With the exception of Plains Indian Sign Language and Pacific Northwest sawmill sign languages, highly developed alternate sign languages (sign languages typically employed by and for the hearing) share not only common structural linguistic features, but their use is also characterized by convergent ideological commitments concerning communicative medium and linguistic modality. Though both modalities encode comparable denotational content, speaker-signers tend to understand manual-visual sign as a pragmatically appropriate substitute for oral-aural speech. This paper suggests that two understudied clusters of alternate sign languages, Armenian and Cape York Peninsula sign languages, offer a general model for the development of alternate sign languages, one in which the gesture-to-sign continuum is dialectically linked to hypertrophied forms of interactional avoidance up-to-and-including complete silence in the co-presence of affinal relations. These cases illustrate that the pragmatic appropriateness of sign over speech relies upon local semiotic ideologies which tend to conceptualize the manual-visual linguistic modality on analogy to the gestural communication employed in interactional avoidance, and thus as not counting as true language.
Demythologizing Plains Indian Sign Language History