Beside the point: Mothers' head nodding and shaking gestures during parent-child play.

Understanding the context for children's social learning and language acquisition requires consideration of caregivers' multi-modal (speech, gesture) messages. Though young children can interpret both manual and head gestures, little research has examined the communicative input that children receive via parents' head gestures. We longitudinally examined the frequency and communicative functions of mothers' head nodding and head shaking gestures during laboratory play sessions for 32 mother-child dyads, when the children were 14, 20, and 30 months of age. The majority of mothers produced head nods more frequently than head shakes. Both gestures contributed to mothers' verbal attempts at behavior regulation and dialog. Mothers' head nods primarily conveyed agreement with, and attentiveness to, children's utterances, and accompanied affirmative statements and yes/no questions. Mothers' head shakes primarily conveyed prohibitions and statements with negations. Changes over time appeared to reflect corresponding developmental changes in social and communicative dimensions of caregiver-child interaction. Directions for future research are discussed regarding the role of head gesture input in socialization and in supporting language development.