Many are slaves to their prejudices, whether they are aware of them or not. In being so, they treat the rest of the world according to their blindness.
If one favors Blacks over Whites, even in the back of their minds, they will applaud and recognize the actions of Blacks and ignore, minimize, or dismiss the actions of Whites, regardless of the actual merit of the action. If one favors Whites over Hispanics, they will applaud and recognize the actions of Whites and ignore the actions of Hispanics.
If one favors women over men, they will listen to and give recognition to women, while denigrating the actions of men.
If one favors men over women, they will listen to and give credence to men, and dismiss the same actions of women.
When someone points out to them proof that their prejudice is not based in reality, they come up with rationales and nonsensical phrases in defense, like "the exception proves the rule", or "that's just the way it is".
Prejudice in all forms is not a passing personal folly, but a detriment to the human race. A school teacher who favors one race over another is sabotaging the futures of the students in his or her class. An employer who favors one gender over another is undermining the very lives of those he or she does not hire, as well as selling the business short. A student who seeks Spiritual guidance ignores beneficial guidance from those he or she dismisses, and blindly follows another who fits into their prejudice. A husband ignores his wife and gives his attention to his male friends; a wife ignores her husband to attend to her female friends. A member of a group of friends spreads negativity about someone who they feel threatened by so the others will not welcome the person. A female supervisor who favors males creates situations for male employees to shine, and undermines female employees so they appear less effective, paving the way for the males to be promoted, and blocking the way for the females. A rock band hires the musicians they like, not actually the best musicians, even undermining their own potential. A police officer believes the statement of the abuser over the victim, and the abuser goes free to do it again. A psychiatrist believes the father over the mother of a troubled child, or believes the parents over the child, or the child over the parents, and treats the patient  according to the psychiatrist's prejudice, not according to the reality of the situation. A leader is elected because people like him or her, not according to experience or intelligence. A parent favors a sister over a brother, or a brother over a sister, causing both of them unpredictable emotional scars.
A high school faculty staff nurtures and tutors the students they favor, and ignores and even undermines the students they do not; the students they let "Fall through the cracks" will not have the opportunity they would have had if their needs were addressed like the needs of the others were; how many of these students would have gone into fields such as medicine, how many of them would have contributed to treating disease, finding cures, saving lives?
Prejudice is a filter one sees the world through, it is a common, global trait of the humans species, regardless of gender or nationality. It is not clear yet to science whether it is nature or nurture, whether it is something that we are born with or something we learn from those in our environment. It is clear, however, that some are more aware of their own prejudices than others. It is a blindness, and not addressing one's own prejudice is like arguing that the sky is actually green, while wearing yellow-tinted glasses.

© 2010 Marianne Black Snuggs