Why is ingroup bias a problem?

Ingroup bias is a problem because it causes us to treat people differently depending on whether we are members of the same group.

This can cause us to think negatively about or discriminate against people we hardly know (i.e., the outgroup) and support members of our ingroup on the basis of a shared identity, rather than merit. For example, ingroup bias might lead someone to recommend an acquaintance for a job simply because they went to the same prestigious college.