I believe societal expectations are a major limitation for children at an elementary school level, as well as children in any age group. No matter where a child grows up, be it in poverty or wealth, they are constantly bombarded with expectations, good and bad, from the adults and other children who play major roles in their life, and by society as a whole through mechanisms like advertising and the media. Childhood is supposed to be a time of free-spirited, spontaneous enjoyment of life, where a child is bereft of responsibility and can take genuine enjoyment in almost anything they do. Too often, however, we either consciously or subconsciously try to manipulate children to grow up and be a model for whatever we consider to be a "correct" human being, which sometimes stifles originality and creativity.
Personally, I believe, as Jonathan Kozol seems to in Ordinary Resurrections, that it is best to not be overbearing or intrusive when dealing with children. Let them dream and play and be the irresponsible terrors they naturally are; there's plenty of time for reality later.