In the game of online dating, men and women try to level up, study finds

Couples, married or not, tend to have similar ages, educations, levels of attractiveness and a host of other characteristics. This could mean that people try to find partners who "match" their stats. On the other hand, it could mean that people try to find slightly more attractive mates – which results in the same pattern as the most desirable partners pair off, followed by the next most desirable, and so on.