At least, diversity is not a strength the way that the left typically promotes diversity. Now, for many of us this isn’t a surprise. But it’s always interesting to see the specifics well-documented by others, especially those who are generally predisposed to believe it is.

From the link above:
“Comes now a blockbuster report by political scientist Robert Putnam, author of the runaway bestseller Bowling Alone. Putnam provides supporting fire from Harvard Yard for those who say America needs a time-out from mass immigration, be it legal or illegal, like the immigration moratorium we had from 1924-1965.

“E Pluribus Unum: Diversity and Community in the 21st Century” [PDF]is the title of Putnam’s five-year study, which makes hash out of the politically correct cliché, “Our diversity is our strength.”

After 30,000 interviews, Putnam concludes and reports, against his own progressive convictions, that ethnic and racial diversity can be devastating to communities and destructive of community values.”

Just in case the above article gets nuked, here are some links separately:
Bowling Alone
The study PDF: “E Pluribus Unum: Diversity and Community in the 21st Century”
S. Sailor:  Diversity Is Strength! It’s Also…Oh, Wait, Make That “Weakness”
Negative impact of racial diversity.