Overview

• The associations were independent of family income, pointing to inequality as a societal-level determinant of neurodevelopment.
• MRI data showed reduced cortical surface area and altered connectivity in regions involved in memory, attention, emotion and language among children in higher-inequality areas.
• The analysis used ABCD Study data from 17 states, with higher inequality reported in New York, Connecticut, California and Florida and narrower gaps in Utah, Wisconsin, Minnesota and Vermont.
• Questionnaires at ages 10–11 linked these brain differences to worse mental-health scores, with some alterations statistically mediating the inequality–mental health relationship.
• The authors proposed policies such as progressive taxation, expanded safety nets and universal healthcare and called for international replication, noting the observational design cannot establish causation.