This program explores the extent to which spatial polarization produces a society that is increasingly polarized in attitudes, valuations, life styles and behaviour and, thus, less socially cohesive. Our focus will be on neighbourhoods as locales for social interaction, socialization, identity formation, and for building social capital. If neighbourhoods, through a process of spatial sorting, come to consist of communities with very different social composition there is a risk that society-wide common values and solidarity between groups cannot be established. Spatial polarization can produce neighbourhoods with concentrations of socially marginalized individuals that provide poor contexts for social integration. The research program uses a novel approach to social classification based on life-course patterns in education, income, employment, and family formation. Three broad questions will be addressed: To what extent do individuals that follow similar life course trajectories tend to cluster into similar neighbourhoods? To what extent are individuals’ attitudes formed in and influenced by their neighbourhood residential context? To what extent are the adult life courses of children and adolescents influenced by their exposure to different types of neighbourhoods during childhood? Further, the program considers how neighbourhoods change their composition over time and how such dynamics influence people’s attitudes and well-being.