PhD defence
Creating a sign language out of everything and everywhere: An example from the deaf people of Bissau
- M. Sousa da Silva Martins
- Date
- Thursday 19 February 2026
- Time
- Address
-
Academy Building
Rapenburg 73
2311 GJ Leiden
Supervisor(s)
Summary
This thesis traces the formation of a deaf community in Guinea-Bissau and the emergence of its sign language, Língua Gestual Guineense (LGG), offering rare real-time documentation of how a language develops from gestural roots. The relative absence of medical approaches to deafness enabled a free-signing environment in schools and informal meeting places. Within two decades, the first generation of signers in Bissau established a proud community and shaped an autochthonous sign language.
The analysis of gestures reveals three main pathways of incorporation into LGG: direct incorporation, incorporation of variants, and incorporation of overlapping networks of polysemous and synonymous gestures. While gestures entered the lexicon with minimal change, signers have exploited gesture variation in form and meaning to drive lexical growth. Innovative methods relying on small-group elicitation and deaf participants’ metalinguistic insights shed new light on the degree of gesture conventionalisation in Bissau. Gestures serving as communicative bridges provided a linguistic starting capital, which is particularly evident in kinship terms. This research also discovered that gender-based social dynamics influenced other lexical semantic domains. For instance, male signers are likely to have created colour and country name signs motivated by football references.
Linguistically, LGG exhibits rapid expansion through compounding, derivation, and grammaticalisation. The latter process can be seen in how the gesture for ‘hit’ evolved into signed markers of comparative and emphatic structures. Altogether, LGG exemplifies both universal processes of language creation and the imprint of a local shared world, showing how new languages are created out of everything and everywhere.
PhD dissertations
Approximately one week after the defence, PhD dissertations by Leiden PhD students are available digitally through the Leiden Repository, that offers free access to these PhD dissertations. Please note that in some cases a dissertation may be under embargo temporarily and access to its full-text version will only be granted later.
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