Dependency Thesis

"In those cultures, young children were expected to contribute substantially to the community, says Dr. Ochs. Children in Samoa serve food to their elders, waiting patiently in front of them before they eat, as shown in one video snippet. Another video clip shows a girl around 5 years of age in Peru's Amazon region climbing a tall tree to harvest papaya, and helping haul logs thicker than her leg to stoke a fire.
"By contrast, the U.S. videos showed Los Angeles parents focusing more on the children, using simplified talk with them, doing most of the housework and intervening quickly when the kids had trouble completing a task."

Shirley S. Wang in The Wall Street Journal discusses a UCLA study of middle-class families.