儿童早期分类与基于类别的归纳的一致性

传统的观点认为,儿童早期的分类是基于类别的归纳的基础。根据这种观点,儿童早期的分类与基于类别的归纳是一致的。该研究在不同材料条件下测试了4岁儿童面临知觉相似和概念冲突时的自由分类与归纳推理的一致性。研究结果显示,在照片条件下,4岁儿童的自由分类和基于类别的归纳是不一致的,儿童的分类主要是基于知觉相似的,而基于类别的归纳主要是基于概念的;在线条画条件下,儿童的分类与基于类别的归纳是一致的,都主要是基于知觉相似的。这些结果显示,儿童早期的分类和基于类别的关系是复杂的。     

Preschoolers' use of surface similarity in object comparisons: taking context into account

Previous research has emphasized the role of within-match similarity in children's comparisons. The current study investigated another potentially important contributing factor, namely the distinctiveness of the matching items relative to other items in the scene. Using a well-known relational mapping task, we found that 3- and 4-year-olds made more correct matches between identical objects when those objects were maximally distinctive from the foils. In a cross-mapping experiment, where same relative size was pitted against object similarity, 3-year-olds made more incorrect object matches when the objects were both similar to each other and distinctive from the foils. Furthermore, 3- and 4-year-olds performed the same, regardless of within-match similarity, so long as the ratios of within-match and nonmatch similarity were roughly equal. These findings suggest that children's comparisons are guided by a ratio consisting of many pairwise similarity relations, including (but not limited to) the degree of within-match similarity.     

Young children's rapid learning about artifacts

Tool use is central to interdisciplinary debates about the evolution and distinctiveness of human intelligence, yet little is actually known about how human conceptions of artifacts develop. Results across these two studies show that even 2-year-olds approach artifacts in ways distinct from captive tool-using monkeys. Contrary to adult intuition, children do not treat all objects with appropriate properties as equally good means to an end. Instead, they use social information to rapidly form enduring artifact categories. After only one exposure to an artifact's functional use, children will construe the tool as 'for' that particular purpose and, furthermore, avoid using it for another feasible purpose. This teleo-functional tendency to categorize tools by intentional use represents a precursor to the design stance - the adult-like tendency to understand objects in terms of intended function - and provides an early foundation for apparently distinctive human abilities in efficient long-term tool use and design.     

Vowel categorization skill and its relationship to early literacy skills among first-grade Québec-French children

Six-year-old children's ability to categorize words on the basis of vowel categories was examined at the beginning of first grade and again after 6 months of formal schooling. The potential effects of relative proximity of vowels in the vowel space, of syllable structure, and of input phonology were assessed. Also, the effect of literacy instruction on vowel categorization and the relationship of vowel categorization with vowel spelling and reading skill were investigated. Results indicate that the ability to categorize vowels does not develop uniformly but is affected by the degree of spectral/articulatory proximity between vowels, by syllable structure, and potentially by characteristics of the input phonology. Error analyses further indicate that children have fuzzy category boundaries between vowels adjacent on the height continuum. The pattern of results on oral categorization and written tasks suggests a reciprocal relationship. Categorization ability improved after 6 months of schooling. However, vowels that children found more difficult to categorize were also more difficult to read and spell.     

Effects of categorical labels on similarity judgments: a critical analysis of similarity-based approaches

Our goal in the present study was to evaluate the claim that category labels affect children's judgments of visual similarity. We presented preschool children with discriminable and identical sets of animal pictures and asked them to make perceptual judgments in the presence or absence of labels. Our findings indicate that children who are asked to make perceptual judgments about identical items judge discriminable items less accurately when making subsequent similarity judgments. Thus, labels do not generally affect children's perceptual similarity judgments; rather, children's reliance on labels to make similarity judgments appears to be attributable to flaws in the methodological approaches used in prior studies. These results have implications for the role of perceptual and conceptual information in children's categorization and induction.     

