Acoustical Society of America, 63, 456-468. Byrne, R. W. .... The ambiguous-race face illusion. ... Processing value modulates cross race face recognition.
Published in Social and Personality Psychology Compass Vol 2, Issue 2, March 2008, pp. 1052-1072
Social Categorization and Stereotyping: How Social Categorization Biases Person Perception and Face Memory
Kurt Hugenberg & Donald F. Sacco Miami University
Word Count: 7609 (main text)
Author’s Notes: The authors would like to thank Amanda Diekman for her helpful comments on this manuscript. The preparation of this chapter was supported by NSF grant BCS-0642525 awarded to the first author.
Abstract The current article offers a brief history of research and theory related to social categorization and stereotyping. We begin by outlining research focusing on category selection, category activation, and category application. We then discuss the consequences of social categorization, noting that one of the most important and ubiquitous effects of social categorization is homogenization or assimilation. We then extend this research related to the assimilative consequences of social categorization to the realm of face memory. Specifically, we introduce the Categorization-Individuation Model (see also Hugenberg et al., 2008) as a new model of the Cross-Race Effect (CRE), or the difficulty many perceivers have in recognizing members of other racial groups. The Categorization-Individuation Model argues the CRE is due to the tendency to categorize out-group members but individuate in-group members. Finally, we summarize the extant research in support of this new model of person memory and close by discussing the current state of, and potential future directions for, social categorization research. (159 words)
Social Categorization and Stereotyping: How Social Categorization Biases Person Perception and Face Memory
While attitudes may be social psychology’s most indispensable concept (Allport, 1935), social categorization may run a close second. To a great extent, social categorization is one of the cornerstones of the social cognitive revolution in social psychology. The idea that we spontaneously and effortlessly group social targets into categories, and mentally represent and activate beliefs about those categories, is an old one in social psychology (Bruner, 1957; Allport, 1954; Tajfel & Wilke, 1963). Indeed, the processing efficiency gleaned from such categorization lies at the heart of classic social cognitive theory on person perception (Brewer, 1988; Fiske & Neuberg, 1990; Fiske & Taylor, 1991). Activating and applying social category information, or stereotyping, allows us to navigate a complex social environment by simplifying judgments and conserving cognitive capacity (Macrae, Milne, & Bodenhausen, 1994). In most social situations, we do not need perfect information about others around us. Instead, we can often satisfice (Simon, 1945) by using category information to get adequate knowledge of those around us, sufficient to meet our goals. With these ideas in mind, the current chapter provides a brief overview of social categorization research, with an eye toward understanding when social categorization occurs, what categories are selected, as well as the homogenizing effects of categorization on perception, cognition, and memory. Finally, we propose a novel extension of theory on social categorization to a new domain: face recognition. Specifically, we propose that the well-replicated Cross Race Effect (CRE) in face recognition is not due primarily to differential expertise with same-race and cross-race faces, as is often claimed, but instead is largely the result of social categorization and its sequelae. We present evidence from our
laboratory and others indicating that social categorization alone can create, exacerbate, and even eliminate face recognition deficits, both of same-race and cross-race targets, bringing this wellestablished recognition bias under the aegis of social cognitive theory.
The Conditional Automaticity of Social Categorization Given the cognitive efficiency of categorization, and the apparent ease with which categories are activated and applied (Allport, 1954), there has been a robust debate as to whether categories are always activated when category members are observed. Indeed, a number of theorists have argued that social categorization, and the subsequent activation of stereotypes is an unconditional phenomenon, occurring even upon the mere presentation of a social target (see Bargh, 1999 for a review). Most theorists now agree, however, that social categorization tends to occur most powerfully in situations where perceivers think about others as social beings. In one clear example, Macrae, Bodenhausen, Milne, Thorn, and Castelli (1997) presented to participants a series of faces interspersed with a series of non-social stimuli (e.g., chairs, mugs), and manipulated whether a small white dot appeared somewhere on the stimulus. One group of participants was instructed to report the presence or absence of the white dot, a second group was instructed to merely respond to the appearance of the stimulus, whereas a final group was instructed to make animate-inanimate decisions about the stimuli. After each stimulus appeared a letter string which was either a word stereotypic or counter-stereotypic of women, or a nonword letter string. Participants decided whether each letter string was an actual word, or a nonword, which served as a lexical decision task, testing the activation of stereotypes of women. Macrae and colleagues found that stereotypes of women were only activated by female faces when participants were asked to make inanimate-animate decisions with respect to the faces.
