Groups Face Research Articles

Investigating the other-race effect in working memory.

People have difficulties in remembering other-race faces; this so-called other-race effect (ORE) has been frequently observed in long-term recognition memory (LTM). Several theories argue that the ORE in LTM is caused by differences in earlier processing stages, such as encoding of ingroup and outgroup faces. We test this hypothesis by exploring whether the ORE can already be observed in visual working memory (VWM)-an intermediate system located between encoding processes and LTM storage. In four independent experiments, we observed decreased performance for outgroup faces compared to ingroup faces using three different VWM tasks: an adaptive N-back task, a self-ordered pointing task, and a change detection task. Also, we found that the number of items stored in VWM is smaller for outgroup faces than for ingroup faces. Further, we explored whether performance differences in the change detection task are related to the classic ORE in recognition memory. Our results provide further evidence that the ORE originates during earlier stages of cognitive processing. We discuss that (how) future ORE research may benefit from considering theories and evidence from the VWM literature.

Attending to identity cues reduces the own-age but not the own-race recognition advantage

Adults’ ability to recognize individual faces is shaped by experience. Young adults recognize own-age and own-race faces more accurately than other-age and other-race faces. The own-age and own-race biases have been attributed to differential perceptual experience and to differences in how in-group vs. out-group faces are processed, with in-group faces being processed at the individual level and out-group faces being processed at the categorical level. To examine this social categorization hypothesis, young adults studied young and older faces in Experiment 1 and own- and other-race faces in Experiment 2. During the learning phase the identity-matching group viewed faces in pairs and completed a same/different task designed to enhance attention to individuating cues; the passive-viewing group memorized faces presented individually. After the learning phase, all participants completed an identical old/new recognition task. Both passive-viewing groups showed the expected recognition bias, but divergent patterns were observed in the identity-matching groups. Whereas the identity-matching task eliminated the own-age bias, it neither eliminated nor reduced the own-race bias. Collectively, these results suggest that categorization-individuation processes do not play the same role in explaining the two recognition biases.

Fear acquisition and liking of out-group and in-group members: Learning bias or attention?

The present study explores the notion of an out-group fear learning bias that is characterized by facilitated fear acquisition toward harm-doing out-group members. Participants were conditioned with two in-group and two out-group faces as conditioned stimuli. During acquisition, one in-group and one out-group face was paired with an aversive shock whereas the other in-group and out-group face was presented without shock. Psychophysiological measures of fear conditioning (skin conductance and pupil size) and explicit and implicit liking exhibited increased differential responding to out-group faces compared to in-group faces. However, the results did not clearly indicate that harm-doing out-group members were more readily associated with fear than harm-doing in-group members. In contrast, the out-group face not paired with shock decreased conditioned fear and disliking at least to the same extent that the shock-associated out-group face increased these measures. Based on these results, we suggest an account of the out-group fear learning bias that relates to an attentional bias to process in-group information.

Acute Stress Reduces Perceived Trustworthiness of Male Racial Outgroup Faces

Outgroup members are often perceived as threating and untrustworthy, and this is particularly true for judgments of outgroup males. As race influences perceptions of group membership, male racial outgroup faces (MROFs) are judged as less trustworthy than male racial ingroup faces (MRIFs). Neurologically, this effect is mediated by amygdala activation, a brain region central to the processing of fear-related stimuli, threat detection, vigilance regulation and facial trustworthiness. As acute stress up regulates amygdala activity and promotes hyper-vigilance towards threatening stimuli, we hypothesised that acute stress would result in increased vigilance and lower trustworthiness judgements towards MROFs. In contrast, we expected that stress would have no effect on MRIFs. Using a within-subjects design, White-Dutch male participants rated the perceived trustworthiness of White males (ingroup) and Arab males (outgroup) under stress and during the absence of stress (baseline). Stress significantly reduced trust towards racial outgroup members, whilst trust towards racial ingroup members was maintained. Understanding the mechanisms by which stress differentially affects social behaviors towards outgroups is of theoretical and practical relevance to our understanding of the biological basis of ethnocentrism and xenophobia.

