In human sexual behavior, promiscuity is the practice of having casual sex frequently with different partners or being indiscriminate in the choice of sexual partners. The term can carry a moral judgement if viewed in the context of a mainstream social ideal for sexual activity to occur only within exclusive committed relationships. A common example of behavior viewed as promiscuous within the mainstream social ideals of many cultures is a one-night stand.
Severe and impulsive promiscuity, along with a compulsive urge to engage in illicit sex with attached individuals is a common symptom of borderline personality disorder, but most promiscuous individuals do not have this disorder.
What sexual behavior is considered promiscuous varies between cultures, as does the prevalence of promiscuity, with different standards often being applied to different genders and civil status. Feminists have traditionally argued a significant double standard exists between how men and women are judged for promiscuity. Historically, stereotypes of the promiscuous woman have tended to be negative, such as "the slut", while male stereotypes have been more varied, some expressing approval, such as "the stud" or "the player", while others imply societal deviance, such as "a womanizer". A scientific study published in 2005 found that promiscuous men and women are judged equally harshly and a recent poll showed that both genders tend to express strong preference for sexually conservative partners. Although later studies show evidence that a double standard does show up within group settings.
Promiscuity is common in many animal species. Some species have promiscuous mating systems, ranging from polyandry and polygyny to mating systems with no stable relationships where mating between two individuals is a one-time event. Many species form stable pair bonds, but still mate with other individuals outside the pair. In biology, incidents of promiscuity in species that form pair bonds are usually called extra-pair copulations.