Birds do it. Bees do it. But what exactly is it that we humans do? Do we choose to fall in love? The latest research asserts romantic love is not so much a swelling of emotions, but a physical drive as powerful as hunger.
One study had people who said they were in love look at pictures of their beloved as they were given brain scans. Activity in the brain's "reward system" leads researchers to conclude romantic love creates a physical drive, very different from sexual urges, that perseveres until it receives its prize, compelling lovers to yearn for one another for as long as it takes until they can be together.
The lead researcher of the study, and author of a new book, Why We Love, says scientifically, sex and romance are two different things. And what is commonly thought as the drive for love, explains anthropologist Helen Fisher of Rutgers University in New Brunswick, N.J., is actually three different desires.
"One is the sex drive that gets you out there looking for anything remotely appropriate," says Fisher. The next is "romantic love, that giddiness of first love that enables you to focus that mating energy and conserve your courtship time. And the third mating system in the brain is attachment."
Inside the Brains of Men and Women
The most powerful of the three desires may not be sex but romance, Fisher adds.
"People don't die for sex," she says. "I've at looked at poetry all over the world, even as much as 4,000 years ago. People live for love, they die for love, they sing for love, they dance for love."
While many women may be convinced men's brains are wired more powerfully for sex, Fisher says there's evidence men are also powerfully wired for romance.
"Men fall in love faster than women do, because men are so visual," she notes. "And three out of four people who kill themselves over love are men, not women."
Fisher adds: "You know, this is a powerful drive, and an essential part of humanity. … It would be very unadaptive if men didn't fall in love just as powerfully as women."
The author acknowledges men are more visual, but there's an important reason for that: "For millions of years, a man had to look at a woman and size her up and see if she would be a good reproductive partner, if she could bear him healthy babies."
She adds: "In our male subjects, a part of the brain lit up, became active, that is associated with visual stimuli. So men, when they look at a sweetheart, are using all kinds of visual mechanisms."
By contrast, women exposed to pictures of their sweethearts activated a different part of their brains, Fisher notes. Both men and women got "complicated emotional reactions … elation, euphoria, the obsessive thinking."
But in women, a part of the brain associated with memory recall is also activated. she says. "I think what's going on is for millions of years women had to remember, did he bring me buffalo meat last week, they've got to remember. … And women still remember. They remember all the details of a relationship."
Why Romance Fades
But if romance, not sex, is so powerful and so important in a life, and if the brain scan shows men are activated by romance as strongly as women are, why does romance fade so fast?
"I think it evolved for an important reason," explains Fisher, "which is to enable to focus your mating energy on one individual at a time, thereby conserving courtship time and energy. We would all die of sexual exhaustion, and we wouldn't get to our jobs … if we had this intense emotion all of our lives."
She adds: "I think what goes on generally is you move away from that intense feeling of romantic love into a deeper sense of calm and peace and unity with the person, attachment associated with a different brain system."
Couples don't fall out of love, they fall into attachment, she believes. But there is a way of preserving that feeling of romance, suggests Fisher — doing novel things together.
"One thing that I and my colleagues [on this project] have established is that love does change over time. And if you do want to continue that obsession and craving and elation and focused attention on that person, do novel things with him or her. That drives up levels of dopamine in the brain. That's one of the main chemicals associated with romantic love."
Fisher notes George Washington once said of all the things that he'd ever done in his life, the most important to him was one afternoon with a particular woman.
"People never forget love," she said.