Social Identity Theory

People receive part of their identity from the social groups that they belong to.  This can be a key issue in a feeling of belonging.  It is through a group affiliation that many people gain their self esteem.  This self esteem is derived from belonging and interactions within the group.  It is the feeling of being part of the "We" that comes with group membership.  But with the territory can come a bias of superiority.  This can lead to beliefs that the ingroup which they belong is better than the outgroup which others belong.  Our social identity can cause us to categorize using heuristics about others.  It also can cause us comparisons which tend to benefit our ingroup with a bias of privilege and favoritism.  On the other hand, is it necessarily a bad thing to strive for belonging?  After all we are social beings according to Aristotle.