No abstract

Comparison mechanisms have been implicated in the development of abstract, relational thought, including object categorization. D. Gentner and L. L. Namy (1 999) found that comparing 2 perceptually similar category members yielded taxonomic categorization, hhereas viewing a single member of the target category elicited shallower perceptual responding. The present experiments tested 2 predictions that follow from Gentner and Namy's (1999) model: (a) Comparison facilitates categorization only when the targets to be compared share relational commonalities, and (b) providing common labels for targets invites comparison, whereas providing conflicting labels deters it. Four-year-olds participated in a forced-choice task. They viewed 2 perceptually similar target objects and were asked to "find another one." Results suggest an important role for comparison in lexical and conceptual development. Children are phenomenally effective word learners. They gain new words at an astonishing rate. Research aimed at explicating the processes by which children accomplish this feat of learning has engendered a paradoxical set of findings. On the one hand, there is considerable evidence that children's categorization of objects is conceptually driven. Young children often categorize on the basis of deep, nonobvious conceptual aspects of objects such as function (e.g., can be eaten), casual properties (e.g., has eyes so it can see), and relations to other things in the world (e.g., grows on

In 3 experiments, we examine the relation between language acquisition and other symbolic abilities in the early stages of language acquisition. We introduce 18-and 26-month-olds to object categories ( e g , fruit, vehicles) using a novel word or a novel symbolic gesture to name the objects. We compare the influence of these two symbolic forms on infants' object categorization. Children at both ages interpreted novel words as names for object categories. However, infants' interpretations of gestures changed over development. At 18 months, infants spontaneously interpreted gestures, like words, as names for object categories; at 26 months, infants spontaneously interpreted words but not gestures as names. The older infants succeeded in interpreting novel gestures as names only when given additional practice with the gestural medium. This clear developmental pattern supports the prediction that an initial general ability to learn symbols (both words and gestures) develops into a more focused tendency to use words as the predominant symbolic form. INTRODUCTIONEarly in development, infants begin to use symbols to refer to objects, actions, and events in the world. This symbolic capacity is a fundamental aspect of human cognitive function and manifests itself in many aspects of everyday life such as the ability to read and interpret maps, to understand traffic signals, to interpret wedding rings as an index of marital status, and to use written and spoken language. Words, like traffic signals and wedding rings, can serve as symbols. However, unlike many symbolic forms, words are embedded in a complex, generative linguistic system. Language incorporates a fundamental ability to symbolize but also elaborates upon it in ways that other symbolic forms do not.Thus, although linguistic and symbolic abilities clearly overlap, language learning requires more complex abilities than learning a simple symbol-toreferent mapping (such as learning that a green light means go). However, this distinction between language acquisition and symbol development is less clear at the point when infants first start to produce words. Infants' initial strides in word acquisition involve predominantly learning to make word-to-referent mappings, for example, learning what objects in the world the words "Mommy" and "doggy" indicate. Thus, early word acquisition focuses on the symbolic nature of words. This developmental fact leads to the primary focus of this article, how the general ability to learn symbols relates to word acquisition, early in language development.The goal of these studies is to examine the extent to which infants distinguish between words and other types of symbols and how the distinction between word-learning and other symbolic behaviors might change with development. Much of the literature on early word-learning has made the assumption that the processes underlying word acquisition are unique to words from the onset of acquisition (see, e.g., Behrend, 1990;Grant & Karmiloff-Smith, 1991;Mervis & Bertrand, 1993;Petitto, 1988;S...

No abstract

Many researchers have argued that early cognitive development is characterized by a conceptual preference for thematic over taxonomic relations. However, more recent research indicates that infants and toddlers may not favor thematic relations. To resolve this discrepancy, the conceptual preferences of children ranging from 2 to 4 years of age were examined, using a forced-choice task including a target (e.g., a carrot), a thematic alternative (e.g., a rabbit), and a taxonomic alternative (e.g., a tomato). The effects of age, experimenter's instructions, hierarchical level (basic vs. superordinate), and stimulus medium (pictures vs. objects) were examined systematically. Children revealed no pervasive preference for either thematic or taxonomic relations. This challenges the notion of a developmental shift in conceptual preferences and suggests a more continuous trajectory in early conceptual development. Within the field of cognitive development, there is a robust finding that preschool-age children have a conceptual preference for thematic over taxonomic relations (