I think that the frat houses have many of the key elements of an organization. There are the elements of Membership there- you have to pay to be in a frat and you have to be part of the group and chose to join one certain one. There is a sense of Permanency, members come and they go, but through all of these transitions, the organization outlasts them. There is a division of labor, everybody has certain jobs to do. There is a hierarchy of authority, there are presidents and vice presidents, secretaries and treasurers. There are meetings where these people take over different parts. The organization does a lot of volunteering and events and these things need to be planned.