Resting frontal alpha asymmetry is associated with rejection sensitivity beyond anxiety and depressive symptoms in young adults.

Rejection sensitivity is a disposition to anxiously expect, perceive, and strongly react to interpersonal rejection. We examined whether it is associated with resting frontal alpha asymmetry (FAA) beyond internalizing symptoms. The sample included 337 Chinese first-year undergraduates aged 16-22 years with usable electroencephalography (EEG) data. Participants completed the Rejection Sensitivity Questionnaire and measures of trait anxiety, depressive symptoms, and somatic anxiety, followed by approximately 6min of eyes-closed resting EEG. Primary FAA was calculated as ln(mean right-frontal alpha power) - ln(mean left-frontal alpha power), with each hemispheric mean based on six electrodes. Primary inference used multiple imputation with 20 datasets; complete-case analyses with HC3-robust inference and additional sensitivity analyses assessed robustness. In the adjusted imputed model, greater FAA was associated with higher rejection sensitivity (β =.231, 95% CI [.085,.377], p =.002). In complete cases, FAA explained an additional 5.2% of variance, Fchange(1, 326) = 21.03, p <.001, and remained significant under HC3-robust inference (β =.232, 95% CI [.083,.381], p =.002). Results were stable after handedness adjustment, restriction to right-handed and adult participants, influence diagnostics, winsorization, and an alternative FAA calculation. Domain findings were supportive because two subscales had modest reliability. Secondary analyses indicated positive frontal and smaller negative parietal/posterior associations; alpha showed the clearest independent association in a joint multiband model. These findings identify resting FAA as a modest, non-diagnostic correlate of social-evaluative threat sensitivity, consistent with motivational-lateralization accounts.