Established romantic partners tend to exhibit similarity on a host of characteristics, from demographics to personality and mental health. Rather than emerging over time, this similarity appears to result from a pairing process tied to attraction during the early stages of relationship initiation. One such potential process is captured in the matching hypothesis. The matching hypothesis contends that individuals evaluate their own social desirability, often defined in terms of physical attractiveness, and seek partners who have equivalent social desirability. Although well-known, the matching hypothesis maintained little empirical support for decades. Recent evidence provides tentative suggestion that people do selectively pursue partners who are like them on some aspects of social desirability, pointing to the potential role of self-guided matching in early-stage relationship initiation.