The profoundly, prelingually deaf can and do acquire language; it's just gestural rather than verbal. The sign language most commonly used in the U.S. is American Sign Language, sometimes called Ameslan or just Sign. Those not conversant in Sign may suppose that it's an invented form of communication like Esperanto or Morse code. It's not. It's an independent natural language, evolved by ordinary people and transmitted culturally from one generation to the next. It bears no relationship to English and in some ways is more similar to Chinese--a single highly inflected gesture can convey an entire word or phrase. (Signed English, in which you'll sometimes see words spelled out one letter at a time, is a completely different animal.) Sign can be acquired effortlessly in early childhood--and by anyone, not just the deaf (e.g., hearing children of deaf parents). Those who do so use it as fluently as most Americans speak English. Sign equips native users with the ability to manipulate symbols, grasp abstractions, and actively acquire and process knowledge--in short, to think, in the full human sense of the term. Nonetheless, "oralists" have long insisted that the best way to educate the deaf is to teach them spoken language, sometimes going so far as to suppress signing. Sacks and many deaf folk think this has been a disaster for deaf people.

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