The empirical case for role-governed categories

Most theories of categorization posit feature-based representations. Markman and Stilwell (2001) argued that many natural categories name roles in relational systems and therefore they are role-governed categories. There is little extant empirical evidence to support the existence of role-governed categories. Three experiments examine predictions for ways that role-governed categories should differ from feature-based categories. Experiment 1 shows that our knowledge of role-governed categories, in contrast to feature-based categories, is largely about properties extrinsic to category members. Experiment 2 shows that role-governed categories have more prominent ideals than feature-based categories. Experiment 3 demonstrates that novel role-governed categories are licensed by the instantiation of novel relational structures. We then discuss broader implications for the study of categories and concepts.     

Why do categorization effects occur in comparative judgment tasks?

Three experiments were conducted to understand what eliminates the symbolic distance effect for reaction times (RTs) when subjects learn that items belong to categories. Artificial city locations were judged, and artificial states served as categories. In Experiment 1, whether or not categories were presented and the amount of categorization practice were manipulated. Only those subjects who had practice categorizing cities into states showed a reduced symbolic distance effect for different-state pairs. Analyses of serial position curves indicated that categorization produced faster RTs to different-as compared with their adjacent same-state pairs and it also produced faster RTs for same-state pairs closer to the category border. The border seems to serve as an anchor and facilitates RTs. In Experiments 2a and 2b, distance judgments were made by subjects who either had or had not categorized artificial cities into states. Subjects who learned categories gave larger estimates of distance between cities belonging to different states than to cities belonging to the same state. Categorization seemed to place cities from different states farther apart in psychological space, making their locations more discriminable. This, along with the use of the category border as an anchor, might explain why categorization effects occur in this location judgment task.     

Visual categorization of social interactions

Prominent theories of action recognition suggest that during the recognition of actions the physical patterns of the action is associated with only one action interpretation (e.g., a person waving his arm is recognized as waving). In contrast to this view, studies examining the visual categorization of objects show that objects are recognized in multiple ways (e.g., a VW Beetle can be recognized as a car or a beetle) and that categorization performance is based on the visual and motor movement similarity between objects. Here, we studied whether we find evidence for multiple levels of categorization for social interactions (physical interactions with another person, e.g., handshakes). To do so, we compared visual categorization of objects and social interactions (Experiments 1 and 2) in a grouping task and assessed the usefulness of motor and visual cues (Experiments 3, 4, and 5) for object and social interaction categorization. Additionally, we measured recognition performance associated with recognizing objects and social interactions at different categorization levels (Experiment 6). We found that basic level object categories were associated with a clear recognition advantage compared to subordinate recognition but basic level social interaction categories provided only a little recognition advantage. Moreover, basic level object categories were more strongly associated with similar visual and motor cues than basic level social interaction categories. The results suggest that cognitive categories underlying the recognition of objects and social interactions are associated with different performances. These results are in line with the idea that the same action can be associated with several action interpretations (e.g., a person waving his arm can be recognized as waving or greeting).     

Crossed categorization outside the lab: Findings from a factorial survey experiment

Crossed categorization studies investigate intergroup attitudes in situations when two categorization dimensions are simultaneously salient, often looking at artificial groups in laboratory settings. The current study tests (a) patterns of evaluation in crossed categorization scenarios when more than two real-life categorization dimensions are crossed, and (b) the moderating role of identity importance. We conduct a factorial survey experiment with a diverse sample (N = 524), crossing eight categorization dimensions. The results provide strong support for the additive pattern of crossed categorization, challenging the view that with an increased number of categories category-based information processing will not be used. Identity importance predicts the strength of intergroup bias only on the dimension of religion, which was the dominant dimension in this sample. The study contributes to multiple and crossed categorization literature by testing some of its key assumptions using a design that increases the ecological validity of the findings.     

Do development and learning really decrease memory? On similarity and category-based induction in adults and children

In a recently published study, Sloutsky and Fisher [Sloutsky, V. M., & Fisher, A.V. (2004a). When development and learning decrease memory: Evidence against category-based induction in children. Psychological Science, 15, 553-558; Sloutsky, V. M., & Fisher, A. V. (2004b). Induction and categorization in young children: A similarity-based model. Journal of Experimental Psychology: General, 133, 166-188.] demonstrated that children have better memory for the items that they generalise to than do adults. On the basis of this finding, they claim that children and adults use different mechanisms for inductive generalisations; whereas adults focus on shared category membership, children project properties on the basis of perceptual similarity. Sloutsky & Fisher attribute children's enhanced recognition memory to the more detailed processing required by this similarity-based mechanism. In Experiment 1 we show that children look at the stimulus items for longer than adults. In Experiment 2 we demonstrate that although when given just 250ms to inspect the items children remain capable of making accurate inferences, their subsequent memory for those items decreases significantly. These findings suggest that there are no necessary conclusions to be drawn from Sloutsky & Fisher's results about developmental differences in generalisation strategy.     

