PROJECT SUMMARY The environmental input that children receive, in interaction with their genetically-influenced characteristics, has been linked to psychological development. In early life, caregiving behavior is a defining feature of the environment. Infants and young children depend on their caregivers to provide not only the instrumental care necessary for their survival but the psychosocial input critical for their healthy development. Decades of research point to the adverse long-term consequences for children when early caregiving goes awry. Currently, however, there are limitations to the accuracy of models of the effects of caregiving behavior on child development, and, therefore, for leveraging extant evidence to inform interventions and policies focused on improving the caregiving environment and enhancing psychological development. First, although caregiving is a multi-dimensional construct, many studies measure one dimension of caregiving or combine multiple dimensions irrespective of their potential unique antecedents and effects. Second, most studies of caregiving and development use correlational designs involving observations of singleton children raised in their families of origin, failing to consider the effects of parent and child genetics on the caregiving children receive and on their psychological outcomes. In order to increase the accuracy of models for the effects of exposure to psychosocial neglect and enrichment on children’s psychological development, this project examines distinct dimensions of enriching caregiving in early life (i.e., emotional and cognitive stimulation) as predictors of distinct child outcomes (i.e., socioemotional and cognitive development), while accounting for the contributions of parent and child genetics to observed associations between these forms of caregiving and these outcomes. Specifically, leveraging measures of caregiving behavior in early life and children’s socioemotional and cognitive functioning collected in three longitudinal studies of 1) children raised in foster care and institutions (the Bucharest Early Intervention Project; N=136), 2) a behavioral genetic study of twins and multiples raised in their biological families (the Texas “tiny” Twin project; N=626), and 3) a population-based panel study of genotyped mother–child dyads (the German Socioeconomic Panel – Innovation Sample; N=1,600), this project tests the hypothesis that different forms of caregiving measured on a continuum of neglect to enrichment have distinct consequences for child socioemotional and cognitive development, and disentangles the contributions of parent and child genetics through direct genetic effects and indirect social genetic effects (i.e., “genetic nurture”) to the nature of children’s caregiving environments and their developmental outcomes. Findings from this project will provide insights into how caregiving and genetics work together to influence children’s psychological development, and will provi...