How do we decide? There's a lot of research on the subject, and what scientists have found goes a long way toward explaining the current high divorce rate. In her fascinating book, Fisher says timing is a huge factor. You are more likely to feel that you are "in love" if you are already emotionally aroused. That can be caused by lots of things—suffering through a difficult experience like moving to a new city or recovering from a failed relationship, for example. Once you are in that emotional state, proximity helps. It's a little like the plot of A Midsummer Night's Dream, where a little love juice sprinkled in the eyes (the metaphorical equivalent of emotional arousal) makes someone inclined to adore the first person he or she spots.

Despite the conventional wisdom that opposites attract, Fisher says that we generally marry people who are very much like us, who share the same ethnic, social, religious, educational and economic background. And people who have the same level of physical attractiveness and intelligence, as well as similar values, interests and social and emotional skills. Since some of these traits (such as intelligence and social skills) are influenced by DNA, scientists think that at least a portion of the attraction we feel is genetically driven. We seek similar genetic types.

Beyond these characteristics, women and men seek different things, Fisher says. For example, men are attracted by facial and body symmetry. Evolutionary biologists say this preference has evolved because women with these characteristics are more likely to bear healthy children, and propagating the species is what we're all about. Women tend to be attracted by a man's status in the world. That can express itself in many ways—intelligence, a self-confident personality, even height. Women also appear to be hard-wired to look for men who have strong cheekbones and jaws—traits associated with testosterone.

In the last couple of centuries, as women have gained more financial and legal autonomy, the idea of romantic love has played a greater role in the choice. That's reinforced by popular culture, which celebrates the idea of soulmates miraculously finding each other. As women have been able to earn more, researchers have found that the importance of a man's earning power in this equation appears to have declined somewhat. In their own admittedly unscientific survey, Ford and Drake say they found the same thing: "Our survey of women in their twenties revealed that most have no preference for a man with money . . . Some girls even said they would go for a subordinate 'if he was cute'." For lower-income women, though, money is still critical. One recent study of single mothers, for example, concluded that many would have married the father of their children—if he'd had a job. But a man without a paycheck? No way. Many studies have also shown that couples fight more about money than about any other single issue (including sex or how to raise the kids), and that's even more true in times of economic difficulty, like now.

Ideally, of course, we would all marry men who keep our hearts and our bank accounts overflowing with joy. If that describes your marriage, great. If not, Ford and Drake's advice might be worth listening to—as an antidote to all the overly sentimental views of marriage that surround us. "Falling in love does feel good," they say, "but the problems arise when we make it our number one priority." That's probably not a message June brides want to hear right now, but at least a few will probably wish they had once the honeymoon's over.

© 2009