Object Properties and Object Kind: Twenty-One-Month-Old Infants' Extension of Novel Adjectives

Three experiments examined the conditions under which infants acquiring English succeed in mapping novel adjectives, applied ostensively to individual objects, to other objects with the same property (color or texture). Twenty-one-month-old infants were introduced to a target (e.g., a yellow object) and asked to choose between (1) a matching test object (e.g., a different yellow object) and (2) a contrasting test object (e.g., a green object). Infants hearing the target labeled with novel adjectives were more likely than those hearing no novel words to choose the matching test object. Infants also revealed an emerging distinction between novel adjectives and nouns. Finally, infants' expectation regarding the extension of adjectives appears to unfold within the support of a familiar basic-level category. Infants extended novel adjectives to the matching test object when all objects were all drawn from the same basic level category; they failed to do so when the objects were drawn from different basic level categories.     

Children's use of syntactic and pragmatic knowledge in the interpretation of novel adjectives

In Study 1, English-speaking 3- and 4-year-olds heard a novel adjective used to label one of two objects and were asked for the referent of a different novel adjective. Children were more likely to select the unlabeled object if the two adjectives appeared prenominally (e.g., "a very DAXY dog") than as predicates (e.g., "a dog that is very DAXY"). Study 2 revealed that this response occurred only when both adjectives were prenominal. Study 3 replicated Study 1 with Hebrew-speaking 3- and 4-year-olds, even though in Hebrew both types of adjectives appear postnominally. Preschoolers understand that prenominal adjectives imply a restriction of the reference of nouns, and this knowledge motivates a contrastive pragmatic inference regarding the referents of different prenominal adjectives.     

How Two- and Four-Year-Old Children Interpret Adjectives and Count Nouns

We examined the role of object kind familiarity (i.e., knowledge of a count noun for an object) on preschoolers' sensitivity to the relation between a novel word's form class (adjective or count noun) and its reference (to a material kind-property or to an object kind). We used a forced-choice match-to-target task, in which children learned a word for one object (e.g., a metal cup), and then chose between 2 other objects. One was from the same object kind but a different material kind (with different related properties, such as color and texture; e.g., a white plastic cup); the other was from a different object kind but the same material kind (with the same related properties; e.g., a metal spoon). In Experiment 1, children learned either a count noun (e.g., "This is a zav") or an adjective (e.g., "This is a zav one"). Within each form class, we crossed the familiarity of the referent object kind (familiar and unfamiliar) with the age of the children (2- and 4-year-olds). The principal finding was that in interpreting an adjective, 4-year-olds were more likely to choose the object sharing material kind with the target if the target was familiar than if it was unfamiliar. No such familiarity effect was evident among 2-year-olds. In Experiment 2, we employed a more unambiguously adjectival frame (e.g., "This is a very zav-ish one"), and replicated the results of Experiment 1. We interpret the results in terms of 2 proposed word learning biases: one that learners initially expect any word applied to an unfamiliar object to refer to a (basic-level) kind of object, and a second that learners prefer words to contrast in meaning. We consider several interpretations of the observed age difference.     

Nouns Mark Category Relations: Toddlers'' and Preschoolers'' Word-Learning Biases

Recent research suggests that preschool children approach the task of word learning equipped with implicit biases that lead them to prefer some possible meanings over others. The noun-category bias proposes that children favor category relations when interpreting the meaning of novel nouns. In the series of experiments reported here, we develop a stringent test of the noun-category bias and reveal that it is present in children as young as 2 years of age. In each experiment, children participated in a 5-item match-to-sample task. Children were presented with a target item (e.g., a cow) and 4 choices, 2 of which belonged to the same superordinate category as the target (e.g., a fox and a zebra) and 2 of which were thematically related to the target (e.g., milk and a barn). In Experiment 1 we demonstrate that novel nouns prompt preschool children to attend to superordinate-level category relations, even in the presence of multiple thematic alternatives. In Experiment 2, we ascertain that the bias is specific to nouns; novel adjectives do not highlight superordinate category relations. In Experiment 3, we demonstrate the noun-category bias in 2-year-olds. The nature and utility of the noun-category bias are discussed.     

