To have a preconceived notion about something or someone, with lack of self reasoning, is what one calls a prejudice. Humans pleasure in judging others, some even do it for a living, others for leisure.
So why do people do it? When an organism lives in the vicinity of another organism, animal instincts of survival come into play. Humans being the ones with the brain, usually end up using it to distinguish oneself from the others. Societal norms make humans desire for distinction and superiority, an innate defence mechanism for survival.
A human being is allowed to use the brain independently only when liberated from the finite arms of society. When one does it, one realizes the actual power of the brain and the expansive nature of universe.
Radiologist l Cyclist l Blogger