Earlier quoted context omitted.
Racial and ethnic diversity really seem like non issues...they are pretty superficial differences within a work environment. Age, children, and sex are a little more relevant, and even those are pretty minor and only loosely correlated with traits relevant in a work environment. Bringing a windows guy into a unix shop, or hiring a sales guy too early at a product development stage startup, or hiring a stupid or lazy…
Racial and ethnic diversity really seem like non issues...they are pretty superficial differences within a work environment. Superficial diversity is really overvalued. And very undervalued by people in the majority ...
I really haven't observed ethnicity or race as a primary factor in team dynamics. Even first language, assuming people have a minimal level of fluency, hasn't been a major factor; even with my minimal French, I've ended up hanging out with French video gamers and sci fi fans (all 3 of them at a big base; they spoke maybe 100 words of English) vs. a bunch of other Americans.
Volitional things like the kind of music you like, the job you do, your hobbies, etc. are really a much bigger factor, at least in my limited experience, than race or ethnicity.