This book brings new insight from social psychology to explore migrant integration in Western Europe. Through a series of survey studies it illustrates the importance of sociopolitical conditions, such as political polarization and discriminatory climates, for understanding cross-national variation in migrant integration outcomes. The author investigates how migrants integrate; what factors facilitate or hinder successful integration; and how successes and failures along the way affect subsequent integration outcomes. An inspiring read for researchers and students alike interested in migration studies, political behaviour, social psychology, and international policy, this book aims to promote more effective migrant integration policies within the European Union and elsewhere.