(4 of 4)
Happily, romance needn't come to ruin. Even irrational animals like ourselves would have quit trying if the bet didn't pay off sometimes. The eventual goal of any couple is to pass beyond serial dating--beyond even the thrill of early love--and into what's known as companionate love. That's the coffee-and-Sunday-paper phase, the board-games-when-it's-raining phase, and the fact is, there's not a lick of excitement about it. But that, for better or worse, is adaptive too. If partners are going to stay together for the years of care that children require, they need a love that bonds them to each other but without the passion that would be a distraction. As early humans relied more on their brainpower to survive--and the dependency period of babies lengthened to allow for the necessary learning--companionate bonding probably became more pronounced.
That's not to say that people can't stay in love or that those couples who say they still feel romantic after years of being together are imagining things. Aron has conducted fMRI studies of some of those stubbornly loving pairs, and initial results show that their brains indeed look very much like those of people newly in love, with all the right regions lighting up in all the right ways. "We wondered if they were really feeling these things," Aron says. "But it looks like this is really happening."
These people, however, are the exceptions, and nearly all relationships must settle and cool. That's a hard truth, but it's a comforting one too. Long for the heat of early love if you want, but you'd have to pay for it with the solidity you've built over the years. "You've got to make a transition to a stabler state," says Barry McCarthy, a psychologist and sex therapist based in Washington. If love can be mundane, that's because sometimes it's meant to be.
Calling something like love mundane, of course, is true only as far as it goes. Survival of a species is a ruthless and reductionist matter, but if staying alive were truly all it was about, might we not have arrived at ways to do it without joy--as we could have developed language without literature, rhythm without song, movement without dance? Romance may be nothing more than reproductive filigree, a bit of decoration that makes us want to perpetuate the species and ensures that we do it right. But nothing could convince a person in love that there isn't something more at work--and the fact is, none of us would want to be convinced. That's a nut science may never fully crack.