The Pew Center has an interesting research report showing this contradiction both for political diversity and for socioeconomic and religious diversity.
Politics: Americans profess to want political diversity in their communities — true of all Americans, especially for Democrats, Liberals, Whites and Blacks and more wealthy Americans: Note: for conservative Republicans it is almost a tossup with 49% wanting to live in a diverse political environment and 43% wanting to live around others who share their views. That said, more and more Americans are living in politically segregated communities. Bill Bishop and Robert Cushing, whose interesting book “The Big Sort” showed how Americans are self-segregating politically note that these trends continued apace in 2008. Nearly half of all votes (48%) cast for President in 2008 were in counties that sided with Obama or McCain by a margin of at least 20 percentage points (i.e., at least 60-40). Ironically, even a clear majority of Democrats living in these landslide counties want to live among a mix of political views (62%) and by a razor thin plurality Republicans in landslide counties prefer to live among political diversity (46% to 44%). [Note: Bishop believes that people choose to live among people who share their backgrounds, tastes and lifestyles, and that these preferences are increasingly correlated with political views.]
Race, Religious and Socioeconomic Diversity:
Patterns here are similar as with regard to political diversity. Most Americans want to be among a mix of races, religions, people of varied socioeconomic classes.
The big divergence comes with attitudes towards immigrants. Most Americans (other than liberal Democrats and Hispanics) prefer to live in a community with few immigrants rather than many immigrants, despite the research of Rob Sampson that shows that immigrants are more law-abiding than Americans on average. [The researchers note that the form of the question had to be different for immigrants since just one in eight Americans are immigrants, and thus they did not ask whether you want to live in a community with a mix of immigrants and non-immigrants or not. It is possible that the wording form influenced the responses.
So what's going on? The researchers note that it could be a "talk-is-cheap" phenomenon with people giving answers that they think interviewers want to hear or "saying the right thing". Political correctness held that the increases in answers among Americans of their attitudes toward race were just cheap talk, and then we find with the election of Obama that a majority of Americans ARE willing to elect a president who is black, so we should be wary of asserting that people are always lying about their feelings.
With regard toward racial attitudes we find that comfort levels are very different with regard to diversity among blacks and whites. Whites prefer to live in communities that are say 15-20% non-white whereas Hispanics or Blacks often have an ideal *diversity* rate of 50% white and 50% black. Part of what is going on in white flight is non-whites moving into neighborhoods and the percentage of non-whites rising above most whites' comfort levels. As the whites leave, the percentage non-white rises higher and higher, causing more whites to move out, and the community winds up becoming predominantly non-white.
The report notes that black/white segregation has declined significantly since 1960 (when 70% of blacks lived in predominantly black neighborhoods), "but immigrant segregation as well as Hispanic and Asian segregation has increased in recent decades. [Some of these measures are sensitive to what measures one uses to measure segregation -- the so called dissimilarity index or the isolation index: as the population of groups rises or falls in percentage terms, their isolation indices can change formulaicly without them actually moving across neighborhoods.] “Even with this increasing spatial isolation of the well-to-do, however, blacks are still nearly three times as segregated from whites as are affluent Americans from those who are less well off.”
Read the Pew Report “Americans Claim to Like Diverse Communities but do They Really” here.