dogs may bark, but the caravan moves on." And, indeed, that caravan is moving on. Women are moving back into the job market. And I say back into the job market, because this is not new. For millions of years, on the grasslands of Africa, women commuted to work to gather their vegetables. They came home with 60 to 80 percent of the evening meal. The double income family was the standard. And women were regarded as just as economically, socially and sexually powerful as men. In short, we're really moving forward to the past.

Then, women's worst invention was the plow. With the beginning of plow agriculture, men's roles became extremely powerful. Women lost their ancient jobs as collectors, but then with the industrial revolution and the post-industrial revolution they're moving back into the job market. In short, they are acquiring the status that they had a million years ago,10,000 years ago,100,000 years ago. We are seeing now one of the most remarkable traditions in the history of the human animal. And it's going to have an impact.

I generally give a whole lecture on the impact of women on the business community. I'll only just say a couple of things, and then go on to sex and love. There's a lot of gender differences; anybody who thinks men and women are alike simply never had a boy and a girl child. I don't know why it is that they want to think that men and women are alike. There's much we have in common, but there's a whole lot that we do not have in common.

We are -- in the words of Ted Hughes, "I think that we were built to be -- we're like two feet. We need each other to get ahead." But we did not evolve to have the same brain. And we're finding more and more and more gender differences in the brain. I'll only just use a couple and then move on to sex and love. One of them is women's verbal ability. Women can talk.

Women's ability to find the right word rapidly, basic articulation goes up in the middle of the menstrual cycle, when estrogen levels peak. But even at menstruation, they're better than the average man. Women can talk. They've been doing it for a million years; words were women's tools. They held that baby in front of their face, cajoling it, reprimanding it, educating it with words. And, indeed, they're becoming a very powerful force.

Even in places like India and Japan, where women are not moving rapidly into the regular job market, they're moving into journalism. And I think that the television is like the global campfire. We sit around it and it shapes our minds. Almost always, when I'm on TV, the producers who call me, who negotiate what we're going to say, is a woman. In fact, Solzhenitsyn once said, "To have a great writer is to have another government."

Today 54 percent of people who are writers in America are women. It's one of many, many characteristics that women have that they will bring into the job market. They've got incredible people skills, negotiating skills. They're highly imaginative. We now know the brain circuitry of imagination, of long-term planning. They tend to be web thinkers. Because the female parts of the brain are better connected, they tend to collect more pieces of data when they think, put them into more complex patterns, see more options and outcomes. They tend to be contextual, holistic thinkers, what I call web thinkers.

Men tend to -- and these are averages -- tend to get rid of what they regard as extraneous, focus on what they do, and move in a more step-by-step thinking pattern. They're both perfectly good ways of thinking. We need both of them to get ahead. In fact, there's many more male geniuses in the world. When the -- and there's also many more male idiots in the world. (Laughter) When the male brain works well, it works extremely well. And what I really think that we're doing is, we're moving towards a collaborative society, a society in which the talents of both men and women are becoming understood and valued and employed.

But in fact, women moving into the job market is having a huge impact on sex and romance and family life. Foremost, women are starting to express their sexuality. I'm always astonished when people come to me and say, "Why is it that men are so adulterous?" And I say, "Why do you think more men are adulterous than women?" "Oh, well -- men are more adulterous!" And I say, "Who do you think these men are sleeping with?" And -- basic math! (Laughter)

Anyway. In the Western world, women start sooner at sex, have more partners, express less remorse for the partners that they do, marry later, have fewer children, leave bad marriages in order to get good ones. We are seeing the rise of female sexual expression. And, indeed, once again we're moving forward to the kind of sexual expression that we probably saw on the grasslands of Africa a million years ago, because this is the kind of sexual expression that we see in hunting and gathering societies today.

We're also returning to an ancient form of marriage equality. They're now saying that the 21st century is going to be the century of what they call the "symmetrical marriage," or the "pure marriage," or the "companionate marriage." This is a marriage between equals, moving forward to a pattern that is highly compatible with the ancient human spirit.

We're also seeing a rise of romantic love. 91 percent of American women and 86 percent of American men would not marry somebody who had every single quality they were looking for in a partner, if they were not in love with that person. People around the world, in a study of 37 societies, want to be in love with the person that they marry. Indeed, arranged marriages are on their way off this braid of human life.

I even think that marriages might even become more stable because of the second great world trend. The first one being women moving into the job market, the second one being the aging world population. They're now saying that in America, that middle age should be regarded as up to age 85. Because in that highest age category of 76 to 85, as much as 40 percent of people have nothing really wrong with them. So we're seeing there's a real extension of middle age.

And I looked -- for one of my books, I looked at divorce data in 58 societies. And as it turns out, the older you get, the less likely you are to divorce. So the divorce rate right now is stable in America, and it's actually beginning to decline. It may decline some more. I would even say that with Viagra, estrogen replacement, hip replacements and the incredibly interesting women -- women have never been as interesting as they are now. Not at any time on this planet have women been so educated, so interesting, so capable. And so I honestly think that if there really was ever a time in human evolution when we have the opportunity to make good marriages, that time is now.

