Sign language
A. The signing of deaf people is not simply a series of gestures. Sign languages are actual languages, with a grammar of their own, that must be carefully learned. There are dozens of sign languages. America’s is called American Sign Language, or ASL, but Britain has a different one, as do other countries.
B. Most of the signs do not mean what an outsider might suppose, just as the correspondence between a barking mammal and the sequence of sounds d-o-g is arbitrary. For example, to convey the sign for “home” you must hold the tips of the fingers and thumb of one hand together, place them against one side of the mouth, and move them back toward the ear. That is obviously not the sign we would spontaneously come up with for the word, nor would we spontaneously know, upon seeing the sign, what it in fact means. ASL has about 4,000 signs.
C. The world’s sign languages parallel spoken ones in their “natural history.” Many of today’s sign languages trace, at least partly, to one created in France in 1775 at a school for the deaf. This, then, was a kind of Proto-World for sign language. Sign languages have dialects, as well.
D. In being new languages, sign languages can be seen as creoles. Just as children exposed to a pidgin will expand it into a full language, in Nicaragua in the 1980s, deaf children at a school where each child was using gestures in an individual way created a systematic new sign language in one generation.
E. Like creoles, sign languages have simpler grammatical structure than most older languages. This is due not only to the youth of the languages but also to the fact that facial expression can perform some of the work that spoken languages need words for. Nevertheless, sign languages have their more complex aspects, such as having classifiers according to shape that Chinese and other languages have.
F. As creoles develop dialect continua toward a dominant language, some varieties of ASL are more affected by English than others. There are also various systems for writing ASL, although it remains primarily a spoken language.
