SignMorph aims to explore two of the most fundamental questions in linguistics: (1) how much do the languages of world resemble and differ from each other? and (2) what factors can explain these similarities and the differences? We aim to address this question by exploring the sign languages of deaf communities which can provide unique insights into these issues. We are interested in how three specific factors have impacted how the linguistic structure of sign languages resemble or differ from each other. First, unlike spoken languages, sign languages are produced and perceived entirely in the visual-gestural modality: they are produced by movements of the hands, face, head, and body and perceived by our eyes. How does the visual-gestural, rather than auditory-oral, modality allow for links between sign language structure and meaning that may be different from spoken languages? Second, many researchers assume that many sign languages are 'younger' languages than most spoken languages, as many signing communities have only emerged in the last three centuries, and some very much more recently than that. This project gives us an opportunity to explore how their relatively short histories may have influenced language change processes that create grammatical structure. Third, signing communities are uniquely diverse in how sign languages are transmitted from one generation to the next. In many signing communities, there is a larger proportion of child-to-child transmission of sign languages, rather than parent to child transmission which is more typical of most other communities. There may also be varying ages of first language acquisition (something seen only very rarely in hearing people), and varying interaction with other deaf and hearing signers in their social networks.
We will explore these questions by comparing linguistic structures across three broad subtypes of sign languages and signing communities: (1) macro-community sign languages. such as British Sign Language, used across an entire nation state, (2) micro-community sign languages, used in specific towns and villages such as Kata Kolok in Bali, and (3) younger sign languages from recently emerged signing communities, such asGuinea Bissau Sign Language. This will allow us to compare aspects of sign language structure used in communities with different sociolinguistic profiles and with different histories. For example, the Guinea Bissau signing community began after the establishment of the first school in 2000. This contrasts with the British signing community, which began to emerge in its modern form in the 18th century or possibly earlier. Similarly, in the Kata Kolok community, many deaf children are exposed to signing from birth, compared to those in the British community, where this is only true of a minority of signers.
We have five specific overall objectives: (1) to understand the notions of linguistic 'complexity' that have been used to compare and contrast spoken and signed languages, (2) to explore what we can learn about the linguistic structure of sign languages by comparing data from different types of signing community, (3) to understand the relationship between the grammar of sign languages and the visual-gestural modality, (4) to understand more about the relationship between the grammar of sign languages and learnability, and (5) to investigate the relationship between the linguistic structure of sign languages and social structure in different types of signing communities.