Hypergamy

Hypergamy (colloquially referred to as marrying up) is the act or practice of seeking a spouse of equal or higher socio-economic status, or caste status than oneself.

The term is often used more specifically in reference to a widespread tendency amongst human cultures for females to seek or be encouraged to pursue male suitors that are comparatively older, wealthier or otherwise more privileged than themselves. Hypergamic behaviours can be explained in terms of genetic economic necessity, in which societies with high levels of gender inequality are more likely to have women who "marry-up" for the benefit of their children, and more likely to have men who "marry-down" to ensure that their mates have a higher incentive to remain faithful.

The word "hypogamy" typically refers to instances of the opposite occurring: marrying a person of lower social class or status.

Society
In contemporary society, human females continue to exhibit strong mate-selective preferences for spouses who are at least equal to them in terms of attained educational level, job status, social standing, and capital accumulation. In comparison males tend to place higher emphasis on the value of physical attractiveness in a woman alone.

In an anthology about money and relationships by many prominent female writers, the authors expressed that the role money plays in determining how women select long-term male partners is often considered a taboo subject.

Dynamics
In any population, low status males face relatively greater difficulties in finding long-term relationships due to hypergamic pressures. A contributing reason is that low status females often still aspire to obtain mates with greater social standing than themselves.

Hypergamy can also create difficulty for women with high social status in finding long-term relationships. Very high status women may have to choose from a relatively small pool of men, that being, men who are still 'above' themselves in measures of perceived social status. As an individual woman increases in relative social status, there are proportionally less men in a population, in a relative sense, who remain above her status-wise - shrinking the long-term partner pool.

The practice is also observed among gay couples.

Variance
One study found no statistical difference in the number of women or men "marrying-up" in a sample of 1109 first-time married couples in the United States.