In large urban areas people know how to establish private zones of solitude even in crowds. urban golffman analyse this as an instance of socialization called

This is an instance of socialization called Gesellschaft. This occurs within a large, urban society in which social bonds are based on impersonal and specialized relationships, with little long-term commitment to the group or consensus on values

The answer is Gesellschaft. It is the making of rational will and is characterized by contemporary, cosmopolitan civilizations with their administration bureaucracies and big industrialized organizations. In the Gesellschaft, normal self-interest and scheming conduct act to deteriorate the old-fashioned bonds of family, relationship, and religion that infuse the Gemeinschaft’s structure.