Children’s Tolerance of Word-Form Variation

How much morphological variation can children tolerate when identifying familiar words? This is an important question in the context of the acquisition of richly inflected languages where identical word forms occur far less frequently than in English. To address this question, we compared children’s ( , mean age 4;1, range 2;11–5;1) and adults’ ( , mean age 21 years) tolerance of word-onset modifications (e.g., for stug: wug and wastug) and pseudoaffixes (e.g., kostug and stugko) in a label-extension task. Word-form modifications were repeated within each experiment to establish productive inflectional patterns. In two experiments, children and adults exhibited similar strategies: they were more tolerant of prefixes (wastug) than substitutions of initial consonants (wug), and more tolerant of suffixes (stugko) than prefixes (kostug). The findings point to word-learning strategies as being flexible and adaptive to morphological patterns in languages. 1. Children’s Tolerance of Word-Form Variation In language development, an important question is how young children go about the task of acquiring and correctly associating new words with their referents, a process sometimes referred to as word-to-world mapping. This process has mainly been investigated in English, a language, where word forms tend to be identical or very similar across different contexts, due to the impoverished inflectional morphology of English. In this study, we explore the question of how morphological changes impact the interpretations of new words for novice language learners. Children have been shown to have a strong bias toward mapping unfamiliar words onto unfamiliar objects [1]. They also are capable of learning new words after only a few exposures [2], an ability known as “fast mapping.” In perhaps the earliest study of fast mapping, Carey and Bartlett [2] asked children to select a “chromium” tray (olive green in color) when given two choices, an object with a color (red) that they already had a name for and one they did not. They found that children were highly biased to select the nonprimary color item. To test if the child had actually learned the new color term, children were retested a year later and half of the children demonstrated retention. This fast-mapping tendency has proven to be a robust and reproducible phenomenon across many studies (e.g., [3–5]): when given an object that is familiar and one that is unfamiliar, children associate a new name with the unfamiliar object at levels far above chance. Markman and her colleagues have interpreted this bias as reflecting