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Helen E. Fisher, Ph.D. biological anthropologist, is a Senior Research Fellow at The Kinsey Institute at Indiana University, and a Member of the Center For Human Evolutionary Studies in the[…]

A conversation with the biological anthropologist and Rutgers University professor.

Question: What are the three brain systems for love?

Helen Fisher: I do think that we’ve evolved three distinctly different brain systems for love.  One is the sex drive, the craving for sexual gratification. The second one is romantic love, that elation, the giddiness, the euphoria, the obsession, the craving of passionate, obsessive love.  And the third is attachment.  That sense of calm and security you can feel for a long-term partner. 

And rather than being stages, these three brain systems can operate, really in any kind of combination.  I mean, you could walk into a party, you’re ready to fall in love, you talked to somebody, they say just the perfect joke and they’re the right size and shape and height and background, and boom.  You trigger the brain system for romantic love.  And then, once you’ve fallen in love with them, you feel very sexually drawn to them.  Or, you can start out with a sexual relationship with somebody and then fall in love with them.  Or, you can know somebody for many years.  Maybe it’s a boyfriend of a friend of yours and you’re married to somebody else and then times change, people become available and suddenly you’ve fallen in love with somebody who you’ve had a deep and very nice friendship with. So, any one of these brain systems can happen first; attachment, romantic love, or the sex drive.

Question: What does the brain look like when it’s in love?

Helen Fisher: Everybody’s always wondered what happens in the brain when you’ve fallen in love, and we all know actually how you feel when you fall in love.  But actually, what happens in the brain is, a tiny little factory near the base of the brain called the ventral tegmental area become active, and in some particular cells, called the A10 cells, they begin to make dopamine.  Dopamine is a natural stimulant.  And from the ventral tegmental area it’s sent too many brain regions, particularly the reward system; the brain system for wanting, for craving, for seeking, for addiction, for motivation and in this case, the motivation to win life’s greatest prize, which is a good mating partner.

Question: Can casual sex trigger love?

Helen Fisher: I think that all three of these brain systems can interact with one another, particularly when you have sex with somebody.  Any kind of sexual stimulation of the genitals triggers the dopamine system in the brain and can push you over that threshold into falling in love with that person.  And in fact, with orgasm, there’s a real flood of oxytocin and vasopressin, other chemicals in the brain associated with the feeling of deep attachment.  So, casual sex is really never casual unless you’re so drunk you can’t remember it; something happens.  As a matter of fact, in one study of over a thousand people, over 50% of both men and women reported that their first kiss of somebody was sort of the kiss of death.  They had begun quite attracted to a person sexually and romantically and then when they kissed them, it was so horrible for them that it turned them off completely.  So, casual sex is just plain old not casual.  Something can happen.  You can either fall madly in love with this person, or you can begin a deep sense of attachment to them. 

As a matter of fact, I’ve been working with a graduate student named Justin Garcia, and he and I believe that people go into hookups, or one-night stands hoping to trigger a longer relationship.  And in fact, in a study that he did of 515 men and women in a college in the northeast, he asked them why they went into this hookup; this one-night stand.  Fifty percent of women and 52% of men reported that they went into the sexual experience hoping to trigger a longer relationship, and in fact, 1/3 of them did. 

So, consciously, when people go into the one-night stands, they probably aren’t thinking, oh, I’m going to trigger the brain system, or the dopamine system in the brain and make this person fall in love with me, but somehow, intuitively, they know that sex is powerful and that it can trigger powerful feelings of love.

Question: Can we learn to love people that off the bat might not seem like they’re for us?

Helen Fisher: Yeah.  I think you can learn to love people who you absolutely would reject if you saw them on paper, or even looked at them in a picture because people grow on you.  And if they fit within your love map, your unconscious list of what you’re looking for in a partner at all, the data shows that the more you see them, the more you like them, and the more you regard them as similar to yourself. 

So, that’s one of the big problems in courtship is we give up too fast.  We overweight what we don’t like about a person and don’t proceed to overlook that and move on and find out what we really like.  As a matter of fact, I often say to people who are dating, “Stop looking for what’s wrong with this person and start looking for what’s right, and then focus on that.” 

