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.