What it is: A personal preference or prejudice which influences a person's thinking and decision-making.
What it means: People who are biased let their personal preferences sway their thinking, which means that their judgements are likely to be one-sided. If in a conflict or dispute you give the views or interests of one side more weight (because you personally support it) than the other, you are letting bias warp your judgement. In short, you are being unfair, particularly if you don't make it clear that your views are based on your prejudice. It's important to spot bias and prejudice wherever it exists, because people often try to hide it - even from themselves.
Think about it: Watch for bias in yourself and others, at home, school/college, and work. How can it be recognised? - not all choices are made for biased reasons. Think of ways to suggest, tactfully, that an opinion or decision isn't fair, if you're sure it's biased. Define the differences between being prejudiced and being at the receiving end of prejudice. Does being at the receiving end mean becoming prejudiced oneself? If so, is there a way out of this cul-de-sac?