We also fall in love when the timing is right; and often with someone who lives or works nearby. Your childhood plays a huge role in your romantic choices, although no reliable patterns have ever been established. 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, as I told the Match.com executives, 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."
Yet your choice of mate will color every aspect of your life: your morning conversations in bed and at the breakfast table; your friendships, family reunions and weekend frolics; where you live; how you raise your children; most likely even your career. And certainly this choice will affect your tomorrows. Those babies you are likely to produce and send forth to multiply are your genetic future. Only a few times in your life will you mix your seed with that of another and pitch your DNA toward infinity.
So whom you choose matters.
In fact, I found it hard to believe that evolution would leave this decision entirely to our human whims. I suspected that psychologists had simply not looked for the underlying biological mechanisms that direct our romantic choices.
So 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?
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. Patrick, I would come to realize, had a good deal of the Explorer in him.
I drew another blank sheet of paper from my desk drawer. What else did I know about personality?