Children Use Non-referential Gestures in Narrative Speech to Mark Discourse Elements Which Update Common Ground.

While recent studies have claimed that non-referential gestures (i.e., gestures that do not visually represent any semantic content in speech) are used to mark discourse-new and/or -accessible referents and focused information in adult speech, to our knowledge, no prior investigation has studied the relationship between information structure (IS) and gesture referentiality in children's narrative speech from a developmental perspective. A longitudinal database consisting of 332 narratives performed by 83 children at two different time points in development was coded for IS and gesture referentiality (i.e., referential and non-referential gestures). Results revealed that at both time points, both referential and non-referential gestures were produced more with information that moves discourse forward (i.e., focus) and predication (i.e., comment) rather than topical or background information. Further, at 7-9 years of age, children tended to use more non-referential gestures to mark focus and comment constituents than referential gestures. In terms of the marking of the newness of discourse referents, non-referential gestures already seem to play a key role at 5-6 years old, whereas referential gestures did not show any patterns. This relationship was even stronger at 7-9 years old. All in all, our findings offer supporting evidence that in contrast with referential gestures, non-referential gestures have been found to play a key role in marking IS, and that the development of this relationship solidifies at a period in development that coincides with a spurt in non-referential gesture production.