In the new issue of Nature, neuroscientist Larry Young offers a grand unified theory of love. After analyzing the brain chemistry of mammalian pair bonding, Dr. Young predicts that it won't be long before an unscrupulous suitor could sneak a pharmaceutical love potion into your drink.
That's the bad news. The not-so-bad news is that you may enjoy this potion if you took it knowingly with the right person. But the really good news, as I see it, is that we might reverse-engineer an anti-love potion, a vaccine preventing you from making an infatuated ass of yourself. Although this love vaccine isn't mentioned in Dr. Young's essay, when I raised the prospect he agreed it could also be in the offing.
Could any discovery be more welcome? This is what humans have sought since Odysseus ordered his crew to tie him to the mast while sailing past the Sirens. Long before scientists identified neuroreceptors, long before Britney Spears' quickie Vegas wedding or Larry King's seven marriages, it was clear love was a dangerous disease.
Love was identified as a potentially fatal chemical imbalance in the medieval tale of Tristan and Isolde, who consumed a love potion and turned into hopeless addicts. Even though they realized that her husband, the king, would punish adultery with death, they had to have their love fix.
They couldn't guess what was in the potion, but then, they didn't have the benefit of Dr. Young's research with prairie voles at the Yerkes National Primate Research Center at Emory University. These mouselike creatures are among the small minority of mammals — less than 5 percent — who share humans' propensity for monogamy. When a female prairie vole's brain is artificially infused with oxytocin, a hormone that produces some of the same neural rewards as nicotine and cocaine, she'll quickly become attached to the nearest male. A related hormone, vasopressin, creates urges for bonding and nesting when it is injected in male voles. After Dr. Young found that male voles with a genetically limited vasopressin response were less likely to find mates, Swedish researchers reported that men with a similar genetic tendency were less likely to get married. Dr. Young speculates that human love is set off by a "biochemical chain of events" that originally evolved in ancient brain circuits involving mother-child bonding, which is stimulated by the release of oxytocin.
Researchers have achieved similar results by squirting oxytocin into people's nostrils — not terribly sexy, but it seems to enhance feelings of trust and empathy. Although Dr. Young is not concocting any love potions, he said there could soon be drugs that increase people's urge to fall in love.
"It would be completely unethical to give the drug to someone else," he said, "but if you're in a marriage and want to maintain that relationship, you might take a little booster shot yourself every now and then. Even now it's not such a far-out possibility that you could use drugs in conjunction with marital therapy."
I see some potential here, but also big problems. Suppose you took that potion and then suddenly felt an urge to run off with the next person you spent any time with, like your dentist? What if you went to a business convention and then, like an artificially stimulated prairie vole, bonded with the nearest stranger? What if, like Tristan, you developed an overwhelming emotional connection to your boss' spouse?
Even if the effects could be targeted to the right partner, would you want to start building a long-term relationship with a short-term drug? What happens when it wears off?
A love vaccine seems more practical, and already some drugs seem to inhibit people's romantic impulses. Such a vaccine has already been demonstrated in prairie voles.
I doubt many people would want to permanently suppress love, but a temporary vaccine could come in handy. Spouses going through midlife crises would not be so quick to elope with their personal trainers; elderly widowers might consult lawyers before marrying someone resembling Anna Nicole Smith. Love is indeed a many-splendored thing, but sometimes we all need to tie ourselves to the mast.