A linguist at the University of California, San Diego, Klima got interested in languages that other linguists had dismissed because they were not spoken: sign languages used by the deaf.
Signing was thought to be simple gesturing of spoken language concepts, but when Klima followed up on the work of Gallaudet University professor William Stokoe, who first proposed that American Sign Language was an actual language (and was roundly derided for the notion), Klima looked at such languages carefully starting in 1970, and realized Stokoe was right: sign languages indeed had their own grammar, syntax, dialects, and even poetry, and sign was in fact a distinct language class.
In collaboration with his wife, Ursula Bellugi, Klima then turned his work on its head: showing how language worked in the brain. Klima and Bellugi’s breakthrough work earned them the 1992 Award for Distinguished Contributions from the American Psychological Association. Dr. Klima died September 25 from complications from brain surgery. He was 77.