The observation that children's activity level (AL) differs between novel and familiar situations is well established. What influences individual differences in how AL is different across these situations is less well understood. Drawing on animal literature, which links rats' AL when 1st placed in a novel setting with novelty seeking phenotypes,…

Parent- and lab-based observer ratings were employed to examine genetic and environmental influences on continuity and change in inhibitory control (IC) in over 300 twin-pairs assessed longitudinally at 2 and 3 years of age. Genetic influences accounted for approximately 60% of the variance in parent-rated IC at both ages. Although many of the…

Children ages 18 and 24 months were assessed for the ability to understand and learn from an adult's nonverbal expression of agreement and disagreement with a speaker's claims. In one type of communicative exchange, a speaker made 2 different claims about the identity or location of an object. The hearer nodded her head in agreement with one claim…

The effects of high- versus low-quality child care during 2 developmental periods (infant-toddlerhood and preschool) were examined using data from the National Institute of Child Health and Human Development Study of Early Child Care. Propensity score matching was used to account for differences in families who used different combinations of child…