Thus, the mere presence of a female face, such as when participants merely located a dot on the face, was insufficient to elicit category activation. Instead, it was only in conditions where perceivers actually treated the target semantically, making decisions based upon the content of the stimulus itself, that category activation ensued. In similar research, Macrae and colleagues (Macrae, Bodenhausen, Milne, & Calvini, 1999) extended these findings, showing that category activation also appears limited to situations in which the social stimuli fall within the spotlight of visual attention. Despite the cognitive efficiency afforded by categorization, social categorization itself only seems to occur when we are attending to others, and thinking about them as social targets. Thus, there may be many situations in which we treat others as objects, rather than as social entities (e.g., mindlessly navigating around others on a busy sidewalk), and it is these situations in which category activation may be unlikely to occur. Despite these clear boundary conditions, the activation of social categories is still quite common (if not completely unconditional) in everyday experience. There is, however, consensus that many of the effects of categorization can be offset with sufficient motivation and capacity to process an individual (Brewer, 1988; Fiske & Neuberg, 1990). Whereas categorization relies on the activation of pre-existing category associates and stereotypes, individuation (or piecemeal processing) involves attending to and processing the unique characteristics of the individual. Thus, the process of individuation allows the perceiver to move beyond the shared categorical characteristics to the more specific details of a particular individual. Such extensive processing, however, is quite dependent on both the motivation to process beyond the social category level, and the available cognitive capacity to do so. Thus, the ability to avoid the use of category information with extensive, deliberative processing can be limited by task complexity, time, or processing constraints (e.g., Bodenhausen, 1990;
Bodenhausen & Lichtenstein, 1987). While different models of categorization and individuation may diverge in their details, most are in agreement there is some level of trade-off between the two processes. As individuation increases, the potency of the effects of categorization on judgment are attenuated or eliminated. Activation and inhibition in categorization: Solving the multiple category problem Perhaps the most appealing explanation for the ubiquity of social categorization is the argument for the cognitive efficiency it affords. Categories allow us to infer a great deal of information about others with minimal cost. However, each individual in our environment is multiply categorizable; that is, each individual simultaneously belongs to a whole host of categories. Sex, race, age, sexual orientation, religious affiliation, political party, and occupation are only the tip of the iceberg. Activating all of these categories simultaneously would seem to eliminate the cognitive efficiency that categorization may afford in the first place. To deal with this complex web of social categories, while still retaining the efficiency of social categorization, perceivers commonly select one, or perhaps only a handful of relevant categories, out of the many available categories. In line with selective attention models of cognition, Macrae, Bodenhausen, and Milne (1995) argue that this category selection occurs via a ‘race’ to activation. In this model, a handful of potentially relevant categories ‘race’ to reach a sufficient amount of activation to achieve an attentional threshold, with the ‘winner’ of this race being selected for category activation. Importantly, in this model, ‘losers’ of this race do not simply decay in activation over time back to baseline. Instead, losers of this race to activation may be actively inhibited, allowing for a relatively singular view of the social target. In essence, by inhibiting competing categories, this allows us to think about others in a relatively simplistic way, suppressing
potentially distracting alternate categorizations. To test this hypothesis, Macrae and colleagues (1995) showed participants a Chinese woman who was in one of two contexts: either applying makeup at a mirror, or eating with chopsticks. Macrae and colleagues hypothesized that this contextual manipulation would be sufficient to lead either the sex or the race of the target to be selected as the dominant social category for the target. When she was applying makeup, she would be categorized as a woman; when eating with chopsticks, she would be categorized as Chinese. Of particular interest was what would happen to the non-dominant category. That is, what occurs to the category representation of ‘woman’ when the target was categorized as ‘Chinese?’ To investigate this, participants also completed a lexical decision task designed to measure the category activation of both the category ‘woman’ and the category ‘Chinese.’ As predicted, viewing a Chinese woman applying makeup activated the category ‘female,’ and led to the inhibition of the category ‘Chinese.’ Conversely, observing the same woman eating with chopsticks activated the category ‘Chinese,’ and inhibited the category ‘female.’ Sinclair and Kunda (1999) have provided evidence that this lateral inhibition of competing categories can serve motivational goals, as well. In one study, they had participants receive either positive or negative feedback from either a Black doctor or a White doctor. Participants then completed a lexical decision task designed to measure activation of both the categories Black and doctor. When participants received positive feedback from a Black doctor, the category ‘doctor’ was activated above baseline. Moreover, this positive feedback elicited inhibition of the category ‘Black.’ Conversely, when participants received negative feedback from this Black doctor, the category ‘Black’ was activated whereas the category ‘doctor’ was inhibited below baseline. Thus, self-protective motives appear to be a powerful determinant of which social categories are activated and inhibited.
In our own research, we (Hugenberg & Bodenhausen, 2004) found that these same excitatory and inhibitory processes occur in self-categorization. Just as we commonly categorize others as members of social categories, so too do we categorize ourselves (e.g., Turner, 1987). In this research, we hypothesized that inhibition might be particularly useful in maintaining cognitive consistency in individuals who belong to categories that seem to be in normative conflict. For example, a fraternity member who is also a high-achieving student must simultaneously navigate both the extensive social demands of the fraternity and the extensive academic demands of being a student, sets of demands that are in normative conflict. We hypothesized that when members of the so-called “Greek system” temporarily self-categorize as fraternity or sorority members, they may temporarily inhibit the normatively conflicting selfcategory ‘student.’ Students who are not members of the Greek system, however, would not mentally represent these two social categories as conflicting. As such, for non-Greek members, thinking about the Greek system would activate concepts related to the Greek system, but would not lead to inhibition of the category ‘student.’ To test these hypotheses, we primed both members of the Greek system (fraternity or sorority members) and non-members with either Greek related concepts or a neutral, control prime. All participants then completed a lexical decision task designed to measure activation of both Greek and student categories. As hypothesized, priming Greek-related concepts for non-members led to activation of the category ‘Greek,’ but had no effect on the activation of the category ‘student.’ Priming Greek-related concepts for fraternity and sorority members, however, led to both activation of the category ‘Greek’ and inhibition of the category ‘student.’ Thus, inhibitory processes also appear to be implicated in self-categorization, such that activating one’s membership in one category can reduce the activation of normatively competing categories.
