The contributors to Part 1 of KSH2000 evidently all regard language as a cooperative enterprise (even if only in the sense of both playing or competing or following rules in a game, cf. Dessalles' contribution). This is, apparently, a very interesting and unexpected phenomenon given the way "Darwinian" evolution works. Here are some examples from the works.
'Selfish gene' Darwinism differs from earlier versions of evolutionary theory in its focus on one key question: Why cooperate? ...Darwinism in its modern, socially aware [sic] form provides our theoretical point of departure. (Knight, 2000a:19)
The chief problem for a Darwinian account of human speech, however, is the apparent level of altruism involved. The orthodox position in evolutionary biology (Dawkins, 1976) suggests that organisms are best understood as products of their selfish genes: they do not do things for the good of the group or the species, but in order to propagate copies of their own genetic material. Given this perspective, speech (and many other forms of cooperative behaviour) can be difficult to account for. Why do speakers freely exchange valuable information when the theory of natural selection predicts selfishness? In a hypothetical protolinguistic community, what would prevent the rise of a selfish mutant strain that listened but did not speak? Speaking or signalling always costs something in terms of time and energy, and may involve more indirect costs such as exposing the signaller to greater predation risk. Why not reap the benefits of the informative signals of others, without paying the costs of signalling oneself? Or worse, why not use the communication system to lie, misinforming other for one's own benefit? (Noble, 2000: 40-41)
...Krebs and Dawkins's theory is important and relevant because it forces us to recognise the Darwinian truth that animals, including ourselves, must be expected to be manipulative rather than informative, all things being equal. This fact must be constantly borne in mind in trying to account for the anomalous levels of altruism in speech. (Noble, 2000:42)
Human conversation can be seen as a game in which something is to be won or lost. ...language appears more as a kind of 'sport' than as a way of communicating information. (Dessalles, 2000:62-63)
...for gossip to function as a means of social bonding, it necessarily coevolved with another independent mechanism for establishing commitments to alliances. Raising the costs, in terms of time and energy, of forming coalitions safeguards against exploitation by 'freeriders' - those who accept benefits of social cooperation without paying the costs? (Power, 2000:81-82)
Cognition is likely to enhance fitness even where social strategies are individualistically competitive; this is not true of communication. Why share valuable information with competitors who may turn out to be direct rivals? Why pass over reliable sensory evidence in favour of information received only second-hand? ...This sets up selection pressures against evolution in the direction of speech. (Knight, 2000b:103)
One thing that is clear from the outset is that a model of evolution by natural selection has been uncritically adopted, and the apparent "anomaly" observed with language is a direct result of adopting this theory. In the following sections I show that there is good reason to reject the theory of evolution adopted as it is manifestly inadequate as an explanatory framework - competition/selfishness is simply not as ubiquitous as the theory requires/predicts. Having adopted this theory it is now up to the authors to provide mechanisms by which the predictions of the theory can be brought into line with observed reality. Humans are very cooperative now, and language is a very cooperative enterprise and must have been from the start. All of the works cited from above will reduce in relevance dramatically if it can be shown that in fact there is no "anomaly" to explain.