did females show a preference for males significantly younger than male preferences for females" and that there was a "consistent cross-cultural preference by women for at least same-age or significantly older men".A 2003 AARP study reported that 34% of women over 39 years old were dating younger men.Differences in age preferences for mates can stem from evolutionary mating strategies and age preferences in sexual partners may vary cross culturally.There are also social theories for age differences in relationships as well as suggested reasons for 'alternative' age-hypogamous relationships.A study released in 2003 by the United Kingdom's Office for National Statistics concluded that the proportion of women in England and Wales marrying younger men rose from 15% to 26% between 19.Another study also showed a higher divorce rate as the age difference rose for when either the woman was older or the man was older.A study conducted by David Buss investigated sex differences in mate preferences in 37 cultures with 10,047 participants.
Within sexual selection Darwin identified a further two mechanisms which are important factors in the evolution of sex differences (sexual dimorphism): intrasexual selection (involve competition with those of the same sex over access to mates) and intersexual choice (discriminative choice of mating partners).
However, human males tend to have more parental investment compared to mammal males (although females still tend to have more parental investment).
Thus, both sexes will have to compete and be selective in mate choices.
A British psychological study published in Evolution and Human Behavior in 2010 concluded that men and women, in general, continued to follow traditional gender roles when searching for mates.
The study found that, as supported by other academic studies, most men preferred younger, physically attractive women, while most women, of any age, preferred successful, established men their age or older.