How socially distant are two groups?  One of sociologists top measures is simply the rate of intermarriage.  Since college graduates almost never marry high school dropouts, the two groups are probably extremely socially disconnected.  When intermarriage rates rise, similarly, sociologists naturally infer that caste barriers are coming down.

When people bemoan the cultural divide between natives and immigrants, then, looking at intermarriage rates is a good place to start.  I reproduce recent National Academy of Sciences data on this point below.  But before you look, ask yourself: “What do I expect to see?”

So what do you think?