Right Amygdala Volume Predicts Mother–Child Relationship Quality

• Kathryn Hennessy, Neuroscience, University of Delaware

• Mary Dozier, Department of Psychological & Brain Sciences, University of Delaware

The right amygdala plays a key role in processing emotional and social information and has been associated with threat sensitivity and trust-related judgements. Positive caregiver relationships provide the foundation for healthy emotional and social development throughout childhood and adolescence. However, there is a lack of research examining whether structural differences in the right amygdala predict the quality of children’s relationships with their caregivers. This study examined the association between right amygdala volume and mother-child relationship quality. Participants (N = 99) were taken from a larger, longitudinal study. Right amygdala volume was calculated from high-resolution MRI scans and compared with normative volume data at age 13. Mother-child relationship quality was assessed at age 14 using the Network of Relationships Inventory-Relationship Quality Version (NRI-RQV) questionnaire, which included measures not only of companionship but also of a composite of positive emotions, named closeness, comprising the subscales of companionship, intimate disclosure, emotional support, approval, and satisfaction. Data were analyzed using JASP, with total gray matter volume as a control variable to account for individual differences in overall brain size. Results revealed a significant inverse association between right amygdala volume and mother-child companionship (r (98) = -.26, p = 0.009), indicating that larger right amygdala volume predicted lower reported companionship. The association between right amygdala volume and overall closeness was not significant (r (98) = -.19, p = .065). These findings suggest that structural differences in the right amygdala may predict aspects of caregiver relationships, specifically shared positive interactions, and contribute to our understanding of the neural correlates of parent-child relationship quality.