Crossed categorization versus simple categorization and intergroup evaluations: a meta‐analysis

Crossed categorization typically refers to the crossing of two dichotomous social dimensions, resulting in four groups (double‐ingroup, two mixed groups, and double‐outgroup). This paper reports the results of a meta‐analysis comparing the effects of crossed categorization on intergroup evaluations with the effects of simple categorization on intergroup evaluations. The crossed categorization paradigm is shown to increase or decrease ingroup bias, depending on how ingroup bias is defined in the crossed categorization paradigm. Moreover, just as in simple categorization, ingroup bias in crossed categorization is shown to be greater when the proportionate size of the ingroup is smaller. However, contrary to the patterns established in simple categorization, the reality of the group categorizations does not increase ingroup bias in crossed categorization. We discuss the implications of these results for future research on intergroup evaluations. Copyright © 2001 John Wiley & Sons, Ltd.     

The treatment of relevant and irrelevant outgroups in minimal group situations with crossed categorizations

Among a sample of Belgian high school boys, the author attempted to determine on the basis of social identity theory (H. Tajfel & J. C. Turner, 1979) whether an outgroup's relevancy in intergroup comparisons influences the amount of intergroup discrimination. Relevancy was manipulated by the use of 2 trivial categorization dimensions that were orthogonally crossed. In 1 of the crossed categorization conditions, this procedure resulted in the formation of 4 groups, whereas in the 2nd condition, only 2 of these groups were effectively formed. Nevertheless, the participants in both conditions were instructed to evaluate 4 groups--either 4 actual groups (1st condition) or 2 actual and 2 hypothetical groups (2nd condition). In both conditions, the intergroup evaluations exhibited the same pattern--that is, they did not differentiate their ingroups from the partly overlapping groups but were clearly biased against the double outgroup.     

The Treatment of Relevant and Irrelevant Outgroups in Minimal Group Situations With Crossed Categorizations

Abstract

Among a sample of Belgian high school boys, the author attempted to determine on the basis of social identity theory (H. Tajfel & J. C. Turner, 1979) whether an outgroup's relevancy in intergroup comparisons influences the amount of intergroup discrimination. Relevancy was manipulated by the use of 2 trivial categorization dimensions that were orthogonally crossed. In 1 of the crossed categorization conditions, this procedure resulted in the formation of 4 groups, whereas in the 2nd condition, only 2 of these groups were effectively formed. Nevertheless, the participants in both conditions were instructed to evaluate 4 groups–either 4 actual groups (1st condition) or 2 actual and 2 hypothetical groups (2nd condition). In both conditions, the intergroup evaluations exhibited the same pattern–that is, they did not differentiate their ingroups from the partly overlapping groups but were clearly biased against the double outgroup.     

The crossed-categorization hypothesis: Evidence of reductions in the strength of categorization, but not intergroup bias

Deschamps and Doise’s (1978) classic crossed categorization hypothesis states that both category differentiation and intergroup bias should be reduced in crossed conditions (e.g., race × gender groups comprised of Asian females, Asian males, White females, and White males) compared to simple conditions, where people vary on just one social category. Although there has been extensive work testing this hypothesis, we suggest that conclusions from this work are limited because (1) almost none of it has examined category differentiation outcomes, (2) several studies that have examined intergroup bias effects have not directly tested the classic hypothesis, and (3) no studies have examined both categorization and bias outcomes simultaneously. We conducted two experiments to overcome these limitations. In Experiment 1, target race (Asian or White) and gender were manipulated. In Experiment 2, target relationship status (single or significant other) and hometown size (big town or little town) were manipulated. In both experiments, categorization was weaker in crossed than simple conditions, but there was no evidence of reduced intergroup bias in crossed contexts.     