Determinants of Category Selection Beyond specific theory regarding excitatory and inhibitory processes in social categorization, a great deal of theory and research have addressed the question of what factors will actually lead one category to be selected over another. Based on Bruner’s (1957) original conception that category salience is determined by relative accessibility and fit between the target and category attributes, more recent research has shown that the salience of a social category is greater for chronically accessible social categories (e.g., sex, race) that are normatively relevant to the judgment under consideration (e.g., issue or emotional relevancy; Blanz, 1999). One rather specific example of how chronic accessibility influences category activation can be seen in the context of how individuals high and low in racial prejudice are influenced by procedures that attempt to prime this social category. Lepore and Brown (1997) identified high and low prejudice individuals and assigned half of these participants to a priming condition that exposed them to words intended to activate the social category of Blacks (e.g., ethnic, colored) and half to a no prime, control condition. Their results indicated that high prejudice participants in the priming condition increased their ratings of the target on the negative stereotypic dimensions and decreased their ratings of the target on the positive stereotypic dimensions. However, low prejudice participants in the priming condition were much less affected by the category activation prime (although they showed a pattern of results opposite that of high prejudice participants). Collectively, these results indicate that some aspects of category selection are flexibly determined based upon both situational and perceiver characteristics. There is also evidence that social targets that deviate from the ‘norm,’ or who are otherwise distinctive, are more likely to be categorized based on those social categories that
violate normalcy. Extending the idea that ‘White’ and ‘male’ are the normative categories in the U.S., Stroessner (1996) had participants categorize Black and White, male and female targets. He found that men are categorized more quickly by race than by sex while women are categorized more quickly by sex than by race, a reflection that individuals focus on targets’ nonnormative dimensions during social categorization processes. Other research has shown similar effects and has also indicated that the speed with which participants categorize targets by race and by sex is also capable of predicting the attribution of race stereotypic traits as well (Zarate & Smith, 1990). Taken together, these results indicate that in many cases, individuals will categorize others based on information about a target that is considered non-normative, and that this categorization can lead to stereotypic judgments. Research has also revealed that category fit can also be a powerful determinant of categorization. For example, in our own research, we (Hugenberg & Bodenhausen, 2004) investigated how a racially ambiguous target’s facial expression might influence how that target is categorized. Specifically, we showed participants a series of racially ambiguous faces, and manipulated the facial expression on each face on a within-subjects basis. Consistent with the stereotype of Blacks as aggressive, we found that faces that better fit the category by displaying an angry expression were categorized as Black more frequently. Moreover, individuals with higher levels of implicit prejudice were more likely to show this bias to categorize angry faces as Black. These results suggest that when attributes of a social target are consistent with the attributes of a particular social category (e.g., angry expressions with the Black stereotype), this can strongly influence category selection. Finally, there is also an increasing body of research indicating that social categorization is often determined by the processing goals or motivational states of the perceiver. For example,
Fein and Spencer (1997) found evidence that the motivation to reaffirm one’s self-worth may cause people to activate and apply negative stereotypes to members of stereotyped groups. In one study, participants were exposed to either a Jewish or non-Jewish job applicant and either experienced a success or a failure experience. The results indicated that participants derogated the Jewish applicant (e.g., rated her as less competent compared to the non-Jewish applicant) after a recent failure experience but rated the Jewish applicant as highly as the non-Jewish applicant following a success experience, suggesting that derogating a member of an out-group may provide individuals who have recently failed with an opportunity to restore their damaged self-worth. Although Fein and Spencer did not make specific claims about category inhibition, these results do show some similarities to the work of Sinclair and Kunda (1999), who found that both category activation and inhibition are determined by self-protective motives. Collectively, these results suggest that determining how a social target is ultimately categorized is influenced by a number of factors. Specifically, individuals with chronic activation of a particular social category (e.g., high-prejudice individuals) are more likely to categorize a member of a stereotyped group due to the salience of this social category. It is also the case that individuals often categorize individuals on dimensions that are considered nonnormative. The extent to which the attributes of a target fit to a category or an evaluative context is capable of determining social categorization processes as well. Finally, research indicates that temporary motivational states, such as reaffirmation and impression formation goals, are capable of both activating and inhibiting the application of social categorizations. The Homogenizing Effects of Social Categorization. While the processes underlying category activation and application are critical, these processes have retained such widespread research interest primarily because of their
