"Implicit Association Tests" (IATs) can tap those hidden, or automatic, stereotypes and prejudices that circumvent conscious control. Project Implicit — a collaborative research effort between researchers at Harvard University, the University of Virginia, and University of Washington — offers dozens of such tests.

We believe the IAT procedure may be useful beyond the research purposes for which it was originally developed. It may be a tool that can jumpstart our thinking about hidden biases: Where do they come from? How do they influence our actions? What can we do about them?

Biases and behavior
A growing number of studies show a link between hidden biases and actual behavior. In other words, hidden biases can reveal themselves in action, especially when a person's efforts to control behavior consciously flags under stress, distraction, relaxation or competition.

Unconscious beliefs and attitudes have been found to be associated with language and certain behaviors such as eye contact, blinking rates and smiles.

Studies have found, for example, that school teachers clearly telegraph prejudices, so much so that some researchers believe children of color and white children in the same classroom effectively receive different educations.

A now classic experiment showed that white interviewers sat farther away from black applicants than from white applicants, made more speech errors and ended the interviews 25% sooner. Such discrimination has been shown to diminish the performance of anyone treated that way, whether black or white.

Experiments are being conducted to determine whether a strong hidden bias in someone results in more discriminatory behavior. But we can learn something from even the first studies:

• Those who showed greater levels of implicit prejudice toward, or stereotypes of, black or gay people were more unfriendly toward them.
• Subjects who had a stronger hidden race bias had more activity in a part of the brain known to be responsible for emotional learning when shown black faces than when shown white faces.

Leading to discrimination?
Whether laboratory studies adequately reflect real-life situations is not firmly established. But there is growing evidence, according to social scientists, that hidden biases are related to discriminatory behavior in a wide range of human interactions, from hiring and promotions to choices of housing and schools.

In the case of police, bias may affect split-second, life-or-death decisions. Shootings of black men incorrectly thought to be holding guns — an immigrant in New York, a cop in Rhode Island — brought this issue into the public debate.

It is possible unconscious prejudices and stereotypes may also affect court jury deliberations and other daily tasks requiring judgments of human character.