Distinctiveness effects in children's long-term retention

In 3 experiments, kindergarten and second-grade children's retention was examined in the context of 2 distinctiveness manipulations, namely, the von Restorff and bizarre imagery paradigms. Specifically, children learned lists of pictures (Experiments 1a and 1b) or interactive images (Experiment 2) and were asked to recall them 3 weeks later. In Experiments 1a and 1b, distinctiveness was manipulated perceptually (changing colors) and conceptually (changing categories or switching to a numeral), whereas in Experiment 2, distinctiveness concerned the interaction (common or bizarre) between the referents. The results showed that (a) older children retained more information than younger children, (b) younger but not older children failed to benefit from numerically distinct information, and (c) distinctiveness in other domains facilitated children's retention. These results highlight the importance of distinctive information in children's retention.     

Basic level and superordinate level categorization by autistic, mentally retarded, and normal children

Three experiments designed to test autistic children's nonverbal and verbal categorization abilities are reported in this paper. In the first two experiments, 14 autistic children were compared to 14 retarded and 14 normal children matched on verbal mental age. Their ability to categorize pictures from basic level categories and from biological and artifactual superordinate level categories was assessed using a matching-to-sample procedure. The three groups of subjects were similar in their performance. Basic level categorization was easier than more abstract categorization, and for all three groups, prototypicality played a role in categorizing superordinate level concepts; that is, children in all three groups made more errors categorizing peripheral examples. In the third experiment, a subgroup of 7 autistic children showed evidence that their lexicons were well organized and that they appreciated the meaning relationships among words at the superordinate level. These findings suggest that autistic children do not suffer a specific cognitive deficit in the ability to categorize and form abstract concepts, as has been previously suggested in the literature.     

Unsupervised categorization and category learning.

When people categorize a set of items in a certain way they often change their perceptions for these items so that they become more compatible with the learned categorization. In two experiments we examined whether such changes are extensive enough to change the unsupervised categorization for the items-that is, the categorization of the items that is considered more intuitive or natural without any learning. In Experiment 1 we directly employed an unsupervised categorization task; in Experiment 2 we collected similarity ratings for the items and inferred unsupervised categorizations using Pothos and Chater's (2002) model of unsupervised categorization. The unsupervised categorization for the items changed to resemble more the learned one when this was specified by the suppression of a stimulus dimension (both experiments), but less so when it was almost specified by the suppression of a stimulus dimension (Experiment 1, nonsignificant trend in Experiment 2). By contrast, no changes in the unsupervised categorization were observed when participants were taught a classification that was specified by a more fine tuning of the relative salience of the two dimensions.     

Complexity discrimination as a determinant of children's preferences in collative motivation

Collative motivational preferences for increasing complexity in kindergarten and fourth-grade children were studied by varying the types of elements that constituted complexity gradation conditions along a similarity-distinctiveness continuum. A paired-comparisons procedure was used to assess children's relative preference for one to five levels of complexity within each condition. The highest gradation condition yielded a clear positive function between preference and number of elements, as well as the most reliable performance by children, but the two lower conditions yielded both positive and negative functions when subsamples were analyzed in homogeneous groupings. Obtained negative functions were interpreted as aesthetic or affective dimensions conflicting with the collative exploratory dimension. Differences between gradation conditions were consonant with a proposed arbitrary definition of variety as a distinctive condition of complexity.     

Inference and coherence in causal-based artifact categorization

In four experiments, we tested conditions under which artifact concepts support inference and coherence in causal categorization. In all four experiments, participants categorized scenarios in which we systematically varied information about artifacts’ associated design history, physical structure, user intention, user action and functional outcome, and where each property could be specified as intact, compromised or not observed. Consistently across experiments, when participants received complete information (i.e., when all properties were observed), they categorized based on individual properties and did not show evidence of using coherence to categorize. In contrast, when the state of some property was not observed, participants gave evidence of using available information to infer the state of the unobserved property, which increased the value of the available information for categorization. Our data offers answers to longstanding questions regarding artifact categorization, such as whether there are underlying causal models for artifacts, which properties are part of them, whether design history is an artifact’s causal essence, and whether physical appearance or functional outcome is the most central artifact property.     