The role of linguistic labels in inductive generalization

What is the role of linguistic labels in inductive generalization? According to one approach labels denote categories and differ from object features, whereas according to another approach labels start out as features and may become category markers in the course of development. This issue was addressed in four experiments with 4- and 5-year-olds and adults. In Experiments 1 to 3, we replicated Yamauchi and Markman’s findings with adults (Journal of Memory and Language, 1998, Vol. 39, pp. 124–148, and Journal of Experimental Psychology: Learning, Memory, and Cognition, 2000, Vol. 26, pp. 776–795) and extended the paradigm to young children. In Experiment 4, we compared effects of labels with those of highly salient visual features. Overall, results of these experiments provide strong support for the idea that early in development labels function the same way as other features, but they may become category markers in the course of development. A related finding is that whereas categorization and induction may be different processes in adults, they seem to be equivalent in young children. These results are discussed with respect to theories of development of inductive generalization.     

Goal-discrepant situations prime goal-directed actions if goals are temporarily or chronically accessible

This research tested the hypothesis that perception of goal-discrepant situations automatically (i.e., without conscious intent) facilitates access to representations of instrumental actions if goal representations are mentally accessible. Employing a probe-recognition paradigm, Experiment 1 established that sentences describing situations that are discrepant with the goal of "looking well-groomed" (e.g., having dirty shoes) automatically increased the accessibility of representations of appropriate instrumental actions (e.g., polishing) in comparison to control situations, but only when participants frequently pursued the goal. Experiments 2a and 2b suggest that this effect was due to chronic accessibility of the goal representation and demonstrate that the same effects occur if the accessibility of the goal is temporarily enhanced (by subliminal priming) for people that nonfrequently pursue the goal.     

The magic spell of language: linguistic categories and their perceptual consequences

Language is a tool that directs attention to different aspects of reality. Using participants from the same linguistic community, the authors demonstrate in 4 studies that metasemantic features of linguistic categories influence basic perceptual processes. More specifically, the hypothesis that abstract versus concrete language leads to a more global versus local perceptual focus was supported across 4 experiments, in which participants used (Experiment 1) or were primed either supraliminally (Experiments 2 and 3) or subliminally (Experiment 4) with abstract (adjectives) or concrete (verbs) terms. Participants were shown to display a global versus specific perceptual focus (Experiments 1 and 4), more versus less inclusiveness of categorization (Experiments 2 and 3), and incorporation of more rather than less contextual information (Experiment 3). The implications of this new perspective toward the language-perception interface are discussed in the context of the general linguistic relativity debate.     

How long to get to the “gist” of real-world natural scenes?

This study aimed at assessing the processing time of a natural scene in a fast categorization task of its context or “gist”. In Experiment 1, human subjects performed 4 go/no-go categorization tasks in succession with colour pictures of real-world scenes belonging to 2 natural categories: “Sea” and “mountain”, and 2 artificial categories: “Indoor” and “urban”. Experiment 2 used colour and grey-level scenes in the same tasks to assess the role of colour cues on performance. Pictures were flashed for 26 ms. Both experiments showed that the gist of real-world scenes can be extracted with high accuracy (>90%), short median RT (400-460 ms) and early responses triggered with latencies as short as 260-300 ms. Natural scenes were processed faster than artificial scenes. Categories for which colour could have a diagnostic value were processed faster in colour than in grey. Finally, processing speed is compared for scene and object categorization tasks.     

Pushing moral buttons: The interaction between personal force and intention in moral judgment

In some cases people judge it morally acceptable to sacrifice one person’s life in order to save several other lives, while in other similar cases they make the opposite judgment. Researchers have identified two general factors that may explain this phenomenon at the stimulus level: (1) the agent’s intention (i.e. whether the harmful event is intended as a means or merely foreseen as a side-effect) and (2) whether the agent harms the victim in a manner that is relatively “direct” or “personal”. Here we integrate these two classes of findings. Two experiments examine a novel personalness/directness factor that we call personal force, present when the force that directly impacts the victim is generated by the agent’s muscles (e.g., in pushing). Experiments 1a and b demonstrate the influence of personal force on moral judgment, distinguishing it from physical contact and spatial proximity. Experiments 2a and b demonstrate an interaction between personal force and intention, whereby the effect of personal force depends entirely on intention. These studies also introduce a method for controlling for people’s real-world expectations in decisions involving potentially unrealistic hypothetical dilemmas.     

