CHAPTER TEN THE ADAPTIVE PROBLEM OF ABSENT THIRD-PARTY PUNISHMENT GORDON P. D. INGRAM, JARED R. PIAZZA, JESSE M. BERING Abstract: Language is a uniquely human behaviour, which has presented unique adaptive problems. Prominent among these is the transmission of information that may affect an individual‘s reputation. The possibility of punishment of those with a low reputation by absent third parties has created a selective pressure on human beings that is not shared by any other species. This has led to the evolution of unique cognitive structures that are capable of handling such a novel adaptive challenge. One of these, we argue, is the propositional theory of mind, which enables individuals to model, and potentially manipulate, their own reputation in the minds of other group members, by representing the beliefs that others have about the first party‘s intentions and actions. Support for our theoretical model is provided by an observational study on tattling in two preschools, and an experimental study of giving under threat of gossip in a dictator game. Language makes humans unique. Other animals employ complex systems of communication (Hauser, 1997), but their communicative signals are indexical in reference (Deacon, 1997). As with non-verbal communication in humans, the reference of animal signals inheres in the drawing of attention to the presence of a stimulus. The stimulus referred to may be internal, such as dominance/submission displays in dogs (Lorenz, 1966, Figure 3) or emotional signals in humans (Ekman, 1999). Or the stimulus may be external, such as predator alarm calls in vervet monkeys (Cheney & Seyfarth, 1990), the waggle dance in honeybees (Dyer, 2002), or pointing in humans (Kita, 2003). Alone among animals, humans employ an additional, symbolic mode of communication in the form of language: human communicative signals do not always refer to stimuli directly, but may refer to other combinations of symbols (Deacon, 1997).