Boundaries be buggered. The whole world has angry teenagers. Many parts of the world have some kind of machismo culture (although some are fed from US and Afro-caribbean cultures and images). Only in the USA (in the developed world) do these kind of massacres happen (Anders Breivik is a whole different ballgame) and without the US devotion to and lack of control of guns male teenage meltdowns would result at worst in one or two dead - not dozens.

USA - it's time to start to grow up.

And the "hand on your ha'penny" brigade - wake up - people who have good sex lives are generally happy people. People did not go on gun rampages in Europe in the late 40s and 50s because they were aware of enough killing in war that "I'll kill you" was seen as sociopathic, not "healthy assertiveness".