Why Do We Love?

Who she is: Anthropologist and author of books about the biological nature of love and sex

What she does: What is love? Why do we choose the people we choose? How do men and women vary in their romantic feelings? Is there really love at first sight? How did love evolve? For decades, Rutgers University anthropologist Dr. Helen Fisher has been working to answer these eternal questions.

How she does it: Helen has traveled from the Kalahari Desert in southern Africa to Tokyo, Moscow, and back to her home in New York City to determine if one culture perceives love differently than another. She then used fMRI technology to actually look inside the brains of 40 men and women who said they were madly in love. Fascinating, huh?


By Hope Katz Gibbs

In her 2005 book, “Why We Love: The nature and chemistry of romantic love,” Dr. Helen Fisher explains: “My research has proven to me that everywhere, people fall into romantic love. I have come to see this passion as a fundamental human drive. Like the craving for food and water and the maternal instinct, it is a psychological need, a profound urge, an instinct to court and win a particular mating partner.”

Her next book, “Why Him? Why Her?” took the question to another level. “In it, I analyzed how people can find real love by understanding their personality type,” she shares.

The research of that book, which is the fifth she’s written in the last two decades, is the basis of the Chemistry.com questionnaire that matches people with appropriate brain chemistries. (More on that later.)

We begin our discussion with Dr. Helen by talking about that eternal question: Why do humans love?


Fisher says there are three basic mating drives, which inhabit different parts of our brains:

Lust: The craving for sexual gratification, which emerged to motivate our ancestors to seek sexual union with almost any partner.

Romantic Love: The elation and obsession of being in love with a mate, which enabled the ancients to focus their attention on a single individual at a time, and conserve time and energy.

Attachment: The sense of peace and security one feels toward a long-time mate, which motivated our ancestors to stay together long enough to rear their young.

Although Fisher admits that the magic of love cannot be underestimated, she is convinced that the species’ need to procreate is the primary motivator behind all of these mating drives.

“If you have four children, and I have no children, your genes are going to live on and mine are going to die off,” she says. “ So we all know deep down inside that our sexual behavior is going to have important consequences.”

But what, exactly, is going on in the brain when we experience those feelings of lust, romantic love, and attachment?

The science of mating

To find out, Fisher used fMRI technology to actually look inside the brains of 40 men and women who said they were madly in love.

Her most important finding was that as lovers gazed at photos of their sweethearts, the fMRI showed activity in the caudate nucleus—the large shrimp-shaped region that sits deep near the center of the brain.

“It is a very primitive part of the brain, called the reptilian brain or R-complex because it evolved long before mammals proliferated some 65 million years ago,” Fisher explains, noting that this part of the brain is an enormous engine and part of the brain’s reward system.

The researchers also found that lovers have heightened activity in the ventral tegmental area (VTA)—another central part of the reward circuitry of the brain.

“This result was what I was looking for,” says Fisher, who had hypothesized that romantic love is associated with elevated levels of dopamine and/ or norepinephrine, two key neurotransmitters. “The VTA is a mother lode of dopamine-making cells.

With their tentacle-like axons, these nerve cells distribute dopamine to many brain regions, including the caudate nucleus. And as this sprinkler system sends dopamine to many brain parts, it produces focused attention, as well as fierce energy, concentrated motivation to attain a reward, and feelings of elation, even mania—the core feelings of romantic love.”

In other words, Fisher was able to actually observe chemical changes in the brain as her subjects looked at the photos of their loved ones, giving her an insider’s view of some of the chemical underpinnings of love.

Why Him? Why Her?

In 2006, Fisher was asked by Match.com to become the scientific advisor to a new sister site, Chemistry.com. Based on her fMRI research, she crafted Chemistry Profile, a personality assessment and matching system, which includes dozens of questions ranging from “is your sock drawer ready for public inspection?” to “Are your friends the social crowd, intellectuals, adventurers, or activists?”

Other questions ask the user to identify a mate’s ideal body type, fitness regime, favorite Friday night date, and religious preferences.

Although the questions seem straightforward, Fisher says she actually uses the answers to identify which chemicals are most dominant in the brain: dopamine, serotonin, testosterone, and/ or estrogen.

Dopamine-driven Explorers: People with naturally high levels of dopamine tend to be risk-takers, novelty-seekers, artistic, creative, and curious. Fisher found that 26% of the 40,000 men and women she polled fell into this category.

Serotonin-driven Builders: Those with a lot of serotonin tend to gravitate toward the traditional. They are calm, social, popular, loyal, conscientious, and tend to be organized and enjoy rules. Often, they are pillars of society and good in business. About 29% of the population polled fell into this category.

Testosterone-driven Directors: This group is direct, and skilled at understanding rule-based systems. They tend to be highly analytical, logical, and emotionally contained. They are also bold and ambitious, and account for about 16% of Fisher’s polled population.

Estrogen-driven Negotiators: Those with high amounts of estrogen have good people skills, an active imagination, are altruistic, idealistic, and nurturing. They tend to see the “big picture,” but are not very detail-oriented. Approximately 25% of the people polled fit into this category.

“Although everyone has a combination of chemicals, one or two tend to dominate,” Fisher explains. “I have found that time and again, dopamine-driven Explorers go for each other, serotonin-driven Builders are also attracted to each other. But, testosterone-driven Directors and estrogen-driven Negotiators are happiest when they mate.”

The reason, Fisher says, goes back to our basic drive to survive and propagate the species.

“If you are good at seeing the big picture, as Negotiators are, you need someone who is analytical and detail-oriented to help you survive so you look for a Director,” she says. “Similarly, if you are a traditionalist who is calm and really likes rules—as the serotonin-driven Builders are—you’ll want to mate with someone who looks at the world in the same logical, rule-based way you do.”

The future

Fisher’s research leads her to a few forecasts about the future of love and relationships.

“Since women started returning to the workforce a few decades ago, the balance of power between the sexes has shifted,” she notes, explaining that for centuries in hunting and gathering societies, women were on equal footing with men, going out to gather the evening meal and being equally responsible for the survival of the family and community.

“But with the invention of farming tools that required physical strength, women were relegated to seemingly secondary chores of keeping house and having children. Arranged marriages dominated, and mating became more of an economic and sometimes political agreement between families.”

Fisher expects this shift in male-female roles to gain strength. As more women graduate from college—not to mention earn almost as many PhDs as men—their economic and political power will only continue to grow, and Fisher expects women to “return to the place of power they held before the plow was invented.”

“Men are now being pressured to please a woman—or she won’t have them back,” Fisher insists. “Going forward, men are definitely going to have to work a little harder to get and keep a mate.”

Fisher also believes that the pursuit of romantic love later in life will increase. As more baby boomers hit 50—and realize they could live another 40-50 years—many will be looking around for someone new to “light their fire,” she forecasts. “Romantic love is deeply threaded into our human spirit. If we don’t have that in our lives, we feel like we are missing something. And we are.”

About Helen Fisher

A world-renowned anthropologist and an expert in the science of human attraction, Dr. Helen Fisher has authored four books: “The Sex Contract,” “Anatomy of Love,” “The First Sex,” and her most recent “Why We Love.” She is currently working on a fifth book about why we choose one partner over another.

Dr. Fisher is also a research associate in the Department of Anthropology at Rutgers University. Her perspectives on love, sexuality, women, and gender differences have been featured in Time magazine, National Public Radio, NBC, the BBC, and CNN.

To find out which chemicals dominate your brain, take Helen Fisher’s quiz on www.chemistry.com. For more information about the author and her books, visit: www.helenfisher.com..