Donald Gray Triplett

Donald Gray Triplett (September 8, 1933 – June 15, 2023) was an American banker known for being the first person diagnosed with autism. He was diagnosed by Leo Kanner in 1943 and was labeled as "Case 1".

Triplett was interested in rhymes and would give one-word answers to questions—usually "yes" or "no". He developed an interest in spinning blocks, pans and other round objects, and a dislike for tricycles and swings. He was initially uninterested in slides but began to play on them when he was alone. He had many meltdowns and was afraid of being spanked. He was, however, unable to associate his meltdowns with the punishment. He displayed echolalia and reversed pronouns—often using "you" to refer to himself and "I" to refer to the person to whom he was speaking. Upon entering a room, he went to the toys right away, ignoring the other people present in the room—including other children and a Santa Claus actor his father had hired. His mother had difficulty getting him to look at her. His interactions with people included giving them nicknames and shooting rubber bands at them. He lived alone in the large house that he grew up in and later inherited. He died of cancer at home on June 15, 2023, at the age of 89.

Legacy John Donvan and Caren Zucker interviewed Triplett, chronicling his life story for an article "Autism's First Child" in The Atlantic. He was later featured in the book In a Different Key (2016), which was later adapted into a documentary for PBS. His family members say that his life "offers hope to parents".