Why nouns are learned before verbs: Linguistic relativity versus natural partitioning

Verbs are harder to learn than nouns: verbs are very rare in the first 50 words of children's vocabularies, even until the third year of life. Proposes that this "noun bias" is universal, explained by a universal prediliction of languages to straightforwardly map nouns onto object concepts. That is, the variable underlying the so-called "noun bias" is not lexical category per se, but rather something like concreteness - the reason that children's first words are primarily nouns is that the concepts referred to by nouns are conceptually more basic than the concepts referred to by verbs, prepositions, or other predicative words. Thus, the referents of many nouns are easily extracted from context by basic mechanisms of object perception and pragmatic inference - so children can assume very early on that, whatever language they are learning, a single object concept maps to a single noun. This simplicity, or naturalness, explains why nouns are acquired more rapidly than verbs early in language learning. Verbs express relations among nouns, and which relation a particular speaker has in mind is rarely accessible from observation alone. Hence, verbs are learned in the context of a vocabulary of known nouns.