The Effects of Limited and Conflicting Stereotypic information on Group Categorization in Northern Ireland1

The process of group categorization, as suggested by Tajfel and Turner's (1979) theory of intergroup comparison, was examined under conditions of intergroup conflict in Northern Ireland. The theory predicts that under “normal” conditions groups have a need to distinguish themselves from others. The present study investigates how individuals in Northern Ireland under extreme environmental pressures to identify both their own and other groups, can use learned stereotypic cues in making such categorizations. Results suggested that such limited information was highly effective in the process of categorization, with both Protestant and Catholic subjects exhibiting significant agreement and confidence in identifying unknown persons on the basis of stereotypic cues Conflicting information was found to reduce subject's confidence levels, with conflicting Catholic cues being more disruptive than Protestant ones     

The minimal group paradigm: Categorization into two versus three groups

The minimal group paradigm (Tajfel, Billig, Bundy and Flament, 1971) has been influential in the study of intergroup relations. Thus far, most minimal group experiments have divided the subjects either into two groups, or have categorized them on two separate dichotomous dimensions in cross-categorization experiments. This study examines the minimal group paradigm using three distinct and independent groups. Comparison of the results with three minimal groups with those of a baseline two-group experiment shows that with a three-group structure there is no significant ingroup bias. It is suggested that the two-group minimal group experiment shows ingroup bias because subjects access a dichotomous categorization, and that this dichotomous categorization primes a competitive orientation. A two-group context may be particularly efective in evoking an ‘us versus them’ contrast. Self-categorization as a group member is more likely to occur in the presence of two groups whereas three minimal groups renders an ‘us–them’ contrastive orientation less salient. The absence of intergroup discrimination found in the present minimal group study may be limited to the behaviour of minimal or artificially created groups. In the real world of intergroup relations discrimination towards multiple outgroups is a well-known phenomenon. While this study should be regarded as only preliminary research, further elaboration and specification of the conditions under which multiple group contexts may hinder intergroup discrimination is required.     

Intergroup Conflict

This article outlines some of the main social‐psychological bases of intergroup conflict, illustrating the many ways in which social psychology can contribute to the study of conflict. The most convincing theoretical account is provided by perspectives that concentrate on the distinct nature of intergroup phenomena (especially social identity theory). Two of the most promising social‐psychological interventions to reduce intergroup conflict are also reviewed. The first is based on improving contact between members of previously hostile groups; the second attempts to change the structure of social categorizations (via decategorization, recategorization, and crossed categorization). This social‐psychological perspective is proposed as a key part of a necessary, multi‐disciplinary approach to intergroup conflict.     

Social categorization and attitude change

Two experiments were carried out investigating the effect of categorization on attitude change. It was predicted that the division of a number of individuals into two subgroups (categorization), in such a way that initial attitudes correlate with subgroup membership, would lead to accentuation of attitudinal differences between subgroups. It was further predicted that an identical distribution of initial attitudes without superimposed categorization would lead to convergence of attitude positions. In experiment 1, the effect of a male-female classification on attitude change was studied. It was indeed found that subjects changed their attitudes in the direction opposite to the position of the outgroup (intergroup attitude differentiation), but only for groups who were initially more extreme than the comparison group. In the control condition (no categorization), conformity effects were observed. In experiment 2, an antagonistic intergroup setting was induced. In this situation, strong intergroup attitude differentiation effects were observed, which were not affected by the magnitude of the initial intergroup discrepancy. In the control condition, subjects did not show conformity to the overall group mean, but maintained their initial noncentral attitude position.     

Movement Synchrony Influences Intergroup Relations in a Minimal Groups Paradigm

Studies show that synchronizing movements with others encourages a collective social identity, leading to increased cooperation within a group. The current study investigated whether movement synchrony impacts social categorization and cooperation across intergroup boundaries. Two 3-person groups were brought together under movement synchrony conditions designed to emphasize different social categorizations of the aggregate: all individuals moved to the same beat, each minimal group moved to a different beat, or each individual moved to a different beat. Results demonstrate that movement synchrony influenced social categorization and cooperation across intergroup boundaries. Implications for approaches to intergroup relations using movement synchrony are noted.     

