A large study by the National Institute of Health concluded that 16 million
Americans suffer from Intermittent Explosive Disorder where they lose their temper, throw things, even run their cars into another driver because of their sudden, uncontrollable rage. The study shows a definite genetic component to the disorder, which usually manifests by age 14. Sufferers of the disorder seem normal enough, but violently lose their tempers with very little provocation.
"People think it's bad behavior and that you just need an attitude adjustment, but what they don't know ... is that there's a biology and cognitive science to this," said Dr. Emil Coccaro, chairman of psychiatry at the University of Chicago's medical school.
Road rage, temper outbursts that involve throwing or breaking objects and even spousal abuse can sometimes be attributed to the disorder, though not everyone who does those things is afflicted.
By definition, intermittent explosive disorder involves multiple outbursts that are way out of proportion to the situation. These angry outbursts often include threats or aggressive actions and property damage. The disorder typically first appears in adolescence; in the study, the average age of onset was 14.
If there is truth to this study then it raises the question of whether people with this disorder should be allowed behind the wheel of a vehicle without some sort of medication or therapy. It isn't something a regular drivers test could uncover.