The impact of cross-linguistic variation in gesture on sign language phonology and morphology

A considerable body of literature points at parallels between gestural elements and sign language structures. This raises the question to what extent variation in gesture environment may lead to related variation across sign languages, or,mutatis mutandis, to what extent similarities in gesture environment may lead to similarities across (otherwise unrelated) sign languages.This article will address that question by reviewing a series of studies relating to size and shape specifying (SASS) signs and gestures in signed and spoken languages in West Africa. The review finds that the use of body-based SASS gestures coincides with the use of body-based SASS signs in the sign languages studied, which in turn aligns with (a) restrictions on the number and types of handshapes used in space-based SASS signs, (b) limited use ofspace-based size depictionin lexical items (Nyst, 2018), and (c) a gap in the repertoire of phonemic handshapes.I conclude that culture-specific patterning in gesture environment may impact on cross-linguistic variation in SASS morphology and handshape phonology. As such, the gestural environment presents an explanation why SLs may be alike or different, in addition to shared ancestry, language contact, and iconicity.