Semantics circle: Cognitive and communicative pressures shaping languages' lexicons

Abstract

Human languages vary in terms of which meanings they lexicalize, but there are important constraints on this variation. What explains these constraints? An influential proposal has been that languages are under two competing pressures: the pressure to be simple (e.g., to have a small lexicon size) and to allow for informative (i.e., precise) communication with their lexical items, and that some of the constraints on languages' lexicons are a consequence of languages finding a good way to trade off between the two pressures  (Kemp and Regier, 2012 and much subsequent work). However, in certain semantic domains, it is possible to reach very high levels of informativeness even if very few meanings from that domain are lexicalized. This is due to productive morphosyntax, which may allow for construction of meanings which are not lexicalized. Consider the semantic domain of natural numbers: many languages lexicalize few natural number meanings as monomorphemic expressions, but can precisely convey any natural number using morphosyntactically complex numerals. In such semantic domains, lexicon size is not in direct competition with informativeness. What explains which meanings are lexicalized in such semantic domains?  We will argue that in such cases, languages are (near-)optimal solutions to a different kind of trade-off problem: the trade-off between the pressure to lexicalize as few meanings as possible (i.e, to minimize lexicon size) and the pressure to produce as morphosyntactically simple utterances as possible (i.e, to minimize average morphosyntactic complexity of utterances). This study in conjunction with previous work on communicative efficiency suggests that, in order to explain which meanings get lexicalized across languages and across semantic domains, a more general approach may be that languages are finding a good way to trade off between not two but three pressures: be simple, be informative, and minimize average morphosyntactic complexity of utterances. I will end by discussing a potential avenue for future work, relating to how one may build on this finding to distinguish among competing hypotheses about semantic primitives in different semantic domains.