Overview

• Researchers analyzed MRI data from 10,071 children aged 9–10 in the ABCD Study across 17 states, linking state income-distribution scores to neuroimaging measures.
• Higher inequality correlated with reduced cortical surface area and altered functional connections in regions supporting attention, emotion, memory and language.
• Follow-up questionnaires at ages 10–11 found worse mental-health symptoms for children in higher-inequality states, with some brain measures statistically mediating this association.
• Inequality was quantified on a 0–1 scale, with higher-inequality examples including New York, Connecticut, California and Florida, and more equal states including Utah, Wisconsin, Minnesota and Vermont.
• The authors propose stress and social-comparison pathways and recommend policies such as progressive taxation, stronger safety nets, universal healthcare and community investment, while emphasizing the observational design and need for replication.