During this period, a popular belief was that mental retardation and mental illness were completely genetic, and caused most, if not all, social ills such as poverty, drunkenness, prostitution, crime, and violence. The response to this belief was to segregate or sterilize people who were labeled mentally retarded or mentally ill so that they could not reproduce and destroy the gene pool.
Pictures of people who committed arson, murder, or other acts of violence were often drawn in newspapers to suggest the presence of mental retardation. As late as 1920, the Public Health Service combined "criminals, defectives, and delinquents" into a single category.
By the 1920s, the "menace" theme peaked in our country as Dr. Henry Goddard, a psychologist at the Vineland Training School, explored the role of the environment versus the role of heredity on the lives of persons with disabilities. Dr. Goddard and his research assistants decided to explore the family history of a woman they named Deborah Kallikak ("Kallikak" being a fictitious name taken from the Greek words for "good" and "bad"), who lived in their institution. They claimed they discovered that Deborah's great-great-great-grandfather was a revolutionary war soldier named Martin Kallikak. Apparently, Martin had relations with a "feeble-minded" bar maid.