What Makes Romantic Partners Compatible?

Are You an Explorer, Builder, Director, or Negotiator?

Helen Fisher

It was an early June evening in 2006, the sky still pink and blue, the sea smells wafting through the windows as I sat in a folding chair on the second story of a fancy Italian restaurant. An older gentleman was conducting a short wedding ceremony, one mixed with rituals from the Christian, Jewish and Apache traditions. And before me glowed the two celebrants, Patrick and Suzanne—one of the first couples to marry after meeting on the Internet dating site I had helped to design, Chemistry.com.

Someone played a flute. And as the bride and groom walked down the makeshift aisle between our seats, we blew bubbles at them from the little bottles left on our chairs.

"Love hopes all things," the Bible says. I hoped for Patrick and Suzanne. But I also had a reason to be optimistic about their marriage. I knew some things about their personalities because both had taken my personality test, a series of questions I had devised to establish some basic things about a person's biological temperament. Both had told me their test results. And from these data, I was confident that Patrick's particular chemical profile would complement Suzanne's, creating a biological and psychological cocktail that would keep them captivated with each other for years.

Temperament and Love

We have many inborn tendencies. Indeed, scientists now believe some 50 percent of the variations in human personality are associated with genetic factors. We inherit much of the fabric of our mind.

But what is personality?

Psychologists define it as that distinct cluster of thoughts and feelings that color all of a person's actions.

Your personality is more than just your biology, of course. Personality is composed of two fundamentally different types of traits: those of character and those of temperament.

Your character traits stem from your experiences. Your childhood games; your parents' interests and values; how people in your community express love and hate; what relatives and friends regard as polite, dangerous or exciting; how they worship; what they sing; when they laugh; what they do to make a living and relax—these and innumerable other cultural forces combine to build your unique set of character traits.

The balance of your personality is your temperament, all of the biologically based tendencies you have inherited, traits that emerge in early childhood to produce your consistent patterns of feeling, thinking and behaving. As the Spanish philosopher Jose Ortega y Gasset put it, "I am, plus my circumstances." Temperament is the "I am," the foundation of who you are.

It is this part of the human spirit I had examined in Patrick and Suzanne—their biological temperament.

Born "Me"

No one knows precisely how many traits of temperament we human beings inherit. But studies of identical twins suggest we inherit many. Psychologist Thomas Bouchard, director of the Minnesota Twin Study, proposed that dozens of personality traits have a degree of heritability. As he wrote in 1984, "Both the twin studies and the adoption studies converge on the surprising finding that common family environmental influences play only a minor role in the determination of personality."

We express constellations of related biological traits, creating what are commonly called personality types. After doing extensive research on the biological underpinnings of them, I have come to believe that each of us expresses a unique mix of four broad basic personality types. Moreover, our primary personality type steers us toward specific romantic partners. Our biological nature whispers constantly within us to influence who we love.

These thoughts and more were swimming through my mind as I blew those bubbles at Patrick and Suzanne on that enchanting wedding evening. I thought both had found their soul mate.


Psychologists have determined that men and women tend to fall in love with individuals from the same ethnic and socioeconomic background; with those of a similar level of intelligence, education and physical attractiveness; with individuals holding similar religious, political and social values; and with those who have a similar sense of humor. We also fall in love when the timing is right; and often with someone who lives or works nearby. We tend to fall in love with someone who provides us with the things we need. And people often fall in love with those who are in love with them.

But how two individual personalities match up remains unknown. People do not necessarily court, live with or marry someone with similar or different personality traits. In fact, some 470 studies have examined the mesh of two personalities in a marriage. And psychologist Marcel Zentner summed up these data, saying, "Preference for similarity in personality characteristics varies substantially across traits and individuals." As he put it, "How two personalities may be best combined in a relationship remains at present an unresolved issue."

When the folks at Match.com asked me to consider helping them develop a sister site for their Internet dating service, one designed for men and women interested in a long-term partnership, I said I would think about it during the festive midwinter lull.

The holiday season twinkled on. But on New Year's Day I realized I had to come to grips with this opportunity—a chance to apply the newest data in neuroscience to the essential question of who you love, perhaps even help people find "the one."

So I sat down at my empty desk and pulled out a blank sheet of paper. What did I know about personality?

The Biology of Personality

Dopamine. I began with this brain chemical because I had studied the activities of this powerful and ubiquitous neurotransmitter for several years.

On impulse, I listed some of the personality traits I knew were associated with specific genes in the dopamine system: the propensity to seek novelty; the willingness to take risks; spontaneity; heightened energy; curiosity; creativity; optimism; enthusiasm; mental flexibility. I decided to call those men and women who expressed the traits associated with this biology Explorers.

I drew another blank sheet of paper from my desk drawer. What else did I know about personality?

Well, individuals who have inherited particular genes in the serotonin system tend to be calm, social, cautious but not fearful, persistent, loyal, fond of rules and facts and orderly. They are conventional, the guardians of tradition. And because these men and women are also skilled at building social networks and managing people in family, business and social situations, I dubbed those who had inherited this constellation of genetic traits Builders.

I had also studied testosterone. Although testosterone is often associated with males, I knew that both men and women are capable of expressing particularly strong activity in this neural system. Moreover, those who inherit this chemistry tend to be direct, decisive, focused, analytical, logical, tough-minded, exacting, emotionally contained and good at strategic thinking. They get to the point. Many are bold and competitive. They excel at figuring out machines, mathematical formulas or other rule-based systems. Many are good at understanding the structure of music, too. I named these people Directors.

