Institutions for Defective Delinquents (IDDs) were created in the United States as a result of the eugenic criminology movement. The practices in these IDDs contain many traces of the eugenics that were first proposed by Sir Francis Galton in the late 1800s. Galton believed that "our understanding of the laws of heredity [could be used] to improve the stock of humankind." Galton eventually expanded on these ideas to suggest that individuals deemed inferior, those in prisons or asylums and those with hereditary diseases, would be discouraged from having children.
The term "defective delinquents" was first used in 1910 by the eugenicist Orlando F. Lewis of New York, or Walter Fernand of Massachusetts. In any case it was in wide distribution by the end of 1912. This new identification of a class of (broadly described) mentally deficient criminals, already imprisoned by state and local governments, caused a conversation about what sort of institution they could best belong in:
Superintendents of the feebleminded now argued that delinquent and disruptive defectives should be removed to more secure, prisonlike quarters. Following suit, prison officials used "defective delinquent" to designate their institutional problems, arguing that intractable prisoners should be segrated in specialized, hospital-like institutions. Nonetheless, a spokesperson for the Massachusetts Board of Insanity pointed out, defective delinquents should definitely not be sent to hospitals for the mentally ill, for they tend to escape and commit sex offenses and arson.
As of 1912, the following institutions reported that defective delinquents constituted at least 20% of their populations:
The first dedicated IDD opened on June 1, 1921 at the New York Eastern Reformatory at Napanoch and was opened to prisoners “whose intelligence quotient lies between 35 and 75, and whose chronological age is 16 years or older.” Patient-convicts in IDDs each had an extensive profile consisting of genealogy, various results from tests measuring levels of cognition, and descriptions of mental illnesses like alcoholism or schizophrenia that eugenicists associated with an inferior gene pool. Various other tests, such as a modified version of the Binet-Simon Weighted Cube Test, which quantified ethical decision-making, were run to further the understanding of “feeble-mindedness.”