This research is based on the premise that it is vital to gain a greater understanding of how children think about others and how this may influence their thoughts, feelings, behaviours and social interactions within the primary classroom. This paper reports findings from mixed methods research utilising focus groups, individual interviews and surveys which explored children's self-perceptions within the classroom context. A particular focus was put on childhood identity in terms of views of self in relation to others. 182 children aged between 10 and 12 years participated in this UK study which was conducted within English primary school settings. The focus of this presentation explores how the girls in the study perceived information regarding others and utilised this information for self-evaluations, often disregarding other more salient and objective forms of information. Using social identity theory to explore girls' use of, and reliance on, social comparative information, this paper discuss the motivation underlying girls' social comparisons, the ensuing misperceptions of capability (self-efficacy) and difficulties in challenging such reliance on others for sense of self.