Children's Inductive Inference with Synonymous Labels

Children’s Inductive Inference with Synonymous Labels Bryan J. Matlen (bmatlen@andrew.cmu.edu) Department of Psychology, 5000 Forbes Avenue Pittsburgh, PA 15213 USA Anna V. Fisher (fisher49@andrew.cmu.edu) Department of Psychology, 5000 Forbes Avenue Pittsburgh, PA 15213 USA Karrie E. Godwin (kegodwin@andrew.cmu.edu) Department of Psychology, 5000 Forbes Avenue Pittsburgh, PA 15213 USA Abstract Prior research indicates that young children can generalize object properties on the basis of category information when it is conveyed by identical labels or semantically similar labels at the same level of taxonomy (i.e., synonyms) (Gelman & Markman, 1986). However, in previous research semantic similarity was confounded with co-occurrence probability. Therefore, it is possible that synonym-based induction observed in prior research stemmed from children relying on cues other than the semantic similarity of labels. The present study investigated synonym-based induction with labels that do and do not co-occur in child-directed speech. Results indicated that adults made inferences on the basis of the semantic similarity of labels regardless of co-occurrence probability. In contrast, 4-year-old children generalized based on synonymous labels at above chance levels only when synonyms co-occurred in child-directed speech. Keywords: Labels. Synonyms. Word Learning. Induction. Cognitive Development. Categories. Introduction Labels are pervasive in thought. Within the first six years of life, a child may learn up to 14,000 labels (Markman, 1990). It has been suggested that labels convey an object’s category, thereby facilitating knowledge generalization (Gelman & Markman, 1986). For example, if a sheepdog has a certain property, would a bulldog be likely to share the same property? Though this question has no definitive answer, one might surmise that, both the sheepdog and the bulldog are likely to possess the property because both are referred to as ‘dogs. ’ It is well documented that adults rely on category information conveyed by labels to generalize from the known to the unknown, however, it remains contested when children begin to do so. Some research has suggested that children can rely on category information conveyed by labels as early as 13 months of age (Welder & Graham, 2001). Numerous studies have indicated that toddlers and preschool-age children view labels as communicating objects’ kind, and that identical labels elicit category-based induction in young children as well as adults (Gelman 1988; Gelman & Coley, 1990; Gelman & Markman, 1986; Jaswal, This interpretation has recently been challenged on the grounds that children may treat labels as perceptual attributes of objects rather than as category markers (Sloutsky & Fisher, 2004). Under this view, when two objects share a label, children engage not in category-based induction, but instead in label-based induction. In other words, children may rely on shared labels in the course of induction not because they understand that labels refer to categories, but because auditory information (including category labels) has a higher attentional weight than visual information early in development (Robinson & Sloutsky, 2004; Sloutsky & Napolitano, 2003). Indeed, there is ample evidence that auditory modality dominates the visual modality in infancy (Lewkowicz, 1994; Robinson & Sloutsky, 2004, 2007) and that these effects extend into early childhood (Napolitano & Sloutsky, 2004). Furthermore, there is evidence that a similarity-based account of early induction (which considers labels to be features of objects contributing to the overall perceived similarity) can readily account for children’s reliance on identical labels in the course of property induction as well as categorization tasks (Sloutsky & Fisher, 2004; Sloutsky, Lo, & Fisher, 2001). Both label-based and category-based accounts predict that children should rely on identical labels during the course of induction. One way to tease apart these two perspectives, is to convey category membership via non-identical semantically similar labels: If it is the case that children perceive labels as windows into categories, then children’s generalizations based on semantically similar labels should be similar to their generalizations based on identical labels. If however, children are willing to generalize based on identical labels but not on semantically similar labels, then induction early in development can be label-based without necessarily being category-based. There are two ways to convey semantic similarity using non-identical labels: by using hierarchically-related labels (e.g., poodle-dog) or semantically-similar labels at the same level of taxonomic hierarchy (e.g., puppy-dog). For the purpose of brevity, semantically similar labels at the same level of taxonomic hierarchy will be henceforth referred to as synonyms. It has been shown that the ability to base