Prejudice refers to a preconceived judgment, opinion or attitude directed toward certain people based on their membership in a particular group. It is a set of attitudes, which supports, causes, or justifies discrimination. Prejudice is a tendency to over categorize.
Prejudice is a preconceived attitude that has commonly been used in referring to judgments of one’s race, but is also used when referring to sex, ethnicity, religion, and sexual orientation. The most comprehensive and accepted definition of prejudice was introduced by Gordon Allport . Mr. Allport defined prejudice as “aversive or hostile attitude toward a person who belongs to a group, simply because he belongs to that group, and is therefore presumed to have the objectionable qualities ascribed to that group.”
Prejudice can be classified into three different categories: cognitive prejudice, affective prejudice, and conative prejudice. Cognitive prejudice refers to what people believe is true, stereotypes. These beliefs include expectations, impressions, criticisms, and assumptions. Affective prejudice refers to what people dislike and like. It holds an emotional aspect of prejudice. Conative prejudice refers to how people are inclined to behave  and be can be observed by others through discrimination. There is a correlation between the three types of prejudice and are entwined so closely; it is impossible to define one without defining the other . However, all three do not have to exist within one individual for prejudice to exist.
There are several different explanations for the origins of prejudice. One explanation considers personality as an origin of prejudice. According to the personality theory of prejudice, people are prejudice because it meets particular needs associated with their personality. These researchers theorize that certain personality types contribute to discrimination, such as closed-mindedness, dogmatism, and authoritarianism . Accordingly, individuals who have developed prejudice in this manner are not just prejudice toward one group, but have a tendency to be prejudice towards anyone who does not belong to their group. Another explanation for prejudice is that it is learned and it develops through social learning. The social learning view states that negative attitudes toward different groups are acquired due to what children see and hear from parents, teachers and friends and because they are rewarded for assuming these views . The media may also play a role in the social learning theory of prejudice. Many times the stereotypes that are portrayed in the media may be a person’s main source of information pertaining to particular groups of people. Accordingly, prejudice can be learned through conditioning and these attitudes can develop throughout the lifespan. A third perspective is called the social identity theory. This explanation suggests that people divide their social world into two categories-us (the in-group) and them (the out-group). Contrasting beliefs and feelings are usually attached to members of one’s in-group and to members of out-groups . Members of the in-group are viewed more positively while members in the out-group are viewed more negatively. Some researchers suggest that individuals may identify with specific groups in order to boost their self-esteem.
Relevance to Childhood Development
Research has found that children can differentiate among people based on racial cues as early as 3 years of age. By the age of 4 their racial awareness allows them to distinguish explicitly among members of different racial groups . By the age of 4, children who belong in an ethnically dominant group are able to precisely identify the group in which they belong to, they are able to show preferences for this group, and display strong biases towards their in-group. It is believed that by around the ages of 6 and 7, these biases peek and then show a gradual decline as the child ages. However, some research indicates that the biases remain at the same level until the age of 12. It is developmentally appropriate for children to notice differences and this alone is not an issue. Problems occur when negative values are taught, learned, and attached to the differences.
Prejudice can have a negative effect on the social and moral development of children. Due to misconceptions or negative experiences a child may never socialize with someone belonging to an out-group. This child may go on believing negative things about all people belonging to particular groups and may even see a positive person belonging to an out-group as an exception.  believes that children taught to hate different racial, ethnic, religious, or national groups are suffering a corruption of their moral development. He states that this moral corruption satisfies the definition of psychological abuse. These children are not able to show tolerance or respect for individual differences.