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.     

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.     

Social categorization and similarity in intergroup behaviour

The present study is one of a series exploring the role of social categorization in intergroup behaviour. It has been found in our previous studies that in ?minimal' situations, in which the subjects were categorized into groups on the basis of visual judgments they had made or of their esthetic preferences, they clearly discriminated against members of an outgroup although this gave them no personal advantage. However, in these previous studies division into groups was still made on the basis of certain criteria of ?real' similarity between subjects who were assigned to the same category. Therefore, the present study established social categories on an explicitly random basis without any reference to any such real similarity. It was found that, as soon as the notion of ?group' was introduced into the situation, the subjects still discriminated against those assigned to another random category. This discrimination was considerably more marked than the one based on a division of subjects in terms of interindividual similarities in which the notion of ?group' was never explicitly introduced. In addition, it was found that fairness was also a determinant of the subjects' decisions. The results are discussed from the point of view of their relevance to a social-cognitive theory of intergroup behaviour.     

Social comparison and social identity: Some prospects for intergroup behaviour

Recent studies have reported that the variable of social categorization per se is sufficient for intergroup discrimination. This paper presents an explanation of these findings in terms of the operation of social comparison processes between groups based on the need for a positive ingroup identity. The relationship between perceived social identity and intergroup comparison is elaborated theoretically, and it is argued that social comparisons give rise to processes of mutual differentiation between groups which can be analyzed as a form of ‘social’ competition. Social competition is distinguished from realistic competition (conflict of group interests). New data is reported which strengthens this interpretation of the ‘minimal’ categorization studies. It is found that minimal intergroup discrimination takes place in the distribution of meaningless ‘points’ as well as monetary rewards and that social categorization per se does not lead to intergroup behaviour where the subjects can act directly in terms of ‘self’. Other studies on intergroup biases are reviewed to argue for the generality of social competition in intergroup situations.     

The distracting effect of material reward: An alternative explanation for the superior performance of reward groups in probability learning

To determine whether the distraction effect associated with material rewards in discrimination learning can account for the superior performance of reward groups in probability learning, the performance of 144 school children (preschool, second, and fifth grades) on a two-choice successive discrimination task was compared under three reinforcement conditions (material reward, marker, and knowledge of results). The two events in the task had different frequencies of occurrence, as in probability learning, yet they appeared in a constant order to make 100% payoff possible. The subjects in the reward and marker groups learned the task more slowly, and the nonlearners among them used stereotyped alternation patterns to a greater degree than subjects in the knowledge-of-results condition. These findings suggest that a distracting effect of material reward is present in probability learning and may explain the superior performance of reward groups typically found in probability learning studies.     

Considering multiple criteria for social categorization can reduce intergroup bias

Two experiments tested the notion that considering multiple criteria for social categorization can reduce intergroup bias. In both experiments, participants were required to consider alternative ways in which people could be classified, other than an initially salient intergroup dichotomy. In Experiment 1, the authors found that generating alternative social classifications that were unrelated to an initial target dichotomy reduced intergroup bias compared to a control condition. In Experiment 2, this effect was replicated and the authors found that unrelated, but not related, categorizations were necessary to reduce bias. This article adds support to the view that increasing categorical complexity is a useful tool in bias reduction. These findings are discussed in the context of a developing model of multiple categorization effects.     

Social Categorization and the Perception of Groups and Group Differences

The classification of human beings into distinct groups is a fundamental feature of social perception. Problematic phenomena, such as prejudice, discrimination, and intergroup conflict, are commonly traced back to categorization. We explore the minimal conditions under which categorization occurs and the basic mechanisms by which it affects cognition and behavior. We show that comparisons between groups are not necessary for categorization, reveal the conditions under which people overestimate or underestimate differences between groups, and sketch a model showing how social categorization gives rise to differences in the evaluation of ingroups and outgroups and to differences in the accuracy of judgments of ingroups and outgroups. We conclude with reflections on intergroup conflict and the role of moral judgment in such conflicts.     

