Recent studies indicate continuing cultural differences between residents of larger and smaller communities. This paper argues that these differences persist because they are constantly generated anew. Innovations emerge in metropolitan centers and diffuse from them to smaller places, so that there is always a gap between the two. Predictions from this model are evaluated with poll data, covering 20 years, on changing social attitudes. The results are consistent with the predictions. Patterns in the rates of opinion change indicate d hierarchical diffusion model in which early adoption and/or rate of diffusion are positively associated with community size.