现代汉语心理形容词带宾语结构研究

心理形容词是形容词的一个次类,它们从形式到语义上都与普通形容词有区别,一个明显差异是汉语中存在大量心理形容词带宾语的现象。心理形容词虽然与心理动词在语法分布上有交叉,但其所带宾语充当的论元角色和意向力的方向均不相同。以此为基础,《语法讲义》关于谓词小类的划分可以进一步细化。     

Lexical form class information guides word-to-object mapping in preschoolers

We demonstrate that lexical form class information can play a powerful role in directing the establishment of word-to-object mappings in referentially ambiguous situations. A total of 144 3- and 4-year-olds heard a novel label, modeled syntactically as either a proper name or an adjective, for a stuffed animal of a familiar kind. We then added a second object of the same kind and asked children (1) to choose one of the two objects as the referent of a second novel label, also presented syntactically as either a proper name or an adjective, and (2) to decide whether this second label could also apply to the object they did not choose. In each of three experiments, preschoolers were most likely to reject two words for the same object if both words were proper names (as if one dog could not be both "Fido" and "Rover"). They were significantly less likely to do so if both were adjectives (as if one dog could be both "spotted" and "furry") or if one was a proper name and the other was an adjective (as if one dog could be both "Fido" and "furry"). Information about lexical form class thus contributed significantly to the formation of linkages between words and objects.     

Establishing New Subcategories: The Role of Category Labels and Existing Knowledge

Previous research has revealed that novel nouns highlight category relations at superordinate and basic levels but, paradoxically, make subordinate classification more difficult for preschool children. In Experiment 1, we provide additional evidence that novel nouns put 3-year-old children at a disadvantage in subordinate classification. We suggest that this reflects young children's inclination to label and classify objects at the basic level. In Experiments 2 and 3, we identify 2 circumstances under which 3-year-old children alter their basic level expectation. In Experiment 2, we provide children with specific information to distinguish the relevant subclasses. In Experiment 3, we introduce the novel nouns in conjunction with the familiar basic level labels. Under each of these circumstances, novel nouns do not present an obstacle to subordinate classification. Children's linguistic biases (e.g., the noun-category bias) and their existing knowledge and vocabularies jointly influence early conceptual development.     

The Principle of Mutual Exclusivity in Word Learning: To Honor or Not to Honor?

According to Markman and Wachtel, children assume that nouns pick out mutually exclusive object categories, and so each object should have only one category label. While this assumption can be useful in word learning, it is not entirely reliable. Therefore, children need to learn when to and when not to make this assumption. 6 studies examined whether knowledge about hierarchical organization of categories and about cross-language equivalents for object labels can help children limit their use of this assumption appropriately. These studies revealed that adults as well as children resisted assigning 2 novel names to the same object in some situations. By age 4, children also seemed to know enough about categorization to accept 2 names for an object if the names picked out categories from different levels of a hierarchy (e.g., animal and lemur) but not if they picked out categories from the same level (e.g., lemur and seal). Moreover, monolingual as well as bilingual children seemed to know enough about languages to accept 2 names for the same object if the names clearly came from different languages. Together, these findings suggest that even preschool children can make use of knowledge about language and categorization to fine tune the mutual exclusivity assumption in order to use it effectively in word learning.     

Children's inductive inferences within superordinate categories: the role of language and category structure

One important function of categories is to allow inferences that extend beyond surface appearances. In 2 studies, preschool and second-grade children were tested on their understanding that members of a category have similar internal parts. In 1 study, children were taught new information about the internal structure of various objects (e.g., an apple), then were probed to determine how far they generalized the new information (e.g., to another apple, to other fruit, to an unrelated object). In a second study, children participated in an open-ended interview that probed whether various types of objects had "the same kinds of stuff inside." Children at both ages and in both studies drew many inferences concerning the internal children to report that members of a basic-level category had the same internal parts. Older children drew more inferences at the superordinate level than did younger children. Older children were also more sensitive to differences in category domain (natural kind vs. artifact) at both basic and superordinate levels. Altogether, these results suggest that preschool children assume that basic-level categories share internal parts. They need to refine this belief at the basic level and to extend it to superordinate-level categories.     

Infant Chimpanzees Spontaneously Perceive Both Concrete and Abstract Same/Different Relations

We used a familiarization-novelty procedure to determine whether 4 infant chimpanzees spontaneously perceive the sameness of and the difference between both concrete objects and relations between objects. In Experiment 1, a single object was presented on the Familiarization Trial 1 and the animal's looking time recorded. On the Test Trial 2, an object was presented that was either identical to or different from that shown on Trial 1. Looking times on Test Trial 2 were less when the same item had been presented on the preceding familiarization trial. Novel items on Trial 2 were attended to longer, indicating that the infant chimpanzees perceived concrete objects were either the same or different. In Experiment 2, a single pair of objects was presented on the Familiarization Trial 1, and handling time was measured. The objects in a pair were either the same or different (e.g., AA vs. CD). On the Test Trial 2, a new object pair (e.g., BB vs. EF) was presented that instantiated either the relation shown on Trial 1 or the alternative relation. Handling time on Trial 2 was influenced by the relation instantiated on Trial 1. Handling times on Test Trial 2 were less when the identical relation had been presented on the preceding familiarization trial. Novel relations on Trial 2 were attended to relatively longer. This result indicates that infant chimpanzees perceive similarities and differences between abstract relations as well as between concrete objects. That is to say, they perceived relations between relations in Experiment 2. Despite this ability to perceive both concrete and abstract "same/different" relations, the same chimpanzees subsequently failed to use the latter knowledge in a matching-to-sample task in Experiment 3. Although they successfully matched single objects, they were unable to match object pairs instantiating the same relation (e.g., if AA then match BB; if CD then match EF). These results contradict claims that failure to learn an instrumental discrimination involving abstract relations reflects an inability to detect such relations. In every species there may be a disparity between the ability to perceive spontaneously a property of the world and the ability to use the concept instrumentally.     

