“Motherese”, the name of the type of language that infants generally hear, consists of simple sentences such as “Nora want a bottle?” and “Are you tired?”. These sentences almost always contain a noun and a verb. Yet, the infant’s vocabulary massively over-represents nouns in the first 100 words or so, while massively under-representing the verbs (never mind adjectives or adverbs, which almost never appear in the first 100 words infants produce; see, e.g., Goldin-Meadow, Seligman, and Gelman 1976). Even more surprising is that the over-representation of nouns to verbs holds even though