1. The electroencephalographic distributions for 160 children with primary behavior disorders, 139 adults with psychopathic personality and 98 parents of 58 patients were presented.2. These were contrasted with the electroencephalographic distributions reported by Gibbs(7) for normal controls, epileptics and relatives of epileptics.3. The electroencephalographic distributions of the parents of the patients approached the one for normal controls; those for primary behavior disorders and psychopathic personality were most similar to the one for relatives of epileptics but radically different from the one for epileptics.4. The EEGs of 40 patients with either primary behavior disorders or psychopathic personality revealed a highly significant relationship to the combination of the EEGs of their respective parents.