Without criteria for what counts as a U/N-shaped developmental trajectory, it is not clear how many legitimate "Us" really exist. Many, if not all, "Us" may turn out to be illusions borne out of our sampling methods, task construal, and blurry lenses of description. (Contains 2 figures.)

Distributional information is a potential cue for learning syntactic categories. Recent studies demonstrate a developmental trajectory in the level of abstraction of distributional learning in young infants. Here we investigate the effect of prosody on infants' learning of adjacent relations between words. Twelve- to thirteen-month-old infants…