Communicative Gestures Benefit Communicators

Gestures are an integral part of speaking. They allow expression of thoughts that are difficult to articulate. They promote fluency of speech. Can gestures also facilitate reasoning, problem solving, and other cognitive processes? In the present task, people assembled an object and then made a video explaining how to assemble, using speech and gesture or gesture alone. A control group merely reassembled. Explainers reassembled the object more accurately than controls, and gesturers more accurately than those who both spoke and gestured. This suggests that teaching is an effective way to learn and that gestures facilitate assembly performance, a finding attributable to the compatibility of gestures and assembly actions. Explainers decomposed the object into parts and exhibited or pointed to them. They broke the action into steps. The critical difference was that gesturers modeled action but speakers modeled structure. Action information is essential for assembly performance.