In a study that asked 515 people why they went into a hookup, 50 percent of women and 52 percent of men reported that they hoped to trigger a longer relationship.

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.  In 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 in 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 not 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. 

Recorded on January 6, 2010