Proceedings of the Annual Meeting of the Cognitive Science Society

In both gesture and sign, objects and events can be represented by reproducing some of their features iconically.Iconic gestures do not typically appear until well into children’s second year of life, suggesting that the cognitive and/or com-municative resources required are not trivial. Here we investigate how manual iconicity develops in two different communica-tive systems. Using longitudinal video corpora, we compare the emergence of manual iconicity in 52 hearing children learninga spoken language (co-speech gesture) to a deaf child creating a manual communication system (homesign). We focus on theshape of the hand, asking how handshape use changes between age 1 and 5, and how handshape choice relates to semanticcontent. We find broadly similar patterns of handshape development in co-speech gesture and homesign. This suggests that thecognitive building blocks underlying children’s ability to iconically map forms to meanings are shared across vastly differentcommunicative systems.