That difference suggests difference in the effect of media on legitimation of violence. In Japan, the media influence, which is relatively weak to begin with, competes against strong social norms and rules that often contradict the media influence. Therefore the net effect of the media on behavior is relatively small.
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Although I understand (and see value in) the heart of your argument I disagree with your description of media influence in Japan as being weak. Yes, I know you wrote "relatively weak" - in comparison with the US - but even so I disagree.
If you ever go for an extended stay and really absorb the scene, or even, from afar, carefully observe Japanese pop cultural currents you'll know why this is off the mark.
.d.
--------- Dwayne, you're going to hell.
Well yes, perhaps but fortunately I like it hot.