摘要: Greenberg’s (1963) Universal 34 states that “No language has a trial number unless it dual. No dual plural.” We present an associative model of the acquisition grammatical based on RescorlaWagner learning theory (Rescorla & Wagner, 1972) predicts this generalization. Number as real-world category is inherently structured: higher numerosity sets are mentioned less frequently than lower sets, and always contain sets. Using simulations, we demonstrate these facts, along with general principles probabilistic learning, lead to emergence Hierarchy.