Final answer:
The in-group is a group that an individual identifies with and feels is a part of their identity, opposite to an out-group which they do not belong.
Step-by-step explanation:
The in-group is the set of people with whom we share a common identity. An in-group is a group that an individual feels they belong to and perceive as an integral part of who they are. This contrasts with an out-group, which is a group someone does not belong to and may feel a sense of competition or disdain towards. People tend to have tendencies such as seeking approval from, showing loyalty to, and maintaining or improving their status within their in-group. These affiliations can be based on anything from sports teams, and unions, to sororities, and can sometimes lead to negative behaviors such as ethnocentrism, racism, or heterosexism if the in-group defines others as 'not like us' and inferior.