Article dans une revue: Socially disadvantaged students are less likely to aspire to the top educational pathways than their advantaged classmates who have the same test scores. We identify two behavioural biases that explain most of this gap: socially disadvantaged students are less aware of the top educational pathways and underestimate their academic ability relative to their advantaged peers. We also find that lower educational aspirations at a point in time are associated with poorer school outcomes later on, after controlling for many important factors. Debiasing aspirations through information campaigns and self-esteem building programmes could thus help reduce social inequality in educational attainment.