Hypergamy

Across studies, 3 out of 4 women rated socioeconomic status as more important in a prospective marriage partner than did the average man.

[15] An empirical study examined the mate preferences of subscribers to an online dating service in Israel that had a highly skewed sex ratio (646 men for 1,000 women).

Despite this skewed sex ratio, they found that "On education and socioeconomic status, women on average express greater hypergamic selectivity; they prefer mates who are superior to them in these traits... while men express a desire for an analogue of hypergamy based on physical attractiveness; they desire a mate who ranks higher on the physical attractiveness scale than they themselves do.

"[16]: 51 One study did not find a statistical difference in the number of women or men "marrying-up" in a sample of 1,109 first-time married couples in the United States.

[17] Gilles Saint-Paul (2008) proposes a mathematical model that purports to demonstrate that human female hypergamy occurs because women have greater lost mating opportunity costs from monogamous mating (given their slower reproductive rate and limited window of fertility compared to men), and thus must be compensated for this cost of marriage.