Gynaecologist William Howell Masters and psychologist Virginia Eshelman Johnson pioneered research into the nature of human sexual response and the diagnosis and treatment of sexual disorders and dysfunctions from 1957 until the 1990s. This book examines their influential scientific sex research and its groundbreaking implications for sex therapy and the study of human sexuality. Until now, these developments have been largely ignored in sociology. The book illuminates how Masters and Johnson have constructed their apparently scientific ideas about sexual function and dysfunction with reference to dominant Western discourses about sexuality. In addition, the book will explore some of the wider theoretical, conceptual and historical issues relating to the study of human sexuality. These will include a critical evaluation of conventional accounts of the history of the sociology of sex, particularly in the United States, major theoretical frameworks used in the study and understanding of human sexuality, and some of the key concepts underpinning sex research and sex therapy.