They note that the Cold War sparked a socially conformist identity which tended to be self-conscious of its appearance to the outside world. Some historians argue that sexual revolution was not a complete break from earlier Western sexual attitudes but rather a liberalization after a conservative period that only existed between the 1930s and 1950s. Many people, however, feel that one specific cause cannot be selected for this large phenomenon. Other data suggest the 'revolution' was more directly influenced by the financial independence gained by many women who entered the workforce during and after World War II, making the revolution more about individual equality rather than biological independence. One suggested trigger for the modern revolution was the development of the birth control pill in 1960, which gave women access to easy and reliable contraception. The term appeared as early as 1929 the book Is Sex Necessary?, by Thurber & White, has a chapter titled The Sexual Revolution: Being a Rather Complete Survey of the Entire Sexual Scene.
In general use, the term refers to a later trend of equalizing sexual behavior which occurred primarily during the 1960s, although the term has been used at least since the late 1920s. The sexual revolution refers to a change in sexual morality and sexual behavior throughout the Western world.
