In my dissertation, I focus on the documentation and comparison of indigenous sign languages in Yucatán, Mexico. I conducted fieldwork in four Yucatec Maya communities with a high incidence of deafness. Because deaf people born into these villages have never had access to an established sign language, they have developed their own local sign languages to communicate with each other and their hearing relatives. Yucatec Maya Sign Languages (YMSLs) are young languages that have emerged over the past decades.

The sign languages in the four communities are historically unrelated, but their shared cultural background and the influence of co-speech gestures used by hearing speakers of Yucatec Maya lead to striking similarities in their lexicon and grammar. At the same time, YMSLs display a high degree of variation related to sociolinguistic factors, such as family membership, age, education or language acquisition from deaf adults. In my dissertation, I argue that we can use the phenomenon of variation in young, micro-community sign languages as a window to find out how linguistic conventions are established and which sociolinguistic variables are relevant for shaping sign language structures.

My dissertation consists of four sub-studies. In Study I, I employ the framework of translanguaging to examine the semiotic resources used by deaf and hearing Yucatec Maya to interact with each other and with people from other communities. I demonstrate that the repertoire of Yucatec Maya conventional gestures, positive attitudes towards deafness and sign language, as well as shared cultural knowledge, facilitate communication between deaf and hearing people and lead to overlap between sign languages without any historical affiliation. This study constitutes the first application of the translanguaging theory to studies of sign language emergence. Study II investigates cardinal numbers in YMSLs from three villages. I found that some features of Yucatec Maya counting gestures are preserved but that distinct number paradigms evolved in the three YMSL communities. YMSL numerals exhibit variation as a result of linguistic and sociolinguistic factors. Study III explores how YMSL signers convey a linguistic distinction between objects and actions and discusses if these strategies more generally distinguish nouns from verbs. Two possible strategies of the noun-verb distinction were examined; both have an equivalent in hearing people’s gestures but have been integrated into YMSLs in different ways. In Study IV, I focus on a conventional gesture used by hearing Yucatec Maya to specify the height of upright – usually human – referents and analyse how it has been incorporated into YMSLs from four villages. Comparing the form, meaning and distribution of height-specifiers in Yucatec Maya gestures and YMSLs, I demonstrate paths of lexicalisation and grammaticalisation from gesture to sign.

Apart from providing documentation of underdescribed, endangered languages, my dissertation makes several theoretical contributions. I demonstrate that language age is not the only variable relevant to the emergence of complex linguistic structures, but that other sociolinguistic factors, such as the distribution of deafness across families, networks of interaction and attitudes toward deafness play a role. Moreover, I present evidence that gestures can enter lexicon and grammar of a sign language simultaneously, challenging previous accounts of lexicalisation and grammaticalisation.

This article examines ideologies underlying the rating of sign language vitality. The discussion is based on a 2011 survey by UNESCO and the International Institute for Sign Languages and Deaf Studies, and a newer survey by UNESCO, released in 2018. Ideologies of biodiversity and culture that appear in discourse about language vitality generally are examined. Three of the factors used to determine the vitality scores of 15 sign languages during the first survey (Safar and Webster, 2014; Webster and Safar, 2019) are considered from an ideological perspective. Further ideological issues that surfaced during this survey are then explored through a case study on endangered village sign languages in Mexico. Lastly, some ideological aspects of UNESCO's 2018 survey are scrutinised, including its accessibility to deaf signers, emphasis on hierarchical globalist structures, and presentation of sign languages as bounded entities that fit into binary categories. We find problems with framing sign languages within endangerment ideologies and relying on academic perceptions of 'language' that differ from the beliefs of language communities themselves. These vitality surveys provide a starting point for more robust mixed-methods assessments, which should take more account of sign language communities' own perspectives.

In this article, I analyse how conventional height-specifier gestures used by speakers of Yucatec Maya become incorporated into Yucatec Maya Sign Languages (YMSLs). Combining video-data from elicitation, narratives, conversations and interviews collected from YMSL signers from four communities as well as from hearing nonsigners from another Yucatec Maya village, I compare form, meaning and distribution of height-specifiers in gesture and sign. Co-speech gestures that depict the height of upright entities - performed with a flat hand, palm facing downwards - come to serve various linguistic functions in YMSLs: a noun for human referents, a verb GROW, a spatial referential device, and an element of name signs. Special attention is paid to how height-specifier gestures fulfil a grammatical purpose as noun-classifiers for human referents in YMSLs. My study demonstrates processes of lexicalisation and grammaticalisation from gesture to sign and discusses the impact of gesture on the emergence of shared sign languages.

