Stereotype is in accordance with gender, race, age or other professional to fix certain impression on people's social classifications formation. And most of the stereotypes were formed by the hearsay, rather than practical experience as the basis of factual basis. We unwittingly have become accustomed to the world is simplified stereotype after. Because in social life, we do not have time and energy to each of the group members have carried out in-depth understanding and our living area is limited, so the other members of the group outside the living area and our people, we only some common sense or experience we have contacted've learned to deduce all of this group. Because our time and energy is limited, so we often "brought on by" rather