The value of particular aggressive acts derives from social labeling. Whether a particular form of aggression is regarded as adaptive or destructive depends on who bears the consequences. Under social learning theory, people are endowed with neurophysiological mechanisms that enable them to behave aggressively, but the activation of these mechanisms depends on appropriate stimulation and is subject to cognitive control. Origins of aggression, according to social learning theory, are observational learning, reinforced performance, and structural determinants. Instigators of aggression are modeling influences, aversive treatment (physical assaults, verbal threats and insults, adverse reductions in reinforcement, and thwarting), incentive inducements, instructional control, and bizarre symbolic control. Regulators of aggression include external reinforcement, punishment, vicarious reinforcement, and self-reinforcement. 5 figures, 130 references.