Learning and transfer of category knowledge in an indirect categorization task

Knowledge representations acquired during category learning experiments are ‘tuned’ to the task goal. A useful paradigm to study category representations is indirect category learning. In the present article, we propose a new indirect categorization task called the “same”–“different” categorization task. The same–different categorization task is a regular same–different task, but the question asked to the participants is about the stimulus category membership instead of stimulus identity. Experiment 1 explores the possibility of indirectly learning rule-based and information-integration category structures using the new paradigm. The results suggest that there is little learning about the category structures resulting from an indirect categorization task unless the categories can be separated by a one-dimensional rule. Experiment 2 explores whether a category representation learned indirectly can be used in a direct classification task (and vice versa). The results suggest that previous categorical knowledge acquired during a direct classification task can be expressed in the same–different categorization task only when the categories can be separated by a rule that is easily verbalized. Implications of these results for categorization research are discussed.     

On the asymmetry in the cognitive construal of ingroup and outgroup: A model of egocentric social categorization

A model of egocentric social categorization (ESC-model) is presented. It predicts an asymmetry in the cognitive construal of ingroups and outgroups which is traced back to an egocentrism in the cognitive differentiation of the social world. The more specific assumptions are: (1) At the most basic level of cognitive differentiation, the perceiver distinguishes between the categories ME and NOT-ME. (2) This basic level categorization predicates an asymmetry in the cognitive construal of ingroup and out-group as social categories: The ingroup is construed as a heterogeneous aggregate of separate entities and the outgroup as a homogeneous social category. (3) Egocentric social categorization thus facilitates self-definition in terms of personal identity relative to self-definition in terms of social identity. The ESC-model is highly relevant to research on perceived ingroup and outgroup homogeneity. Moreover, it alerts researchers to the possibility of ‘quasi-intergroup’ situations in which the outgroup, but not the ingroup, is a salient entity. This article also discusses the relationship between the ESC-model and self-categorization theory and points out some prospects for future research.     

Comparison and contrast in perceptual categorization

People categorized pairs of perceptual stimuli that varied in both category membership and pairwise similarity. Experiments 1 and 2 showed categorization of 1 color of a pair to be reliably contrasted from that of the other. This similarity-based contrast effect occurred only when the context stimulus was relevant for the categorization of the target (Experiment 3). The effect was not simply owing to perceptual color contrast (Experiment 4), and it extended to pictures from common semantic categories (Experiment 5). Results were consistent with a sign-and-magnitude version of N. Stewart and G. D. A. Brown's (2005) similarity-dissimilarity generalized context model, in which categorization is affected by both similarity to and difference from target categories. The data are also modeled with criterion setting theory (M. Treisman & T. C. Williams, 1984), in which the decision criterion is systematically shifted toward the mean of the current stimuli.     

Infants' categorization of novel objects with more or less obvious features

In five experiments, 14- to 15-month-old infants' categorization of objects on the basis of more or less obvious features was investigated. Using an object examining paradigm, a total of 200 infants were familiarized with novel objects that shared either more obvious features (i.e., easily visible) or less obvious features (i.e., accessible by lifting a flap), followed by an in-category object and an out-of-category object. When only perceptual information was available, infants formed a category on the basis of the more obvious features but not on the basis of the less obvious features (Experiments 1 and 3). When infants were provided with animacy cues and/or object names, they formed categories on the basis of either more or less obvious features (Experiments 2, 4, and 5). The results of these studies delineate the role of animacy cues and object names in establishing categories on the basis of less obvious features.     

The role of explanation in categorization decisions

Research into the role of explanation on the categorization process has yielded conflicting conclusions. Some theorists stress the importance of explanation, arguing that explanations provide a causal structure necessary to the categorization process. Others discount its significance, arguing that explanation is neither necessary nor sufficient for categorization. Experimentally, explanation has shown modest success in accounting for some categories but not others. Across three experiments, we test whether the central features of a category are the ones that capture the most explanatory structure. The objectives of the current study are threefold: to determine the importance of explanation in natural kind and artifact categorization; to understand the implications of feature correlations as they relate to explanation; and to further delineate the benefit of explanation outside of a functional role. Experiment 1 demonstrates that explanation plays a more dominant role in artifact versus natural kind categorization. Experiment 2 provides evidence that correlated features are neither necessary nor sufficient for categorization. Moreover, it demonstrates that, in the absence of correlation, people still rely on explanation for artifacts but not for natural kinds. Experiment 3 tests to what extent functional information underlies explanation in artifact categorization. We demonstrate that functional relations are not necessary for explanatory‐based categorization. Our results, coupled with previous evidence, suggest a dichotomous role for explanation‐based categorization. On the one hand, explanation is virtually ignored when categorizing biological kinds; on the other, explanation fosters artifact categorization. Implications for categorization and category‐specific disorder are considered.     

