Narrow Results

The defining problem of animal signalling theory is how reliable communication systems remain stable. The problem comes into sharp focus when signals take an arbitrary form, as human words do. Many researchers, including many in evolutionary linguistics, assume that the Handicap Principle is the only recognised solution to this paradox, and hence conclude that the process that underpins reliability in humans must be exceptional. However, this assumption is false: there are many examples of cheap yet reliable signals in nature, and corresponding evolutionary processes that might explain such examples have been identified. This paper briefly reviews the various processes that ay stabilise communication and hence suggests a three-way classification: signals may be kept honest either by (i) being an index, where meaning is tied to form; (ii) handicaps, in which costs are paid by the honest; or (iii) deterrents, in which costs are paid by the dishonest. Of these, the latter seems by far the most likely: humans are able to assess individual reputation, and hence hold the threat of social exclusion against those who signal unreliably.

No abstract received.

Ambiguity is commonplace and indeed inevitable in everyday language; an utterance produced in one context can have a quite different meaning in another context. Despite this, listeners almost always converge upon the speaker's intended meaning. How is the achieved? Grice's cooperative principle (Grice, 1975) provides a still widely accepted answer. It comprises four maxims of conversation: quality (tell the truth), quantity (do not say too much or too little), relation (be relevant) and manner (be clear and concise). It is, according to Grice, because listeners assume that speakers follow these maxims that they are able to interpret utterances in a contextually sensible way.

Since Grice's seminal contribution, numerous refinements, additions and extensions to his work have been proposed (e.g. Horn, 1984; Levinson, 1983). The Gricean foundation, however, remains widely accepted. This acceptance means that the neo-Gricean framework has also been influential in several related disciplines, including psycholinguistics (Clark, 1996), the philosophy of language (Lycan, 2008), and indeed language evolution (Cheney & Seyfarth, 2005; Gärdenfors, 2006; Haiman, 1996; Hurford, 2007). One alternative is Relevance Theory (Sperber & Wilson, 1995), which supplants the four maxims with a single notion of relevance, which is claimed to be more basic than the Gricean maxims. As such, Relevance Theory constitutes "an ambitious bid for a paradigm-change in pragmatics" (Levinson, 1989, p.469).

One way in which we can choose between competing theories in linguistics is to use evolutionary considerations (Kinsella, 2009). This presentation (which is based upon Scon-Phillips, in press) will describe a very basic and simple evolutionary game-theoretic model of the evolution of communication. It assumes only that listeners maximise their payoffs, and that speakers do the same, given that listeners will do this. Two entirely general statements about the evolution of communication are generated. These are functional descriptions that will apply to all evolved communication systems. It is then asked what they imply for linguistic communication in particular.

The answer is that they predict, quite precisely, the two principles of relevance that lie at the heart of Relevance Theory: that listeners will seek to maximise relevance, and that the very production of an utterance brings with it a guarantee of relevance. This suggests that something like Relevance Theory, and the cognitive mechanisms that it posits, must be correct; and hence that Relevance Theory, rather than the Gricean paradigm, should be the default framework for pragmatics.

Note from Publisher: This article contains the abstract and references.

Communication is not a trait possessed by one or another individual. Rather, it is an interaction between two or more individuals (Krebs & Dawkins, 1984; Maynard Smith & Harper, 2003; Scott-Phillips, 2008). This is reflected in contemporary definitions of communication, which emphasise that whether a given behaviour is a signal depends on whether there is a corresponding response, and vice versa (Maynard Smith & Harper, 2003; Scott-Phillips, 2008). This suggests a chicken-and-egg problem: if signals and responses depend upon each other to explain their adaptive value, then how can communication emerge in the first place? The existing ethological literature provides two answers to this question: ritualization and sensory manipulation. In ritualization, signals evolve from behaviours that were originally only cues. For example, the use of urine to mark territory may have begun as a marker of fear, produced by animals leaving territory in which they felt safe, which other animals then used as the cue of the focal individual's presence (Maynard Smith & Harper, 2003). In sensory manipulation, signals evolve from behaviours that were originally only coercive. For example, many mating displays may have begun as scenarios in which a preference for objects of a certain colour allowed the behaviour of soon-to-be receivers to be manipulated by others (Bradbury & Vehrencamp, 2000)…

In a combinatorial communication system, some signals consist of the combinations of other signals. Such systems are more efficient than equivalent, non-combinatorial systems, since fewer elements are required to express the same number of possible messages. Despite this obvious adaptive advantage, there are only a handful of attested examples in nature (Hurford, 2011). Yet, at the same time, human language is massively combinatorial: many different types of combination can—along with other linguistic phenomena (syntax, phonetics, etc.)—contribute to meaning. How, then, do we account for the rarity of combinatorial communication systems in non-human species while accommodating the considerable combinatorial complexity of human language?…

Evolutionary stability is the defining problem of animal signaling theory (Maynard Smith & Harper, 2003). If it pays a signaler to signal dishonestly, at least on average, then we should expect dishonest signals to evolve. If this occurs, the receivers best reaction is, again on average, simply to ignore signals from these signallers, and so we should expect this indifference to evolve too. The end result is that the system has collapsed, and no further communication takes place. Under what circumstances does this outcome not come to pass…