Question: Is everyone born to love?

Helen Fisher: In my reading, I have found that occasionally there is a human being that has never felt intense romantic love.  I personally have met two people who had never felt it until their mid-50’s.  Both of them were happily married, one man, one woman, both of them had children with their partner; both had built a very nice social life, and personal life, and good marriage.  But they had never felt that intense romantic love.  And both of them actually said the same thing to me.  They said, “I would go to something like Romeo and Juliet, and I just didn’t understand why people would be killing themselves over this.”  And then both of them fell in love with somebody in their mid-50’s.  On both cases, it was not their spouse.  In both cases, they chose not to pursue the relationship with the other person, and stayed with their partner with whom they were feeling deep attachment.  So, there are people who have never felt romantic love, but the vast majority of us do. 

I and my colleagues have put 49 people who were madly in love into a brain scanner, 17 who had just fallen love, 15 who had just been rejected in love, and 15 who reported that they were still in love after an average of 21 years of marriage.  And in all cases, we found activity in parts of the brain that are so primitive, so primordial, so old.  As a matter of fact, I think that no only all human beings, or almost all human beings, around the world love and always have.  But I think that other animals too fall in love also.  I mean, you can see a fox in the beginning of the mating season.  He will focus on a particular female.  He’s got intense energy, the way you do when you fall in love.  He doesn’t eat or sleep.  He’s constantly nuzzling up against her and licking her face and patting her body.  If you saw this on a park bench in New York City, you would think that this was romantic love.  And in two species they’ve actually measured some of what happens in the brain during that moment of attraction and you see the same dopamine activity.  Different parts of the brain, but you see an elevation of dopamine activity in other animals the way you do in people. 

So, we inherited the drive to love.  It is a drive.  It’s a basic, not even mammalian, you see it in birds.  As a matter of fact, Darwin described love at first sight among two ducks. 

Question: What is love?

Helen Fisher: Love is a lot of things to a lot of different people, but I do think that we all have inherited these three basic brain systems for mating and reproduction; the sex drive, romantic love, and deep feelings of attachment.  But when you take a look around the world at world poetry, I think poetry is a very good litmus test. I think poetry is a very good indication of the emotions.  And all over the world you see the same descriptions of romantic love.  For example, the first thing that happens when you fall in love is a person takes on what I call “special meaning.”  As George Bernard Shaw said, He said, “Love consists of overestimating the differences between one woman and another.”  And indeed, we do.  And then you focus on this person.  That person’s car is different from any other car in the parking lot.  The street they live on is different, the music they like is different.  Everything about them is special and you focus on it.  In fact, before I began putting people into the brain scanner, I would ask them, what do you not like about your sweetheart?  And they would list what they didn’t like and then they would sweep that aside and just focus on what they did like. 

Another basic characteristic of romantic love is intense energy.  You can walk all night and talk til dawn, real mood swings, elation when things are going well, crashing into terrible despair when you don’t get an email, or don’t get a call, real possessiveness, it’s called “mate guarding” among animals.  Most people don’t care if they’re casually sleeping with somebody.  They don’t care if that person is sleeping with somebody else, but when you’re in love, you really care. 

But the three main characteristics of romantic love are:  intense craving for emotional union with this person.  You like to sleep with them, but real emotional union with them, and intense motivation to win them, what people will do when they’re in love.  And last, but no least, obsessive thinking.  You can’t stop thinking about this person.  Somebody is camping in your head.  It’s also quite uncontrollable.  Stendahl once said, “Love is like a fever.  It comes and goes quite independently of the will.”  And indeed it does.  It just visits you.  The brain system becomes triggered and you’re off to the races. 

Question: Does passion diminish after a certain amount of years?