consequences. It is certainly beyond the scope of the current paper to outline all of the effects of social categorization, so instead we focus on one of the most important and ubiquitous effects of social categorization. From visual perception, to memory, to judgment, categories can to lead to strong assimilative effects (but see Biernat, 2003). In short, categories homogenize. In 1963, Tajfel and Wilke provided seminal evidence for the homogenizing effect of categorization on visual perception (see also Corneille, Klein, Lambert, & Judd, 2002). In this now classic study, Tajfel and Wilke presented to participants a series of lines of monotonically decreasing length. Critically, the longer of the lines were given a different category label than the shorter lines; for example, the longer lines were labeled as ‘A’s and the shorter lines labeled as ‘B’s. The mere presence of this category label was sufficient to elicit a greater perception of difference between the longest of the short lines and the shortest of the long lines. In other words, category labels increased perceived differences between categories, and reduced perceived differences within the categories. In an analogous and more recent display, Levin and Banaji (2006) showed that merely categorizing a face as Black or White can distort the perceptions of the lightness of the skin tone of a target. In one study, racially ambiguous BlackWhite morphed faces were explicitly labeled by the experimenters as being Black or White. Participants were then asked to match the skin tone of the target to reference samples of luminance. As predicted, explicit social category labels shifted the perceived skin tone of the target toward the category prototype. When the racially ambiguous faces were labeled as ‘Black,’ participants perceived the skin tone of the targets to be darker than when the same faces were categorized as ‘White.’ More recent evidence on the phenomenon of categorical perception mirrors these homogenizing effects of categorization (see Harnad, 1987). In this domain, two stimuli from a
morph continuum are presented, and participants are asked to decide whether the two stimuli are identical stimuli, or are two slightly different stimuli. Critically, participants are only permitted to see the stimuli very briefly, eliminating the possibility of extensive comparisons. For example, in one experiment, Corneille, Hugenberg, and Potter (2007) morphed happy and angry expressions (on the same person) together at 10% intervals, creating a set of people showing a series of increasingly happy expressions. Participants saw two of these morphed stimuli, which were either identical stimuli (e.g., two identical 80% angry morphs), or were stimuli that differed by 20% in the morph continuum (e.g., a 100% angry morph and an 80% angry morph). Replicating the classic categorical perception phenomenon, participants had a more difficult time distinguishing between stimuli within the category angry or happy (e.g., between 100% angry and 80% angry expressions, or between 100% happy and 80% happy expressions), than when the categories crossed the category boundary (e.g., between a 60% angry and a 40% angry [and thus 60% happy] expression). Thus, it was more difficult to distinguish between two angry expressions, than between a happy and an angry expression, even though the physical differences between the morph levels were held constant (see also Etcoff & Magee, 1992). This same categorical perception phenomenon occurs for race as well. Levin and Beale (2000) morphed Black and White faces together, and found perceivers more easily distinguished two morphed stimuli separated by 20% in the morph continuum when they crossed the racial category boundary (i.e., between a slightly Black [40% morph] and a slightly White face [60% morph]), than between two faces separated by 20% on the morph continuum that did not cross the category boundary (e.g., between a 70% Black and a 90% Black face). Supporting these behavioral data, neuroscientific research investigating categorical perception has indicated greater activation of face responsive ERPs (N170) for morphed faces that cross the category
boundary than for within-category faces, despite the physical differences between the morph levels of the faces being held constant (Jacques & Rossion, 2006); an indication that the homogenizing effect of categorization influences even low level perceptual processes associated with distinguishing between stimuli. This general tendency to perceive less variability within, as opposed to between categories (even when objective variability is held constant) has been replicated within numerous classes of stimuli, both social and non-social (Beale & Keil, 1995; Burns & Ward, 1978; Smith, Kemmler Nelson, & Appleton, 1994; Liberman, Cooper, Shankweiler, & Studdert-Kennedy, 1967), and even among non-human mammals (e.g., Kuhl, 1981), indicating this categorical effect is an extraordinarily robust consequence of categorization. This tendency for social categorization to lead to more perceptions of homogeneity does not just occur in perception, but also in memory. Within the social-cognitive literature, the observation of greater within-category than between-category confusions in the “Who said what?” paradigm (Taylor, Fiske, Etcoff, & Ruderman, 1978; Klauer & Wegener, 1998) could be considered a manifestation of the same phenomenon. In this paradigm, perceivers tend to confuse the speakers of statements made by members of the same social category (e.g., a statement made by one African American is mistakenly assigned to another African American). This suggests that perceivers commonly encode category-specifying information about targets at the expense of individuating information, leading to more frequent within-category confusions, but very infrequent between-category confusions. Similarly, social categorization can even distort the memory for categorized exemplars after encoding. For example, Corneille, Huart, Bequart, and Bredart (2004) showed participants Asian-White morphed faces, with either a preponderance of White-prototypic (70% White / 30%
Asian) or a preponderance of Asian-prototypic (30% White / 70% Asian) features. During a later recognition phase, participants were then asked to decide which of five target faces had been previously seen. Critically, the five faces always included the target face (e.g., 70% Asian), but the four distractors consisted of two faces that were more prototypic of the target’s category (e.g., an 80% and a 90% Asian morph of the same identity), and two faces that were less prototypic of the target’s category (e.g., a 50% Asian and a 60% Asian morph of the same identity). As predicted, Corneille and colleagues found that memory was distorted in the direction of the category. For a 70% Asian face, perceivers most commonly selected faces that were more prototypically Asian (i.e., the 80% or 90% Asian version of the face). Similar memory distortions caused by social categorization occur with sex as well (Huart, Corneille, & Bequart, 2005). Beyond the homogenizing effects that social categorization has on perception and memory, the stereotyping literature also shows that such categorization processes have a variety of effects on the search for information, on judgments, and on decisions. To the extent that an individual is categorized as a member of a particular social group, that individual is judged to possess stereotypic attributes of prototypical members of that group (e.g., Bodenhausen & Macrae, 1998; Fiske & Neuberg, 1990). As a result, stereotypes elicit homogenization effects such that stereotyped individuals are perceived as more similar to typical members of that group and judgments about that individual are based on this social category membership. Both classic and contemporary research have documented a variety of domains related to social judgment and decision making that are affected by the homogenizing effects of stereotypic categorizations, especially in ambiguous social contexts.
