One will often hear it asserted that diversity improves team performance and even corporate performance. Surely there are situations where this is true--an ad campaign designed by a team of white guys from the Midwest would probably not do terribly well in New York or Los Angeles--but it is often presented as a universal truism. Well, a recent meta-analysis argues that diversity probably does not, as a general rule, improve team performance, though it may very well be advantageous for certain types of tasks.
Some readers* may feel threatened by this finding, or may be tempted to argue with it, but there is no moral content to that finding. The statement "People ought to be inclusive in their recruitment and hiring practices" can be defended on simple moral grounds, irrespective of the truth value of the statement "A diverse team is more productive than a homogeneous team." An "Ought" statement cannot be derived from an "Is" statement. I am quite comfortable believing that fairness and inclusion are morally defensible irrespective of whether they are, According To A Recent Study, profitable. Morality isn't always profitable, and doesn't need to be profitable. If it were profitable we wouldn't call it "morality", we'd call it "self-interest." A stable society will certainly try to align morality and self-interest as much as possible, but they needn't be 100% in alignment.
The fact that this type of social science might discomfit people is part of the modern zeitgeist. On the right, "morality" seems to be about judging other people's sex lives; in all other aspects of life the right believes that the only morality that matters is the morality (such as it is) of the market. Consequently, the right needs to be sold on the market value of diversity. On the left, I think that the belief in some concept of inclusion and diversity is sincere, but they aren't really comfortable with moral language. The Boomers rebelled against the morality of their elders, the educated members of Generation X (my generation) were taught to embrace subjectivity, and the Millenials seem to be afraid of having their values challenged, so everyone is ill-equipped to deal with "is/ought" distinctions from a left-leaning perspective. The Boomers would feel stodgy saying "ought", we Xers would feel anti-intellectual saying "ought", and the Millenials would be fine with "ought" but would need to see a trauma counselor if somebody disagreed with them. So we're all more comfortable if social science simply tells us that our value preferences are also perfectly congruent with everyone's self-interest, because then there's no need to debate "ought" statements.
If, however, we recognize that there's no "is" statement that can refute or prove an "ought" statement, and if we are comfortable with the divide between morality and self-interest, then a meta-analysis questioning the direct material benefits of diversity needn't threaten our value system. But this would require us to have confidence in our value system, rather than to be timid about it.
EDIT: I just realized that a few months ago I had blogged about a related point made by de Tocqueville. All of this has happened before and will happen again.
*Here I generously assume that I have readers.