Recently, there are intense conflicts arising in our society. People with different political stances joined together, gave labels to represent themselves, and fought to preserve what they value in society. Some relatively radical persons would 'un-friend' or even attack those who hold different opinions from them. This phenomenon surprised many Hong Kong citizens, making them wonder how a difference in political stance could create such an intractable conflict, and why even friends and relatives could hardly discuss the issue calmly and listen to each others' opinions. Indeed, the above phenomena could be explained by some of the theories and concepts in social psychology.
Social psychologist William G. Sumner developed two important concepts ---- 'in-group' and 'out-group'. In-group refers to the group that a person psychologically identifies with as being a member, for instance your own class, or the political group that holds the same political ideologies as you. Members of in-group would help and cooperate with each other, or even evaluate each other more positively, and allocate more resources to each other (e.g. some people donated money and goods to people who share their political ideas). Such behaviour was coined as 'in-group favouritism'.
By contrast, an out-group is a social group with which an individual does not identify, for example classes other than own, people with different political ideas. Out-group is often being regarded as an opponent by members of the in-group. Especially when there is conflict of interest, when out-group is being seen as hindering the goal of the in-group, and when the out-group is seen as posing threat to members of the in-group. Under such circumstances, 'out-group derogation' would occur, resulting in stigma, aggressive behaviours, or even wars.
So what can we do to reduce biases and prejudices, and help reconcile such conflict in society? It was proposed by social psychologists that people tend to simplify the complex world by classifying people into categories, which would make people disregard individual differences, but form a set of characteristics to describe a group of people (e.g. 'Yellow ribbons are …', 'Blue ribbons are…', 'Policemen are…'), leading to discrimination and prejudice. To reduce such prejudice, people must come into contact with individual members of out-groups, discover similarities between individuals of out-group and themselves, so as to reduce biases and conflicts.