We Americans are not an inherently more violent people than folks in other countries. We're not inherently more prone to mental health problems. The main difference that sets our nation apart, what makes us so susceptible to so many mass shootings, is that we don't do enough, we don't take the basic common sense actions to keep guns out of the hands of criminals and dangerous people. What's different in America is that it's easy to get your hands on a gun.
Barack Obama, Memorial service for DC Navy Yard shooting victims, Sep 22, 2013