Helen Fisher: I think that most people believe that romantic love dies after a certain number of weeks, months, or years.  But my colleagues and I have actually proved that wrong.  The first author on our most recent brain scanning study is Bianca Casavedo.  And Bianca, and the rest of us, wanted to see what happens in the brain among people who report that they are still in love, not loving, but in love with somebody after an average of 21 years of marriage.  And so, in New York, we put 17 people who said they were still in love with their spouse into the brain scanner and we found exactly the same activity in this tiny little factory near the base of the brain that we found among those who had just fallen madly in love in the ventral tegmental area.

So, you can sustain romantic love long-term.  But we did find one difference.  When you just fallen in love, we find activity in a brain region associated with anxiety, and among those who were in love long-term, that has disappeared, and instead you now feel a sense of calm.  And so what I think is going on among people who are in love long-term is they still want that man to come home for dinner and they still want to sit down and talk about the day and they still want to go on that vacation together, and they want to share their lives, they’re not thinking of divorce, they feel that sense of romance and tingling sensation.  But if they don’t get a phone call at lunchtime, they don’t crumble in a corner and cry.  That anxiety is replaced with calm. 

Question: What are the differences in relationships that start in high school versus later in life relationships?

Helen Fisher: I haven’t studied the differences in the brain between those who met in high school and those who met later in life.  But I do think that those who met in high school have some wonderful advantages.  And that is that they know each other’s parents, they knew the dog that she grew up with and his younger sister, and the fact that he was a high school star and that she was wonderful at the Jitter Bug, at dancing.  You know, they have all those memories that are wonderful.  This is one of the reasons I think that, there’s a real trend right now of older people divorcing and then finding their first love on the Internet and falling in love with somebody who they really were in love with in high school.  And they do have that advantage of this understanding of the house they grew up in, the kind of car that he drove, etc., etc.; the kinds of things that really bring continuity. 

As a matter of fact, I’ve interviewed some of these people who had reconnected much later.  And one of them was a couple, they were probably both in their 60’s, and I asked him whether she had changed at all.  And he said, “Not at all.”  And then I saw photographs of the two of them in high school standing in front of a Christmas tree and I could see them clearly now.  And they were so dramatic – I mean they both gained 100 pounds, they were so dramatically different.  But once you get a vision of who this person is, if you can hold on to this, you will create a happy relationship.

Question: What are the similarities and differences between how men and women define intimacy?

Helen Fisher: I’m working with the dating site,, which is a division of  And I’ve put a questionnaire on that dating site and 5 million people have taken that questionnaire.  Any way, about 12,000 take that questionnaire every week.  And so, about a month ago, I put an intimacy scale onto that dating site to see whether there were some gender differences, and with the different types of personalities regarded intimacy differently.  And I found no gender difference on two questions.  Ninety-five percent of both men and women agreed that they felt it was extremely intimate to go off and do something adventurous with their partner.  And 95% agreed, men and women, that having a deep conversation about the relationship was intimate. 

So, I’m beginning to think that we don’t understand men anymore than we understand women.  As a matter of fact, men fall in love faster than women do because they are so visual.  Men are more dependent on their girlfriends and wives because they’ve got fewer intimate connections with other men.  Men are two and a half times more likely to kill themselves when a relationship is over, and men are more likely to remarry after a spouse has died or deserted them.  So, I think as we come to understand women, I think we are also going to come to understand men. 

There’s one difference in intimacy between men and women that I think comes out of our evolutionary past.  Women tend to get intimacy out of face-to-face talking.  We swivel until we are right in front of each other, we lock eyes with what is called “the anchoring gaze,” and we talk.  And we regard that as intimate. 

And men tend to sit side-by-side and look straight forward and not look at each other at all and regard that as intimate.  And I think they both come from our evolutionary past.  I think women’s intimacy comes from millions of years of holding their baby in front of their face, cajoling it, reprimanding it, educating it with words.  And so words and face-to-face contact is intimate to women. 

Whereas, I think for millions of years, men had to sit behind a bush on the grasslands of Africa and keep their eye on the grasslands hoping a zebra is going to come by so that they can hit it in the head with a rock and they can’t be sitting there talking with somebody like this.  They’ve got to talk while they’re looking forward.  And I think this can complicate relationships.  You’ll see a man and a woman on a park bench and the man is talking looking straight ahead, and the women has moved every single part of her body around in order to have eye contact. 

