This isn't really surprising, but the study authors seem to think it is.
Employees are more likely to quit if few of their co-workers share the same race. That's the popular thinking among diversity consultants. The problem is: employing workers of many different races actually has little effect on turnover, according to one of the few case studies exploring how workplace demographics affect employee behavior.
"The most important takeaway is diversity itself doesn't matter much in terms of turnover for most groups of workers," says Professor Jonathan Leonard
No surprise there. Politicians are always the ones worrying about diversity, not business people. Good business people don't seek to promote or deny diversity – they seek to hire the right people and create a good work environment for them.
The study did have something I didn't expect…
One surprising finding of the study, however, is that women seem to dislike gender diversity. In fact, women are more likely to quit when the gender diversity of their workplace is close to fifty-fifty than when it is mostly female or mostly male.
I don't know why this might be, but I will speculate that gender balanced workplaces have more flirting, dating, and sexual tension, and some women are either uncomfortable in that environment, or perceive it as some sort of competition that they don't like.