Developmental evidence for sensitivity to hierarchical structure in the noun phrase

In most of the world's languages, complex noun phrases are created by placing adjectives closest to the noun, and demonstratives farthest away, with numerals in the middle (e.g., "this one short paper"). Theoretical linguistics suggests that this tendency may result from a typical hierarchical structure, in which adjectives form an immediate constituent with nouns, numerals combine with that sub-constituent, and demonstratives combine with the resulting unit. Recent experimental studies also support this idea, showing learners prefer orders that follow this hierarchy (e.g., Martin et al. 2020). However, it is unknown whether this same preference is found in children, who have less experience than adults with these structures, and who might be less sensitive to the hierarchical structure of language. Here, we investigate ordering preferences in 5-6-year-old children. Results show that children, like adults, prefer hierarchy-following orders, strengthening the hypothesis that the prevalence of these orders reflects a universal cognitive bias.