Complex First? On the Priority of Nouns in Language Acquisition and Evolution

Complex First? On the Priority of Nouns in Language Acquisition and Evolution Markus Werning (markus.werning@rub.de) Department of Philosophy II, Ruhr University Bochum 44780 Bochum, Germany (P4) For a cortically implemented syntax-semantics interface, the more widely distributed a concept’s neural realization is, the more effort it takes to establish a link between the concept and some lexical expression thereof. (P5) In ontogeny and phylogeny, capabilities demanding more effort, all other things being equal, develop and, respectively, evolve later than those demanding less effort. Abstract The paper points to an apparent paradox in the science of language. It regards the semantics of nouns and consists of a set of together incompatible, but individually well confirmed propositions about the evolution and development of language, the semantics of word classes and the cortical realization of word meaning. Theoretical and empirical considerations support the view that the concepts expressed by concrete nouns are more complex and their neural realizations more widely distributed in cortex than those expressed by other word classes. For a cortically implemented syntax-semantics interface, the more widely distributed a concept’s neural realization is, the more effort it takes to establish a link between the concept and its expression. If one assumes the principle that in ontogeny and phylogeny capabilities demanding more effort develop, respectively, evolve later than those demanding less effort, the empirical observation seems paradoxical that the meanings of concrete nouns, in ontogeny and phylogeny, are acquired earlier than those of other word classes. Keywords: evolution of language, language acquisition, compositionality, modularity, complexity, frames, situated conceptualization Introduction When one conjoins relatively well supported views on language acquisition and typology with frequently held views on the neural realization of meaning and some general principles of evolution and development, one seems to arrive at what I shall call the Complex-First Paradox. At its core is the question why concepts of substances, typically expressed by concrete nouns, seem to lexicalize ontogenetically and phylogenetically so early, even though they are apparently semantically far more complex than concepts that lexicalize later. The paradox consists of five propositions each of which seems plausible in its own right and is supported by empirical or theoretical reasons. The set of propositions – as is the nature of paradoxes – is apparently inconsistent, though, and thus points to an explanatory deficit in linguistic theory (Werning, 2008, (P1) The meanings of concrete nouns, in ontogeny and (probably) phylogeny, are acquired earlier than those of many – eventually even all – other word classes. (P2) The meanings of concrete nouns are substance concepts. (P3) Substance concepts are semantically more complex and their neural realizations more widely distributed in cortex than those expressed by the other word classes in question. The paradox should be obvious now: Assume that the meanings of concrete nouns like daddy, milk, and cat are indeed semantically more complex or, to use another word, thicker than the meanings of other word classes, e.g., adjectives like blue, big, and bold. If one accepts that meanings are mental concepts, the view is illustrated as follows: The substance concept [milk] has not only perceptual components of various modalities like [white], [fluid], and [sweet], but also components that relate to affordances like [to drink]. The attributive concept [blue], in contrast, seems to be relatively thin: it does not decompose into distinct conceptual parts and seems to pertain to the visual domain only. Assume, furthermore, that conceptual complexity correlates with a wider distribution of the conceptual parts, respectively, their neural realizations in the cortex. One then expects the neural correlate of [milk] to pertain to visual, tactile, gustatory, and action-related regions. In contrast, the correlate of [blue] seems to be bound to the visual cortex. Following another of the assumptions, a word-to-meaning assignment ought to be more easily tractable for a cortically realized syntax- semantics interface if the neural correlate of the meaning is relatively local, rather than widely distributed. Consequently, the link between the adjective blue and the attributive concept [blue] should require less effort than the link between milk and [milk]. Take it as a quite general principle of evolution now that with regard to one and the same domain incrementally more complex capabilities ceteris paribus evolve later than simpler ones. There had to be feathers first, only then some reptile species could evolve wings. Vision could succeed in evolution only after light-detection had evolved. It seems to be a simple truth that lies behind it: Natura non facit saltus. There is an outright analogy in development: A child must have acquired the capability to hold a stick before it will be able to use a hammer. Children have to acquire simple closed syllables (CVC, e.g., come) before they are able to pronounce syllables with complex codas (CVCC, e.g., cast). Given those assumptions, how can it be that the meaning of the noun milk ontogenetically and phylogenetically still is