Since A. Turing did his pioneering work on morphogenesis by coupling diffusion and chemical reactions, many models of cooperative phenomena, making use either of sets of continuous differential equations or discrete networks of cellular automata, have continually produced the same kind of phenomenon: starting from an homogeneous initial state (which may be set by a random distribution of states over the elements of a network), the system evolves "spontaneously" towards a stable state where a macroscopic structure in space and/or in time can be recognized. This evolution is the result of local laws of interaction between the coupled phenomena or the connected automata. This phenomenon is very general and is observed for a wide range of local laws of interaction (continuous, boolean, threshold functions, etc.) and connections.