This is only one of several entry routes into the CNS by microbes. Impulsive, explosive anger is frequently associated with frontal lobe dysfunction. One teen-ager with frontal lobe dysfunction I evaluated for rape and murder had such poor impulse control that he expressed his annoyance with the judge by attempting to attack and strangle him during his trial. Many head injuries cause injury to the tips of the frontal and temporal lobes. This combination of frontal and temporal lobe injury, in some cases, contributes to an impairment of both impulse control and bonding capacity, which increases aggressive potential.
Compulsive aggressiveness is associated with an overactivity of the cingulate gyrus.
This finding supports the view that such individuals have difficulty with mental flexibility, shifting their thoughts and motivation. Many other types of neurological impairments which prevent health adaptive functioning may also contribute to dysfunction associated with violence. It is again important to emphasize the presence of any of these findings does not necessarily cause violence but instead different combinations and interactions contribute to violence. It is my opinion that we have not given adequate attention to the role of infectious disease in causing dysfunction that contributes to violence. It is my hypothesis that certain regions of the world that are more endemic to infections that affect the brain are associated with a higher incidence of violence and war.