Here’s a fact that may not surprise you: the children of the rich perform better in school, on average, than children from middle-class or poor families. Students growing up in richer families have better grades and higher standardized test scores, on average, than poorer students; they also have higher rates of participation in extracurricular activities and school leadership positions, higher graduation rates and higher rates of college enrollment and completion.
Whether you think it deeply unjust, lamentable but inevitable, or obvious and unproblematic, this is hardly news. It is true in most societies and has been true in the United States for at least as long as we have thought to ask the question and had sufficient data to verify the answer.
What is news is that in the United States over the last few decades these differences in educational success between high- and lower-income students have grown substantially.