PROJECT SUMMARY/ABSTRACT More than 10 million youth in the United States live in poverty and experience structural inequality. Experiences organized by structural inequality (e.g. adversity, income) are well known to confer risk for adverse mental health outcomes in part by shaping neural structure and function. At the same time, brain development is highly plastic and shifts to meet the needs of the environment. Despite emerging research finding behavioral and neural differences between adversity and non-adversity exposed youth – differences that reflect adaptive developmental processes – few research studies have explored the processes that develop to support youth in navigating environments characterized by inequality. For individuals from disadvantaged backgrounds (as a result of structural inequality), cognitive processes are likely to be shifted towards meeting the environmental challenge of obtaining material resources needed for day-to-day survival. One way in which individuals impacted by structural inequality achieve this is through forming, utilizing, and maintaining social relationships. Social relationships provide a range of resources, including social capital and social support. Underlying the maintenance of supportive social relationships is mentalizing– the ability to understand and take the perspectives of others’ thoughts and emotions. Based on available evidence, we hypothesize that increased engagement in mentalizing serves as a protective factor against psychopathology for adolescents who experience structural inequality. The proposed project will leverage a multi-modal longitudinal study to examine the impacts of structural inequality on mentalizing, cognitive empathy, and associated neural correlates that may support the acquisition of social support and promote positive mental health outcomes. Three aims guide this research: (1) exploring how structural inequality impacts mentalizing, associated neural networks, and cognitive empathy, (2) examining how mentalizing supports the maintenance of social support, and (3) evaluating mentalizing and cognitive empathy as an underlying protective mechanism against psychopathology among youth who experience structural inequality. These aims will be addressed by leveraging a large study of adolescent youth (expected n = 275) who will participate in a passive neuroimaging task and complete behavioral and self-report measures. Resources that will support this research include access to this longitudinal sample, multiple research facilities, and a strong mentorship team with expertise in developmental neuroscience, resilience, and structural inequality. The proposed research will enrich theories regarding how neurodevelopmental processes are shaped by the environmental experience and identify protective factors that can be leveraged to inform mental health treatments.