Effects of linguistic context on the acceptability of co-speech gestures

Abstract

We ask whether iconic co-speech gestures are judged as more natural by naive participants when their content is entailed by a preceding context, or repeated in the same utterance, or when they contribute new information (i.e., are nontrivial). Our results show, first, that the acceptability of co-speech gestures is not affected by whether they are entailed by a preceding context (they are not "hard presupposition triggers"). In contrast, our second finding is that gestures are affected by content in the same utterance, such that they are judged more acceptable when they reinforce information already present in the proposition. In addition, gestures varied widely in how acceptable they were judged even in the same information contexts, which we take to be an indication that we are just scratching the surface of a more general question about the felicity of co-speech gestures, of which the current study provides a first experimental foundation.