982 Nature-Inspired Cooperative Strategies for Optimization Juan R. González University of Granada, Spain Alejandro Sancho-Royo University of Granada, Spain David A. Pelta University of Granada, Spain Carlos Cruz University of Granada, Spain IntroductIon Biological entities (ranging from bacteria to humans) can engage in many and varied types of social inter- action, from altruistic cooperation to open conflict. A paradigmatic case of social interaction is cooperative problem solving (CPS), where a group of autonomous them in a parallel and coordinated fashion to solve the problem is justified because of the following fact: no algorithm outperforms another one in all circumstances. Besides, experiences in the field of optimization show that problem instances can be grouped in classes and there exists an algorithm for each class that solves the problems of that class most efficiently.