According to the organizational-activational hypothesis, organizational effects of testosterone during (prenatal) brain development moderate activational effects of adult testosterone on behavior. Accumulating evidence supports the notion that adolescence is another period during which sex hormones organize the nervous system. Here we investigate how pubertal sex- hormones moderate the activational effects of adult sex-hormones on social cognition in humans. To do so, we recruited a sample of young men (n=507, ∼ 19 years of age) from a longitudinal birth cohort, and investigated if testosterone exposure during adolescence (from 9 to 17 years of age) moderates the relation between current testosterone and brain response to faces in young adulthood, as assessed with functional magnetic resonance imaging (fMRI). Our results showed that the cumulative exposure to testosterone during adolescence moderated the relation between adult testosterone and both the mean fMRI response and functional connectivity (i.e., ...