The study found very few instances of older women pursuing much younger men and vice versa.
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).
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.
Although the "cougar" theme, in which older women date much younger men, is often portrayed in the media as a widespread and established facet of modern Western culture, at least one academic study has found the concept to be a "myth".
Females demonstrate a complementary pattern, being willing to accept considerably older males (on average 8 years older) and were also willing to accept males slightly younger than themselves (on average 5 years younger).
This is somewhat different to our close evolutionary relatives: chimpanzees.
A study conducted by David Buss investigated sex differences in mate preferences in 37 cultures with 10,047 participants.
In all 37 cultures it was found that males preferred females younger than themselves and females preferred males older than themselves.
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 ...As well as asking participants a number of questions on mate selection criteria, they also had to provide the oldest and youngest partner they would accept.It was found that for all ages males were willing to accept females that are slightly older than they are (on average 4.5 years older), but they accept females considerably younger than their own age (on average 10 years younger).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.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.Age-disparity relationships have been documented for most of recorded history and have been regarded with a wide range of attitudes dependant on sociocultural norms and legal systems. Relationships with age disparity of all kinds have been observed with both men and women as the older or younger partner.In various cultures, older men and younger women often seek one another for sexual or marital relationships.