Sign Languages of Western Highlands, Papua New Guinea, and their Challenges for Sign Language Typology

Abstract

The diverse sign languages (SLs) between established deaf community SLs and homesign have been called the “grey area” of SL linguistics, by virtue of their resistance to classification and the fact that they are understudied (Nyst, 2010, p. 416). This thesis investigates the languages of 12 deaf people living in the Nebilyer/Kaugel region of the rural Papua New Guinea highlands, with the view to situating them within the extant sociodemographic typology of SLs. I do this by considering sociodemographic data of deaf individuals, comparison of sign bases to determine lexical consistency, and emic perspectives of users. As a result of these analyses, I find that the diverse but interrelated languages of these 12 deaf people are not well classified within the existing sociodemographic taxonomy of SLs. In order to expand that taxonomy, I first present the concept of a sign network, which is a network of strong and weak sign ties, with strength defined as the presence of fluent, regular signed communication between individuals, irrespective of deaf/hearing status. I offer the new category of a nucleated network SL, the sign network of which is characterised by a central deaf individual with multiple strong sign ties to other individuals, who prototypically are all hearing. This is differentiated, I argue, from a canonical homesign language such as David’s (Goldin-Meadow, 2003), which is characterised by only weak sign ties to other individuals, either deaf or hearing. As such, I advocate for the extension of Horton’s (in press) typological category of “individual homesign” to account for regular contact not only with deaf signers, but hearing ones as well. In determining the degree of lexical consistency between SLs, I present the metric of sign base comparison, predicated on the idea that even in iconic signs, there is a measure of arbitrariness underlying which aspect of a referent is selected (cf. Planer & Kalkman, 2019). This is a useful tool for work with SLs whose users exhibit a high degree of intra-signer variation in form, and thus cannot be well compared using the standard model of sublexical parameter comparison (cf. McKee & Kennedy, 2000; Guerra Currie, Meier, & Walters, 2002). I account for the high level of lexical consistency between Nebilyer/Kaugel SLs with the notion of a regional sign network, which is a sign network characterised by an abundance of weak sign ties between individuals in a larger region. I propose that signs diffuse along these weak sign ties, which accounts for lexical consistency between the languages of largely unconnected deaf people and their networks. The regional sign network model provides an explanation for similarly reported degrees of lexical consistency in other rural SL situations, where this cannot be explained wholly in terms of independent invention or recruitment of majority community gesture (e.g. Osugi, Supalla, & Webb, 1999). This research enriches the sociodemographic typology of SLs, filling in missing links in the “grey area”, and offering tools to continue to do so (Nyst, 2010, p. 416). More broadly, it also contributes to our understanding of how patterns of human sociality condition language shape.