Out-group Bias explores the concept of prejudice and discrimination in society. It examines the psychological and social origins of out-group bias, and how it can manifest in different ways. It looks at how out-group bias can lead to negative outcomes,
From Wikipedia
In-group favoritism, sometimes known as in-group–out-group bias, in-group bias, intergroup bias, or in-group preference, is a pattern of favoring members of one's in-group over out-group members. This can be expressed in the evaluation of others via the ultimate attribution error, in the allocation of resources, and in many other ways.