Later-generation descendants of immigrants generally negotiate their heritage and mainstream culture, and all the factors that affect the mediation play a crucial role. During early adolescence, the extent to which individuals may identify with the two cultures is largely determined by the attitudes of family towards integration and the attitudes of host countries in terms, for instance, of social rejection. We empirically assess the influence of heritage and dominant culture on teens’ scholastic effort and attitude towards school. The analysis relies on a sample of teens aged 14, born in the UK between 2000 and 2002; the data are drawn from the Millennium Cohort Study Sixth Sweep. The results show that ethnic background along with religion count and that the experience of social rejection has a negative influence. Overall, the evidence shows the possibility that all the factors that help the mediation between ethnic background and mainstream culture by promoting the development of a cohesive identity foster the motivation of scholastic effort.