Steve Mellon, Post-Gazette Lu-in Wang, professor at the University of Pittsburgh School of Law, is author of the book "Discrimination by Default: How Racism Becomes Routine," which examines how much racism is less purposeful than it is thoughtless.

Most people would say, "What, me discriminate?"

Yet plenty of people often perceive that others are being discriminatory toward them.

"I was interested in understanding more of the subtle dynamics" of why that is, says Lu-in Wang.

The University of Pittsburgh School of Law professor researched and wrote a book on the subject that could get people thinking differently about how they and others think and act.

The book, "Discrimination by Default: How Racism Becomes Routine," was published last month by New York University Press. It's law-focused and part of an academic series, but its style and subject matter make it relevant to a broad audience.

The "by default" of the title has multiple meanings, but Ms. Wang homes in on the default settings that most of us passively accept for our computers. Those settings can become the expected, the standard. We may not even realize there are other options.

The same thing happens with discrimination, so that "we take it for granted and fail to recognize the extent to which it influences how we operate in the world."

A terrible result of unconscious bias was the 1999 shooting of frightened black African immigrant Amadou Diallo in the Bronx by police who mistook the wallet he pulled out for a gun.

Such bias also can have less heartbreaking but still substantial consequences, from a person being denied a job, or being stopped and searched, or being found guilty, or being charged more for a purchase.

People in power don't necessarily discriminate by design, she writes, nor do those discriminated against necessarily think that. "We expect and accept these outcomes -- largely because we do not recognize them as discriminatory, but instead as simply the way things are: standard operating procedures."

Among the examples she explores is a personal one, when a male doctor who gave her some bad news seemed to expect her, because she's a woman, to cry. She didn't want to, but she faked a few tears just so she could leave. "In the process, I likely confirmed my doctor's assumptions," she wryly concludes.

She explores "self-fulfilling ster-eotypes," which many people don't want to challenge, because they want to believe the world is stable and predictable.

In her Oakland office, she offers a stereotype she knows she has shared with other professors: a belief that the backward-ballcapped guys slumped in the back row of class are going to have attitude problems, and so professors may avoid calling on them. But in fact, they may be the most engaged students. Likewise, a prof who believes the young woman in the front row will be shy may not call on her, and fulfill that prophecy as well -- not intentionally, but by default.

In the book, Ms. Wang describes "situational racism," the complex idea that people discriminate based more on the situation rather than innate character. Experts "believe that hard-core, committed bigots comprise a much smaller share of the population than in the past," she writes. "Today, more people seem to embrace egalitarian values and to truly want to treat others fairly. Certainly, they want to see themselves as the kind of people who would not discriminate. Most people probably do not realize the extent to which they do discriminate, however, because they are acting on unconscious biases -- whether cognitive (race and other group-based stereotypes), motivational (the desire to maintain and promote the interests of their own group), sociocultural (internalized societal values, beliefs, and traditions), or a combination thereof."

Ms. Wang also discusses "failures of imagination," which can lead to the majority having empathy for people like them who are in trouble while ignoring the much worse suffering of people who are different -- often reflected in media coverage, too -- and "counterfactual thinking," which also can lead us to treat unequal and negative outcomes as normal and acceptable. That, she writes, has long been the case with racial profiling.

Just the threat of being stopped can cause minorities to alter their lives in various ways -- from driving bland cars to avoiding white neighborhoods altogether, which costs society as a whole. So do well-documented racial disparities in medical care, into which she also delves.

Ms. Wang, who also wrote "Hate Crimes Law," studied and quotes much social psychology and other research. She found that hate crimes against minorities and gays often are motivated by mundane factors, rather than passionate hatred.

Still, "It makes you really paranoid, walking down the street, if you read some of this stuff," she says with a laugh.

Realizing you might be acting unwittingly in discriminatory ways also could make you paranoid, she acknowledges.

But she believes that just stopping to raise that possibility can be a helpful first step. "It doesn't mean that I'm a bad person." She advises individuals to "slow down a bit" in their interactions and ponder: How are you interpreting the other person's behavior?

The law, which tends to require intent to prove and punish discrimination, she thinks "should change in small ways," but she's not calling for huge penalties or liability.

In the book she suggests subtle ways institutions such as the courts and hospitals might succeed at "overriding the default."

Ms. Wang, who teaches subjects such as contracts, civil procedure and antitrust law, next plans to write about economic discrimination, which she says will be even more interesting. But "Discrimination by Default" provides plenty of food for thought, even for her.

She says it surprised her "how little we are aware of as we go about operating in the world."