The document discusses the concept of identity and how it defines who we are through our social categories. Identity influences our decisions and behavior as different social norms are associated with different social categories. While people have some choice in their identity, others may try to change how people see themselves and their norms. Identity is fundamental to behavior and can be limited by racial, ethnic and social class boundaries. It is one of the main determinants of economic position and well-being. A person's behavior depends on how they see themselves, and identity plays a central role in how societies and organizations function.