That is the title of a new and very important paper by Klaus Desmet and Romain Wacziarg, here is the abstract:
This paper conducts a systematic quantitative study of cultural convergence and divergence in the United States over time. Using the General Social Survey (1972-2016), we assess whether cultural values have grown more or less heterogeneous, both overall and between groups. Groups are defined according to 11 identity cleavages such as gender, religion, ethnic origin, family income quintiles, geographic region, education levels, etc. We find some evidence of greater overall heterogeneity after 1993 when averaging over all available values, yet on many issues heterogeneity changes little. The level of between-group heterogeneity is extremely small: the United States is very pluralistic in terms of cultural attitudes and values, but this diversity is not primarily the result of cultural divides between groups. On average across cleavages and values, we find evidence of falling between-group heterogeneity from 1972 to the late 1990s, and growing divides thereafter…
This, from the paper, is also illuminating:
For some questions, such as several questions on sexual behavior and public policies, there is growing social consensus. For others, such as questions on gun laws and confidence in some civic institutions, we find growing disagreements. Some of these dynamics can be understood as transitions from one end of the belief spectrum to the other. For instance, on the issue of marijuana legalization, attitudes have moved from generalized disagreement to majority agreement, so heterogeneity rose and is now falling. Overall, we find some evidence of a systematic tendency toward greater heterogeneity after 1993 when averaging over all available memes, yet on many issues heterogeneity changes little.
By the way, “urbanicity” shows “declining levels of cultural fixation,” contrary to what you often read.
Overall I take this to be an optimistic set of results.