What drives support for or opposition to redistributive taxation and spending? Why is ethnic diversity associated with inequality and a lack of redistribution? This book argues that many individuals, recognizing that they live in a world of uncertainty, use the groups of which they are a member as a heuristic to understand how welfare states are likely to impact them. This leads to reduced support for redistribution among the wealthy, whose disproportionate influence over policy in turn leads to less redistribution. Group Interests, Individual Attitudes develops the argument with a series of empirical implications, which are then tested using data from a variety of sources. It examines regional and ethnic politics in the United Kingdom, Germany, Slovakia, Canada, and Italy, using a combination of qualitative and quantitative evidence, existing and new surveys, and observational and experimental methods. The evidence is largely consistent with a heuristic theory, allowing us to see group politics in a new light.