The emergence of referential shift devices in three young sign languages

Speakers use a range of devices, such as nouns and pronouns, to introduce referents and to indicate a shift between multiple referents. Sign languages also exploit different devices for signalling reference and referential shift. In established sign languages, the hands convey words and proforms, while the face, head, and body also contribute to the reference system, both mimetically and abstractly. Here we investigate how a system of referential shift emerges at different points in the development of young languages with varying socio-linguistic characteristics: Israeli Sign Language (large, heterogeneous, geographically dispersed population), Al-Sayyid Bedouin SL, and Kufr Qassem SL (smaller, homogeneous village/town settings). Early on, signers favor both lexical symbols and mimetic use of the body for shifting reference. Over time, more abstract structures with more simultaneous complexity increase. These factors interact with characteristics of the language community, suggesting a role for the amount and type of interaction in the emergence of reference in language.