What sexual behavior is considered socially acceptable, and what behavior is "promiscuous", varies much among different cultures. Behavior that is considered promiscuous for a married or unmarried individual in one culture may be considered acceptable in another culture. Within a culture, men and women are not necessarily held to the same standards. For example, a man may or may not be considered promiscuous for engaging in sexual activity with someone he was not married to, even in cultures where a woman would be considered promiscuous for the same behavior.
Accurately assessing people's sexual behavior is difficult, since there are strong social and personal motivations, depending on social sanctions and taboos, for either minimizing or exaggerating reported sexual activity. Extensive research has produced mathematical models of sexual behavior comparing the results generated with the observed prevalence of STDs to statistically estimate the probable sexual behavior of the studied population.
The number of sexual partners an individual has varies within a lifetime, and varies widely within a population. In the U.S., seven women is the median number of lifetime female sexual partners; four men is the median number of male partners for women; 29 percent of men and 9 percent of women report to have had more than 15 sexual partners. Studies of the spread of STDs consistently demonstrate that a small percentage of the studied population have more partners than the average man or woman, and a smaller number of people have fewer than the statistical average. An important question in the epidemiology of venereal diseases is whether or not these groups copulate mostly at random (with sexual partners from throughout a population) or within their social groups (assortative mixing).
A 2006 comprehensive global study (analysing data from 59 countries worldwide) found no firm link between promiscuity and sexually transmitted diseases. This contradicts other studies.
The words "womanizer", "player", "skirt-chaser" and "rake" may be used in reference to a man who has love affairs with women or men he will not marry or commit himself to. Typically, the love affairs are sexually motivated, with varying emotional connection and attachment. The names of real and fictional seducers have become eponyms for such promiscuous men. The most famous are the historical Casanova (1725-1798), the fictional Don Juan who first appeared in the 17th century, Lothario from Nicholas Rowe's 1703 play The Fair Penitent, How I Met Your Mother's Barney Stinson, and perhaps most famously, Ian Fleming's literary and film character James Bond.
During the English Restoration period (1660-1688), the term rake was used glamorously: the Restoration rake is a carefree, witty, sexually irresistible aristocrat typified by Charles II's courtiers, the Earl of Rochester and the Earl of Dorset, who combined riotous living with intellectual pursuits and patronage of the arts. The Restoration rake is celebrated in the Restoration comedy of the 1660s and the 1670s. After the reign of Charles II, and especially after the Glorious Revolution of 1688, the rake was perceived as negative and became the butt of moralistic tales in which his typical fate was debtor's prison, permanent venereal disease, and, in the case of William Hogarth's A Rake's Progress, venereally-caused insanity and internment to Bedlam.
Two examples of promiscuous animals are the primates chimpanzees and bonobos. These species live in social groups consisting of several males and several females. Each male copulates with many females, and vice versa. In bonobos, the amount of promiscuity is particularly striking because bonobos use sex to alleviate social conflict as well as to reproduce.