A transactional model composed of family factors and individual child characteristics that are hypothesized to influence the development of dysfunctional sibling relationships will be tested. At the core of this model is the assumption that individual child characteristics place certain sibling dyads at risk for conflictual relations. This model further predicts that maladaptive sibling management strategies employed by mothers and fathers exacerbate sibling at risk status. These maladaptive sibling management strategies are more likely to occur in families in which the overall emotional climate is unhealthy and where parents have few emotional resources. The purpose of the present proposal is to examine, cross-sectionally and longitudinally, the contributions of sibling management strategies, family emotional climate, and parental personal resources to conflicted sibling relationships. At each level of analysis (e.g. individual child, sibling, parent-sibling, parent personal resources, family emotional climate) multiple measures which feature established psychometric properties and construct validity will be employed, with both observational and self-report measurement strategies included whenever possible. Data will be obtained from fathers, mothers, older siblings, and younger siblings.