As a matter of fact, I’ve had various men in my life who talk to me with their eyes completely shut and I think it’s because it’s too intimate for them.  I mean, for millions of years men faced their enemies, they really sat side-by-side with friends.  So, one of the things that I do with a man to make him comfortable is sit side-by-side with him and look straight ahead; particularly if I’m going to have a difficult conversation with him. 

Question: Is it true that men have a propensity for cheating more than women?

Helen Fisher: I’ve looked at adultery in 42 societies and you see in every single place, even in cultures where you can get your head chopped of for it.  So, there’s every reason to think that we’ve got some biological propensities for it.  Now, people say, no, to adultery.  We don’t have to be adulterous, but it’s remarkable how many people are.  And the newest data that in people under age 40, women are just as adulterous as men.  And so, I suspect that the last 10,000 years of keeping women in the kitchen and the home has – and the very strict rules against female adultery in many societies has curbed female adultery so that we think that only men do it.  But the bottom line is that every single time there’s a man who is sleeping around, he is quite often sleeping around with a woman.  And so just doing the math you begin to assume that women are probably just as adulterous as men. 

But I actually think that men and women are in a sort of collusion about this.  Men want to think that men are more adulterous than women and women want men to think that men are more adulterous than women.  So, we’ve got ourselves believing that men are more adulterous. 

There’s a great deal of data over the last, oh the data goes back to the 1920’s anyway, that men are more adulterous.  And what’s interesting is that the degree of adultery hasn’t changed a great deal.  Today, the indication is, for the general population, about 1/3 of men will be adulterous at some point during their marriage, and about 15% of women will be adulterous at some point during their marriage.  But as I say, among people under the age of 40, it seems to be the same amount for women as well as men.

Question: Do you agree with phrase, “once a cheater, always a cheater?”

Helen Fisher: I don’t think a person is always a cheater.  No, there’s always variations here.  I study personality types.  And the kind of person who is very expressive of the dopamine system, I call them the explorer, they tend to be novelty seeking, risk taking, curious, creative, spontaneously generous.  They’re the kind who will walk into a bar and buy everybody a drink, irreverent; they don’t follow the rules unless they make sense for them, quite liberal, very adaptable and flexible.  And I would guess that this particular personality type would be more inclined to adultering. 

However, when you find the right person, I would guess there’s a lot of people who have been adulterous for a good deal of their lives and then they get tired of it.  They find the really the right person for them, the kind of person that will get off the couch and go straight to Saudi Arabia on vacation, or straight to Ireland for a particular song festival, or they finally find somebody who can play as hard and fast and is a sexual as they are, or they find somebody who they respect so much that they don’t want to risk it.  I do think people change. 

You know, some people have a tendency towards alcoholism and they give up drinking.  Some people certainly have a tendency towards smoking cigarettes and they give up cigarettes.  Some people succeed in giving up gambling, or losing weight.  We do all kinds of thing with our lives that we biologically might no be inclined to do.  And I think adultery is one.  People can give up adultery.  However, I do think that this evolved, this restlessness in long relationships evolved and we do, as a species have a tendency towards adultery.

Question: Why are we attracted to some people and not others?

Helen Fisher: Nobody knows.  This is what we do know.  This is what psychologists know.  They do know that we tend to fall in love with somebody from the same socioeconomic background, same ethnic background, same general level on intelligence, same general of good looks, same religious and social values.  We tend to be drawn to somebody who can give us the lifestyle that we are looking for.  Our childhood certainly plays a role, and we are now beginning to find some biological things that draw you to some people rather than others.  New data shows that women with a particular immune system are drawn to men who have an opposite immune system.  So, there’s a lot of factors.  Timing plays a role, proximity plays a role.  There’s many factors in who you love, who you choose.  

