Proceedings of the Annual Meeting of the Cognitive Science Society

Understanding the relationships between gesture, speech, and thought bears on how we conceptualize language and embodied cognition. We asked whether the gestures U.S. politicians produced when presenting ideas as similar (listing) or different (contrasting) varied in handshape, form, or movement. We found that location was more likely to change during contrasting, while movement pattern was more likely to change during listing. In a follow-up experiment, we showed that these gestures impacted participants’ perceptions of how similar the items discussed by the politician were, even when the auditory information was unavailable. When participants could see politicians’ gestures, they rated listed topics as more similar and contrasted items as more different, even when the videos were muted. We conclude that gesture during political speech can both reflect and affect judgements of similarity and difference.