Poverty and Education

The documentary made me think a lot about the weight of poverty on people's lives.
In both Stanton and Riverside school, the situation was that children were from poor families. In Stanton, children's family situation, in which poverty, drugs, and abuse were everyday occurrence, influenced children negatively, making them tired just to survive each day. In Riverside, children's family situation, in which poverty was the main issue, influenced children to work instead of go to school. I think this environmental factor (poverty) prevent children from what the adults (teachers/adults/government) want them to learn. If this is true, then does it mean that some condition needs to be met in order for children to learn?
Another question I had was what "good education" means. Children learn, even without teachers. What works and what doesn't in each society and culture is also different so we cannot say that one way of educating children is better than the other. I would have liked to see what the classroom was like at Riverside.
Moreover, what kind of knowledge do these children need? I think the necessity is also different according to culture and society. Some children needs to learn how to deal with everyday situations, like how Mr. Coats was teaching his students in Stanton.
Writing this blog, it lead me to think about the purpose of education... If the purpose of education is happiness of the learners, then what should be taught how?