Causal status and coherence in causal-based categorization.

Research has documented two effects of interfeature causal knowledge on classification. A causal status effect occurs when features that are causes are more important to category membership than their effects. A coherence effect occurs when combinations of features that are consistent with causal laws provide additional evidence of category membership. In this study, we found that stronger causal relations led to a weaker causal status effect and a stronger coherence effect (Experiment 1), that weaker alternative causes led to stronger causal status and coherence effects (Experiment 2), and that “essentialized” categories led to a stronger causal status effect (Experiment 3), albeit only for probabilistic causal links (Experiment 4). In addition, the causal status effect was mediated by features' subjective category validity, the probability they occur in category members. These findings were consistent with a generative model of categorization but inconsistent with an alternative model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How causal knowledge affects classification: A generative theory of categorization.

Several theories have been proposed regarding how causal relations among features of objects affect how those objects are classified. The assumptions of these theories were tested in 3 experiments that manipulated the causal knowledge associated with novel categories. There were 3 results. The 1st was a multiple cause effect in which a feature's importance increases with its number of causes. The 2nd was a coherence effect in which good category members are those whose features jointly corroborate the category's causal knowledge. These 2 effects can be accounted for by assuming that good category members are those likely to be generated by a category's causal laws. The 3rd result was a primary cause effect, in which primary causes are more important to category membership. This effect can also be explained by a generative account with an additional assumption: that categories often are perceived to have hidden generative causes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stripes do not a zebra make, or do they? Conceptual and perceptual information in inductive inference.

Four-year-olds' and adults' inferences based on shared conceptual properties, category labels, and perceptual information were assessed in 4 experiments. Stimuli included novel animals (Studies 1, 3, and 4) and familiar animals (Study 2). Experiments suggest that both category membership information and similarity (in the form of conceptual information and perceptually provided information) affect inferences. Furthermore, conceptual attribute information and category membership information were used differently by adults but not by children. It is concluded that the inferential behavior of children and adults is influenced by perceptual information, conceptual attribute information, and category membership information, as well as by hypotheses about how these kinds of information relate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analogical and category-based inference: A theoretical integration with Bayesian causal models.

A fundamental issue for theories of human induction is to specify constraints on potential inferences. For inferences based on shared category membership, an analogy, and/or a relational schema, it appears that the basic goal of induction is to make accurate and goal-relevant inferences that are sensitive to uncertainty. People can use source information at various levels of abstraction (including both specific instances and more general categories), coupled with prior causal knowledge, to build a causal model for a target situation, which in turn constrains inferences about the target. We propose a computational theory in the framework of Bayesian inference and test its predictions (parameter-free for the cases we consider) in a series of experiments in which people were asked to assess the probabilities of various causal predictions and attributions about a target on the basis of source knowledge about generative and preventive causes. The theory proved successful in accounting for systematic patterns of judgments about interrelated types of causal inferences, including evidence that analogical inferences are partially dissociable from overall mapping quality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Causal-Model Theory of Conceptual Representation and Categorization.

This article presents a theory of categorization that accounts for the effects of causal knowledge that relates the features of categories. According to causal-model theory, people explicitly represent the probabilistic causal mechanisms that link category features and classify objects by evaluating whether they were likely to have been generated by those mechanisms. In 3 experiments, participants were taught causal knowledge that related the features of a novel category. Causal-model theory provided a good quantitative account of the effect of this knowledge on the importance of both individual features and interfeature correlations to classification. By enabling precise model fits and interpretable parameter estimates, causal-model theory helps place the theory-based approach to conceptual representation on equal footing with the well-known similarity-based approaches. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Diagnosticity and Prototypicality in Category Learning: A Comparison of Inference Learning and Classification Learning.

Category knowledge allows for both the determination of category membership and an understanding of what the members of a category are like. Diagnostic information is used to determine category membership; prototypical information reflects the most likely features given category membership. Two experiments examined 2 means of category learning, classification and inference learning, in terms of sensitivity to diagnostic and prototypical information. Classification learners were highly sensitive to diagnostic features but not sensitive to nondiagnostic, but prototypical, features. Inference learners were less sensitive to the diagnostic features than were classification learners and were also sensitive to the nondiagnostic, prototypical, features. Discussion focuses on aspects of the 2 learning tasks that might lead to this differential sensitivity and the implications for learning real-world categories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Word, thought, and deed: The role of object categories in children's inductive inferences and exploratory play.

