Contrary to what we would like to believe, there is no such thing as a structureless group. Any group of people of whatever nature that comes together for any length of time for any purpose will inevitably structure itself in some fashion. The structure may be flexible; it may vary over time; it may evenly or unevenly distribute tasks, power and resources over the members of the group. But it will be formed regardless of the abilities, personalities, or intentions of the people involved. The very fact that we are individuals, with different talents, predispositions, and backgrounds makes this inevitable. Only if we refused to relate or interact on any basis whatsoever could we approximate structurelessness – and that is not the nature of a human group.
http://www.jofreeman.com/joreen/tyranny.htm