By portraying the views and perspectives of children labelled as 'low-attaining', this text makes a significant contribution to the debate on within-class attainment grouping in primary schools. Extensive, active individual interviews plus observations over three terms facilitated rich insights into whether, and if so, how 23 'low-attaining' primary-school children assimilated cultural values designating them as having the subordinate status to other children. We consider the implications of our findings for social justice, employing an innovative analytic framework based on Nancy Fraser's conceptualisation of justice as 'parity-of-participation'. Our research illustrates that these children had absorbed values about 'success' that posed considerable obstacles to them and led to feelings of isolation, and a lack of social participation. In particular, the children found some aspects of attainment grouping obstructive to social interaction. Reactions to these discomforts sometimes led them towards subtly subversive behaviour or alternatively to flat-out denials of difficulty.