Lexical overlap in young sign languages from Guatemala

In communities without older standardized sign languages, deaf people develop their own sign languages and strategies for communicating. This analysis draws on data from a lexical elicitation task completed by deaf people living in Nebaj, a town in Guatemala. Some deaf signers in Nebaj have deaf relatives or deaf peers they interact with daily, while others are the only deaf signer in their immediate communicative ecology. This analysis uses the Jaccard similarity index to quantify lexical overlap at two scales: the wider linguistic community and local sign ecologies. Signers who interact with other deaf signers have higher rates of lexical overlap with signers from the surrounding community than signers who do not know other deaf signers. When signers have frequent sustained interactions with the other signers in their immediate communicative ecology, they have higher rates of overlap within their local ecology than the wider community. This adds to a growing literature that suggests that interaction is a primary driver of convergence on shared lexical forms within communities of language users. Unique features of the communicative histories of signers of young sign languages are also discussed as factors that contribute to variable rates of lexical overlap in this community.