Timeline of a Love Affair
Something keeps people together after the thrill wears off, however. "At a certain point there's a crossover from passion to intimacy," Bartell says, although, "that's not to say there's no passion in a relationship after that." People keep loving each other in a special way, and they keep having sex.
It seems likely that hormones are involved in intimacy, which psychologists also call attachment. Some research points to oxytocin and vasopressin, hormones thought to give us the "warm fuzzies." These hormones may also play a role in bonding between human mothers and babies. Studies of small rodents called prairie voles show oxytocin hastens attachment in mating voles and may even have the power to make non-monogamous voles act monogamously. But it isn't clear if what's known about voles applies to the love affairs of adult humans.
If people were simple creatures, the hormonal process of romantic attachment would keep all love affairs going strong after passing through the "limerence" stage. People are not simple, and many couples who were perfectly, blissfully in love a year ago have split up and are seeing other people today.
Love affairs that start with falling in love may be set up to fail. Initially the lovers are in denial about any faults their beloved may have, and they're impervious to logic should anyone else suggest that the relationship may be a bad idea. After "limerence" wears off, certain things become painfully apparent.
So-called "fatal attraction" is another reason why love affairs end. In fatal attraction, a quality that one initially finds attractive in a lover is the same quality that sinks the relationship. For example, we may fall for a person's delightful sense of humor, but then come to see it as flakiness. Attractive qualities are usually two-sided. If a sexy and charming partner cheats, it's because he or she is charming and sexy to other people, too. A thrilling person may actually be dangerous. A doting, attentive lover may be overly possessive.
Researchers studying the love affairs of college students found that fatal attraction was involved in one-third of breakups. Extreme qualities were most likely to be "fatal." Lovers who were attracted to partners who were very different from them were also more likely to split up.