Learning to anticipate threat is crucial in guiding protective behavior. In classical conditioning, single trial learning can result in long-lasting fear associations. To examine whether threat learned through social communication is equally stable, an instructed fear paradigm was used with two repeated sessions on 1 day (Study 1; N = 43) and with separate sessions on 3 consecutive days (Study 2; N = 30). Startle EMG, skin conductance level (SCL), and self-report data were recorded during alternating periods of instructed threat and safety.Within 1 day, threat-potentiated startlewas present across sessions but threat-enhanced SCL decreased (Study 1). Across days, threat effects subsided with different timing for startle EMG, SCL, and self-report (Study 2). The present findings are a laboratory analog for the persistence of socially transmitted fear, which can be amazingly resistant to extinction (e.g., in specific phobias) even in the absence of aversive experiences.