This is your brain in love

You say romance is brief because nature only wanted us absolutely nuts until we managed to conceive. After we have children, attachment, a different chemical reaction that results in feelings of stability, kicks in to bind a couple together to raise those kids. What would you say to those who find the prospect of attachment too monotonous to contemplate? And is the idea of "till death do us part" wishful thinking?

Americans come out of a farming tradition, as all Westerners do. The whole concept of "till death do us part," that is our idea, because we have so much property. But we are probably built to be restless in long relationships. And now, when we break up -- well, it's not like the grasslands of Africa where you pick up your spear and walk off. You've got cars and houses and college educations to pay for. But for most of human evolution there was a lot of serial pair-bonding. You would form a pair bond for a while, have a child, break up, fall in love again, have another marriage, another child, break up again, and then somewhere in middle age probably form another long-term relationship -- and maybe were adulterous on the side. From a Darwinian perspective, this makes sense. It enables you to raise babies in a stable partnership while you go out and collect more resources for the babies you have with an affair, or to have more babies if you're a man.

We live a long time, and we're nicely wired to fall in love several times in our lives. So this trend we have now of a long period of extended practice [with having different partners] before beginning a long attachment is a good one. Because we weren't built to be happy; we were built to reproduce. Lust, romantic love, attachment, these three different systems, we all have them to various degrees, and some people find it easier to form a long-term attachment than other people do. And I do think that there's a chemical basis to that. Divorce does run in families. Some people need thrills all the time -- and if they do have a marriage they're almost always adulterous within a couple years of that marriage. I think everyone of us lies in bed in night and tries to decide how we're going to [find and keep love]. I mean, that's the problem. We have a brain that can simultaneously feel deep attachment to one person while we feel mad romantic attraction to someone else.

It seems that in your book you caution against casual sex. Did I read you right?

All I say in the book is watch out. I'm not in the should business. But I do think knowing what we know about how these brain systems are connected, it might be worthwhile to keep an eye on whom you copulate with. Because casual sex might not be so casual. Most liberated contemporary adults have copulated with someone they will never love. And women are just as able to copulate without love as men. I think we have a real misunderstanding in this culture of the intensity of male romantic love and female sexuality. Three out of four people who kill themselves after a love relationship has ended are men, not women. Men are much more likely because they have fewer friends -- so they put more into relationships than women. They're not as expressive as women.

But neither women or men are too good at love 'em and leave 'em. You can be the other woman -- for a while. But at some point some of that brain circuitry kicks in and you fall in love. These three brain systems -- the sex drive, romantic love and attachment -- are connected, particularly the romantic love and sex drive. When you fall in love you want to start hopping in bed with the person, in part because the elevated levels of dopamine associated with romantic love can trigger testosterone, the hormone of desire, of sex craving. But the reverse can happen -- testosterone can elevate the activity of dopamine and you can fall madly in love with someone that you hadn't intended to. And so a lot of people, the very young especially, they do a lot of sleeping around, and some can fall in love with people they don't want to take home, don't want to marry, could never have kids with, and boom! -- they spend the next five years with this person and spend the rest of their lives wondering why they did that.

So the idea that one could always keep having sexual adventures without real emotional consequences, that's a fairy tale we've been telling ourselves?

It's not gonna happen. With orgasm, levels of oxytocin go up in women and vasopressin in men -- they call these the satisfaction hormones because they do give a sense of calm and peace and security and often a cosmic sense of union. If you have enough of them with somebody you're going to feel attached to them.

Another ostensible boon you caution against in the book is the use of antidepressants -- specifically SSRIs, or selective serotonin reuptake inhibitors, which elevate serotonin levels. They can endanger our ability to fall in love?

If you're about to kill yourself you should definitely take these medications. Or if you can't get out of bed -- no question about it, they can be absolutely essential to people. But the problem in America is that people are on them for months and years, and they don't realize they are jeopardizing powerful systems that are connected. Of course, serotonin-enhancing medications blunt emotions -- that's the point. But these medications can affect romance and attachment in more subtle ways. SSRIs dampen the ability to have orgasms, which is a mechanism of attachment and a form of mate assessment. And if you're not having an orgasm with somebody on a regular basis you are not juicing your brain with attachment chemicals.

A woman learns a great deal about a man in bed -- is he patient, is he kind, does he persevere until she has her orgasm? The female orgasm is what they call fickle -- it doesn't always happen. That used to be regarded as a maladaptive trait, but evolutionary psychologists now think it's a very adaptive one because it allows a woman to distinguish between Mr. Right and Mr. Wrong. So when you kill a woman's capacity to have an orgasm you're killing the mechanism by which she assesses potential partners. There's a very sensitive ring of nerves outside of the vagina, and the clitoris is very sensitive, and these become less sensitive when you take SSRIs. And they are also mechanisms that help a woman reach orgasm.

From a male's perspective, seminal fluid has dopamine and norepinephrine in it, as well as serotonin and testosterone and estrogen -- all kinds of things they've now shown have an antidepressant effect. When a man doesn't deposit them in the vaginal canal, [he's not able to influence a woman's mood positively, and therefore not able to] trick a woman chemically into liking him. So these courtship devices are being jeopardized. It's a little bit like taking a medication that blurs your vision.

People from around the world are e-mailing you for relationship advice. Do you actually respond personally to them?

I would imagine the day might come when it's too much for me. At this point it certainly is not. I do say to them, "I'm an anthropologist -- I'm not in this business, I'm not a psychologist, but I'll tell you, this is how I feel about it." That whole chapter on how to control love in "Why We Love" -- I wasn't going to put that in there. And then I thought to myself, how could I write a whole book about love's brain circuitry, about something that makes us suffer such despair when it goes bad, and not say one word about how to handle this? Of course I'll take a lot of flak from my colleagues, but I take a lot of flak anyway -- if you write a trade book you're in trouble. But what is the point of information if you don't broaden it out? In these e-mails, people are bleeding with despair. And I'm supposed to say, "I'm terribly sorry. I know all about this subject but I'm not going to talk to you"? You can't do that to people!

So how can we control love?

The only one way I really know of to kick in that dopamine system and to help spark love, particularly in a long-term relationship, is to do novel things together. Novelty is associated with elevated activity of dopamine and norepinephrine -- those are the same stimulants associated with cocaine and amphetamines. Novelty can step up that system. Some people can just go to a different restaurant. You don't have to go skydiving. Other people, maybe they should.

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