On the first day of the Sonia Sotomayor confirmation hearings, one senator after another demanded assurances the judge would not allow her background to influence her decisions on the U.S. Supreme Court.

Sen. Jeff Sessions, of Alabama, the ranking Republican on the Senate Judiciary Committee, decried anyone "who believes it is acceptable for a judge to allow their personal background, gender, prejudices or sympathies to sway their decision in favor of or against parties before the court."

It's certainly fair to demand that members of the high court set aside personal politics and prejudice in their deliberations. But it seems odd to me that a series of white men can so easily assume themselves and everyone who looks like them to be impartial — and, at the same time, conclude someone of a different background would inevitably make tainted decisions.

Unfortunately, though, it is an all-too-common instinct. In every field, it seems, people from underrepresented groups must prove themselves able to transcend their identity. "A person of color is immediately suspected of bringing bias and perspective into their decisions," observes Luis Fraga, a political scientist at the University of Washington.

Peer reviewers search for distortion in the research of scholars of color. Editors press minority journalists to see whether they can fairly cover their own people. But those of us who are white enjoy a great privilege instead — our objectivity is presumed.

We would do well to follow Sotomayor's advice — that is, to pay attention to the lenses through which we see the world. In the oft-quoted 2001 speech at UC Berkeley, Sotomayor said that personal history can make someone wise. Again in the hearing Tuesday, Sotomayor acknowledged her own life story as a Latina can shape her reactions. But in both situations, she did not stop there. She clearly pointed to the need for judges to examine those feelings and, as she put it Tuesday, "accept that they may not be appropriate."

In the Berkeley speech, too, Sotomayor urged her audience to vigilantly check the assumptions, presumptions and perspectives derived from experience and heritage. "She was trying to get all of us to realize that your background, perspective, the cultural richness you bring "... provides potential insight, but also may bias you," Fraga says.

But white people rarely have to think about the ways in which our cultural and social experience of skin color affects us. We are not called to do so — both our majority status and messages from institutions such as the media and medicine feed the assumption we have no special perspectives, that our truth is the "real" truth.

Mainstream news outlets commonly present white perspectives as if they were representative. When reporting on its poll about race relations last year, for instance, The Washington Post emphasized the great progress achieved over the past decade. Only a quarter of all Americans now consider racism a big problem, its survey found, a decline by more than 50 percent from a decade ago. Only later in the story did one read about a striking difference in views: 44 percent of black people did see racism as an important societal problem, fully twice as many as whites. Similarly, USA Today reported last year that "Hopes on Race Relations are High" with Barack Obama's candidacy, overlooking sharp distinctions among African-Americans, Latinos and whites in their thoughts about racism.

Despite the diversity of U.S. society, white remains the normative background that all others must blend into or be contrasted against. Consider prescription medicines. They usually are tested in clinical studies that involve mostly white patients. Yet I've never heard mention of the "white" birth control pill or the "white" antihistamine Zyrtec. In contrast, the heart treatment BiDil, the first drug approved based on studies in a black population, was labeled specifically for African-Americans and marketed mainly to them.

Life experience matters. In fact, the whole field of cognitive and experiential psychology is based on that concept: "Almost every result we have shows that (it matters) in some way," says Harvard University experimental psychologist Mahzarin Banaji.

Unfortunately, white men and women often close our eyes to this fact when it comes to the impact of our own race on our own decisions. As Fraga says, with her insistence that identity shapes perception, Sotomayor rightly "requires all of us to take a deep look in the mirror."

Sally Lehrman is an award-winning reporter and writer on medicine and science policy and is author of "News in a New America," a fresh take on developing an inclusive U.S. news media. Reach her at slehrman@bestwrit.com.