Perhaps the problem with those of us that are observing tyrannical behavior from children is not the class of neighborhood we live in (but thank you for implying that we are all living in the slums), but rather the population of the neighborhood we live in. I live in Southern California. There are people on top of people here. And many of these people have children. So obviously it makes sense that I might observe MORE misbehaving children than a person who lives in say...South Dakota.
And as a point of reference I was eating out in nice, expensive, fancy restaurants since I was an infant. Only once in my life did I start acting up in a restaurant. And my father took me outside and (shock) talked to me. No beating, no spanking, no screaming, no threatening. And I never misbehaved in a restaurant again.
Once I acted up in a grocery store. I wanted a toy, and my mother said no (imagine that, telling a child no). And I threw a little temper tantrum, and my mother walked away until she was out of my line of sight. And sure enough, within a moment or two I stopped acting up and went to find my mother. (And because I could NEVER get a toy from the grocery store, I developed a deep rooted love of school supplies. Mom would let me get them because they were educational, and I would want them because it was something new to play with.)
So no, I was not an angel. But my parents TAUGHT me EXACTLY what was expected. And they never once had to hit me to do it.