Schools and teachers affect achievement differences too, of course. There have been manyrecent studies of how school and classroom environments affect reading and readingdevelopment. Sociocultural researchers are interested in how, when, why, and howmuch students learn in different classrooms and schools as explanations for why somechildren achieve more than others. Unfortunately, many studies have shown that somepopulations of children receive a very different education than others (Allington, 1977,1983; Anyon, 1997; Finn, 1999; McDermott, 1977; Michaels, 1981; Rist, 1970), and thepattern is clear: Across the nation, instruction, materials, students’ school experiences,and expertise of teachers are of lower quality in schools serving children of poverty thanin schools serving middle-class kids. This does not mean that all teachers and schoolsserving poor kids are bad, of course; there are many examples to the contrary. Yet, thisis and has been a national trend for a long time. 

"Reading Instruction for Diverse Classrooms": Ellen McIntyre, Nancy Hulan, Vicky Layne, 2011 The Guilford Press