Gestural development,dual-directional signaling,and the transition to words

This paper describes the emergence and development of three object-related gestures: pointing, extending objects, and open-handed reaching, in four first-born infants from 9 to 18 months during natural interactions with their mothers. It examines the changing characteristics of the gestures and the acquisition of conventional words in accompaniment. Furthermore, it investigates the role that the capacity for dual-directional signaling, sending simultaneously two coordinated but divergently directed nonverbal signals of gesture and gaze, may play in this transition. Analysis revealed that dual-directional signaling appeared concurrently across gestures. In addition, dual-directional signaling was employed in a socially adjusted manner, more with pointing, especially spontaneous pointing when the mothers' attention could not be assumed. Verbal accompaniments appeared with gestures only when the children had mastered dual-directional signaling. Then words emerged approximately simultaneously with more than one kind of gesture.