Hm, if upbringing is mereley seen in the rather small frame of family => I disagree.
Kids and their parents live in a certain environment - and consist of a lot of people - their beliefs - beliefs of their culture - media - games - news - gender roles etc.
So, even if parents try to live and educate in the terms of non-violent methods, their kids are still exposed to the rest.
What do to do? No clue <img src="/ubbthreads/images/graemlins/puppyeyes.gif" alt="" /> - one way is to show up positive examples in history, where peace, non-violent communication and cooperation lead to constructive results - another way would be if schools, culture, politicians, parents (all adults) would approve of non-violence and live it, so kids learn by watching. These examples are rare - very rare, why? It takes 2 for peace and only 1 for violence.
There seems to be a violent streak in every one of us - depends how we determine it, where our borders are and how we develop (self-)responsibility, (self-)respect or endurance. It is "easier" in short terms IMO to use violence and believe, this settles a problem - not "easier" on long terms, as violence is a spiral. Even if some individuals manage non-violence, what is with others? It's a terrible disease - wish, we had an antidote.
Kiya
I agree about latent violence being there and looking for a channel to come out - but I wish, this would NOT be exercised in games, movies (entertainment). And I wish, news would show up both sides. Maybe, we need a few 100 yrs more to learn that life is more worth than death?
