You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Comprehensive_school

Context:
Gesamtschulen might put bright working class students at risk according to several studies. It could be shown that an achievement gap opens between working class students attending a comprehensive and their middle class peers. Also working class students attending a Gymnasium or a Realschule outperform students from similar backgrounds attending a comprehensive. However it is not students attending a comprehensive, but students attending a Hauptschule, who perform the poorest.

Question:
From what group does an achievement gap separate working class students at comprehensive schools?

middle class peers