Racism May Weaken the Brain-Behavior Association among African American Children: The Case of Amygdala Volume-Emotion Regulation Link

Abstract

Introduction: The amygdala has a central core role in regulating emotions. However, less is known about the racial/ethnic variation in the relevance of amygdala volume for emotion regulation of US children. According to the Minorities’ Diminished Returns (MDRs) phenomenon, due to racism, segregation, and social stratification (rather than innate differences due to genetics), some of the individual-level individual social determinants, could lose some of their relevance for African American (in comparison to White) children. Purpose: Conceptualizing race as a social factor that reflects structural racism and discrimination and building on the MDRs framework, we explored racial variation in the magnitude of the association between amygdala volume and emotion regulation/impulsivity of US children. Methods: For this cross-sectional study, we used baseline data which included behavioral, social, and structural magnetic resonance imaging (MRI) data of 6030 US children ages 9-10. Data came from the Adolescent Brain Cognitive Development (ABCD) study. The primary outcomes were positive and negative urgency. These were measured using Urgency, Premeditation (lack of), Perseverance (lack of), Sensation Seeking, Positive Urgency, and Impulsive Behavior Scale (UPPS-SS) UPPS-SS. The independent variables were right and left amygdala volume. The covariates were age, sex, parental education, household income, parental marital status, neighborhood socioeconomic status, and ethnicity. Race was the moderator. Results: Children with larger amygdala volumes had lower positive and negative urgency. The correlations between amygdala volume and positive and negative urgency were modified by race. For White children, children had better emotion regulation when they had a large amygdala. For African American children, positive and negative urgency did not show an association with amygdala size. Conclusions: The results can be explained by the Minorities’ Diminished Returns (MDRs) hypothesis. In line with MDRs and as a result of structural and interpersonal inequalities, such as school segregation, the amygdala-emotion regulation seen for White children does not replicate for African American children. For White children, however, in the absence of higher-level social determinants, amygdala size correlates with emotion regulation. The brainbehavior link is weaker for African American children whose lives are less predictable and affected by experiences of racial discrimination. Unequal effects of equal resources across racial groups are due to racism and discrimination, not biological innate differences such as genetics.