The impact of interaction on variation in Zinacantec Family Homesign

Emerging sign languages provide the opportunity to observe the process by which signers create and converge on a lexicon. Some studies report that emerging sign languages exhibit more lexical and sub-lexical variation than their longer-established counterparts, which has been interpreted as evidence for a lack of conventionalization. However, a growing body of recent literature takes the view that this variation is not random but rather shaped by the social organization of the signing community. The present study aims to test the hypothesis that variation is conditioned by frequency of interaction, focusing on Zinacantec Family Homesign (‘Z sign’), a sign language developed over the past four decades by members of an extended family in an indigenous community of southern Mexico. The investigation takes into account both lexical variation and sub-lexical variation, across signers as well as within individual signers over time. These quantitative data are interpreted in terms of a model of the family as a sociolinguistic community that can be sub-divided according to patterns of interaction among different members of the family. This study contributes to the literature on variation in micro-community sign languages by examining the impact of interaction on the distribution variation at two levels of linguistic organization in an almost maximally small linguistic community.