Show your hands — Are you really clever? Reasoning, gesture production, and intelligence

This study investigates the relationship of reasoning and gesture production in individuals differing in fluid and crystallized intelligence. It combines measures of speed and accuracy of processing geometric analogies with analyses of spontaneous hand gestures that accompanied young adults' subsequent explanations of how they solved the geometric analogy task. Individuals with superior fluid intelligence processed the analogies more efficiently than participants with average fluid intelligence. Additionally, they accompanied their subsequent explanations with more gestures expressing movement in non-egocentric perspective. Furthermore, gesturing (but not speaking) about the most relevant aspect of the task was related to higher fluid intelligence. Within the gestures-as-simulated action framework, the results suggest that individuals with superior fluid intelligence engage more in mental simulation during visual imagery than those with average fluid intelligence. The findings stress the relationship between gesture production and general cognition, such as fluid intelligence, rather than its relationship to language. The role of gesture production in thinking and learning processes is discussed.