People’s preferences about the fair distribution of resources vary within and between different populations, and this affects many economic and political outcomes. This paper argues that a source of these differences is the social transmission of fairness norms from peers during adolescence. The authors ran an experiment on transmission of fairness norms in a friendship network of 1115-year-olds. Observing others’ choices affects young people’s fairness norms, as expressed in both their own choices and the attitudes they express. The results show how young people can adopt redistributive norms via the social influence of their peer group. The paper also examines how the strength of social influence varies with friendship status and network position.