Caught in the act: When impressions based on highly diagnostic behaviours are resistant to contradiction

Research and theory emphasizing the role of cue diagnosticity in judgment (e.g. Skowronski and Carlston, 1987, 1989) suggests that under the proper conditions: (a) negativity effects should be observed in judgments of honesty/dishonesty; (b) positivity effects should be observed in judgments of intelligence/unintelligence, and (c) intelligence-implicative and dishonesty-implicative cues should be increasingly difficult to contradict as those cues become more extreme. Two experiments yielded data consistent with these predictions. In addition, two other important findings emerged from these studies. The results of Experiments 1 and 2 indicated that subjects do not respond as if highly diagnostic cues are sufficient for category membership, suggesting that the representational format of trait categories does not correspond to the format suggested by the ‘classical model’ of categorization. The results of Experiment 2 also indicated that negativity and positivity effects are not substantially altered by a role-playing manipulation designed to increase subjects' involvement in the judgment task.     

Studies of implicit prototype extraction in patients with mild cognitive impairment and early Alzheimer's disease

Studies of incidental category learning support the hypothesis of an implicit prototype-extraction system that is distinct from explicit memory (Smith, 2008). In those studies, patients with explicit-memory impairments due to damage to the medial-temporal lobe performed normally in implicit categorization tasks (Bozoki, Grossman, & Smith, 2006; Knowlton & Squire, 1993). However, alternative interpretations are that (a) even people with impairments to a single memory system have sufficient resources to succeed on the particular categorization tasks that have been tested (Nosofsky & Zaki, 1998; Zaki & Nosofsky, 2001) and (b) working memory can be used at time of test to learn the categories (Palmeri & Flanery, 1999). In the present experiments, patients with amnestic mild cognitive impairment or early Alzheimer's disease were tested in prototype-extraction tasks to examine these possibilities. In a categorization task involving discrete-feature stimuli, the majority of subjects relied on memories for exceedingly few features, even when the task structure strongly encouraged reliance on broad-based prototypes. In a dot-pattern categorization task, even the memory-impaired patients were able to use working memory at time of test to extract the category structure (at least for the stimulus set used in past work). We argue that the results weaken the past case made in favor of a separate system of implicit prototype extraction.     

Categorization processes in mental comparisons

Five experiments explore categorization and category-based congruity effects in mental comparisons. The first 4 experiments concentrate on categorization of infinite-set small items. The experiments vary the additional items presented and whether those items appear once (Experiments 1-2) or repeatedly (Experiments 3-4). Additional items include other small items (Experiment 1), relatively large items (Experiments 2-4), and items involving nonsize dimensions (Experiment 4). The critical small items show a complete congruity effect only in Experiments 1 and 3. Results suggest that categorization of infinite-set items may be based on range information alone (Experiment 1) but that multiple categorizations based on multiple ranges (Experiment 2) may require attentional effort. Results implicate categorization as a central process in mental comparison, despite differences in ease of categorization across paradigm.     

Inter‐category versus intra‐category fit: when social categories match social context

The goal of the research reported in this article was to examine whether social categorization, commonly thought to be a function of accessibility and intra‐category fit, is also sensitive to changes in inter‐category fit. Intra‐category fit refers to the match between a target person's features and stored categorical knowledge, inter‐category fit to the extent to which category memberships and targets' features covary across perceived group members. In Experiments 1, 2, and 3, members of social categories of low, medium, and high accessibility, respectively, were shown in a group discussion. Inter‐category fit was manipulated in three steps. Category salience in memory increased as an additive function of accessibility and inter‐category fit. Experiment 4 replicated the effects of inter‐category fit while intra‐category fit and the information presented for individual discussants were held constant. The present studies are the first to demonstrate an effect of inter‐category fit on a relatively direct measure of spontaneous social categorization. Copyright © 2004 John Wiley & Sons, Ltd.