Roughly 22 million Americans -- 8.9 percent of the adult population-- have impulsive anger issues and easy access to guns. 3.7 million of these angry gun owners routinely carry their guns in public. And very few of them are subject to current mental health-based gun ownership restrictions. Those are the key findings of a new study by researchers from Harvard, Columbia and Duke University. "Anger," in this study, doesn't simply mean garden-variety aggravation. It means explosive, uncontrollable rage, as measured by responses to the National Comorbidity Survey Replication in the early 2000s. It is "impulsive, out of control, destructive, harmful,"...