One Cow Does Not an Animal Make: Young Children Can Extend Novel Words at the Superordinate Level

Six match-to-sample picture/object selection experiments were designed to explore children's knowledge about superordinate words (e.g., "food") and how they acquire this knowledge. Three factors were found to influence the learning and extension of superordinate words in 3- to 5-year-old children (N = 230): The number of standards (one versus two), the type of standards presented (from different basic-level categories versus from the same basic-level category), and the nature of the object representations used (pictures versus objects). A different pattern of superordinate word acquisition was found between 3-year-olds and 4- and 5-year-olds. Although 4- and 5-year-olds could learn and extend novel words to superordinate categories in the presence of two picture exemplars from different categories or a single three-dimensional (3-D) exemplar, 3-year-olds could do so only in the presence of two 3-D exemplars. These findings indicate that young children's acquisition of superordinate words is influenced by multiple factors and that there is a developmental progression from multiple exemplars to single exemplars in superordinate word learning.     

The Influence of Shape Similarity and Shared Labels on Infants'' Inductive Inferences about Nonobvious Object Properties

This study examined the influence of object labels and shape similarity on 16- to 21-month-old infants' inductive inferences. In three experiments, a total of 144 infants were presented with novel target objects with or without a nonobvious property, followed by test objects that varied in shape similarity to the target. When objects were not labeled, infants generalized the nonobvious property to test objects that were highly similar in shape (Experiment 1). When objects were labeled with novel nouns, infants relied both on shape similarity and shared labels to generalize properties (Experiment 2). Finally, when objects were labeled with familiar nouns, infants generalized the properties to those objects that shared the same label, regardless of shape similarity (Experiment 3). The results of these experiments delineate the role of perceptual similarity and conceptual information in guiding infants' inductive inferences.     

Long-Term Memory for Context-Specific Category Information at Six Months

The ability of 6-month-old infants to remember a functional category acquired in a specific context was assessed in 3 experiments via an operant procedure in which infants learned to perform a specific action (a footkick) to activate an object suspended before them. In Experiment 1, infants trained with different exemplars in the same context transferred responding to a novel exemplar in the same but not a different context 24 hours later. Experiment 2 revealed that infants' reactivated memory of category training remained intact and context-specific after 3 weeks. In Experiment 3, a novel category exemplar was able to reactivate the forgotten memory of category training only in the encoding context. At 6 months, information about the place where categories are constructed is prerequisite for retrieval of a category concept from long-term memory. This requirement insures that early category concepts remain stable over relatively long periods.     

Semantic Constraints on Word Learning: Proper Names and Adjectives

4 experiments examined 3- and 4-year-olds' interpretations of novel words applied to familiar objects in the sentence frame, "This Y is X," where X is a novel word, and Y is a familiar basic-level count noun (e.g., "dog", "cup"). These novel words are ambiguous and could be interpreted either as proper names (e.g., "Fred") or as adjectives/mass nouns (e.g., "red"/"lead"). The experiments addressed 2 questions. First, do children appreciate that the words can be construed either as proper names referring to individuals or as adjectives/mass nouns referring to salient properties/material kinds? The results showed that children could easily make either interpretation. Second, what factors affect children's tendency to make either a proper name or an adjective/mass noun interpretation? In the experiments, children learned the novel words for a range of animals and artifacts. Most children who learned the words for typical pets (e.g., a bird) made proper name interpretations, as did the majority of those who learned the words for certain non-pet animals (e.g., a caterpillar) described as possessed by someone, but only about half of those who learned the words for such non-pet animals not so described. Very few children who learned the words for either simple (e.g., a shoe) or complex (e.g., a boat) artifacts made proper name interpretations. The results provide clear evidence of the role of semantic information in constraining children's interpretation of a novel word, and they help to refine an understanding of what counts as a nameable individual for preschoolers.     