In now classic research, Sagar and Schofield (1980) showed Black and White children a variety of ambiguously aggressive behaviors performed by Black and White targets. They found that participants, regardless of their race, rated the same behavior as more threatening when performed by a Black, as opposed to a White target. These authors argued that the association of the category of Black with aggression led participants to interpret the behaviors of Black targets in a manner consistent with the stereotype. In essence, the individual Black targets were perceived as more prototypic of the category Black; in this case, as more aggressive. In a similar set of findings, we (Hugenberg & Bodenhausen, 2003) found that White perceivers tend to see anger lingering on Black as compared to White faces. In this research, we had participants complete an IAT measuring the strength of their implicit anti-Black prejudice, and then to detect the onset and offset of anger for matched Black and White faces. Critically, as implicit prejudice increased, so too did the tendency for perceivers to use the race of the target to interpret the expression. Individuals higher in prejudice saw anger occurring earlier on and dissipating later on Black, as opposed to White targets. This research is another indication that stereotypes can lead individuals to perceive members of stereotyped groups as prototypical, assimilating the target to the expectation for the group. In this case, an individual Black target is perceived of as more threatening than a nearly identical White target. One common process responsible for the effects of stereotypes on social judgments is the tendency of individuals to seek out stereotype confirming information and to ignore stereotype disconfirming information. For example, Darley and Gross (1983) led participants to believe that a child came from a high or low socioeconomic background. Participants were then assigned to view, or not view, a video of the child performing an academic test, and were subsequently asked to rate the child’s performance. The results of this study indicated that
individuals who viewed the performance tape used information about the child’s SES to pick out information that confirmed the stereotypic attributes associated with the particular socioeconomic status information they were given. Specifically, those who were told that the child was from a low socioeconomic background perceived that child as possessing more of the “typical” characteristics associated with low SES (lower intelligence/ability) while those told that the child was from a high SES background categorized the child as more similar to the prototypical high SES child (higher intelligence/ability). Beyond judgments related to personality traits and facial affect, the homogenizing effects of stereotypes are also capable of directly influencing many relevant real world decisions. In the context of hiring decisions, for example, research indicates that although White participants are equally likely to hire both a highly qualified Black or White job candidate as well as equally unlikely to hire both a weakly qualified Black or White job candidate, White individuals are more likely to make the recommendation to hire an ambiguously qualified White candidate as opposed to an ambiguously qualified Black candidate (Dovidio & Gaertner, 2000). In essence, when individuals are presented with ambiguous information about a target, they are likely to use the stereotypes of the social categories to aid in their decision. It is also the case that individuals’ stereotypes are capable of influencing even life-anddeath decisions; specifically the decision to shoot or to not shoot Black and White targets. In this research, individuals viewed images of either armed or unarmed Black and White targets and were asked to make a rapid decision to either shoot or not shoot a target. The results of several studies indicated that both Black and White participants were quicker to make the correct decision to not shoot an unarmed White target (versus Black target) and to shoot an armed Black target (versus White target) and that the magnitude of this bias varied with participants’
knowledge of the cultural stereotype associating African Americans with aggression (Correll, Park, Judd, & Wittenbrink, 2002). Thus, individuals’ stereotypic perception that African Americans are more aggressive led them to perceive individual Black targets in the context of the prototype of this social category, which influenced their decision to shoot these targets. Collectively, there seems to be a long and growing list of research indicating that social categories about which individuals hold stereotypes will lead to the homogenization of individuals within that social category, such that they will be perceived as more like prototypical members of that social group. Such homogenization of individual group members has a number of significant consequences for judgment and decision-making processes. Not only do the stereotypes associated with social categories influence judgments related to a target’s personality and affect, but stereotypes have been implicated in domains related to hiring decisions, decisions to shoot a potential perpetrator, as well as myriad other important decisions. Such research is an indication of the ubiquity of stereotypes that result from social categorizations and their numerous consequences. Throughout the cognitive stream, from visual perception to memory, categorization seems to increase the perception of homogeneity within categories. Drawing on this research, we propose to extend our understanding of the homogenizing effects of social categorization to the domain of face recognition, attempting to explain an old problem in a new way. Specifically, many people report having difficulty recognizing members of racial groups other than their own. Research on this phenomenon, known as the Cross Race Effect (or alternately, the Own Race Bias) indicates this difficulty distinguishing between the faces of members of racial out-groups is a surprisingly common phenomenon. It seems to occur across racial groups, in many different
