All known human societies establish social order by punishing violators of social norms. However, little is known about how the human brain processes the punishment threat associated with norm violations. We use fMRI to study the neural circuitry behind forced norm compliance by comparing a treatment in which norm violations can be punished with a control treatment in which punishment is impossible. Individuals’ increase in norm compliance when punishment is possible exhibits a strong positive correlation with activations in the lateral orbitofrontal cortex and right dorsolateral prefrontal cortex. These
activations are also modulated by the social nature of the task. Moreover, activation in lateral orbitofrontal cortex shows a strong positive correlation with Machiavellian personality characteristics. These findings indicate a neural network involved in forced norm compliance that may constitute an important basis for human sociality. Different activations of this network reveal individual differences in the behavioral response to the punishment threat and may thus provide a deeper understanding of the neurobiological sources of pathologies such as antisocial personality disorder.