do you have children?

I ask this because I watched the evolution of this stuff in the interactions with my own kids - the eldest routinely sought to dominate his younger siblings. I submit to you that its behavior that comes naturally to SOME people in SOME circumstances, and unless it is halted and retrained, becomes a way of life. Kids are not naturally "good" or "bad", but they are little scientists who will experiment with behavior until they achieve a desired outcome. Hence, boundaries.