PROJECT SUMMARY The parent project (R01HD076390; PI’s: Morris, Shaw, Mendelsohn) is designed to examine the Smart Beginnings (SB) model, a 0-3 year program that addresses barriers improving child school readiness for low-income families via parenting interventions through: 1) utilization of pediatric primary care as a universal platform to facilitate population-level engagement and scalability; 2) provision of a tiered preventive intervention through universal primary prevention (Video Interaction Project [VIP], delivered through health care) integrated with a selective, targeted secondary intervention (Family Check-Up [FCU], delivered through strategic home visiting). The parent grant examines the impact of the integrated model in a RCT of 400 families, with treatment offered from 0 to 3 years and follow-up assessments of prosocial and problem behavior continuing at child ages 4 and 6. The parent-child relationship during early childhood (i.e., birth to 5) is commonly identified as a critical target of intervention for socioeconomically disadvantaged children and is the primary intervention target of the Smart Beginnings model. However, when assessing the consequences of parenting and dyadic parent-child qualities on children’s short- and long-term development, parenting constructs are typically assessed at single timepoints. This operationalization of parenting neglects to acknowledge that parenting behavior and qualities of the parent-child dyad likely evolve as children realize developmental milestones (e.g., walking, talking, increased desire for autonomy) and familial contexts shift (e.g., loss of employment, birth of a new child, COVID-19 pandemic)—experiences that are thought to increasingly impact low-income and racially/ethnically diverse families. The degree to which parenting remains stable or changes across early childhood has been found to differentially predict later child functioning among some samples. However, this body of work is scant and has rarely explored patterns of change and stability in parenting and dyadic characteristics—and the implications of these patterns on children’s development—among low-income, racially and ethnically diverse samples. As a logical extension of the parent project, we propose to use this diversity supplement to allow a promising minority predoctoral student to assess the contributions of longitudinal stability in parenting (e.g., cognitive stimulation, positive regard, negative regard) and dyadic parent-child qualities (e.g., joint attention, affective mutuality) across early childhood on children’s school-age functioning, test whether participation in the Smart Beginnings intervention and racial/ethnic identity moderate these associations, and gain expertise in observational methods for parent-child interaction during early childhood, longitudinal modeling, and preventive interventions to promote low-income, ethnically/racially diverse young children’s school readiness.