This paper examines the effect of school social class composition on pupil learner identities in British primary schools. In the current British education system, high-stakes testing has a pervasive effect on the pedagogical relationship between teachers and pupils. The data in this paper, from ethnographic research in a working-class school and a middle-class school, indicate that the effect of the "testing culture" is much greater in the working-class school. Using Bernsteinian theory and the concept of the "ideal pupil", it is shown that these pupils' learner identities are more passive and dominated by issues of discipline and behaviour rather than academic performance, in contrast to those in the middle-class school. While this study includes only two schools, it indicates a potentially significant issue for neo-liberal education policy where education is marketised and characterised by high-stakes testing, and schools are polarised in terms of social class. (Contains 3 notes.)