Gesture size affects numerical estimates in quantifier comprehension

People think and talk about numerical magnitude in terms of space, and co-speech gestures reflect this, with English speakers using expansive gestures when talking about greater quantities. Existing gestural research on the spatial conceptualization of number has largely looked at gesture production, but we do not know whether gestures can influence the interpretation of imprecise or underspecified numerical expressions such as quantifiers. Looking at the quantifier several as a test case, this study investigates the influence of manual inwards-directed (i.e., hands move closer the torso) and outwards-directed (i.e., hands move away from the torso) co-speech gestures on comprehenders' conceptualization of quantities associated with several through three preregistered experiments. Our results suggest that gesture modulates the interpretation of several such that speakers moving their hands outwards and thereby creating space between their hands lead to higher quantity estimates, compared to speakers not gesturing, or moving their hands inwards. We discuss the implications of our findings for future work in numerical cognition, multimodal communication, and pragmatics. (PsycInfo Database Record (c) 2025 APA, all rights reserved).