In the early 1940's, Leo Kanner and Hans Asperger, pioneers in the field of autism, used the terms 'autism' and 'autistic' (independently of each other) and  thus the label was born. The labels come from the greek word autos, meaning self. Kanner used the term to describe children with classic autism, while Asperger described more able and intelligent individuals. Much later, Dr. Lorna Wing of Great Britain coined the term Asperger's Syndrome to define the more able individuals with autism.

In the late 1940's, Bruno Bettelheim, a Hungarian who emigrated to the United States and became the director of the Sonia Shankman Orthogenic School in Chicago, claimed that the source of autism was "refrigerator mothers" - cold, unfeeling parents who drove their children into mental isolation. His theories were internationally accepted for more than two decades. It was later discovered that much of Bettelheim's "expertise" was exaggerated or unfounded, and that he did not have the necessary qualifications to either run a school or posit theories about the causes of autism.

In 1964, Bernard Rimland, a psychologist and father of an autistic son, wrote Infantile Autism: The Syndrome and Its Implications for a Neural Theory of Behavior.  In his book, Rimland argued that autism was a biological disorder and not an emotional illness. This book changed the way autism was perceived and had an enormous impact on the future of treatment methods for people with autism and related disorders.