ADAM SMITH'S RATIONAL CHOICE LINGUISTICS

I. LANGUAGE AND OTHER HUMAN ACTIONS Linguistics may be the last of the social sciences to avoid the rational choice approach. Many philosophers, Adam Smith especially, argue that being human is the same as using language. Reason and speech are primitives for him; we no more choose to use language than we choose to be human. His argument in Wealth of Nations is that trade and language are two aspects of the same process; humans trade because we have language, nonhumans do not trade because they do not.(1) Merely because language is a background condition for human choice, however, does not obviate the possibility of rational choice aspects of language. Smith's argument exploits the simple possibility of substitution of one feature of a language with another in such a way as to minimize the time cost of conveying meaning. He distinguishes sharply between what is true for children naturally learning a language with what is true for adults learning a language in which to trade. Perhaps because the rational choice basis of such trade languages (pidgins) is entirely obvious, pidgins have been defined out existence to keep traditional linguistic theory safe from embarrassing contact with rational choice considerations.(2) The claim that a language is spoken by those of homogeneous competence is regarded as true by definition. This web of belief traps rational choice considerations because now, by definition, we have precluded the possibility that one's fluency in a language increases with exposure.(3) Scholars working in pidgin and/or language death are leading the way to question the definitional status of such a specification.(4) Why this might be so will be clearer after we look at Smith's account of a language which loses its grammar. II. IN SMITH'S WORDS In standard histories of linguistics such as Land [1974], Smith is given credit for developing the argument that languages will grow more grammatically complex over time. It is insufficiently noticed that Smith restricts this argument to an isolated language. His example is classical Greek, a language in which he believed all the words were generated internally.(5) The Smithian problem upon which we shall focus is how the grammar of language evolves as the result of trade between people from different languages. Smith does not see any reason why a language learnt in childhood could not have an arbitrarily large number of what modern linguists call inflections: As long as any language was spoke by those only who learned it in their infancy, the intricacy of its declensions and conjugations could occasion no great embarrassment. The far greater part of those who had occasion to speak it, had acquired it at so very early a period of their lives, so insensibly and by such slow degrees, that they were scarce ever sensible of the difficulty. (Smith [1985, 220]). Something very interesting happens when adults need to conduct business across languages. Rational choice considerations enter into the choice of a language's grammatical structure: But when two nations came to be mixed with one another, either by conquest or migration, the case would be very different. Each nation, in order to make itself intelligible to those with whom it was under the necessity of conversing, would be obliged to learn the language of the other. The greater part of individuals too, learning the new language, not by art, or by remounting to its rudiments and first principles, but by rote, and by what they commonly heard in conversation, would be extremely perplexed by the intricacy of its declensions and conjugations. They would endeavor, therefore, to supply their ignorance of these, by whatever shift the language could afford them. Their ignorance of the declensions they would naturally supply by the use of prepositions; ... The same alteration has, I am informed, been produced upon the Greek language, since the taking of Constantinople by the Turks. …