Abstract
BACKGROUND: Substantial heterogeneity exists in how rearing environments influence youths' socioemotional outcomes. This heterogeneity, as suggested by the biological sensitivity to context theory and the differential susceptibility theory, is associated with emotional reactivity patterns and underlying neural functions. The present study investigated amygdalar reactivity to emotional stimuli as a neural signature that amplified the influence of rearing environments on youths' socioemotional outcomes. METHODS: To increase replicability and generalizability, this investigation included two independent studies that methodologically complemented each other. Study 1 employed a large, national, longitudinal dataset (the Adolescent Brain Cognitive Development study; N = 11,875). Study 2 used a community sample of youths (N = 123) with multimethod and multireporter assessments. RESULTS: In study 1, high left amygdalar reactivity to positive stimuli significantly amplified the impact of parental warmth on youths' prosocial behaviors. In study 2, left and right amygdalar reactivity to positive stimuli significantly intensified the associations between family functioning and youths' internalizing problems. These findings were consistent with the biological sensitivity to context theory/differential susceptibility theory hypothesis because significant socioemotional differences were observed at both negative and positive extremes of rearing environments. Additionally, study 2 partially supported the diathesis-stress hypothesis by showing significant differences in youths' vulnerability to negative family environments. Specifically, left amygdalar response to negative stimuli exacerbated the associations between unbalanced family functioning and heightened internalizing/externalizing symptoms. Left amygdalar reactivity to positive stimuli intensified the link between unbalanced family functioning and elevated externalizing problems. CONCLUSIONS: Among youths and adolescents, amygdalar emotional reactivity may serve as a biomarker of differential sensitivity to rearing environments.