cultures, shows a robust effect size across different experimental paradigms, and has proven surprisingly difficult to eliminate (see Meissner & Brigham, 2001 for a meta-analytic review). Extending the corpus of research on social categorization, we propose that the Cross Race Effect is due, in part, to the increased perception of within-group homogeneity. There is good evidence indicating that out-group targets (e.g., cross-race faces) tend to elicit stronger category activation than do in-group targets (e.g., same-race faces; Levin, 1996). The CategorizationIndividuation Model proposes that this stronger category activation can elicit more within-group homogeneity for out-group than for in-group faces, in part leading to the Cross Race Effect, or the tendency to have difficulty recognizing members of racial out-groups. Social Categorization and Face Recognition: The Categorization-Individuation Model Recently, research in our laboratory and others has been interested in how social categorization can affect not just how we perceive and judge others, but also how we remember them. As a species, humans are singularly successful in building and maintaining friendships, groups, and coalitions to achieve our goals. Indeed, prominent theories of human intelligence argue that it is humans’ inherently social nature that led to the evolution of theory of mind, and more generally our powerful abstract thinking capacities (Byrne & Whiten, 1988). For such processing power to be brought to bear on coalition building, however, humans must solve a serious problem; specifically, remembering ‘who is who,’ while simultaneously attending to and processing the other myriad details in our environment. While theoretical social psychologists have not typically studied the problem of face identification per se, it is part of many of our experimental paradigms (e.g., the classic ‘Who Said What?’ paradigm; Taylor et al., 1978), and is very much part of social and cognitive psychology. For example, the extensive eyewitness identification research investigates this very problem of remembering ‘who is who’ (in a
circumscribed domain). Thus, not only is face recognition an inherently social psychological problem, but we further propose that basic social categorization processes play a potent role in who we recognize, and how we do it. At the heart of this proposition is the well-established Cross Race Effect (CRE). For example, White perceivers typically have more difficulty recognizing Black or Asian targets, than they do fellow White targets, an effect that is quite well-replicated across dozens of experiments. Most prominent theories of the Cross Race Effect propose that the CRE is due to a lack of inter-racial contact. Thus, de facto segregation leads to a lack of expertise with faces of different ethnic groups (Chance & Goldstein, 1981). This lack of expertise is proposed to lead to a host of processing or representational deficits for cross-race faces, debilitating subsequent recognition. While variations of this perceptual expertise hypothesis are both long-standing and well accepted, the evidence for the central proposition of this hypothesis seems surprisingly weak. Specifically, while this perceptual expertise hypothesis predicts that better recognition of cross-race faces should improve with increased inter-racial contact, inter-racial contact appears to account for only approximately 2% of the variance in the magnitude of the CRE (Meissner & Brigham, 2001). We argue that the weak relationship between inter-racial contact and the ability to recognize cross-race faces is because the CRE is due not primarily to differential expertise, but rather to the differential tendency to think about cross-race faces in terms of their category membership, rather than in terms of their unique, individuating characteristics. In our Categorization-Individuation Model (CIM; Hugenberg et al., 2008), we propose that thinking of others in terms of social category memberships can both reduce the search for unique, individuating characteristics in cross-race faces (Levin, 1996, 2000), and reduce the motivation
to process those faces (Rodin, 1987). The CIM argues that the Cross Race Effect is simply a manifestation of the tendency to think categorically about out-group members, but to individuate in-group members. ‘Race’ and the Cross Race Effect. This Categorization-Individuation Model of the CRE is not only different than the perceptual expertise models, but also offers provocative new hypotheses about what will improve or reduce both same-race and cross-race face recognition. First, the CIM hypothesizes that there is nothing unique about race in the Cross Race Effect. That is, while perceivers commonly think about members of racial out-groups in terms of their category memberships, any subjectively meaningful in-group/out-group distinction should be sufficient to elicit recognition differences, even when holding constant the perceptual expertise with the stimuli. Indeed, evidence from a series of studies conducted in our laboratory and others confirms this supposition. For example, we (Shriver, Young, Hugenberg, Bernstein, & Lanter, in press) extended this logic to investigate how social class distinctions might be sufficient to elicit face recognition deficits. Specifically, we hypothesized that the recognition advantage enjoyed by same-race faces would be eliminated when those same-race faces were deemed to be of a different socioeconomic status as the perceiver. To test this hypothesis, we had White middle-class university students view a series of Black and White faces presented on both wealth-implying (e.g., large suburban homes) and poverty-implying (e.g., trailer parks) backgrounds. We hypothesized that White faces presented in wealth-implying contexts would be well recognized by White perceivers, whereas White faces presented in poverty-implying contexts would be no better recognized than the cross-race, Black faces. Black targets, however, would be out-group members for these White participants, regardless of the social context; as such, we hypothesized
