The social hygiene movement of the late 19th and early 20th centuries was an attempt by Progressive-era reformers to control venereal disease, regulate prostitution and vice, and disseminate sexual education through the use of scientific research methods and modern media techniques. A mental hygiene movement also developed, partly separately and now generally known as mental health, although the older term is still in use, e.g. in New York state's law.
The social hygiene movement represented a rationalized, professionalized version of the earlier social purity movement. Many reformers, such as Marie Stopes, were also proponents of eugenics. Inspired by Charles Darwin's theory of natural selection, they argued for the sterilisation of certain groups, even racial groups, in society. Indeed, by the 1930s thousands of forced sterilizations of people deemed undesirable took place in America and other countries each year. This continued for several more decades in some countries, though after 1945, the movement was largely discredited.
This link between racial hygiene and social hygiene movements can be seen in Australia, where the Racial Hygiene Association of New South Wales is now named The Family Planning Association.
Social hygiene as a profession grew alongside social work and other public health movements of the era. Social hygienists emphasized sexual continence and strict self-discipline as a solution to societal ills, tracing prostitution, drug use and illegitimacy to rapid urbanization.