9 Communication and cooperation in living beings and artificial agents Achim Stephan, Manuela Lenzen, Josep Call, and Matthias Uhl 9.1 Introduction We are interested in communicative behaviors of living and artificial beings. Sometimes, communicative behaviors serve cooperation, sometimes competition. Sometimes it is for information exchange, sometimes, particularly among human beings, when chatting about the weather it is a form of social grooming. Mostly, communicative behaviors occur within species, but sometimes across species boundaries. Artificial agents are also engaged in behaviors that serve communicative purposes, often for us human users, sometimes among themselves. They are designed to cooperate with us or with each other. Even though communication with artificial agents becomes more and more natural for us, there are still major and decisive differences between human (and animal) communi- cation and communication with and among artificial creatures. Taking a closer look at those differences may help us to better understand the phenomenon of communication in general. The goal of this article is to highlight these differences by comparing communicative and cooperative behaviors of living and artificial beings. Thereby, living beings with their huge variety of communication behaviors take the lead to draw the most salient distinc- tions in both communicative and cooperative behaviors. Then, we apply these distinctions to a variety of behaviors instantiated by artificial agents. We will see what is common and what is distinct, comparing the living world with the artificial: It will turn out that a huge amount of cooperation is possible without direct communication, which can be seen in simpler animals as well as in robots. For more complex tasks, however, communication always plays a major role in terms of information sharing. Furthermore, in some animals and in humans, cooperation also has an important social component, which at the same time influences the form and content of the ongoing communication. It is particularly this feature that is neglected by the classical Shannon–Weaver (Shannon 1948) approach of information theory, according to which the sender encodes some information which the receiver decodes. As we will see, the Shannon–Weaver approach fails to take into account the social constraints which are particularly important in human societies, but can also be observed in, for example, chimpanzee groups. These findings indicate that 09-Wachsmuth-Chap09 6/3/08 10:03 AM Page 179 In: I. Wachsmuth, M. Lenzen, & G. Knoblich (eds.), Embodied Communication in Humans and Machines, Oxford, Oxford University Press, 2008, pp. 179-200.