The principle of normalization had a major impact on our ability to see the tremendous impact attitudes, values and environment have on people with disabilities, and the ways that other citizens understand their roles in the lives of people with disabilities.
The idea that we see people with disabilities having the same needs as all people (that they are "people first") and that the environment can hold people back as much as any condition they might have grew out of the principle of normalization.
In 1969, the International League of Societies for the Mentally Handicapped recognized that "the Principle of Normalization is a sound basis for programming". The ILSMH also stated that "the great majority of the retarded are ordinary people with an ordinary person's needs."
One of the key concepts that emerged with the principle of normalization was the developmental model all people have the capacity to grow and learn regardless of the degree of their disability.
The model shifted the focus from medical approaches to teaching approaches. For some, "mental retardation" stopped being an "affliction to be cured". Earlier models emphasized the static nature of the condition and diagnosis. The developmental model stressed supporting people to learn skills that would assist them in their everyday lives.
From "The Six Hour Retarded Child"