For generations, scientists have studied the peacock feathers of human mating, the swish and swagger that advertise sexual interest, the courtship dance at bars, the public display. They've left the private experience -- what's happening in the brain when we fall for someone -- mostly to poets.
We know there's an inborn human urge to mate, after all. Love is a mystery, a promise, an arrow from Cupid's bow.
Yet, recent research suggests that romantic attraction is in fact a primitive, biological drive, like hunger or sex, some scientists argue. While lust makes our eye wander, they say, it's the drive for romance that allows us to focus on one particular person, though we often can't explain why. The biology of romance helps account for how we think about passionate love, and explain its insanity: why we might travel cross-country for a single kiss, and plunge into blackest despair if our beloved turns away.
This view of romantic attraction rests on observations of passionate behavior across cultures, studies of animals during courtship and, most recently, findings by scientists studying the human brain. Using magnetic resonance imaging (MRI) machines to peer into the brains of college students in the throes of early love -- that crazed, can't-think-of-anything-but stage of romance -- scientists have developed some of the first direct evidence that the neural mechanisms of romantic attraction are distinct from those of sexual attraction and arousal.
Peculiar brain activity
"What we're seeing here is the biological drive to choose a mate, to focus on one person to the exclusion of all others," said Helen Fisher, an anthropologist at Rutgers University in New Jersey, who spells out the biological basis for romantic attachment in a paper that appeared recently in the journal Neuroen-docrinology Letters.
Fisher's group is analyzing more than 3,000 brain scans of 18 recently smitten college students, taken while they looked at a picture of their beloved. She expects the results to build upon the findings of English researchers who recently completed a similar study of young men and women in love. When they were shown a picture of their romantic partner, their brain activity pattern was markedly different from when they looked at a picture of a close friend, reported neurobiologists Andreas Bartels and Semir Zeki of University College London.
The pictures showed that the experience of romantic attraction activated those pockets of the brain with a high concentration of receptors for dopamine, the chemical messenger closely tied to states of euphoria, craving and addiction. Biologists have linked high levels of dopamine and a related agent, norepinephrine, to heightened attention and short-term memory, hyperactivity, sleeplessness and goal-oriented behavior. When they're first captivated, Fisher says, couples often show the signs of surging dopamine: increased energy, less need for sleep or food, focused attention and exquisite delight in details of this novel relationship.
Love is a drug
Bartels and Zeki compared their MRI images to brain scans taken from people in different emotional states, including sexual arousal, feelings of happiness and cocaine-induced euphoria.
The pattern for romantic love was unique.
This power is enough to warp judgment in otherwise sensible people, just as a spike in dopamine activity might.
As psychologists have de-monstrated in several studies, newly smitten lovers often idealize their partner, magnifying the other's virtues and explaining away their flaws.
This idealizing behavior, sometimes called the "pink-lens effect," is often sharply at odds with the perceptions of friends and family, psychologists say.
Yet some idealization may be crucial to building a longer-term relationship, said Pamela Regan, a researcher at California State University, Los Angeles and author of the recently released The Mating Game.
"If you don't sweep away the person's flaws to some extent, then you're just as likely to end a relationship or not even try," she said.
Passionate love's euphoria is enough to push many people through the first two stages of courtship: self-disclosure, the up-all-night storytelling; and interdependence, when lovers are continually together.
But that pink-lens effect might also help people through stage three: conflict, when tension and doubts about the couple's future prompt arguments and soul-searching.
In a 1996 experiment, psychologists at the State University of New York at Buffalo followed a group of 121 dating couples.
Every few months, the couples answered questionnaires designed to determine how much they idealized their partner, and how well the pair was doing. The researchers found that the couples who were closest one year later were those who idealized each other the most.
Benedict Carey is a reporter for the Los Angeles Times, a Tribune Publishing newspaper.