Ever since Darwin there had been an assumption among evolutionary biologists that females were coy and choosy in their sexual behavior while males were the ardent, promiscuous sex.
And yet female langur monkeys were observed actively pursuing males from neighboring troops while, according to the prevailing theory, they should have been chaste rather than chasing. What was even more surprising was that they would exhibit these sexual advances at any stage in their estrous cycle, sometimes even when they were already pregnant.
More than 30 years of subsequent research has confirmed that females in many primate species, humans included, engage in a diversity of sexual strategies to enhance their overall reproductive success.
Read the full, original story here: Promiscuity Is Pragmatic