Gesturing with the hands while talking is an example of Embodied Cognition.
Embodied Cognition refers to social interaction and decision making in social and cognitive psychology. Embodied Cognition argues that the motor system affects cognition just as the mind impacts bodily actions. The gestures while talking suggests that actions serve as visual clues to thoughts. Cognitive science explains that these clues grounded in action have even the capability to change thoughts. It is proposed that involving the motor system enhances barin responses to concepts.