context would have no influence on cross-race recognition. This is exactly what we found. The advantage typically observed for same-race faces was only observed for the wealthy White faces. In a follow-up study, we determined that this weaker recognition for same-race faces in povertyimplying contexts was due to the tendency to categorize these faces as members of the devalued, exclusionary sub-type “White trash.” In a related series of studies, we (Bernstein, Young, & Hugenberg, 2007) also tested whether a Cross Race-like Effect could be observed even when target race was held completely constant, by manipulating other relevant social categories. In our first experiment, we showed White Miami University undergraduates a series of 40 White faces on red and green backgrounds. In our control condition, we simply asked participants to attend closely to the faces in order to be able to recognize them later. Critically, in our experimental condition, we also instructed participants (White Miami University students) that faces on the red backgrounds were fellow Miami University students, whereas faces on the green backgrounds were students at Marshall University (red and green being the school colors of Miami and Marshall University, respectively). As predicted, red and green backgrounds themselves had no influence on the recognition of same-race faces. However, when participants believed that background color was indicative of an important in-group/out-group distinction, a cross-category effect was observed, leading to a significant drop in out-group recognition and a marginally significant increase for ingroup recognition. In our second experiment, we found these cross-category effects in face recognition were robust across even the most minimal of in-group/out-group distinctions. Using a minimal group paradigm, we randomly assigned White participants to ‘red’ or ‘green’ personality types, based on the outcome of a bogus personality test. We then showed participants a series of White faces
on red and green backgrounds, with background ostensibly indicating the targets’ personality types. In line with our hypotheses, we found that participants who believed they had a ‘red’ personality type better recognized faces on red backgrounds, an effect that was reversed when participants believed they had a ‘green’ personality type. Importantly, these differences were found despite the fact that all faces were of the same race as our participants, and the perceptual expertise with the faces was held constant via counter-balancing. In what they label the ‘Ambiguous Race Illusion,’ Maclin and Malpass (2001, 2003) found additional evidence supportive of the hypothesis that the CRE is due to social cognitive mechanisms. In their studies, they showed Hispanic participants a series of ambiguous HispanicBlack faces, and manipulated only the hair style on the faces to be either typically Hispanic or typically Black hairstyles. This minor manipulation of the face was not only sufficient to change the way participants categorized the faces, but was also sufficient to modulate recognition as well. When Hispanic participants saw a face with Hispanic typical hairstyle, they were better at recognizing the face than when the identical face had a Black typical hairstyle. By simply changing the way perceivers categorize the targets, as same-race versus cross-race, subsequent memory for those faces can be improved or degraded. Individuation Eliminates the CRE. Not only does the Categorization-Individuation Model predict cross-category effects in face recognition, but it also offers a novel way to ameliorate the Cross Race Effect. While the only solution to the CRE according to perceptual expertise models is extensive exposure to cross-race faces, the CIM offers a radically different possibility: individuation. Individuation is, of course, the counter-weight to categorization. When perceivers are aware of their propensity to think categorically, are motivated to consider the unique characteristics of others, and have the available cognitive capacity to do so (Brewer,
1988, Fiske & Neuberg, 1990), they can engage in individuation. If the Cross Race Effect is due to the tendency to think categorically about out-group members, but to individuate in-group members, then motivating perceivers to individuate out-group members could reduce or even eliminate the Cross Race Effect. To test this provocative extension of the CIM, we (Hugenberg, Miller, & Claypool, 2007) showed White participants a series of White and Black faces, and instructed them to attend to the faces to facilitate later recognition. While participants in the control condition received no additional information regarding the task, participants in the individuation condition were instructed that they were likely to show the Cross Race Effect and to attend closely to the unique characteristics of cross-race faces in an attempt to eliminate this effect. Just as predicted by the Categorization-Individuation Model, these individuation instructions were sufficient to completely eliminate the CRE, a phenomenon we replicated multiple times using different sets of stimuli. Individuation instructions eliminated the CRE. Thus, it appears that perceivers have sufficient perceptual expertise to distinguish between cross-race faces, but in many situations they do not employ this expertise. Recent data from our laboratory and others provides additional support for the supposition that motives to individuate can ameliorate or even reverse the CRE by improving cross-race recognition. For example, Ackerman and colleagues (2006) showed White perceivers a series of White and Black faces, but manipulated the facial expressions of these faces. In these studies, they find that angry Black faces are better remembered than any other race-expression combination, thus reversing the typically observed CRE. Drawing on the argument that angry faces, or threatening stimuli in general, are important to attend to, these angry Black faces are thereby ‘high-value’ attentional targets, garnering extensive processing and thus individuation.
