Objective : Higher prevalence of traumatic brain injury (TBI) has been reported for detained individuals. TBI may result in erroneously interpreting situations in everyday life, impair problem-solving abilities through dialogue, or negotiation, which may increase aggressive behavior. Knowledge of TBI and its consequences in Dutch penitentiaries is lacking, as virtually no screening, supervision, or treatment is currently provided. Method : The current manuscript assesses differences in self-reported aggression, impulsivity, indication for mild intellectual disability, history of childhood trauma, and emotion regulation in detainees (n = 283) and non-incarcerated controls (NIC; n = 51), with and without a history of TBI. Result : A total of 45.2% of detainees reported a TBI, compared to 29.4% in the NIC group. ANCOVA results revealed no interaction between group and TBI history, indicating that TBI history did not affect behavior in detainees and NIC differently. The main effects revealed higher levels of ...