Individuals track probabilities, such as associations between events in their environments, but less is known about the degree to which experience--within a learning session and over development--influences people's use of incoming probabilistic information to guide behavior in real time. In two experiments, children (4-11 years) and adults…

Epigenetics provides the opportunity to revolutionize our understanding of the role of genetics and the environment in explaining human behavior, although the use of epigenetics to study human behavior is just beginning. In this introduction, the authors present the basics of epigenetics in a way that is designed to make this exciting field…

Bronfenbrenner's (1979) ecological model proposes that events in higher order social ecosystems should influence human development through their impact on events in lower order social ecosystems. This proposition was tested with respect to ecological violence and the development of children's aggression via analyses of 3 waves of data (1 wave…

Mechanisms accounting for the effects of mutually responsive orientation (MRO) at 7, 15, and 25 months in 102 mother-child and father-child dyads on child internalization and self-regulation at 52 months were examined. Two mediators at 38 months were tested: parental power assertion and child self-representation. For mother-child relationships,…

Imitation, vocabulary, pretend play, and socially insightful behavior were investigated in 5,206 same- and opposite-sex 2-year-old twin pairs in the United Kingdom. Individual differences in imitative ability were due to modest heritability (30%), while environmental factors shared between twins (42%) and unique to each twin (28%) also made…

This longitudinal study examined links between disorganization and atypical maternal behavior at 12 and 24 months in 71 adolescent mother-child dyads. Organized attachment and maternal not disrupted behavior were more stable than disorganization and disrupted behavior, respectively. At both ages, disorganization and maternal disrupted behavior…

There is a robust association between prenatal smoking and disruptive behavior disorders, but little is known about the emergence of such behaviors in early development. The association of prenatal smoking and hypothesized behavioral precursors to disruptive behavior in toddlers (N=93) was tested. Exposed toddlers demonstrated atypical behavioral…