Identification of letterlike distortions by preschool children.

In two experiments preschool children chose one of two test forms that looked like previously exposed distortions of a letterlike-form. In Exp. I a distance metric was defined to measure the physical discrepancy between forms. It was found that the distance relationship between distortions and particular test forms did not designate the children's choice behavior. In Exp. II the children were able to choose previously exposed distortions when particular test forms contained novel features. The results are related to distinctive feature and prototype hypotheses to account for children's performance in recognizing forms.     

Induction and categorization in young children: a similarity-based model

The authors present a similarity-based model of induction and categorization in young children (SINC). The model suggests that (a). linguistic labels contribute to the perceived similarity of compared entities and (b). categorization and induction are a function of similarity computed over perceptual information and linguistic labels. The model also predicts young children's similarity judgment, induction, and categorization performance under different stimuli and task conditions. Predictions of the model were tested and confirmed in 6 experiments, in which 4- to 5-year-olds performed similarity judgment, induction, and categorization tasks using artificial and real labels (Experiments 1-4) and recognition memory tasks (Experiments 5A and 5B). Results corroborate the similarity-based account of young children's induction and categorization, and they support both qualitative and quantitative predictions of the model.     

Do children really confuse appearance and reality?

Our understanding of many mental, social and physical phenomena hinges on a general understanding that appearances can differ from reality. Yet young children sometimes seem unable to understand appearance-reality dissociations. In a standard test, children are shown a deceptive object and asked what it really is and what it looks like. Many preschool children give the same answer to both questions. This error has been attributed to children's inflexible conceptual representations or inflexibility in representing their own changing beliefs. However, evidence fails to support either hypothesis: new tests show that young children generally understand appearance-reality discrepancies as well as fantasy-reality distinctions. These tests instead implicate children's failure to understand the unfamiliar discourse format of the standard test. This misunderstanding might reveal a subtler difficulty in making logical inferences about questions.     

The role of motion in children's categorization of objects.

Perceptual cues play a fundamental role in early categorization of objects. What is meant by perceptual cues in the literature, however, is not always clear. It is fair to say that they are typically understood to be static shape cues. A number of recent studies have suggested that dynamic perceptual cues, such as motion, may also be important in early categorization. The study presented here explored the role that motion plays in children's categorization of animal and non-animal kinds, such as geometric figures. Motion was directly pitted against shape as a cue for categorization. Results showed that 4-year-old children, confronted with a choice between shape and motion, significantly used motion cues over shape cues to categorize objects, regardless of whether they were animals or geometric figures. Seven-year-olds also tended to use motion more often to categorize animals but not when dealing with geometric figures. Older children, who have been found to have a clearer natural kind/artifact distinction, seem to appreciate the uniqueness of movement to animals and see motion as more relevant to their categorization but relatively less so to categorize geometric figures. This developmental shift in the categorization of animals and geometric figures based on motion was further confirmed by testing adults on the same tasks. Adults were found to base their judgements significantly more often on motion for animals but not for geometric figures. These findings support the view that children are initially guided by motion in object categorization, suggesting that motion plays an overriding role that is central in the process of concept acquisition and in the mechanisms by which concepts are later structured.     

What do children want to know about animals and artifacts? Domain-specific requests for information

Children's questions may reveal a great deal about the characteristics of objects they consider to be conceptually important. Thirty-two preschool children were given opportunities to ask questions about unfamiliar artifacts and animals. The children asked ambiguous questions such as "What is it?" about artifacts and animals alike. However, they were more likely to ask about the functions of artifacts, but about category membership, food choices, and typical locations of animals. They never asked questions about either artifacts or animals that would be considered inappropriate by adults. The results indicate that children hold different expectations about the types of information important for categorizing living and artifact kinds. Young children conceive of artifacts in terms of functions, but conceive of animals in terms of biologically appropriate characteristics. Such results speak to debates about the role of function in children's biological reasoning and to accounts of children's artifact concepts.     

