For seven years, "American Idol" hosts Paula Abdul and Simon Cowell disagreed, often bitterly, on the show's performances. But could such squabbles mask love? That's what romantic comedies would have us believe. How often have you seen a couple interact like oil and water the entire film, only to realize that they're fated to be together? In pop culture, we see princes marry scullery maids and Harvard lawyers fall for the mechanics who fix their cars. Even Abdul, in her pre-"Idol" days, found love with the animated MC Skat Kat in the video for her 1989 hit "Opposites Attract." Despite the fact that they had nothing in common, their relationship worked.
Unfortunately, the world of science hasn't been able to prove the accuracy of these Paula Abdul lyrics. Instead, researchers find that we tend to seek out people who think and act like us. We may even be seeking our own mirror image. In a 2003 study published in the Proceedings of the National Academy of Sciences, respondents ranked how important certain traits were in a romantic partner, and then they ranked the extent to which they themselves exhibited that trait [source: Angier]. If people thought they were attractive, they wanted a similarly attractive partner. If people thought they were wealthy, they wanted a partner of equivalent status. If people weren't close to their family, they didn't seek out a person who was.
A 2005 study from the University of Iowa found that personal resemblance beyond these obvious markers of wealth or beauty matter more, though. Researchers assessed attitude and personality similarities between newlywed couples. An attitude similarity might be having the same religion or personal belief system, and personality traits were defined as qualities like anxiety, agreeableness, extraversion and conscientiousness. As it turns out, those couples that had more in common personality-wise, as opposed to attitude-wise, were more likely to be very happy and satisfied with their marriages [source: American Psychological Association]. The tricky thing about this finding, though, is the researchers claim that these personality traits take much longer to reveal themselves than attitude similarities do. That means that it may be possible for a heavily tattooed man to find love with a never-been-inked gal -- if they're both the same level of neurotic.
In a 2009 study of online daters, respondents claimed to want someone who represented their opposite, thinking it would balance them out. But even though they said they wanted someone different, the people they contacted actually had very similar personalities to their own [source: Law]. But there does appear to be one instance when it pays to look for someone different from you, and we'll discuss it on the next page.