Iconicity as a communicative strategy: recipient design in multimodal communication for adults and children

Humans are the only species that uses communication to teach new knowledge to novices, usually to children (Tomasello, 1999, Csibra and Gergely, 2006). This context of communication can employ “demonstrations” and it takes place with or without the help of objects (Clark, 1996). Previous research has focused on understanding the nature of demonstrations for very young children and with objects involved. However, little is known about the strategies used in demonstrating an action to an older child in comparison to another adult and without the use of objects, i.e., with gestures only. We tested if during demonstration of an action speakers use different degrees of iconicity in gestures for a child compared to an adult. 18 Italian subjects described to a camera how to make coffee imagining the listener as a 12-year-old child, a novice or an expert adult. While speech was found more informative both for the novice adult and for the child compared to the expert adult, the rate of iconic gestures increased and they were more informative and bigger only for the child compared to both of the adult conditions. Iconicity in gestures can be a powerful communicative strategy in teaching new knowledge to children in demonstrations and this is in line with claims that it can be used as a scaffolding device in grounding knowledge in experience (Perniss et al., 2010).