The interactive development of social smiling.

Infant smiles emerge even in the absence of visual feedback, but their interactive development and intensification appear to be dependent on experiences of visually mediated interaction. Although neonatal smiling has no clear emotional content, social smiling emerges out of attentive engagement with an interactive caregiver. This process illustrates the dynamic systems postulate that real-time interaction is a window on developmental process. On the one hand, specific dimensions of smiling may have qualitatively different psychologically meanings. On the other hand, different features of infant smiling may reflect linked indices of a single dimension of positive emotion that ebbs and flows in time. The resolution of this paradox will likely involve continued attention to the interactive flow of positive emotion communication. This will be facilitated by new methods for measuring smiling and positive emotion in time. Smiling may simultaneously index a desire to interact and the dissipation of arousal associated with that interaction. Infants' capacity to become actively and vigorously caught up in emotionally positive smile-mediated interaction is linked to their ability to regulate that emotion by gazing away from their interactive partners. Ultimately, this attentional control paves the way for infant's tendency to use smiles to initiate early referential communication with a partner. These anticipatory smiles may provide a developmental bridge between early emotionally positive dyadic responsivity and later patterns of social competence.