Over the past 150 years, it seems the study of sex has interacted with society at large to influence, and be influenced by, current morals, ideologies and social behaviours.
In 1896, Richard von Krafft-Ebing published his book Psychopathia Sexualis, a landmark text in the study of sexual mania and deviation comprising 238 case studies. Perversions of the sexual instinct were, he believed, caused by degeneracy, which was popularly defined as hereditary weakness or a taintedness in the family pedigree. Henry Havelock Ellis and Sigmund Freud were instrumental in bringing sexuality out of the Victorian cold, but both were sufficiently influenced by the views of the time to base their interpretations of sexuality in terms of control-repression and drives. Ellis, born in Croydon in 1859, studied medicine at St Thomas's Hospital in London and was a member of the socialist Fabian society. He was a supporter of sexual liberation and wrote several books including a six volume Studies in the Psychology of Sex, published between 1897 and 1910, which was an attempt to analyse what was commonly called the "sexual instinct". The books caused tremendous controversy and were banned for several years. Sigmund Freud is well known for his philosophies and his view of sexual desire as the primary motivational energy in humans. In 1905, he published Three Essays on the Theory of Sexuality in which he posited sexuality as the driving force of neurosis (through repression) and perversion.
Beginning in the 1920s and culminating in the 1940s and 1950s, the science of sexuality moved away from the study of criminals and perverted aspects of sexuality (which at the time included homosexuality) to a tradition more of social bookkeeping focusing on the sexual behaviour of relatively normal people.
In 1938, Dr Alfred C Kinsey, a Harvard-trained professor of zoology, was asked to co-ordinate a marriage course at Indiana University (which consisted of lectures in the biology, psychology, sociology, and ethics of sex and reproduction). He was an excellent and admired taxonomist and a collector by nature. Unable to answer his students' questions on the subject of sex and reproduction because of the paucity of data on human sexuality, he began gathering his own data, and with his research students collected more than 18,000 sexual histories from people (including his own father, who was a deeply religious and domineering man). In 1947, the Kinsey Institute was established as a not-for-profit corporation affiliated to Indiana University. Kinsey published the books Sexual behaviour in the Human Male (1948) and Sexual behaviour in the Human Female (1953). Kinsey was very moralistic about his predecessors in his male book, for example the fact that Ellis would not have face-to-face contact with his research participants, and had little that was positive to say about psychiatrists in general. Kinsey's female book was much more rounded and accessible. Newsweek called it a "progress report" about what Eve chose to say about Eve to the investigators, and commented that people's view of both books would depend on whether they "accepted Kinsey's basic notion that man's behaviour is dictated by needs and subject to the same biological rules that govern the lower animals".
More recently, John William Money (1921-2006), a sex researcher, pediatric psycho-endocrinologist and co-founder of the Gender Identity Clinic at Johns Hopkins, defined the concepts of gender role and identity based on his work with intersex individuals. He established transsexualism as a diagnostic category and an academic discipline. Outspoken and combative, he was a significant figure in the development of the Society for the Scientific Study of Sexuality and in raising the standard of its journal, The Journal of Sex Research.