In his talk, he discussed the possibility that corpus studies could yield evidence against the supposed modularity of language and mind endorsed by, for example, Generative linguists (you can find the abstract here)
Geeraerts began his talk by stating that there seems to be a paradigm shift in linguistics from an analysis of structure that is based on introspection to analyses of behaviour based on quantitative linguistic studies. More and more researchers are adopting quantified corpus-based analyses, which test hypotheses using statistical testing of language behaviour. As a data-set they use experimental data or large corpora. In his talk, he discussed the possibility that corpus studies could yield evidence against the supposed modularity of language and mind endorsed by, for example, Generative linguists (you can find the abstract here)
One further trend Geeraerts identified in this paradigm shift is that these kinds of analyses become more and more multifactorial in that they include multiple different factors which are both internal and external to language. Importantly, this way of doing linguistics is fundamentally different than the mainstream late 20th century view of linguistics.
What is important to note here when comparing this trend to other approaches to studying language is that multifactoriality goes against Chomsky’s idea of grammar as an ideal mental system that can be studied through introspection. In the traditional view, it is supposed that there is some kind of ideal language system which everyone has access to. This line of reasoning then justifies introspection as a method of studying the whole system of language and making valid generalizations about it. However, this goes against the emerging corpus linguistic view of language. On this view a random speaker is not representative for the linguistic community as a whole. The linguistic system is not homogenous across all speakers, and therefore introspection doesn’t suffice.
The main thrust of Geeraerts’ talk was that research within this emerging paradigm also might call into question the assumption of the modularity of the mind (as advocated, for example by Jerry Fodor or Neil Smith): The view of the mind as a compartmentalized system consisting of discrete components or modules (for example, the visual system, language) plus a central processor.
The modularity thesis holds that these separate modules work independently and each feeds its information to the central processing unit. One of the main kinds of evidence adduced for this position are cases of double dissociation. One example would be the modularity of language and intelligence. This means that language skills can be intact while intelligence is negatively affected (an example for this +language – intelligence situation would be Down syndrome), or the other way around (e.g. – language + intelligence à aphasia).
By analogy, this view of modularity was also taken to apply to the language, so that Grammar as a mental system is seen as consisting of independently operating modules (syntax, semantic, pragmatics etc.). In addition, most modularists think that there is one module that is more important than others, namely syntax. This differs from the view of cognitive-functional approaches, which Geeraerts advocates. They don’t assume a hierarchy between the levels of language.
This is the point where it gets quite technical and I won’t go into detail into how Geeraerts proposed to use corpus evidence to falsify the idea of modularity in grammar, but the main idea is that according to him, a multifactorial corpus analysis can show that there are a variety of factors that influence the way utterances are produced. Importantly, such corpus studies (e.g. Speelman & Geeraerts 2009) indicate that these different factors, which include both language-internal (e.g. syntactic patterns, lexical collocations and conceptual closeness) and language-external factors (like speaker characteristics, regional, register variation, dialogues/multilogues vs monologues, private vs public, spontaneous vs prepared speech), seem to interact in such a way that is incompatible with the assumption of informationally encapsulated modules which work independently of each other.
In summary then, Geeraerts makes the case that the corpus-based quantitative turn in linguistics offers an opportunity for falsifying deep seated assumptions of mainstream 20th century linguistics, such as the homogeneity of linguistics and the modularity of grammar
Speelman, Dirk and Dirk Geeraerts. 2009. “”Causes for causatives: the case of Dutch ‘doen’ and ‘laten'”. In Ted Sanders and Eve Sweetser (eds.), Causal Categories in Discourse and Cognition 173-204. Berlin/New York: Mouton de Gruyter.