However, there's always kinds of complications in this. In these three brain systems: lust, romantic love and attachment -- don't always go together. They can go together, by the way. That's why casual sex isn't so casual. With orgasm you get a spike of dopamine. Dopamine's associated with romantic love, and you can just fall in love with somebody who you're just having casual sex with. With orgasm, then you get a real rush of oxytocin and vasopressin -- those are associated with attachment. This is why you can feel such a sense of cosmic union with somebody after you've made love to them.

But these three brain systems: lust, romantic love and attachment, aren't always connected to each other. You can feel deep attachment to a long-term partner while you feel intense romantic love for somebody else, while you feel the sex drive for people unrelated to these other partners. In short, we're capable of loving more than one person at a time. In fact, you can lie in bed at night and swing from deep feelings of attachment for one person to deep feelings of romantic love for somebody else. It's as if there's a committee meeting going on in your head as you are trying to decide what to do. So I don't think, honestly, we're an animal that was built to be happy; we are an animal that was built to reproduce. I think the happiness we find, we make. And I think, however, we can make good relationships with each other.

So I want to conclude with two things. I want to conclude with a worry -- I have a worry -- and with a wonderful story. The worry is about antidepressants. Over 100 million prescriptions of antidepressants are written every year in the United States. And these drugs are going generic. They are seeping around the world. I know one girl who's been on these antidepressants, serotonin-enhancing -- SSRI, serotonin-enhancing antidepressants -- since she was 13. She's 23. She's been on them ever since she was 13.

I've got nothing against people who take them short term, when they're going through something perfectly horrible. They want to commit suicide or kill somebody else. I would recommend it. But more and more people in the United States are taking them long term. And indeed, what these drugs do is raise levels of serotonin. And by raising levels of serotonin, you suppress the dopamine circuit. Everybody knows that. Dopamine is associated with romantic love. Not only do they suppress the dopamine circuit, but they kill the sex drive. And when you kill the sex drive, you kill orgasm. And when you kill orgasm, you kill that flood of drugs associated with attachment. The things are connected in the brain. And when you tamper with one brain system, you're going to tamper with another. I'm just simply saying that a world without love is a deadly place.

So now -- (Applause) -- thank you. I want to end with a story. And then, just a comment. I've been studying romantic love and sex and attachment for 30 years. I'm an identical twin; I am interested in why we're all alike. Why you and I are alike, why the Iraqis and the Japanese and the Australian Aborigines and the people of the Amazon River are all alike.

And about a year ago, an Internet dating service, Match.com, came to me and asked me if I would design a new dating site for them. I said, "I don't know anything about personality. You know? I don't know. Do you think you've got the right person?" They said, "Yes." It got me thinking about why it is that you fall in love with one person rather than another.

That's my current project; it will be my next book. There's all kinds of reasons that you fall in love with one person rather than another. Timing is important. Proximity is important. Mystery is important. You fall in love with somebody who's somewhat mysterious, in part because mystery elevates dopamine in the brain, probably pushes you over that threshold to fall in love. You fall in love with somebody who fits within what I call your "love map," an unconscious list of traits that you build in childhood as you grow up. And I also think that you gravitate to certain people, actually, with somewhat complementary brain systems. And that's what I'm now contributing to this.

But I want to tell you a story about -- to illustrate. I've been carrying on here about the biology of love. I wanted to show you a little bit about the culture of it, too -- the magic of it. It's a story that was told to me by somebody who had heard it just from one of the -- probably a true story. It was a graduate student at -- I'm at Rutgers and my two colleagues -- Art Aron is at SUNY Stony Brook. That's where we put our people in the MRI machine.

And this graduate student was madly in love with another graduate student, and she was not in love with him. And they were all at a conference in Beijing. And he knew from our work that if you go and do something very novel with somebody, you can drive up the dopamine in the brain, and perhaps trigger this brain system for romantic love. (Laughter) So he decided he'd put science to work, and he invited this girl to go off on a rickshaw ride with him.

And sure enough -- I've never been in one, but apparently they go all around the buses and the trucks and it's crazy and it's noisy and it's exciting. And he figured that this would drive up the dopamine, and she would fall in love with him. So off they go and she's squealing and squeezing him and laughing and having a wonderful time. An hour later they get down off of the rickshaw, and she throws her hands up and she says, "Wasn't that wonderful?" And, "Wasn't that rickshaw driver handsome!" (Laughter) (Applause)

There's magic to love! But I will end by saying that millions of years ago, we evolved three basic drives: the sex drive, romantic love and attachment to a long-term partner. These circuits are deeply embedded in the human brain. They're going to survive as long as our species survives on what Shakespeare called "this mortal coil." Thank you. (Applause)