Self-organisation in human dynamics : the law of requisite vorticity

This paper draws on one of the most powerful idea in cybernetics - Ashby's law of Requisite Variety - from the perspective of the new paradigm of complexity (Wolfram, 2002). According to this law, "only variety can destroy variety" (Ashby, 1958), that is, control can be obtained only if the variety of the controller is at least as great as the variety of the situation to be controlled (Beer, 1972). As the variety is an expression of the richness of the field of possible states of the dynamic system, the controller must have enough information about this field in order to recognise the differences between the states and to deal with them. When complexity of the system increases, this kind of information is difficult to obtain. Complex dynamic interactions may lead to chaotic behaviour which is unpredictable because of its extreme sensitivity to minor perturbations. And not only this; dynamic interactions 'breathe' emergence of patterns able to self-organise - change and move, evolve and transfonn in unpredicable way. It is extremely difficult to control variety generated by chaotic and self-organising dynamics. The law of requisite variety invites the managers to seek for ways of destroying, suppressing or killing the variety in order to manage it.