Assumptions of politicians, teachers, and other professionals about integration often fall short of theoretical and empirical support. This work seeks to bridge this gap by proposing a new theoretical concept looking at personal security and testing it empirically with data from 21 European countries. As migration often affects migrants and members of the receiving society alike both have been included in the analysis. Whereas classic identity research strongly relies on qualitative techniques and experimental designs, Yvonne Hapke adopts a quantitative approach. She successfully demonstrates that ethnic closure and xenophobia are the result of damaged or threatened identities and pose a major obstacle to integration. However, welcoming individuals with all of their defining characteristics, needs, and identities helps people to develop trust in others as well as in political institutions and makes them more confident about their country's future.