Chapter 9 argues that the origins of collaborative problem solving can be traced back to mutual collaboration, which built on the evolution of more advanced forms of gestural communication. Elaborative collaborative problem-solving builds on this type of collaboration and requires proximate mutual interaction and sympathy between the collaborators. In contrast, rule-governed collaborative problem solving centers on an idea of fairness and requires that collaborators adhere to specific rules or norms in their collaboration. At least two collaborative cultures were key in the evolvement of this type of collaboration. First, stone tool learning require deliberate practice and the presence of a community of learners with norms. Explicit teaching and individual training built on purposeful activities that were considered valuable, a collaborative culture which over time made it possible to refine stone tools across generations. Second, it is likely that hunter-gatherer groups were important in the development of ideas on equal participation, building on reciprocity and norms that emphasized equal sharing of food. Calculated reciprocity represents a significant move away from the dominance of a few individuals in groups. Equal sharing of food required increased control of emotions and the establishment of norms that kept free riders out. A fair sharing of spoils also permitted role differentiation in groups because not everyone had to participate in the hunt in order to get food.

This chapter provides a broad overview of terminology and concepts in the study of animal communication. First, we focus on the evolutionary origins or phylogenetic causes of communicative signals. We address how communication systems can arise under several circumstances by increasing the reproductive success of both senders and receivers of signals. We summarize terminology describing what is communicated (self-reporting and other-reporting), how it is communicated (different modalities) and to whom it is communicated (conspecifics, heterospecifics). We further discuss how signal design is influenced by the risk of deception. The debate between the information and manipulation perspective of animal communication is briefly outlined. The second part of the chapter focuses on proximate aspects of animal communication. We describe signal acquisition in animals through ultimate mechanisms (biological inheritance, phylogenetic ritualization) and proximate mechanisms (ontogenetic ritualization, cultural learning) with a particular focus on learning. We further discuss signal selection, i.e., to what degree some animals have flexible control over signals and how they adjust them according to the recipient. Last, we discuss new directions and open questions in the study of animal communication, i.e., considerations of compositionality and multimodality, turn-taking, repertoire acquisition and development, flexibility and memory, and the problem of using a one-size-fits-all approach for understanding animal communication systems.