Social categorization and power differentials in group relations

This study investigated the independent effects of power differentials on intergroup behaviour. Using a variant of Tajfel's minimal group paradigm (Tajfel and Turner, 1979), subjects were arbitrarily categorized into groups of differing power (0-100 per cent) at two levels of salience. Subjects were asked to distribute resources to ingroup and outgroup others using Tajfel's matrices. Intergroup perceptions, group identifications and self-reported strategies constituted our other dependent measures. Minimal group results, replicated in equal power conditions, were systematically eliminated in unequal power conditions on the matrix measures but not on the intergroup perception measures. Dominant group members were more discriminatory, felt more comfortable and satisfied than subordinate group members. Though consistent with Social Identity Theory (Tajfel and Turner, 1979), results suggest we may also have identified boundary conditions for minimal group discrimination. Without power, social categorization does not lead to effective discrimination.     

Group power as a determinant of interdependence and intergroup discrimination

This experiment (N = 239) investigated the effects of group power and legitimacy of power differentials on intergroup discrimination, measured through negative outcome allocations and linguistic abstraction. Furthermore, it examined the mechanisms through which group power affects discrimination by testing the mediating role of perceived interdependence and social identification. Three power conditions were created by modifying the standard minimal group paradigm: equal, high and low power conditions. Power was directly proportional (legitimate conditions) or inversely proportional (illegitimate conditions) to group members' performance in a problem-solving task. Results showed that intergroup discrimination in the high and low power conditions was higher than in the equal power condition on both the allocation and the linguistic measures. Legitimacy moderated the effect of group power on negative outcome allocations, while it had a main effect on the linguistic abstraction. In addition, perceived interdependence turned out to be the main mediator of the effect of power on negative outcome allocations. Copyright © 2006 John Wiley & Sons, Ltd.     

RT to tactile stimuli presented ipsi- and contralaterally to the responding hand

Subjects had to react with the hand which received a tactile stimulus (uncrossed condition) or with the hand opposite to the hand which received the stimulus (crossed condition). Four experiments were conducted. In the first three, subjects knew which hand would receive the stimulus and which hand would have to respond. In the first two experiments, subjects reacted to a simple tactile stimulus while in the third subjects had to perform a tactile discrimination before responding. No significant differences in RT under the crossed and uncrossed conditions were observed in the first three experiments. In the fourth experiment, subjects did not know which hand would receive the stimulus, and they also did not know which hand would have to respond. Under these conditions, large significant differences in RT between the crossed and uncrossed condition emerged.

The study includes a criticism of a simple structural interpretation of interhemispheric transmission time (IHTT) as proposed by Bashore (1981). Support is provided for the view that in paradigms of the kind used here, allocation of attention to a psychologically defined hemispace is a more important factor in observed RT than structural links between stimulus and response mechanisms.     

Status differenttals and intergroup behaviour

This study investigated the independent effects of status differential on intergroup behaviour. Using a variant of the minimal group paradigm (Tueland Turner, 1979), subjects were categorized into groups of differing status (high, equal, low) with two levels of category salience (high, low). Using Tajfel's matrices subjects rated the creativity of products ostensibly produced by ingroup and outgroup members. Own group identification, intergroup perceptions and self-reported strategies on the matrices constituted the other dependent measures. Results indicated a main effect for group status but none for salience. Equal status groups discriminated against each other thus replicating the minimal intergroup discrimination effect. High and equal status group members were more discriminatory against outgroups and more positive about their own group membership than were low status group members. In contrast, low status group members engaged in significant amounts of outgroup favouritism. Results also showed that social categorization per se was sufficient to elicit more ingroup than outgroup liking amongst all group members regardless of status differentials between groups. Overall, the results illustrate important aspects of the interplay between group status, social identity, prejudice and discrimination.