Robert L. Campbell (firstname.lastname@example.org) Department of Psychology; 410A Brackett Hall Clemson University; Clemson, SC 29634-1511 USA
The well-attested friction between linguistics and psychology is not a superficial phenomenon. No conception of language has had more influence on psychology and Cognitive Science than the linguistics of Noam Chomsky. Yet Chomskyan linguistics is radically incompatible with viable accounts of knowledge, and of the development or evolution of knowledge. This incompatibility is strongly manifested in two characteristic Chomskyan doctrines: linguistic competence and the autonomy of syntax. The fallacious arguments on which Chomsky relies are analyzed, and their deep implications for Cognitive Science are traced.
No one who works in linguistics or psychology will be shocked to hear of significant friction between the two disciplines; this has been widely attested since the mid- 1960s. Still, it is normally assumed that linguistics can fit under the Big Tent known as Cognitive Science just as well as psychology can. Few child language researchers would attempt to study language development without seeking to incorporate the findings of contemporary linguistics; few psycholinguists would attempt to operate without regard to categories, assumptions, and doctrines derived from linguistics.
Contrary to these impressions, I will argue that important claims made by contemporary linguistics forestall its assimilation into cognitive or developmental psychology. These are not superficial features of linguistic inquiry, lightly modifiable to assure a better fit with psychology. On the contrary, they are fundamental. They will not change unless linguistics comes to be regarded as a purely formal discipline without relevance to psychology--or linguistics is radically reoriented to assure psychological relevance.
To keep this discussion focused, I will consider only the linguistics of Noam Chomsky and his followers. American linguistics is thoroughly dominated by this school; for most contemporary cognitive psychologists, developmental psychologists, and philosophers of mind (although not for most Artificial Intelligence researchers), linguistics is Chomskyan linguistics. Moreover, Chomsky has consistently and persuasively insisted that psychology must pay heed to linguistic formulations, instead of operating in splendid isolation from them. Meanwhile, he has fervently resisted any suggestion that linguistics might have something to learn from psychology.
Chomsky's conception of the data that are relevant to linguistics poses difficulties; so does his conception of learning. But the antipsychological implications of Chomskyan theory and practice are largely traceable to two assumptions: the doctrine of linguistic competence and the doctrine of autonomy of syntax.
Chomsky formulated the distinction between linguistic competence and linguistic performance in Aspects of the Theory of Syntax ( 1965). Though highly controversial when first presented, it has gradually permeated Cognitive Science; nowadays it is commonplace for cognitive and even developmental psychologists to refer to a particular formulation as a "competence theory," in Chomsky's sense.
We have to be careful about the precise meaning of competence and performance here, for they are liable to get conflated with common-sense, useful notions ( Campbell & Bickhard, 1986). We all recognize that a person may know something, or be able to do something, yet may not manifest this knowledge under some conditions. This distinction--between what the person is competent to do under some condition or another, and how the person manifests that competence under these specific conditions-- is not at issue. But we should realize that this common- sense distinction in no way constrains how the skill or knowledge is to be accounted for; it prescribes no specific way of modeling knowledge.
While conducting empirical research in psychology, we may be concerned to sort out the ability of interest to us ("competence") from other abilities ("performance") that are extraneous from our point of view. So, for instance, if I am trying to assess whether a 7-year-old can solve a problem that requires a certain type of reasoning, I would like to be able to exclude memory for the premises as an explanation for the child's performance. Given the purpose of my research, being able to reason in a certain way is "competence," and being able to remember premises beyond a certain length or complexity is "performance."
All the same, what is competence to me may be performance to another researcher; what is an extraneous, confounded nuisance to me may be the primary object of inquiry for someone else. A researcher who wants to track the development of working memory capacity would regard memory for the premises as "competence"; the ability to make that novel inference that so interested me would now become "performance." Again, this second sort of competence-performance distinction in no way dictates how either competence or performance is to be modeled.
Chomsky's distinction is often confused with these other two. It should not be, for it is predicated on very specific