An Experimental Pragmatic Investigation of Depictive Co-Speech Gestures

Abstract

This dissertation examines the pragmatics and semantics of co-speech gesture, gesture produced simultaneously with speech. Using experimental techniques, several patterns are found. First, interlocutors would prefer gestures to not convey communicative content. They instead prefer gestures to be trivial, i.e. truth-conditionally vacuous. Second, linguistic modifiers are preferred over gestural modifiers. This is true even when important information is hypothetically more suited to communication via gesture than via speech. Third, co-speech gesture is not dispreferred as a communication channel simply because it is depictive; at-issue information can be conveyed depictively in a sign language like American Sign Language (ASL). Instead, there seems to be a preference for a single mode of communication. Overall, all studies found pragmatic and semantic asymmetry between gesture and language (spoken or signed).