to mid-twenties, open to relationships with both somewhat older and somewhat younger men; they have a larger potential dating pool than men until age 26. At age 20, women, in a "dramatic change", begin sending private messages to significantly older men. At age 29, they become "even more open to older men". Male desirability to women peaks in the late 20s and does not fall below the average for all men until 36. Other research indicates that women, irrespective of their own age, are attracted to men who are the same age or older. For the Romans especially, "beardlessness" and "smooth young bodies" were considered beautiful to both men and women. For Greek and Roman men, the most desirable traits of boys were their "youth" and "hairlessness". Pubescent boys were considered a socially appropriate object of male desire, while post-pubescent boys were considered to be "ἔξωροι" or "past the prime". This was largely in the context of pederasty (adult male interest in adolescent boys). Today, men and women's attitudes towards male beauty has changed. For example, body hair on men may even be preferred (see below). A 1984 study said that gay men tend to prefer gay men of the same age as ideal partners, but there was a statistically significant effect (p < 0.05) of masculinity-femininity. The study said that more feminine men tended to prefer relatively older men than themselves and more masculine men tended to prefer relatively younger men than themselves. Cross-cultural data shows that the reproductive success of women is tied to their youth and physical attractiveness such as the pre-industrial Sami where the most reproductively successful women were 15 years younger than their man. One study covering 37 cultures showed that, on average, a woman was 2.5 years younger than her male partner, with the age difference in Nigeria and Zambia being at the far extreme of 6.5 to 7.5 years. As men age, they tend to seek a mate who is ever younger. 25% of eHarmony's male customers over the age of 50 request to only be matched with women younger than 40. The 2010 OkCupid study found that female desirability to its male users peaks at age 21, and falls below the average for all women at 31. After age 26, men have a larger potential dating pool than women on the site; and by age 48, their pool is almost twice as