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).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.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).
Parental Investment Theory refers to the value that is placed on a potential mate based on reproductive potential and reproductive investment.
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.
These age preferences were confirmed in marriage records with males marrying females younger than them and vice versa.
This study used 21,245 participants between 18 and 65 years of age who were not involved in a close relationship.