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.