What is "high"? The development of reference points for "high" and "low"

Young children have been characterized as interpreting relative adjectives as if they were nominal or categorical terms. The categorical interpretation of relative terms, however, may be quite complex. Indeed, the mature understanding of relative terms would seem to include a complex system of reference points for the terms' categorical usages. In 5 experiments we examined the complexity of 3-5-year-old children's and adults' categorical interpretations. We specifically examined how reference points for the categorical interpretation of high and low are defined. The definition of reference points relative to the object judged, the vertical position of the observer, and the extent of vertical variation were assessed. 3 major developmental trends were observed: a trend from the application of the terms to only extreme values to their application to broader categories; a trend from nominal-like categories to ones defined flexibly relative to context (e.g., nature of object judged, and extent of vertical variation); and a trend from reference points functioning as focal points to their operating as directional category boundaries. In brief, the results suggest that the categorical usage of relative terms involves a rich and intricate knowledge system and that it takes children considerable time to acquire and organize the relevant pieces of knowledge.     

On Wooden Pillows: Multiple Classification and Children''s Category-based Inductions

Previous research has indicated that preschoolers do not distinguish between properties that are generalizable within a given category and those that are not. 2 possible general constraints on children's cognition are proposed to account for these findings. 3 studies are reported that argue against the presence of such general constraints. We examine preschoolers' understanding of the properties associated with material (e.g., wood, cotton) and object (e.g., chair, pillow) categories. In Study 1, subjects consistently made inductions based on the material compositions of items when asked to predict texture and fragility. In Study 2, the same subjects judged that items that shared material would share an unfamiliar dispositional property (e.g., gets sodden in water), but items that shared object kind would share a novel functional property (e.g., used for accelerating). Study 3 tested a younger sample of 3-year-olds and found the same sensitivity to category type, albeit with larger individual differences. By age 3, children use different modes of categorization to generalize different kinds of phenomena. These results argue against general limitations on children's abilities to use categories to make inductions. Even when children lack specific theoretical knowledge, the ability to organize phenomena into domains allows children to recognize which categories are relevant in different situations. This understanding can provide a basis for the development of more specific theories.     

Priorities in children's expectations about object label reference: form over color

Young children show considerable interest in color similarity; thus we might expect them to use color as a basis for generalizing object labels. However, natural language observations suggest they do not: children tend to overextend labels based on form similarity and rarely, if ever, overextend labels to objects that share only color. Perhaps, then, children give form priority over color in their expectations about object-label reference. This hypothesis was investigated in 2 studies. In a first study, 40 2- and 3-year-olds sorted 10 sets of 3 pictures that contrasted form with color. Children participated in 1 of 2 conditions: half of the children were shown a target object and asked to "find another one" from among the two choice objects, while the other children heard a novel label for the target (e.g., "See this zom?") and were asked to extend the label (e.g., "Can you find another zom?"). 3-year-olds sorted almost exclusively on the basis of form in both conditions, while 2-year-olds performed differently in the 2 conditions: they frequently chose the color match when labels were absent, but selected by form rather than color when asked to extend a novel label. A second study replicated these findings with novel objects that were real rather than pictured. This study also suggested that 3-year-olds grant color some role in their decisions about object-label reference as long as form differences are reduced to a tolerable level. In sum, young children expect form to be more important than color for guiding object-label reference, even though they may find color interesting when not asked to extend labels. This expectation helps explain the speed and relative ease with which children acquire object labels.     

A Horse of a Different Color: Specifying With Precision Infants' Mappings of Novel Nouns and Adjectives

A precisely controlled automated procedure confirms a developmental decalage: Infants acquiring English link count nouns to object categories well before they link adjectives to properties. Fourteen- and 18-month-olds ( n = 48 at each age) extended novel words presented as count nouns based on category membership rather than shared properties. When the same words were presented as adjectives, infants revealed no preference for either category- or property-based extensions. The convergence between performance in this automated procedure and in more interactive tasks is striking. Perhaps more importantly, the automated task provides a methodological foundation for (a) exploring the development of form–meaning links in infants acquiring languages other than English and (b) investigating the time course underlying infants' mapping of novel words to meaning.     

The Development of a Linkage between Count Nouns and Object Categories: Evidence from Fifteen- to Twenty-One-Month-Old Infants

Recent research suggests that, although young children appreciate many different kinds of conceptual relations among objects, they focus specifically on taxonomic relations in the context of word learning. However, because the evidence for children's appreciation of this linkage between words and object categories has come primarily from children who have made substantial linguistic and conceptual advances, it offers limited information concerning the development of this linkage. In the experiments reported here, we employ a match-to-sample task to focus specifically on the development of an appreciation of the linkage between words (here, count nouns) and object categories in infants in the period just prior to and just subsequent to the naming explosion. The results demonstrate that, for 21-month-old infants, most of whom have recently entered the vocabulary explosion (Experiment 1), and for 16-month-old infants, most of whom have yet to commence the vocabulary explosion (Experiment 2), novel nouns focus attention on taxonomic relations among objects. This is important because it reveals a nascent appreciation of a linkage between words and object categories in infants who are at the very onset of language production. Results are interpreted within a developmental account of infants' emerging appreciation of a specific linkage between count nouns and object categories.