The encouragement (or requirement) of diversity sometimes gets labeled reverse racism, under the assumption that encourgaing diversity is only about somehow making up for past injustices by discriminating against today's white men who may never have themselves committed such injustices.

I'm not trying to step into the touchy issue of Supreme Court politics (nor am I arguing that quotas are always a good thing), but I've run across this interesting observation in several contexts recently:

"Participants push themselves to formulate better arguments when they know they will have to justify them."

The writer was referring to race issues in judicial/jury deliberations:

Liptak quotes Justice Scalia observing about Justice Marshall in conference, “Marshall could be a persuasive force just by sitting there. He wouldn’t have to open his mouth to affect the nature of the conference and how seriously the conference would take matters of race.” A series of studies by Sam Sommers, a psychologist at Tufts (often in conjunction with Phoebe Ellsworth), help explain this dynamic. In one 2006 study (involving a mock jury) Sommers found, as expected, that heterogeneous groups deliberated longer and considered a wider range of information than did homogeneous groups. But this effect was not simply due to the contributions of the black participants. In fact, it occurred even when the black participants didn’t contribute to the discussion at all. “White participants were largely responsible for the influence of racial composition, as they raised more case facts, made fewer factual errors, and were more amenable to discussion of race-related issues when they were members of a diverse group.”

This seems to be true when it comes to women in science too:

In recent years “men and women faculty in science, engineering and mathematics have enjoyed comparable opportunities,” the panel said in its report, released on Tuesday. It found that women who apply for university jobs and, once they have them, for promotion and tenure, are at least as likely to succeed as men. But compared with their numbers among new Ph.D.’s, women are still underrepresented in applicant pools, a puzzle that offers an opportunity for further research, the panel said.

The panel said one factor outshined all others in encouraging women to apply for jobs: having women on the committees appointed to fill them.

When considering race/gender issues (in hiring or in the law), racial and gender diversity on hiring committees, juries, and courts is a good thing. This shouldn't be controversial - the same principle operates when we're not talking about race or gender. Scientists who've been around the block know that one of the best things you can do to increase the odds of success for your paper or grant proposal is to have someone outside your lab critique it.

Peer review (at its best) achieves the same thing: when you want to be persuasive to someone who doesn't live in your world, doesn't share your assumptions, or doesn't have the same emotional ties to your work that you do, you work harder to make your arguments more clear, you better justify your assumptions, and in general you do a better job stepping our of your own mind to view the issue from someone else's perspective.