Compositionality, Metaphor, and the Evolution of Language

Abstract One of the great unknowns in language evolution is transition from unstructured sign combination to grammatical structure. This paper investigates central — while hitherto overlooked role functor–argument metaphor. type metaphor pervades modern language, but absent animal communication. It arises semantic clash between default meanings terms. Functor–argument became logically possible protolanguage once sufficient vocabulary and basic compositionality arose, allowing for novel combinations For example, verb hide , a functor, could be combined not only with concrete, spatial entity like food as its argument, also an abstract, non-spatial one anger . Through this clash, reinterpreted metaphorical action. requires possibility term combinability existence compositionality. At same time, it transcends compositionality, forcing non-literal interpretation. We argue that led development into fully-fledged multiple ways. Not did expand expressiveness, drove syntax including conventionalization fixation word order, demonstratives. Thus, fills gaps trajectory protolanguage, some terms simple combinations, elaborate structures human languages.