It didn't make the slightest difference. One day, they became Real Boys and every stick, every lego thing, every banana was a weapon. Their little girl friends, around that time, became more girly despite their mothers' attempts to raise Strong Women. The boys played at protecting the girls... and these kids did NOT have a T.V. Where did this come from?
A few years ago I had a discussion with a pacifist friend: He is into planting indigenous food crops and creating water swales in preparation for the end of the world. I said, "When the end of the world comes, the strongest, baddest, most violent people will survive. Not the food-planters." He disagreed, of course, and I was only giving him a hard time on purpose. We all hate to think that the human race might evolve into something MORE violent and murderous! Our visions of Utopia always involves gardens of Eden and happy loving humans. We raise our sons in hopes that they will fit into a new and peaceful world, not in hopes that they will be sent far away to kill and die.
Yesterday, we bought Nerf Guns. Today, it's mayhem around here. And my sons, raised by an anti-war family, not exposed to violence in the media, have taken to War Games like fish to water.