But I began to – I mean, you can walk into a room and everybody is from your background, same general level of intelligence, same general level of attractiveness and you don’t fall in love with all of them.  So, why is it that we’re almost chemically pulled to one person rather than another?  So, I wanted to see if I could figure out the role of basic body chemistry.  And so I looked through a whole lot of biological data and there’s a lot of chemicals in the brain, but most of those keep the eyes blinking, or help with swallowing, or keep the heart beating, etc.  Not many of them are linking with personality traits. 

Four chemicals, actually six chemicals are related to personality traits.  So, I wrote down on separate sheets of paper all of those traits associated with the dopamine system, the serotonin system, the testosterone system, and the last being the estrogen and the oxytocin system.  And then I decided I would create a questionnaire to see to what degree you express these four basic biological systems.  We all express all of them, but we express some more than others.  And then I would watch on this dating site,, and see not only what you’re chemistry was, but who you were naturally drawn to.  And as it turns out, people who are very expressive of the dopamine system go for people like themselves.  If you are high energy, very curious, have a lot of interests, love novelty, willing to take risks to do new things.  You want somebody like yourself.  And It’s not just jumping off mountains.  I mean, it’s somebody that will go to the opera with you, the theater with you, art exhibits with you, etc. 

So, the “explorer,” what I call the explorer, the high dopamine type, tends to go for people like themselves.  So does the high serotonin type.  I call these people the “builder,” Plato called them the “guardian.”  That’s a better term.  These people are cautious, but not fearful.  They’re conventional, traditional, they are calm, social, they’re very managerial, they’re very thorough, orderly, conscientious, and loyal.  They want somebody like themselves.  Serotonin goes with serotonin. But the last two types, people who are expressive of the testosterone system go for people who are expressive of the estrogen system. 

But the last two types, those of who are expressive of the testosterone system, both men and women, tend to be attracted to those who are their opposites; those who are expressive of the estrogen system.  I think a very good example is Hillary and Bill Clinton.  She is, I think, very expressive of the testosterone system; direct, decisive, tough-minded, certainly very ambitious, self-contained, and what does she go?  She goes for Bill; very much of the high estrogen.  He’s probably got high testosterone too, but he’s certainly high estrogen.  I mean, he cries when Hillary makes a speech, he feels everybody’s pain.  He sees the big picture.  The whole world knows he can’t stop talking; his linguistic skills are in the estrogen system.  He’s got wonderful people skills.  I’m glad the government sent him into North Korea to get those two girls out rather than his wife. 

But anyway, the high estrogen and the high testosterone tend to be attracted to each other.  And what I think they’re doing from a Darwinian perspective is pooling very different resources.  I think the tough-minded high testosterone, what I call the “director,” needs the compassion and the empathy and the people skills of the high estrogen type.  And I think the high estrogen type needs the decisiveness, the directness, the ambitiousness of the high testosterone type.  So, I think we’ve evolved three really different way of playing the mating game.  I think that the high testosterone and high estrogen are pooling very different resources to raise their babies.  They’ve got very find strength between the two of them.  I think that the very traditional type, what I call the “builder,” is capitalizing on very powerful strengths for raising babies when they marry another builder.  This other person is going to respect the rules, they’re going to follow traditions, and they’re going to be loyal.  It’s a very strong combination for raising babies. 

But I wondered, why is it that two of the explorer types, the high dopamine types, if they’re both great adventurers, who’s going to take care of the baby while they race off to climb Mt. Everest?  It began to occur to me, maybe, and I don’t have the data on this yet, maybe these people are more likely to have a series of marriages.  What I call serial monogamy and have children with each different marriage, in which case they’re creating more genetic variety in their young.  So, there are three different ways of passing your DNA onto tomorrow. 

Question: Is technology like online dating changing the way we fall and stay in love? 

