Measuring Behavioral Synchrony as a Dyadic Mechanism of Early Intervention - PROJECT SUMMARY Early supportive caregiving relationships can mitigate the potential negative effects of early adversity. As adverse childhood experiences and their associated risks represent a significant public health crisis, understanding how to promote positive early relationships is crucial. Early childhood presents a window for intervention in the caregiver-child relationship, with the potential to leave a lasting impact on future outcomes. Investigating features of dynamic caregiver-child relationships in naturalistic settings provides valuable insights into the mechanisms that can promote positive developmental outcomes even in challenging conditions. A key feature of successful dyadic interactions is behavioral synchrony, which involves the dynamic coupling and coordination of temporally linked behavior between social partners. Synchronous interactions shape children's self-regulation, school adjustment, and brain development. However, while early interventions target the caregiver-child dyad, current research often fails to measure changes in dyadic mechanisms. Early caregiving intervention programs offer an ideal opportunity to study dynamic changes in behavior synchrony. This project proposes to develop innovative global ratings and coding measures for behavioral synchrony, to examine whether these dyadic mechanisms are sensitive to change across early intervention. This approach addresses a significant gap in understanding how dyadic interactions adapt within early intervention contexts, at a global and microsocial level. Exploring this question mechanistically will enhance our understanding of how and why specific program components are associated with desired outcomes. The current project uses a collection of recorded caregiver-child interactions from a scalable, conceptually-based, and innovative early video coaching intervention in families experiencing economic adversity. Aim 1 proposes the development of a global behavioral synchrony rating scale to code naturalistic caregiver-child interactions, to examine synchrony as a dyadic mechanism. Aim 2 leverages the time series nature of the dyadic data in video clips of caregiver-child interactions. It introduces a micro-level coding system for behavioral synchrony to assess dyadic behaviors in detail, second by second. Aim 3 will investigate whether the proposed measures of behavioral synchrony are sensitive to change in the intervention group compared to an active control group. These contributions will meaningfully add to the extant theoretical, conceptual, and translational work by innovatively examining behavioral synchrony. Guided by Sponsor Philip Fisher at Stanford University, this training and research plan will advance my journey toward becoming an independent researcher and future tenure-track professor. My research focuses on how children's dynamic interactions with their environment enhance well-being and healthy development.