Core knowledge and its limits: The domain of food

Adults, preschool children, and nonhuman primates detect and categorize food objects according to substance information, conveyed primarily by color and texture. In contrast, they perceive and categorize artifacts primarily by shape and rigidity. The present experiments investigated the origins of this distinction. Using a looking time procedure, Experiment 1 extended previous findings that rhesus macaques (Macaca mulatta) generalize learning about novel food objects by color over changes in shape. Six additional experiments then investigated whether human infants show the same signature patterns of perception and generalization. Nine-month-old infants failed to detect food objects in accord with their intrinsic properties, in contrast to rhesus monkeys tested in previous research with identical displays. Eight-month-old infants did not privilege substance information over other features when categorizing foods, even though they detected and remembered this information. Moreover, infants showed the same property generalization patterns when presented with foods and tools. The category-specific patterns of perception and categorization shown by human adults, children, and adult monkeys therefore were not found in human infants, providing evidence for limits to infants’ domains of knowledge.     

Crossed categorization effects on the formation of illusory correlations

This study investigates how stereotypes are formed and whether stereotype formation is reduced by the prevalence of multiple categorizations. Illusory correlations between the desirability of behaviours and two dimensions of social categorization, both containing a majority and a minority category, were assessed in single categorization and crossed categorization conditions. In the single categorization conditions, the usual illusory correlation in favour of the majority category was obtained. In the crossed condition, the combination of the two majority categories was positively discriminated from the remaining three combinations, while no differences were found among the latter. A source‐monitoring analysis of assignment frequencies replicated earlier findings that illusory correlations are due to an evaluative guessing bias, rather than to enhanced memory for individual instances of behaviour. The results show inconsistencies with a distinctiveness‐based and a social categorization account of illusory correlations, but they can be explained in terms of information loss. Copyright © 2001 John Wiley & Sons, Ltd.     

Attention,play, and social behavior in ADHD preschoolers

We investigated attention, play and nonplay behavior in preschool children with attention deficit hyperactivity disorder (ADHD) and a matched control group of non-ADHD children. Forty 4- to 5-year-old children (20 ADHD and 20 matched control) participated. Across a 6-week-period, children's social and play interactions as well as nonplay behaviors were videotaped in the classroom. Videotape recordings were analyzed for the level of attention, cognitive play, and social participation. In addition, children's level of attention and cooperative behavior were observed during two group activities. Findings indicated that ADHD, relative to non-ADHD, children engaged in less overall play and greater functional or sensorimotor play. ADHD children also engaged in more transitional behavior, were less competent with peers, and were less attentive and cooperative during group activities.This research was supported in part by an MCP grant awarded to Dr. Steven Alessandri. The author wishes to thank the children, parents, and the MCP/EPPI preschool staff for their assistance and cooperation.     

The Effect of Experimental Design on Memory for Typical and Distinctive Faces

The effect of experimental design on memory for typical and distinctive faces was investigated in three experiments. In Experiments 1 and 2, a between-subjects, between-lists (distinctive-only faces, or typical-only faces) manipulation of distinctiveness was compared with a within-subjects mixed-list design. The results demonstrated an interaction between design type and distinctiveness, indicating an increase in the rate of misidentifications and a decrease in the response criterion to distinctive faces in the distinctive-only set relative to distinctive faces in the mixed-list condition. Experiment 3 addressed the locus of this effect by comparing the standard mixed-list within-subjects design with two sets of faces in which the target images were different in type from the distractor images, i.e. a typical target-distinctive distractor set and a distinctive target-typical distractor set. The results of this experiment demonstrated that distinctive distractor faces were more readily rejected as new faces when typical target faces were included in the same set. The relative sensitivity of memory for typical and distinctive faces to manipulations of experimental design are discussed with reference to current models of facial distinctiveness.