Do mouths sign? Do hands speak?: Echo phonology as a window on language genesis

Abstract

Although the sign languages in use today are full human languages, certain of the features they share with gestures have been suggested to provide information about possible origins of human language. These features include sharing common articulators with gestures, and exhibiting substantial iconicity in comparison to spoken languages. If human protolanguage was gestural, the question remains of how a highly iconic manual communication system might have led to the creation of a vocal communication system in which the links between symbol and referent are for the most part arbitrary. Posing the question in this way, and regarding sign languages as 'manual' ignores the rich and complex role played by other articulators: body, face, and, in particular, the mouth. As well as manual actions, sign languages include several types of mouth actions. The research reported here focuses on one subgroup: 'echo phonology', a repertoire of mouth actions which are characterised by 'echoing' on the mouth certain of the articulatory actions of the hands. Three different types of data (narratives in 3 European sign languages, code mixing in hearing British Sign Language/English bilinguals, and functional imaging studies) provide examples of a possible mechanism in the evolution of language by which the units of an iconic manual communication system could convert into a largely arbitrary vocal communication system.