They say opposites attract, and admittedly, when looking for a mate, the first thing we notice is his or her appearance. What's attractive and what's not is highly subjective, but did you know that your looks could influence the outcome of your relationship? It's true - well, according to one study. British researchers found that people who couple up "on their level" - that is, partners who are similarly attractive - have more relationship success than those who have a significantly more attractive mate. After studying the photos of and interviewing 100 heterosexual couples who had either broken up or were still together, researchers at Stirling, Chester and Liverpool universities found that the most successful couples resembled one another in that their facial symmetry was similar or neither was more attractive than the other.

Facial symmetry is considered one measure of beauty. Interestingly, when the attractiveness was lopsided, relationships weren't as successful when the woman was significantly more attractive than the man. The downside of dating a beauty like Angelina Jolie or Julia Roberts is apparent to Billy Bob Thornton and Lyle Lovett, and now it seems obvious to everyone else. The researchers hypothesized that attractive women possessed the confidence to end a bad relationship earlier, rather than let it run its course. Less attractive women "may have to make do with what they have, hence the longer relationships," said researcher Rob Burriss. A more attractive male mate had no bearing on the relationship length, interestingly, but the more attractive female mate cut the relationship length to a matter of months, as researchers reported in the journal Personality and Social Psychology Bulletin.