What we tend to do is prejudge others, to categorize certain people we don’t even know. We’ll form a belief or an opinion before it even happens, without any rational reasoning or factual proof. We assume certain things to transpire, which creates false positives.
We become prejudiced of certain things, events, and especially people, as we generalize humans based on their race, religion, or gender.
These stereotypical notions are usually ingrained in us when young, usually from our parents, as we typecast certain groups of people.
There are other prejudices …