Abnormal lateralization in finger tapping and overt aggressive behavior

1. The relationship between abnormal cerebral lateralization and overt aggressive behavior was examined in 41 violent psychiatric patients in a maximum-security hospital. 2. Cerebral lateralization was measured using the Finger Oscillation Test from the Halstead-Reitan Neuropsychological Battery, and aggressive behavior was measured during a six-month period of hospitalization using the Overt Aggression Scale. 3. Patients with the most abnormal pattern of lateralization exhibited the highest frequency as well as the highest severity of overt aggressive behavior. This pattern could not be explained by the influence of age, race, IQ, history of head trauma, brain damage, or psychiatric diagnosis. History of seizures, alcohol abuse, and drug abuse, however, were found to be intervening variables in the lateralization-aggression link. Once their influence was removed using analysis of covariance, there was no relationship between lateralization and aggression. 4. The results suggest that it is unlikely that there is a direct causal relationship between abnormal lateralization and aggressive behavior.