Introduction

Recently, Hauser et al. (2002) argued that if we are to understand human language, several disciplines must work cooperatively. Predictably, these include linguistics and certain areas within psychology and anthropology as well as some relative newcomers: biology and animal behaviour. However, if collaboration can facilitate the investigation of language, long held to be a uniquely human faculty, it is surely indispensable to the study of human communication, for which a number of homologous or analogous processes exist in other species.

In the case of language, a behaviour with countless social benefits, researchers have tended to focus on dyadic interactions. In the typical model, the ‘sender’ is a rational human being who has information. As a social being, the sender wishes to share it. The ‘receiver’, equally rational and social, wants to hear it; so the receiver listens and makes an appropriate response. ‘Communication occurs,’ according to one authoritative source, ‘when one organism (the transmitter) encodes information into a signal which passes to another organism (the receiver) which decodes the signal and is capable of responding appropriately’ (Ellis & Beattie, 1986, p. 3).

Dyadic interactions such as these occur, of course, and deserve linguists' theoretical attention. However, in a gregarious species such as ours – and this is a major point of divergence between social communication and linguistic interaction – dyads are often embedded in aggregations of individuals, in various arrangements (communication networks in the sense of this book), and these will usually include one or more perceptual bystanders.