The Role of Linguistic Labels in Categorization

The Role of Linguistic Labels in Categorization Wei (Sophia) Deng (deng.69@osu.edu) Center for Cognitive Science The Ohio State University 209C Ohio Stadium East, 1961 Tuttle Park Place Columbus, OH 43210, USA Vladimir M. Sloutsky (sloutsky.1@osu.edu) Center for Cognitive Science The Ohio State University 208C Ohio Stadium East, 1961 Tuttle Park Place Columbus, OH 43210, USA Abstract grouped objects taxonomically (e.g., the police car with a passenger car). Gelman and Heyman (1999) demonstrated that young children were more willing to generalize properties from one person to another when both persons were referred to by a noun (i.e., carrot-eaters ) than when both were referred to by a descriptive sentence (e.g., both like to eat carrots ). This evidence, however, does not lend unequivocal support to the idea that labels have to be category markers to make inductive inferences. For example, some researchers suggested that contribution of labels is driven by attentional rather than conceptual factors (Napolitano & Sloutsky, 2004; Sloutsky & Napolitano 2003). There is also evidence that labels contribute to the overall similarity of compared entities and thus to both categorization and induction (Sloutsky & Fisher, 2004). Sloutsky and Fisher (2004) also demonstrated that similarity computed over labels and appearances can accurately predict young children’s responses with the Gelman and E. Markman (1986) task. These findings suggest that reliance on labels does not necessarily indicate that labels are more than features. In a series of studies, Yamauchi and A. Markman (1998, 2000) designed a paradigm that could address this issue directly. Specifically, they compared participants’ performance on classification tasks (e.g., is X a dax? ) with that on induction tasks (e.g., given that X is a dax, does it have Y? ). The tasks are structurally identical, except a critical difference. In the classification task participants predicted the category label of an item given all of its feature values. In contrast, in the induction task, participants predicted the value of a missing feature of an item given its category label and other feature values. These researchers argued that if the label is a feature then performance on classification and induction task should be symmetrical. However, if labels are more than features, then performance on induction tasks should be better than performance on classification Do young children treat labels as features or as category markers? The current study addressed this question by examining the effect of labels on young children's classification and induction. The first experiment replicated previous study on adults demonstrating that adults treat labels as category markers. The other two experiments applied the same paradigm to young children. Children were trained by classification in Experiment 2A and by induction in Experiment 2B, whereas both experiments used the classification and induction tasks that were identical to those in Experiment 1. The results from the three experiments indicated that adults treated labels as category markers, whereas no such evidence was found for young children. Keywords: Cognitive Development, Classification, Induction, Label, Psychology, Human Experimentation. Introduction The ability to use linguistic labels to generalize from the known to the unknown is crucial for learning new information. Although a substantial body of experimental evidence has demonstrated that label has an impact on categorization and induction processes (Gelman & E. Markman, 1986; Sloutsky, Lo, & Fisher, 2001; Welder & Graham, 2001; Yamauchi and A. Markman, 1998, 2000), the mechanism underlying the role of labels is hotly debated. Are labels used as features (similar to other objects’ properties) or as category markers representing category membership? This issue is particularly contentious with respect to the role of labels in early development and developmental changes in this role. Some researchers have argued that labels are more than features. According to this view, labels are category markers used for representing a category. For example, E. Markman and Hutchinson (1984) found that children regarded words presented as count nouns changed the way young children grouped objects. Without labels children grouped objects thematically (e.g., a police car was grouped with a policeman), whereas when the same police car was referred to by a count noun, children