When our hands help us understand: A meta-analysis into the effects of gesture on comprehension.

Speech and gesture are two vital components of communication. Gesture itself provides an external support to speech, potentially promoting comprehension of a spoken message. The question of whether gesture promotes comprehension is not new, with research dating back to the 1970s. However, when gestures are most beneficial to comprehension is poorly understood. This meta-analysis explored 2 questions: whether and when gestures benefit...