Language Evolution and Computation Bibliography

This article explains the evolution of human language and the brain. There are many ways organisms can adapt to moving targets. One of the ways is genetic evolution, when natural selection acts on variation in the population, selecting against those alleles that provide the least fit to the environment. The second way is by utilizing the phenotypic plasticity of a genotype. The third way is by means of systems and organs, which have evolved to cope with fast-changing environments and which have genetic underpinnings also. A set of genes can give rise to different phenotypes depending on the environment in which development takes place. The phenomenon, phenotypic plasticity, may be adaptive in species with variable environments. When natural selection acts to preserve adaptive phenotypes, it can lead to genetic change and to the fixation of specific phenotypes within a population by several evolutionary processes, including the Baldwin effect and genetic assimilation. The human brain is a very specific organ selected for the ability to track fast-changing parts of the relevant environment, which for hominins also included the linguistic environment. The human brain is highly efficient when it comes to language acquisition and production and is more efficient than any other known brain or artificial computing mechanisms.

The recent blossoming of evolutionary linguistics has resulted in a variety of theories that attempt to provide a selective scenario for the evolution of early language. However, their overabundance makes many researchers sceptical of such theorising. Here, we suggest that a more rigorous approach is needed towards their construction although, despite justified scepticism, there is no agreement as to the criteria that should be used to determine the validity of the various competing theories. We attempt to fill this gap by providing criteria upon which the various historical narratives can be judged. Although individually none of these criteria are highly constraining, taken together they could provide a useful evolutionary framework for thinking about the evolution of human language.

The costly signaling hypothesis proposes that animal signals are kept honest by appropriate signal costs. We show that to the contrary, signal cost is unnecessary for honest signaling even when interests conflict. We illustrate this principle by constructing examples of cost-free signaling equilibria for the two paradigmatic signaling games of Grafen (1990) and Godfray (1991). Our findings may explain why some animal signals use cost to ensure honesty whereas others do not and suggest that empirical tests of the signaling hypothesis should focus not on equilibrium cost but, rather, on the cost of deviation from equilibrium. We use these results to apply costly signaling theory to the low-cost signals that make up human language. Recent game theoretic models have shown that several key features of language could plausibly arise and be maintained by natural selection when individuals have coincident interests. In real societies, however, individuals do not have fully coincident interests. We show that coincident interests are not a prerequisite for linguistic communication, and find that many of the results derived previously can be expected also under more realistic models of society.