Lemondrop

Getting married can seem like such a crapshoot: Will you wind up with someone like the stalwart, not-found-anywhere-on-Earth hero of a Nicholas Sparks novel -- or a guy who, down the line, reveals himself to be a total cad? And what part does genetic predisposition play?

This week, the Well column in the New York Times examines the scientific factors determining the likeliness of a partner to cheat. One hot topic indeed.

Specifically, reporter Tara Parker-Pope compares a handful of new studies, including one that seems to debunk the influence of what's previously been called the "infidelity" gene, a variation in the gene that regulates vasopressin -- a male bonding hormone. This new study says that possessing such a glitch might lead to a less stable partnership, but it doesn't necessarily mean you're cozying up to a Tiger.

Yet, the most fascinating findings about the differences between men and women were how we react not genetically, but socially, to cues. In one study, half the subjects were asked to envision flirting with an attractive member of the opposite sex, while the control group imagined a non-charged conversation with the same person. Everyone was subsequently given fill-in-the-blank word puzzles.

For example: Fill in the blanks in the two words below.

L O _ A L T H R _ _ AT


What words did you see? The men who'd envisioned the flirtatious scenario, more often than not, chose neutral words like LOCAL and THROAT, whereas their female counterparts -- who had witnessed the very same scene, mind you -- were far more likely to fill in the loaded options: LOYAL and THREAT.

According to researchers, their reaction points to "a kind of early warning system" alerting the women to a potential mate thief in their vicinity. Nifty -- though none of this really does much to debunk the stereotype of the scary possessive girlfriend, does it?

That aside, the most promising point the article makes about loyalty suggests that long-term happiness in any relationship lies in our own hands, not our genes. Another new study by Arthur Aron, a psychologist and relationship researcher, found that the couples who were most content were strongly influenced by their sense of "self-expansion" in the relationship – in other words, how much a partner enhanced their life and broadened their horizons. Turns out, the more you do that for each other, the better you'll both feel. No unmutated genes, warning bells or sex rehab necessary.

So, while you can't change your vasopressin regulating ability, you sure can affect how fun and motivating and rewarding a partner you are. And you can ask the BF (or GF) to do the same. Personally, I think it's a relief to know that it's free will, not genetic fate, that determines whether we live happily ever after.