Dorsomedial prefrontal cortex and cerebellar contribution to in-group attitudes: a transcranial magnetic stimulation study.

We tend to express more positive judgments and behaviors toward individuals belonging to our own group compared to other (out-) groups. In this study, we assessed the role of the cerebellum and of the dorsomedial prefrontal cortex (dmPFC) - two regions critically implicated in social cognition processes - in mediating implicit valenced attitudes toward in-group and out-group individuals. To this aim, we used transcranial magnetic stimulation (TMS) in combination with a standard attitude priming task, in which Caucasian participants had to categorize the valence of a series of adjectives primed by either an in-group or an out-group face. In two behavioral experiments, we found an in-group bias (i.e. faster categorization of positive adjectives when preceded by in-group faces) but no evidence of an out-group bias. Interestingly, TMS over both the dmPFC and over the (right) cerebellum significantly interfered with the modulation exerted by group membership on adjective valence classification, abolishing the in-group bias observed at baseline. Overall, our data suggest that both the dmPFC and the cerebellum play a causal role in mediating implicit social attitudes.

Correction: Social Groups Prioritize Selective Attention to Faces: How Social Identity Shapes Distractor Interference.

[This corrects the article DOI: 10.1371/journal.pone.0161426.].

The Modulation of Mimicry by Ethnic Group-Membership and Emotional Expressions.

Mimicry has been ascribed affiliative functions. In three experiments, we used a newly developed social-affective mimicry task (SAMT) to investigate mimicry´s modulation by emotional facial expressions (happy, angry) and ethnic group-membership (White in-group, Black out-group). Experiment 1 established the main consistent effect across experiments, which was enhanced mimicry to angry out-group faces compared to angry in-group faces. Hence the SAMT was useful for experimentally investigating the modulation of mimicry. Experiment 2 demonstrated that these effects were not confounded by general aspects of response conflict, as a Simon task resulted in different response patterns than the SAMT. Experiment 2 and pooled analysis of Experiments 1 and 2 also corroborated the finding of enhanced mimicry to angry out-group faces. Experiment 3 tested whether this effect was related to perceptions of threat, by framing angry persons as physically threatening, or not. Selective enhancement of mimicry to out-group persons framed as physically threatening confirmed this hypothesis. Further support for the role of threat was derived from implicit measures showing, in all experiments, that black persons were more strongly associated with threat. Furthermore, enhanced mimicry was consistently related to response facilitation in the execution of congruent movements. This suggests that mimicry acted as a social congruency signal. Our findings suggest that mimicry may serve as an appeasement signal in response to negative affiliative intent. This extends previous models of mimicry, which have predominantly focused on its role in reciprocating affiliation. It suggests that mimicry might not only be used to maintain and establish affiliative bonds, but also to ameliorate a negative social situation.

Culture, group membership, and face recognition. Commentary: Will you remember me? Cultural differences in own-group face recognition biases

