Asymmetry in frontal alpha activation (FAA) has been associated with specific behavior patterns. Greater activation in the left frontal cortex is related to "approach" motivation, while greater activation in the right cortex is associated with "withdrawal" motivation. Moreover, resting FAA is stable over time among adults. This stability has not been demonstrated among adolescents, and the correspondence between resting FAA and personality has been inconsistently observed. The present study examined stability of FAA and the association between resting FAA and behavioral activation among adolescents. At baseline and 4 months, 99 adolescents completed a resting electroencephalogram (EEG) and a pencil-and-paper measure of personality (BIS/BAS). FAA showed good stability over time (Intra-class correlation coefficient=0.65, p<0.001), but there was no correlation between FAA and personality. Results are interpreted in light of a capability model of FAA; namely, that asymmetry may emerge under conditions of stimulation and recede during resting.