Premarital sex is sexual activity practiced by people who are unmarried.Historically, premarital sex was considered a moral issue which was taboo in many cultures and considered a sin by a number of religions, but since about the 1960s, it has become more widely accepted, especially in Western countries.
In some cultures, for example in many modern-day Western cultures, many people do not hold value in sexual abstinence before marriage.
Historically, at least a significant portion of people have engaged in premarital sex, although the number willing to admit to having done so was not always high.
In a study conducted in the United States, 61 percent of men and 12 percent of women born prior to 1910 admitted to having premarital sex; the gender disparity may have been caused by cultural double standards regarding the admission of sexual activity or by men frequenting prostitutes.
Starting in the 1920s, and especially after World War II, premarital sex became more common; this was especially prevalent among women.
By the end of the 20th century, between 75 and 80 percent of Americans had vaginal intercourse before the age of 19.
This has been attributed to numerous causes, including the increasing median age at marriage and the widespread availability of efficient contraceptives.
According to a 2001 UNICEF survey, in 10 out of 12 developed nations with available data, more than two-thirds of young people have had sexual intercourse while still in their teens.
The term was used instead of fornication, which had negative connotations, and was closely related to the concept and approval of virginity, which is sexual abstinence until marriage.
The meaning has since shifted to refer to any sexual relations a person has prior to marriage and removing the emphasis on the relationship of the people involved. It is not clear whether sex between individuals legally forbidden from marrying, or the sexual relations of one uninterested in marrying would be considered premarital.
Alternative terms for premarital sex have been suggested, including non-marital sex (which overlaps with adultery), youthful sex, adolescent sex, and young-adult sex.
These terms also suffer from a degree of ambiguity, as the definition of having sex differs from person to person.