This book begins with a critique of traditional educational research on how class and ethnicity interact with school choice. It takes a new starting point of analysis in concepts of structural and symbolic boundaries, social belonging and emotions. These concepts are introduced to develop an enriched theoretical understanding of school choices and how they are guided and restricted. It sets out to offer a complementary explanation for the segregation found between immigrants and native students in the education systems of many of today's economically rich and migration-intensive societies. The empirical focus is on teachers and students who participate in the most prestigious academic upper secondary school program in Sweden, the Natural Science program. This provides an interesting contrast to analyses that tend to focus downward on programs that normally recruit from economically underprivileged classes and social segments. Sweden is taken as an example, but the analyses go beyond single state boundaries.