This article explores factors affecting the vitality/endangerment levels of sign languages, and how these levels were assessed through an international collaboration using a systematic scoring scheme. This included adapting UNESCO's Linguistic Vitality and Diversity survey and developing a system for determining endangerment levels based on the responses. Other endangerment scales are briefly explored along with UNESCO's, and the survey adaptation and systematic scoring processes are explained. The survey needed to be carefully adapted because even though many spoken language procedures can be also used for sign languages, there are additional challenges and characteristics that uniquely affect sign language communities. The article then presents the vitality scores for 15 languages, including both national and village sign languages, and the major factors threatening their vitality. The methodology of scoring based on averages is innovative, as is the workflow between the questionnaire respondents and scoring committee. Such innovations may also be useful for spoken languages. Future efforts might develop best practice models for promoting sign language vitality and compile diachronic data to monitor changes in endangerment status. The findings can also inform policy work to bring about legal recognition, greater communication access, and the protection of deaf signers' linguistic and cultural identity.

This article looks at translanguaging practices in four Yucatec Maya communities with a high incidence of deafness in the peninsula of Yucatán, Mexico. Deaf and hearing community members draw from a broad spectrum of semiotic resources to interact with each other and with people from other villages in the region: they sign with different degrees of fluency, speak Yucatec Maya and/or Spanish, gesture, draw, point and incorporate objects in their physical surroundings. Human beings have a general tendency to communicate between and beyond different languages and modalities and to creatively adapt their semiotic repertoires to each other to negotiate meaning. On top of that, I show that sociolinguistic and cultural features of Yucatec Maya communities scaffold translanguaging practices. The rich inventory of conventional co-speech gestures of Yucatec Maya speakers, positive attitudes towards deafness and signed language and a critical amount of shared cultural knowledge facilitate communication between deaf and hearing and contribute to the emergence of similar sign languages in historically unrelated communities. The investigation of Yucatec Maya signing communities through a translanguaging lens allows us to critically deconstruct existing classifications of sign languages and varieties. Yucatec Maya Sign Languages are portrayed as a multi-layered network of different villages, families, generations and overlapping deaf and hearing spaces, where translanguaging takes place.

In this article, we examine various strategies used to express cardinal numbers in Yucatec Maya Sign Languages (YMSLs) from three historically unrelated communities in Yucatan, Mexico: Chican, Nohkop, and Cepeda Peraza. Our findings describe some numeral strategies, which remained unattested in previous accounts, and demonstrate that YMSL numerals exhibit patterns of systematic inter- and intracommunity variation as a result of linguistic and sociolinguistic factors. These patterns are still in process of becoming solidified and a high level of individual variation persists. The analysis of numerals in YMSLs provides us with an excellent opportunity to observe the emergence of sociolinguistic variation in young village sign languages. Our study is based on data from elicitation, natural conversations, and interviews, and takes into account several aspects: the influence of Yucatec Maya gestures on the formation of YMSL numeral signs, the regional and intracommunity distribution of numeral signs and numeral strategies, the impact of literacy on YMSL number - expression, the existence of familylects and community members' language attitudes. Finally, we discuss some methodological challenges to studying variation in rural sign languages.

Yucatec Maya Sign Languages (YMSLs) areindigenous sign languages that emerged in Yucatec Maya (YM) villages with a high incidence of deafness.YMSLs are used by deaf and hearing community members, resulting in closelanguage contact between YMSLs and spoken YM. This study investigates howconventional gestures of hearing YM become incorporated into YMSLs andundergo processes of grammaticalisation.Speakers of Mesoamerican languages use a range of “manualclassifiers” (Le Guen, in prep; Zavala, 2000) with specific hand configurationsassigned to specific classes of referents, e.g. animals or plants (Meo-Zilio &Mejía, 1980). These gestures are highly conventionalised across speakers andform important raw material for sign languages emerging in these communities.