Tall, dark, attractive, blue-eyed, blond, intelligent, athletic, funny, fit, shapely -- certain traits turn us on when it comes to finding someone to love.
But with couples breaking up all the time and a 50 percent or so divorce rate, those traits mean little when it comes to what really matters -- finding someone who won't break our heart.
What if we could have proof that our partner was madly, deeply in love with us? What if we could be guaranteed that our partner would never cheat on us? What if we could marry knowing that our partner would never divorce us? What if we could turn a "player" into a loving husband and family man? Would we want to know? Would we gladly sign up to tweak our sweetheart's genetic composition to have the love we want?
As odd as it may seem, we're not that far off.
When it comes to matters of the heart, love has less to do with the heart and more to do with the brain. New technologies, like functional magnetic resonance imaging (fMRI), allow us to look inside the brain when it's in the throes of love -- or just mere attachment love. And they also allow us to weed out a man or woman who, despite promising to love, honor and cherish us above all others "till death do us part," is more likely to break that vow.
It will be a while before we'll be able to purchase or download a hand-held truth-o-meter and use it on a would-be lover, says science journalist Judith Horstman, author of the newly published The Scientific American Book of Love, Sex and the Brain: The Neuroscience of How, When, Why and Who We Love. But breaking a promise is a neurological event, documented by researchers at the University of Zurich in Switzerland, and that means one day all of us might be able to peer inside the minds of those we're thinking of committing to and discover if they're just as committed.
But maybe despite our best judgment we fall for someone whose brain scan proves he's prone to breaking promises anyway; should we forget about him and try to find someone else? Not so fast -- what if we could give him a pill that would turn him into a faithful partner?
A few years ago, scientists looked into what made prairie voles so family-friendly and monogamous -- one of the fewer than 5 percent of mammals that stick with its mate for life -- when its cousin, the meadow vole, acts like a Don Juan, mating with as many females as possible and is clueless about raising its own children. The difference is a protein called the vasopressin receptor, which is ample in the prairie vole but not in the meadow vole. When scientists boosted the vasopressin receptor in the meadow vole, it became monogamous. It's a similar situation with monkeys, some of which are more free-loving than others -- even humans, according to one study. So can we expect a drug that boosts our vasopressin receptor so we could transform a cad into a fantastic dad? "That would depend on a lot of things, including the side effects of the drugs," says Dr. Barry Starr, a geneticist at Stanford University's Tech Museum of Innovation and who runs its "Ask a Geneticist" column. "Vasopressin is obviously involved in a lot more than fidelity and so you'd need to be able to tweak the gene just right in order to see the effects you might see in someone who doesn't cheat."
And, yes, women have vasopressin receptors, too, but for reasons that remain unknown it doesn't seem to influence their behavior as much, Starr says.
Some researchers have looked into what role genes might have in our tendency to cheat, like last year's study on a certain variant of the dopamine gene DRD4 -- and dopamine is the force behind our sexual drives, survival needs and pair-bonding behaviors. That study got a lot of buzz in the press as the one-night stand gene (although the researchers painstakingly noted that their findings were not definitive). And why not: How much easier to blame infidelity on a gene than our own actions? While we might be able to mess with DRD4, there would be ramifications. "We would also curb the effects of risk taking," Starr notes, and that means "fewer new discoveries and fewer financial meltdowns."
Other studies have found potential genetic links to explain why children of divorced parents have a higher risk of divorce and why divorce is common among identical twins (If one twin in an identical twin pair divorced, it's much more likely that his or her twin would be divorced, too).
Since it appears that genetics clearly has some influence over human behavior, it isn't far-fetched to believe that monogamy and a predisposition to divorce might also be somewhat under its spell. So, what do we do with that information? Most of us have no problem testing fetuses for potential genetic problems; in fact, it's recommended for women who get pregnant in their mid-30s. Would we be just as willing to screen a potential partner's genetic pool if we had reliable, accessible tests? Wouldn't it be to our best interest -- not to mention the interest of any potential children we might have -- to weed out those people who will end up being unfaithful or love us and leave us?
While that sort of genetic testing may be years away -- if it ever arrives -- there are already some entrepreneurs who are profiting by touting the benefits of neuroimaging to suspicious spouses and worried would-be lovers, like No Lie MRI. The company's website recommends No Lie's services for "risk reduction in dating," "trust issues in interpersonal relationships" and "issues concerning the underlying topics of sex, power and money."
That makes many uncomfortable. Neuroscience is an exciting new field but the problem, many say, is that brain scans aren't always as accurate as we think they are -- or want them to be. Yet.
"Brain imagining is still very new and it's not very specific, so in these experiments where they correlate certain activity in the brain with emotions, that's an association -- it's not really a cause and effect yet," Horstman tells me.
That doesn't bother people like No Lie MRI's founder Joel Huizenga, who says singles think "this is great for dating, because people never tell you the truth."
But, do we always want to know the truth? "If you build a fortress around your heart, you're keeping pain out but also love," Horstman says. "Our hearts are made to be broken."
Just try telling that to your brain.