The Limits of Self Control

I was writing about violence yesterday and thinking about what it takes to push each of us beyond our endurance of frustration and whatever else draws us to violence. How is it that some people can endure the horrors of torture and maintain control while others explode at athe smallest provocation? I think it is something we learn by the example of our parents, how others around us react to violence and how secure we are about ourselves. Maybe there are more factors as well.