In a similar line of research, we (Shriver & Hugenberg, 2008) showed White participants a series of Black and White faces, each of which was paired with a behavior. Critically, the stereotypicality of the behavior (Black stereotypic versus White stereotypic) and the valence of the behavior (positive versus negative) were manipulated on a within-subjects basis. Similar to Ackerman and colleagues’ (2006) findings, we found that negative Black-stereotypical Black targets (e.g., violent individuals, gang members, welfare recipients) were quite memorable. We also found, however, that positive White-stereotypic Black targets were also very memorable. Thus, Blacks who were high scholastic achievers, were very wealthy, or who were otherwise high in social power were strongly individuated. In essence, we argue the high ‘value’ of processing these targets, regardless of whether this ‘value’ comes from bodily threat or from social power, substantially increases recognition of cross-race faces, eliminating or even reversing the CRE. Thus, regardless of whether individuation is elicited by explicit instructions or motivated by characteristics of the target (e.g., facial expressions, behaviors), it appears increasingly clear that individuation is sufficient to improve cross-race recognition to levels at or above those observed for same-race recognition. While much recent evidence seems consistent with the predictions of the CategorizationIndividuation Model, additional evidence is still required to test the mechanisms underlying these provocative phenomena. One real possibility is that the perceptual and conceptual homogenization that follows from social categorization leads to real difficulty in encoding the distinct individuating characteristics of cross-race (or cross-category) faces. The existing literature also offers a number of other potential mechanisms by which social categorization can influence the ability to recognize faces. For example, Rodin (1987) proposes that social categorization can lead to cognitive disregard of ‘low-value’ individuals. In so far as perceivers
are cognitive misers, and are generally unwilling to unnecessarily deploy cognitive resources (Fiske & Taylor, 1991), many individuals may not be processed beyond mere category levels. Thus, once motivationally irrelevant individuals are categorized (e.g., old man, hippie, cashier), they receive no further attentional resources. Alternately, Levin’s (1996, 2000) feature-selection model proposes that it is not so much that cross-race individuals receive less attention overall, but that attention is instead allocated to different features in same-race and cross-race faces. Whereas attention to same-race faces is paid to the unique characteristics of that face, which allows for strong subsequent recognition, attention to cross-race faces is instead allocated to race-specifying features at the expense of individuating information. Thus, in cross-race faces, perceivers tend to search for characteristics that are shared by members of the category, rather than for characteristics that are unique to that individual, leading to real difficulty in subsequent recognition. Although there are real differences between these different mechanisms, we believe that longstanding, but ill-explained phenomena such as the Cross-Race Effect are almost certainly multiply determined. Realistically, all of these processes are likely implicated in many real-world observances of the CRE; however, more research is still needed to explicate each of these possibilities. A Challenge and Conclusion. Despite all of its strengths, and a long history of powerful empirical demonstrations, exciting new evidence suggests that social categorization is not the only means by which to elicit stereotype-congruent judgments and responses. Social categorization is no longer the only game in town. Instead, the very facial features of others may directly activate associated traits, even without activating the broader category (Livingston & Brewer, 2002). For example, a target’s ‘Afrocentricity,’ or physical features perceived of as prototypical of African Americans (e.g.,
dark skin, wide nose, full lips), might be capable of directly influencing judgments, outside of the assimilative effects of category activation. This direct activation can result in differential stereotypic inferences within a racial category, with individuals having more Afrocentric features being perceived as having stronger Black-stereotypic traits (e.g., Maddox & Gray, 2002). For example, Blair, Judd, and Chapleau (2004) found that judges were quite capable of reducing category-based stereotyping (i.e., the effects of social categorization) as they gave sentences of equivalent length to Black and White offenders who had equivalent criminal histories. However, offenders with equivalent criminal histories as well as from the same racial background (either Black or White) were given longer sentences as the Afrocentricity of their faces increased (i.e., the effects of direct, feature associations). One clear challenge for subsequent research on social categorization will be to understand which ‘stereotyping’ effects are due to category activation, and which are instead due to this more direct route of features activating associates, not necessarily mediated by social categorization. Despite this recent, and exciting challenge, social categorization as a concept, will likely remain central to social cognitive theory. Social categorization is among our most powerful explanatory concepts in social psychology, in part, because it both gracefully explains and predicts human cognition in areas vital to social psychology. It gives us an understanding of important social phenomena, such as stereotyping, person perception, and social judgment. Second, social categorization is so useful a concept because it links social psychology to other disciplines both at lower and higher levels of analysis. For example, this concept integrates social psychological theory both with theory in cognitive science, related to the activation and inhibition of mental representations, as well as with sociological theory related to stereotyping and inter-group conflict. Perhaps most importantly, however, social categorization is so central
to social cognitive research because it so consistently bears intellectual fruit. Indeed, our own model of the Cross Race Effect, the Categorization-Individuation Model, is drawn from the basic tenets of social categorization. Social categorization simply has a history of generating novel research, and is likely to do so for years to come.
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