Helen Fisher: I think that online dating is just the newest way of doing the same old thing.  As a matter of fact, I think it’s actually a little bit more natural.  First of all, people are doing it and a lot more people are going to do it and they’re going to do it because we are no longer marrying the boy we met in high school.  We’re not marrying the girl we met in college.  We’re not even marrying in our early 20’s, and by your late 20’s you sort of know everybody in the office and you’ve gone through all of those boys.  You know, you’ve met everybody in your social circle.  Where are you going to meet people?  And also with a very high divorce rate, there’s a lot of people who are back in the dating game in their mid-30’s, 40’s, 50’s, and higher.  And you can’t stand in the middle of Park Avenue in New York City and flap your dress up and down.  I mean, at some point you’ve to go find a new way of social networking and all of these dating services are doing that.  And among the young people it’s Twitter and Facebook and other social networks.  So, I think that the human animal loves.  We’re born to love.  And we do it all our lives.  It’s the same brain system whether you’re 10 years old, or whether you’re 90 years old.  Children do fall in love.  The sexual component might not be there, but they will become intensely attracted to another child.  And certainly older people fall in love.  There’s good data now the brain system does not change with age.  And we’ve got a society where people are very peripatetic and almost nomadic, and all of these Internet dating sites are a way to meet new people. 

And in many respects, I think that it’s actually more natural.  I know that sounds odd because we’re used to walking into a bar and going up and talking to somebody who we don’t know anything about them, we don’t know if they’re married, we don’t know if they’re in town for the night.  We know nothing about them and yet we seem to think that’s natural.  But actually, it’s much more natural to meet somebody having already known what they do for a living, how old they are, what some of their goals are, what their interests are. 

You know for millions of years, we traveled in these little hunting and gathering bands on the grasslands of Africa.  And a young girl might not know that cute boy over in the next fireplace, but her father knows his uncle, her mother knows his niece, and there’s so many gossip circles that she can find out probably in an hour whether he’s a good dancer, whether he’s got a good sense of humor, whether he’s likely to be a loyal partner.  And so with these new networking sites, you do get to know some basic things about somebody before you meet them, and that’s more natural. 

Question: When it comes to the brain, are there differences between heterosexual and homosexual love?

Helen Fisher: I’ve always maintained that it’s exactly the same brain system.  I mean, gay or straight have the same brain system for fear.  They’ve got the same brain system for curiosity.  They’ve got the same brain system for stubbornness.  And I think that the brain system for romantic love is exactly the same.  Who you fall in love with, that’s different.  But how you feel when you love, that I think is the same.  And I did a questionnaire study of 800 people; 400 in the United States and 400 in Japan.  And I had quite a significant homosexual sub-population who took my questionnaire and I didn’t find any difference at all in the basic characteristics between those who expressed romantic love and were heterosexual and those that were homosexual. 

I think we actually make too much of homosexuality, it’s a little like we made too much of skin color, and now we’re making too much of homosexuality because, as I say, whether you’re a curious person doesn’t mean – whether you’re gay or straight doesn’t add to whether you are curious or whether you’re good at math or whether you’ve got a good sense of humor, or we seem to – I think we way over misunderstood how small the part of the brain that it. 

Question: What has been the strangest reaction from somebody who finds out what you do for a living?

Helen Fisher: I’ll never forget the moment, and it’s only happened a few times, and it was a very fancy room full of people with black tie, not that they’re any smarter, but I thought they might be a little bit more educated.  And it was a woman, and I don’t know how we got on to what I did, and I started talking about love and the brain.  And she looked at me and said, “Why would you want to know?” 

I couldn’t understand it at first because I’m so curious about it, and I finally began to realize she felt that knowing more about romantic love would spoil it and she wanted to keep it in the supernatural.  And my real response to that is, you know, I do know a good deal about romantic love, but you know, you can know every single ingredient in a piece of chocolate cake and then sit down and eat that cake and feel that rush of joy in the same way that you can know everything there is, or a great deal about romantic love and still feel that intense passion just the way anybody else does.  But what it’s really done for me is dramatically expanded my sense of unity I think with all humanity. 

I will look in a museum at a little bracelet that somebody dug up from 20,000 years ago and I think somebody gave that bracelet to somebody, somebody wore it.  Somebody was in love.  Poetry from around the world.  I mean, I look at a baby carriage now and I say, “Oh boy, are you in for something.”  But there’s continuity when you begin to study romantic love.  You feel the deep passion of just about everybody on earth.  

Recorded on January 6, 2010