Previous research (e.g., S. A. Gelman & E. M. Markman, 1986; A. Gopnik & D. M. Sobel, 2000) suggests that children can use category labels to make inductive inferences about nonobvious causal properties of objects. However, such inductive generalizations can fail to predict objects' causal properties when (a) the property being projected varies within the category, (b) the category is arbitrary (e.g., things smaller than a bread box), or (c) the property being projected is due to an exogenous intervention rather than intrinsic to the object kind. In 4 studies, the authors showed that preschoolers (M = 48 months; range = 42-57 months) were sensitive to these constraints on induction and selectively engaged in exploration when evidence about objects' causal properties conflicted with inductive generalizations from the objects' kind to their causal powers. This suggests that the exploratory actions children generate in free play could support causal learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frequency encoding of token and type information.

Two experiments examined how attention to stimulus attributes affects knowledge of frequency of occurrence. In Experiment 1, orienting tasks were used to direct subjects' attention to either the category membership or the initial letters of words. In Experiment 2, subjects' attention to words, category membership, and initial letters was directed with explicit instructions. The results of these two experiments suggest that attention to specific stimulus attributes may be necessary to initiate the encoding of frequency information. We discuss the implications of these results for claims that the encoding of frequency of occurrence is automatic. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lexical semantic and associative priming in Alzheimer's disease.

Semantic memory impairment was investigated in patients with probable Alzheimer's disease (AD) using a threshold oral word reading task to assess priming of different lexical relationships. Healthy elderly controls showed significant priming for associatively related nouns (tempest-teapot) and also for nouns semantically related either because both designate basic-level exemplars of a common superordinate category (cousin-nephew) or because the target names the superordinate category of the prime (daughter-relative). AD patients, in contrast, showed preserved priming of lexical associates but impaired priming of certain semantic relationships. They showed no priming between words designating coordinate exemplars within a category, despite preserved priming of the superordinate category label. Findings are consistent with the view that at least part of the semantic deficit in AD is due to disruption of semantic knowledge that affects relationships among basic-level concepts, more than the relationships between these concepts and their corresponding superordinate category of membership. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading and believing: Beliefs, attributions, and reading achievement in Moroccan schoolchildren.

This article reports data collected in Morocco. Measures of beliefs (metacognitive knowledge of reading skills and strategies, causal attributions, and conceptions of good readers) and reading performance were collected on a cohort of 350 first-grade children over a 5-year period, and on a second cohort of 464 fifth-grade children over a 3-year period. Metacognitive and causal attribution measures predicted significant portions of variance of subsequent reading achievement beyond the effects of background variables and cognitive skills. First-graders' conception of good readers was an important predictor of beginning reading, but metacognitive knowledge of particular reading skills was not. However, among fifth and seventh graders, both metacognitive knowledge about skilled reading and causal attributions to internal factors predicted reading performance. This study is one of the first cross-cultural demonstrations that metacognitive knowledge and other beliefs affect young children's reading. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inference using categories.

How do people use category membership and similarity for making inductive inferences? The authors addressed this question by examining the impact of category labels and category features on inference and classification tasks that were designed to be comparable. In the inference task, participants predicted the value of a missing feature of an item given its category label and other feature values. In the classification task, participants predicted the category label of an item given its feature values. The results from 4 experiments suggest that category membership influences inference even when similarity information contradicts the category label. This tendency was stronger when the category label conveyed class inclusion information than when the label reflected a feature of the category. These findings suggest that category membership affects inference beyond similarity and that category labels and category features are 2 different things. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thematic relations in adults' concepts.

Concepts can be organized by their members' similarities, forming a kind (e.g., animal), or by their external relations within scenes or events (e.g., cake and candles). This latter type of relation, known as the thematic relation, is frequently found to be the basis of children's but not adults' classification. However, 10 experiments found that when thematic relations are meaningful and salient, they have significant influence on adults' category construction (sorting), inductive reasoning, and verification of category membership. The authors conclude that concepts function closely with knowledge of scenes and events and that this knowledge has a role in adults' conceptual representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

I know you are, but what am I? Self-evaluative consequences of judging in-group and out-group members.

When judging another person, people often spontaneously compare this person with themselves. Six studies examined the self-evaluative consequences of such spontaneous comparisons with in-group versus out-group members. They demonstrate that spontaneous comparisons with in-group members primarily involved the activation of specific individuating knowledge about the self. In particular, knowledge indicating that the self is similar to the judged target was rendered accessible. As a consequence, subsequent self-evaluations that were based on the implications of accessible self-knowledge were assimilated toward in-group targets. Spontaneous comparisons with out-group members, however, primarily involved the activation of more general category knowledge about the self. Specifically, knowledge about judges' membership in a group that distinguished them from the target was rendered accessible. Consequently, self-evaluations were contrasted away from out-group targets. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of integral affect and category relevance on crossed categorization.

