How do people living in contemporary Germany react to diversification in their everyday lives? What undergirds pro-diversity perspectives among those who live in rapidly diversifying cities? Conversely, what are their limits, and what groups are excluded? This project aims to elucidate the foundations and mechanisms underlying diversity assent in cities located both in West and East Germany. Two core motivations underlie the project: (1) thus far, it is insufficiently understood what motivates those who oppose right-wing positions, usually a majority among inhabitants of cities in Germany and other Western European countries; and (2) this project builds on a previous large-scale project of the department, “Diversity and Contact”, and explores to what extent attitudes and patterns of interaction have changed, or remained constant, in the decade from 2010 to 2020, i.e., a time of major ruptures and political polarization. A large telephone survey of 2,850 respondents was designed, asking a set of interrelated questions on fundamental dispositions towards diversity, everyday experiences, and diversification dynamics. This includes an innovative set of survey experiments designed to access and measure social norms of tolerance. Results from this survey were anticipated to fill a major research gap in the literature on immigration and orientations toward diversity, which has thus far largely focused on the determinants of hostility and anti-diversity attitudes, rather on the determinants of more open views.