Gestural semantics: Replicating the typology of linguistic inferences with pro- and post-speech gestures

We argue that a large part of the typology of linguistic inferences can be replicated with gestures, including some that one might not have seen before. While gesture research often focuses on co-speech gestures, which co-occur with spoken words, our study is based on pro-speech gestures (which fully replace spoken words) and post-speech gestures (which follow expressions they modify). We argue that pro-speech gestures can trigger several types of inferences besides entailments: presuppositions and anti-presuppositions (derived from Maximize Presupposition), scalar implicatures and Blind Implicatures,' homogeneity inferences that are characteristic of definite plurals, and some expressive inferences that are characteristic of pejorative terms. We further argue that post-speech gestures trigger inferences that are very close to the supplements contributed by appositive relative clauses. We show in each case that we are not dealing with a translation into spoken language because the fine-grained meanings obtained are tied to the iconic properties of the gestures. Our results argue for a generative mechanism that assigns new meanings a specific place in a rich inferential typology, which might have consequences for the structure of semantic theory and the nature of acquisition algorithms.