Male chimpanzees tend to prefer older females than younger and it is suggested that specific cues of female mate value are very different to humans.Buss attributed the young age preference for females to the cues that youth has.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.In August 2010, Michael Dunn of the University of Wales Institute, Cardiff completed and released the results of a study on age disparity in dating.Dunn concluded that "Not once across all ages and countries ...These differences may be sexual, financial or social in nature. Socially, a society with a difference in wealth distribution between older and younger people may affect the dynamics of the relationship.
Thus, both sexes will have to compete and be selective in mate choices.
The theory predicts that preferred mate choices have evolved to focus on reproductive potential and reproductive investment of members of the opposite sex.
This theory predicts both intrasexual selection and intersexual choice due to differences in parental investment; typically there is competition among members of the lower investing sex (generally males) over the parental investment of the higher investing sex (generally females) who will be more selective in their mate choice.
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 alternative social theories for age differences in relationships as well as suggested reasons for 'alternative' age-hypogamous relationships.
These age preferences were confirmed in marriage records with males marrying females younger than them and vice versa.