The authors investigated integral affect effects (insults or compliments from out-group members) on evaluations of crossed-categorization targets (in-group/in-group, in-group/out-group, out-group/in-group (Oi), and out-group/out-group) as discussion partners. The Oi target possessed a category membership that matched the out-group source of affect. The relevance of this category to participants’ own category membership determined the evaluation patterns. As predicted, negative affect lowered evaluations of targets with group memberships relevant to those of the insulting out-group members (Study 1). Positive affect primed the positive aspects of in-group memberships, leading to broader, more inclusive categorizations of targets irrespective of their relevance to the affective source (Study 2). Evaluation patterns across targets also confirmed predictions, with negative and positive affect respectively producing hierarchical and social inclusion patterns. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structural properties of stereotypic knowledge and their influences on the construal of social situations.

This research focused on the role that higher order structural properties of stereotypic knowledge play in the processing of social information. It is argued that stereotypic assumptions about cause–effect relations provide important constraints for the causal structure underlying the perceiver's subjective representation of social information. Experiment 1 shows how, within the context of a jury decision experiment, the causal structure underlying stereotypic knowledge about African Americans influences the construal of causality in a situation involving a member of that group. Results from 2 additional experiments indicate that this construal effect is based in part on stereotypic knowledge affecting the encoding of the trial evidence instead of on biasing responses at the output stage. The implications of these findings are discussed, and a theoretical framework is offered according to which the application of category knowledge involves not only the matching of stereotypic attributes but also the alignment of structural relations in the environment. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Relational similarity and context effects in category verification.

Two experiments with a total of 50 undergraduate and graduate students measured the effects of coordinate falses, which pair 2 exemplars from a common category (e.g., "A dog is a cat"), on latencies to true items in a category verification task. Results show that although, relative to anomalous falses, coordinate falses did not increase latencies to trues, the size of the increase did not vary with the similarity of the coordinates. Furthermore, latencies were faster to coordinate falses that were more similar than to coordinate falses that were less similar. These results suggest relational similarity is as powerful a predictor of performance in category verification as is attribute similarity. Finally, there was some evidence that the increase in latencies was the same for typical and atypical category exemplars. It is concluded that this last finding, if substantiated, indicates that relational information is generally accessed prior to attribute information. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Knowledge Partitioning in Categorization: Constraints on Exemplar Models.

The authors present 2 experiments that establish the presence of knowledge partitioning in perceptual categorization. Many participants learned to rely on a context cue, which did not predict category membership but identified partial boundaries, to gate independent partial categorization strategies. When participants partitioned their knowledge, a strategy used in 1 context was unaffected by knowledge demonstrably present in other contexts. An exemplar model, attentional learning covering map, was shown to be unable to accommodate knowledge partitioning. Instead, a mixture-of-experts model, attention to rules and instances in a unified model (ATRIUM), could handle the results. The success of ATRIUM resulted from its assumption that people memorize not only exemplars but also the way in which they are to be classified. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic memory in Alzheimer's disease: Representativeness, ontologic category, and material.

Alzheimer's disease (AD) patients with semantic memory difficulty and AD patients with relatively preserved semantic memory named pictures and judged the category membership of words and pictures of natural kinds and manufactured artifacts that varied in their representativeness. Only semantically impaired patients were insensitive to representativeness in their category judgments. AD subgroup judgments did not differ for natural kinds compared to manufactured artifacts nor for words compared to pictures. AD subgroup differences could not be explained by dementia severity, memory, reading, and visuoperception. The similarity process for relating coordinate members of a taxonomic category contributes to the normal appreciation of word and picture meaning, and this process is compromised in AD patients with semantic difficulty. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relational properties and memory-based category construction.

Although many experiments have investigated factors that constrain perceptual category construction, there have been no investigations of factors that constrain memory-based (MB) category construction. Six experiments examined the extent to which perceptual and MB sorting were influenced by correlated dimensions, family resemblance principles, and conceptual knowledge. Sensitivity to many types of relational information (e.g., correlated features, causal relations, interactive properties of objects, and family resemblance relations) was observed with perceptual sorting, but these properties were rarely used to organize information in MB sorting conditions. Instead, there was a clear preference to organize categories around single dimensions. Even when perfectly correlated features were causally related, Ss in memory conditions did not use correlations to construct categories. The strengths and limitations of MB analyses and categorizations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)