What is gestural theory?

The gestural theory suggests that human language originated from gestures used for basic communication. According to this theory, early humans communicated through gestures before developing vocal language. Evidence supporting this idea includes similarities in neural systems for gestural and vocal language, as well as the proximity of brain regions responsible for mouth and hand movements in the cortex. From infancy, gestures both supplement and predict speech. This transition from using gestures as a primary means of communication to a supplemental role parallels the idea that gestures preceded vocal language in human evolution.