The concept of aspiration is central to current policy debates about educational and social inequality in the UK. Although aspirations have long been of interest to social scientists there is still uncertainty about how much aspirations influence outcomes and the factors that shape educational and occupational aspirations. I contribute to this policy debate and area of study by examining in detail the mechanisms that shape aspirations and the meaning that young people attach to them. It is often claimed that disadvantaged young people suffer from 'poverty of aspirations'. Contrary to such claims, my findings show that the vast majority of students hold high aspirations for pursuing further academic qualifications, including those from highly disadvantaged backgrounds. I therefore question the grounds for treating 'poverty of aspirations' as a major social problem that should be tackled through interventions designed to raise them. In this mixed methods study I draw on both quantitative and qualitative sources of data. The quantitative data is from the Effective Provision Pre-school, Primary and Secondary Education project (EPPSE). I examine the factors that are predictive of students holding high aspirations at the age of 14. The qualitative data I draw on is from twenty-nine semi-structured interviews with 16-18 years old from a sixth form college in East London. I contribute to the literature by showing in detail how aspirations are shaped by individual, family, school and neighbourhood level processes. In particular, I also show how important family life is in shaping aspirations and that in order to understand aspirations we should focus on the meaning young people attach to them. My findings suggest that our current models of aspirations are in need of refinement because they underestimate how high the aspirations of young people are and therefore struggle to explain how they are related to students' social backgrounds.