Spoken language and sign language

Margaret Deuchar

In terms of design features, spoken and signed languages differ trivially in terms of the latter's not using the vocal-auditory channel; but have been claimed to differ more significantly in the extent to which spoken language is composed of arbitrary signs, while sign languages are based on more iconic signs. This has led to an erroneous demotion of the status of sign languages. A more careful analysis shows that both types of language are comparable on this dimension in their contemporary forms, although there is some evidence that languages of both media have become more arbitrary over time. Similarly, structural analyses of both systems reveal they show a similar degree of 'duality of patterning', both below the structure of the word or sign, and above it at the level of grammar.

Children go through very similar stages in acquiring either system when it is the 'natural' language of their early environment, although at different rates. Initially sign language is learned earlier; but later this advantage diminishes. However, most deaf children learn sign language under unusual conditions, since most (c.90 per cent) do not have native signing parents. Such children are comparable to those 'learning' spoken creoles on the basis of pidgin inputs: features of their signing system are creations of the 'learners' themselves. This provides some support for Chomsky's contention that language acquisition is not heavily dependent on the nature of the linguistic input.