We compared maternal speech in interactions of mothers with their firstborn dizygotic twin and singleton infants. Nine twins and nine singletons were video-recorded at home in spontaneous face-to-face interactions with their mothers, from the 2nd to the 6th month. Continuous micro-analysis revealed that there are more quantitative and qualitative…

Learning to walk allows infants to travel faster and farther and explore more of their environments. In turn, walking may have a cascading effect on infants' communication and subsequent responses from caregivers. We tested for an "inflection point"--a dramatic shift in the developmental progression--in infant communication and caregiver…

Previous research assessing consequences of interpregnancy intervals (IPIs) on child development is mixed. Utilizing a population-based US sample (n = 5339), we first estimate the associations between background characteristics (e.g. sociodemographic and maternal characteristics) and short ([less than or equal to]1 year) and long (>3 years)…

The present study examined teacher sensitivity as a potential moderator of the relationship between children's temperament in infancy and their social development in first grade. Using data from the Study of Early Child Care and Youth Development (NICHD SECCYD), we found that first grade teachers who were sensitive and responsive to students'…