Last in my store of biological knowledge were some of the traits linked with estrogen. Women and men with a great deal of estrogen activity tend to see the big picture: they connect disparate facts to think contextually and holistically, expressing what I call web thinking. They are imaginative. They display superior verbal skills and excel at reading postures, gestures, facial expressions and tones of voice, known as executive social skills. They are also intuitive, sympathetic, nurturing, mentally flexible, agreeable, idealistic, altruistic and emotionally expressive. I christened the people of this broad biological type Negotiators.

Other chemical systems play a role in personality, of course. Two others should be mentioned. Norepinephrine, a chemical closely related to dopamine, undoubtedly contributes to some of the Explorer's traits, especially their energy and impulsivity. And oxytocin—a chemical synthesized, stored and triggered (in large part) by estrogen—most likely plays a role in the Negotiator's compassion, nurturing, trust and intuition. In fact, families of chemicals produce the Explorer, Builder, Director and Negotiator. The specific activities of any one chemical are not as significant as the ratios and interactions among all of them and several other neural systems.

Nevertheless, only dopamine, serotonin, testosterone and estrogen have been directly associated with a wide range of personality traits. So variations in these four chemicals most likely form the foundation of these four basic styles of thinking and behaving.

Your Primary and Secondary Type

We are billboards of our genetic dispositions. And although each of us is a unique blend of all four personality types, we express some of these types more regularly (and more naturally) than others. I, for example, am predominantly an Explorer and secondarily a Negotiator. I have a few traits of the Director and even fewer traits of the Builder; and at times I can act "out of character."

But I have come to think that both your primary and secondary biological type are central to your temperament.

Patrick, Suzanne's new husband, certainly advertised his primary and secondary types: he is primarily a Negotiator and secondarily an Explorer. And Patrick showed many of the qualities of both these types minutes after he bounded into that Italian restaurant on his wedding night.

Foremost, Patrick was instantly likable; he had a fine-tuned sensitivity to those around him and a superb talent for handling people. He radiated warmth and authenticity. Moreover, Patrick "cared." He spent his spare time teaching English to immigrants from Africa and Asia and sending supplies to war refugees in foreign camps. Indeed, his verbal skills, his easy way with people, his compassion and his mental flexibility enabled him to thrive in countries where few dare to work and many fail who do. Patrick was a Negotiator through and through.

But his secondary type, the Explorer, was also highly visible. Patrick was infectiously spontaneous. When asked during the wedding ceremony to sip some wine, he good-naturedly responded, "All of it?" During one of the rock numbers, he grabbed the mic and did an Elvis Presley imitation in his stately white wedding suit—the antics of the true social risk taker. And all evening, he wove through the balloons to every table and dragged complacent "singles" out to swing to the rock ‘n’ roll. Patrick was a fine blend of the verbal, imaginative, compassionate Negotiator and the energetic, novelty-seeking Explorer. Suzanne must have sized him up as soon as she saw his photo and read his essays on Chemistry.com.

I didn't spend much time with Suzanne on her wedding night; she was understandably very busy. But she had told me she was primarily a Director and secondarily a Builder. So I could make some educated estimations about her temperament.

As a Director, Suzanne was most likely more focused than her new husband; she probably shot straight for her goals in a determined yet inventive way. Along with that gorgeous face and hourglass figure, Suzanne was almost certainly more forthright, analytical, exacting and autonomous, too. And as a Builder, she was probably more conscientious and cautious than her new mate.

The "Right" Fit

Most remarkable about that lovely wedding, Patrick and Suzanne fit one of nature's patterns perfectly. As you recall, their primary types, the Negotiator and Director, gravitate to each other. Moreover, their secondary types, the Explorer and Builder, can balance one another, each providing strengths the other needs. So as I watched Patrick and Suzanne exchange their vows, then twirl around the dance floor, I found myself imagining how they would get along in the years ahead. Would they still be in love fifty years from now?

Life won't be all roses for this dynamic couple. Directors admire self-control; so at times Suzanne may think Patrick's impulsivity is a bit over the top. She may become impatient with his intuitive side, too. Directors are logical, and the Negotiator's flights of imagination can leave them feeling ungrounded. Meanwhile, Patrick may occasionally find Suzanne's pragmatism maddening. Their secondary types, the Explorer and Builder, will also have an impact on their relationship: Patrick may occasionally feel hemmed in by Suzanne's caution, while Suzanne may become annoyed when Patrick is impractical.

Nevertheless, nature has given Patrick and Suzanne many complementary primary and secondary traits. With this big boost from their biological dispositions, along with a bit of work and some luck, they have an excellent chance of remaining forever "in sync," just the way they were as they swung around the dance floor that exhilarating wedding night: two very different individuals in perfect step with each other.


This blog is excerpted from "Why Him? Why Her?" by Helen Fisher. The full version is available in the May/June 2009 issue, Can We Change Our Stripes?: The Role of Temperament in Psychotherapy

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Topic: Couples | Sex & Sexuality

Tags: couples | Couples & Family | couples conflict | couples counseling | couples therapist | Couples Therapy | love | love and relationships

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1 Comment

Saturday, February 25, 2017 1:34:51 PM | posted by Georgina Maria Nunez
Nice article but you mention partners with similar personalities are the best fit and then you contradict yourself by saying partners that are opposite are the best fit by complimenting each other.