UC San Diego

This dissertation tests the proposal that mother-infant physical contact facilitates increased maternal responsiveness to infants' cues during both breastfeeding and non-feeding interaction, taking into account the potential contribution of underlying beliefs about responsiveness. These studies demonstrate for the first time that immediate mother-infant physical contact predicts breastfeeding in response to early hunger cues and causes mothers to respond more contingently to infants' vocalizations.

In Chapter 1, responses to an at-home feeding log demonstrate that mother-infant physical contact predicts increased responsiveness to infant hunger cues when initiating feeding and that maternal beliefs predict ending feeding in response to infants' satiation cues. Measures of maternal behavior during an in-lab breastfeeding session show that maternal beliefs about responsiveness predict individual variation in responsiveness to infants' cues during feeding.

In Chapter 2, in-lab measures of maternal responsiveness during a non-feeding dyadic play interaction show that experience with physical contact predicts increased responsiveness to infants' facial cues and questionnaire data shows that experience with physical contact is associated with a particular set of beliefs about responsiveness. Comparisons of maternal behavior during a within-subject manipulation of physical contact show that responsiveness to infant vocalizations increases during mother-infant physical contact, demonstrating experimentally that physical contact has an immediate effect on maternal responsiveness.

These data make a novel contribution to our understanding of maternal responsiveness and challenge the current models of how responsiveness is tested, as responsiveness during feeding has been neglected as a central component of the infant's early learning environment. Given the established importance of maternal responsiveness for social learning, understanding what drives maternal responsiveness is vital to the broader goal of understanding how infant outcomes are shaped by the early social environment.