I did think of an example, I will limit it to just one.

A friend I knew at one time came from a family of 5. They were a middle class family, but each of these kids were always hoarding food away from the others, as well as material possessions. They were also selfish, and wouldn't share if their life depended on it. I guess they were looking out for themselves, to make sure they each got their share.
Also, I know now why I have such a low tolerance for screaming kids in stores, (and don't even get me started about them in restaurants, lol) it's because I never experienced that type of behavior with my son. My mom says the same thing about me! So see, we're not all bad.
Sujin