Spontaneously created sign languages provide a natural laboratory for exploring the human language capacity, allowing a glimpse into how language is created without direct "linguistic input". Such a miniature "speech community" exists in Chiapas, Mexico, where Zinacantec Family Homesign (hereafter ZFHS), a manual communication system used by three deaf siblings and two hearing age-mates, is being created. There is also a hearing infant, now nearing two years of age, who is simultaneously learning ZFHS and the local indigenous language, Tzotzil (Mayan). This research documents this child's bilingual acquisition of Tzotzil and ZFHS and will involve weekly video recordings of the child over the next twelve months. It will also use spontaneous interaction and semi-structured experimental techniques to document the linguistic abilities of the caregiver, in both ZFHS and spoken Tzotzil. Such situations provide an opportunity to explore questions about the nature, origins, and evolution of language. They give insight into how and why particular words come into existence, what sorts of paradigmatic semantic and pragmatic categories accrue to systems of linguistic communication, and how syntax, morphology, and phonology emerge.
Opportunities for research on the languages of the deaf as they evolve in "natural" conditions are rare. Most sign language research works with languages which are either well-established or which have come to the attention of researchers only after the first generation of speakers has disappeared. This research will probe the processes of creation, innovation, and change at the beginning of a language's evolution, working together with the full universe of its speakers. Understanding the potential and expressive capacity of a spontaneously created language like ZFHS, especially in the context of an underrepresented minority populations like Mayan Indians, will impact not only people with communicational disadvantages but, indeed, speakers of minority languages in general, whose communicative abilities are often under-appreciated or recast as direct liabilities to their social and economic lives. Most broadly of all, this research will make a direct contribution to a perennial question: how is human language created, and how does it evolve and structure itself over the time course of successive human generations.
