Beyond the individual in the evolution of language
View/ Open
thesis.zip (61.40Mb)
Date
2009Author
Hawkey, David J. C.
Metadata
Abstract
This thesis concerns the evolution of language. A proliferation of theoretical
models have been presented in recent years purporting to offer evolutionary
accounts for various aspects of modern languages. These models rely heavily
on abstract mechanistic models of the production and reception of language by
modern humans, drawn from various approaches in linguistics which aim at
such models. A very basic and ubiquitous assumption is that expressions have
meaning in virtue of being associated with internal representations, and that
therefore the evolution of language can be modelled on the basis of individuals
trying to produce external manifestations of these internal “meanings”. I examine
the role of this assumption in language evolution theorising, and review evidence
from neuroscience and first language acquisition relevant to the validity of
this assumption. The chaotic nature of the relationship between “meaning” and
the brain undermines the supposition that the evolution of language was driven
by spontaneous association between internal structures and external forms.
I then turn to the philosophical basis of language evolution theorising, adopting
a Wittgensteinian perspective on the cognitive interpretation of linguistic theories.
I argue that the theoretical apparatus of such approaches is embedded in
language games whose complicated rules relate to linguistic behaviour (and idealisations
of that behaviour) but not to neural organisation. The reinterpretation
of such descriptions of language as descriptions of the internal structures of language
users is rejected as a grammatical confusion: if the rules for constructing
linguistic theory descriptions do not mention neural structures, then theoretical
descriptions of the linguistic abilities of an individual say nothing non-trivial
about their internal brain structure. I do not deny that it would, in principle, be
possible to reduce linguistic theories (reinterpreted as mechanistic descriptions)
to neural structures, but claim that this possibility is guaranteed only by leaving
the practice of re-describing physical brain descriptions entirely unconstrained. Thus the idea that we can reasonably infer the behaviour of humans and prehumans
in more primitive communicative environments by manipulation of the
models of linguistic theories is unfounded: we have no idea how such a manipulation
would translate into statements about neural organisation, and so no
idea how plausible such statements about earlier neural organisation (and the resultant
behaviours) are. As such, cognitive interpretations of linguistic theories
provide no better ground for statements about behaviour during earlier stages
in the evolution of language than guessing.
Rejecting internal-mechanism based accounts as unfounded leaves the evolution
of language unexplained. In the latter parts of this thesis, I offer a more neutral
approach which is sensitive to the limited possibilities available for making
predictions about human (and pre-human) behaviour at earlier stages in the evolution
of language. Rather than focusing on the individual and imputed internal
language machinery, the account considers the communicative affordances
available to individuals. The shifts in what individuals can learn to do in interaction
with others, that result in turn from the learning of interactive practices
by others, form the basis of this account. General trends in the development of
communicative affordances are used to account for generalisations over attested
semantic change, and to suggest how certain aspects of modern language use
developed without simply assuming that it is “natural” for humans to (spontaneously)
behave in these ways. The model is used in an account of the evolution
and common structure of colour terms across different languages.