Department of Psychology, Graduate Center, City University of New York, New York City, NY, USA.
Department of Psychology, Hunter College, City University of New York, New York City, NY, USA.
Cognition. 2023 Jan;230:105275. doi: 10.1016/j.cognition.2022.105275. Epub 2022 Oct 7.
Why are children's first utterances short and ungrammatical, with some obvious constructions missing? What determines the lengthening of children's early utterances over time? The literature is replete with references to a one-word, a two-word, and a later multiword stage in language development, but with little empirical evidence, and with little account for how and why utterances grow. To address these questions, we analyze speech samples from 25 children between the ages of 14 and 43 months; we construct distributions of their utterances of lengths one to five by age. Our novel findings are that multiword utterances of different lengths appear early in acquisition and increase together until they reach relatively stable proportions similar to those found in parents' input. To explain such patterns, we develop a probabilistic computational model, VIRTUAL, that posits an interaction between a) varying, increasing resources from various developmental domains and b) target utterance lengths mirroring the input. VIRTUAL successfully accounts for most of the empirical patterns, suggesting a probabilistic and dynamic process that is nonetheless compatible with apparent distinct milestones in development. We provide a new, systematic way of showing how developmental cascade theories could work in language development. Our findings and model also suggest insights into syntactic, semantic, and cognitive development.
为什么儿童的初始言语如此简短且不合语法，还缺失了一些明显的结构？儿童早期言语随时间变长的决定因素是什么？文献中充斥着对语言发展的单字、双字和多字阶段的提及，但实证证据很少，也很少解释言语是如何以及为何增长的。为了解决这些问题，我们分析了 25 名 14 至 43 个月大的儿童的言语样本；我们根据年龄构建了他们一至五个词长的言语分布。我们的新发现是，不同长度的多词言语在习得早期就出现了，并一起增加，直到达到相对稳定的比例，与父母输入中的比例相似。为了解释这些模式，我们开发了一个概率计算模型 VIRTUAL，该模型假设了 a）来自不同发展领域的变化和增加的资源，以及 b）与输入相匹配的目标言语长度之间的相互作用。VIRTUAL 成功地解释了大部分经验模式，表明这是一个概率和动态的过程，但与发展中的明显明显里程碑是一致的。我们提供了一种新的、系统的方法来展示发展级联理论如何在语言发展中发挥作用。我们的发现和模型还为句法、语义和认知发展提供了一些见解。
