How does a pupil's class affect their educational attainment?

In general, pupils from a working class background tend to achieve lower grades than those from a middle-class background.This may be because working class children do not have the same resources as middle-class children. For example, they may not have textbooks or laptops for access to the internet to aid their studies. This would mean they are less prepared for examinations than middle-class children, and thus do not achieve as high a mark.In addition, working class children may have a more disruptive study environment outside of school. Middle-class children may have access to a quieter, stress free environment which will aid their revision and studies to enable them to be more prepared for the exams. Having said this, many schools provide after school sessions for children to study in a quiet space away from distraction, so it could be argued that working-class children have access to this environment just as a middle-class child would. Furthermore, working-class children may not have as much time as others to study outside of school due to family and work commitments. Reasons for the difference in educational attainment could also be due to a teacher's expectations resulting in labelling and the self-fulfilling prophecy. If a pupil turns up to school in an old, ill-fitting school uniform, and perhaps talks a certain way, a teacher my subconsciously label them as an underachiever. Thus putting the pupil in classes that may be aimed at a lower ability than they are, entering them into foundation exams whereby they can't achieve the high grades like the middle-class children in the higher sets can. Or the teacher may express their attitudes towards the child through the behaviour, perhaps not giving them as much help as other children and outright calling them an underachiever, the pupil would then internalise this label and act accordingly, proving the label correct. So it could be that working-class pupils underachieve because of the teacher's negative expectations of them meaning they cannot achieve higher than the expectation, or that they become the expectation.