Groups “live” in the same environment and to coordinate they need to help each other, and that includes criticism, as it can promote positive changes.
Criticism from an out-group member is usually hard to accept as in-group members will think that the reason of the critique is to discriminate or compete with them (2).
Social identity theory says that people have a new identity and they tend to protect their group, and this causes people to perceive and treat others differently, for example stereotypically or discriminatingly (5).
According to Tajfel (1972, 1) social identity theorizes how people