The sexual revolution, also known as the sexual liberation, was a social movement that challenged traditional codes of behavior related to sexuality and interpersonal relationships throughout the Western world from the late 1950s to the early 1970s. Sexual liberation included increased acceptance of sexual intercourse outside of traditional heterosexual, monogamous relationships, primarily marriage. The legalization of "the pill" as well as other forms of contraception, public nudity, pornography, premarital sex, homosexuality, masturbation, alternative forms of sexuality, and abortion all followed.
The term "first sexual revolution" is used by scholars to describe different periods of significant change in Western sexual norms, including the Christianization of Roman sexuality, the decline of Victorian morals, and the cultural shifts of the Roaring Twenties. Sexual revolution most commonly refers to the mid-20th century, when advances in contraception, medicine, and social movements led to widespread changes in attitudes and behaviors around sex. The sexual revolution was influenced by Freud's theory of unconscious drives and psychosexual development, Mead's ethnographic work on adolescent sexuality in Samoa, Unwin’s cross-cultural studies, and the research of Kinsey and later Masters and Johnson, all of which challenged traditional beliefs about human sexuality.