From zero to thrive: A model of cross-system and cross-sector relational health to promote early childhood development across the child-serving ecosystem.

Early relational health between caregivers and children is foundational for child health and well-being. Children and caregivers are also embedded within multiple systems and sectors, or a "child-serving ecosystem", that shapes child development. Although the COVID-19 pandemic has made this embeddedness abundantly clear, systems remain siloed and lack coordination. Fostering relational health amongst layers of this ecosystem may be a way to systematically support young children and families who are facing adversity. We integrate theory, examples, and empirical findings to develop a conceptual model informed by infant mental health and public health frameworks that illustrates how relational health across the child-serving ecosystem may promote child health and well-being at a population level. Our model articulates what relational health looks like across levels of this ecosystem from primary caregiver-child relationships, to secondary relationships between caregivers and child-serving systems, to tertiary relationships among systems that shape child outcomes directly and indirectly. We posit that positive relational health across levels is critical for promoting child health and well-being broadly. We provide examples of evidence-based approaches that address primary, secondary, and tertiary relational health, and suggest ways to promote relational health through cross-sector training and psychoeducation in the science of early development. This model conceptualizes relational health across the child-serving ecosystem and can serve as a template for promoting child health and well-being in the context of adversity.