Literature reports that same-race faces are better recognized than cross-race faces. This cross-race effect has been observed, inter alia, in European Americans (MacLin et al., 2004) as well as in Asian Americans and East Asians (Michel et al., 2006; Hayward et al., 2008). Although research showed that cross-race effects reflect a superiority in the processing of components and configurations of own-race faces (Hayward et al., 2008), empirical evidence showed that (arbitrary) social categorization similarly contributes to an ingroup bias in face recognition (MacLin and Malpass, 2001). This finding suggests that mere social categorization is sufficient to bias face recognition performance in favor of ingroup faces, reflecting a motivational preference to individuate ingroup members (Hugenberg et al., 2010). Following these findings, Ng et al. (2016) examined whether participants' cultural background moderates the effect of arbitrarily determined social group membership on the recognition performance for ingroup/outgroup targets displaying neutral facial expressions. According to their focal hypothesis, North Americans should preferentially define their ingroups on broader social categories, whereas East Asians should define their ingroups with a focus on preexisting relationships established through friendship and family (Brewer and Yuki, 2007). Therefore, Ng and colleagues expected that European Canadians, but not East Asians, would show an ingroup bias in face recognition when group membership is arbitrarily determined by a minimal group manipulation: A color-coding system indicated whether one's own personality fits the personality of a displayed person (Study 1) or whether one's preexisting university affiliation fits that of a displayed person (Study 2). Same colors indicated ingroup faces, different colors indicated outgroup faces. In both studies, European Canadians recognized previously observed ingroup faces better than outgroup faces. East Asian Canadians did not show this bias for arbitrarily determined ingroup faces. Hence, the authors concluded that culture moderates the effect of mere social categorization on face recognition. Overall, these studies provide a valuable extension of previous research by introducing a cross-cultural perspective. However, some crucial aspects should be considered in future research in this field.

Degraded perceptual and affective processing of racial out-groups: An electrophysiological approach

ABSTRACTHuman beings process perceptual and affective information of racial out-groups in a degraded manner. Relative to racial in-group members, we lack perceptual individuation of racial out-group members and empathize their pain to a less degree. To date, however, the relationship between the deficiency of individuation and the impairment of empathy in responding to racial out-groups remains elusive. By recording event-related brain potentials in response to racial in-group and out-group faces portraying pain and neutral expressions, we simultaneously measured neural activity that underpinned individuation and empathy. Deficiency in individuating members of racial out-groups, manifesting as reduced reactivity of face-sensitive N170 in the occipitotemporal region of the brain, predicted attenuation of fronto-central empathic response to the suffering of racial out-groups. Further, the individuation bias mediated the influence of racial prejudice on racial in-group bias in empathic neural responses. These findings suggest an interplay between degraded perceptual and affective processing of racial out-groups.

Party Identity and the Evaluation of Political Candidates

Party Identity and the Evaluation of Political Candidates

Power effects on implicit prejudice and stereotyping: The role of intergroup face processing

ABSTRACTPower is thought to increase discrimination toward subordinate groups, yet its effect on different forms of implicit bias remains unclear. We tested whether power enhances implicit racial stereotyping, in addition to implicit prejudice (i.e., evaluative associations), and examined the effect of power on the automatic processing of faces during implicit tasks. Study 1 showed that manipulated high power increased both forms of implicit bias, relative to low power. Using a neural index of visual face processing (the N170 component of the ERP), Study 2 revealed that power affected the encoding of White ingroup vs. Black outgroup faces. Whereas high power increased the relative processing of outgroup faces during evaluative judgments in the prejudice task, it decreased the relative processing of outgroup faces during stereotype trait judgments. An indirect effect of power on implicit prejudice through enhanced processing of outgroup versus ingroup faces suggested a potential link between face processing and implicit bias. Together, these findings demonstrate that power can affect implicit prejudice and stereotyping as well as early processing of racial ingroup and outgroup faces.

Culture moderates the relationship between interdependence and face recognition.

Recent theory suggests that face recognition accuracy is affected by people’s motivations, with people being particularly motivated to remember ingroup versus outgroup faces. In the current research we suggest that those higher in interdependence should have a greater motivation to remember ingroup faces, but this should depend on how ingroups are defined. To examine this possibility, we used a joint individual difference and cultural approach to test (a) whether individual differences in interdependence would predict face recognition accuracy, and (b) whether this effect would be moderated by culture. In Study 1 European Canadians higher in interdependence demonstrated greater recognition for same-race (White), but not cross-race (East Asian) faces. In Study 2 we found that culture moderated this effect. Interdependence again predicted greater recognition for same-race (White), but not cross-race (East Asian) faces among European Canadians; however, interdependence predicted worse recognition for both same-race (East Asian) and cross-race (White) faces among first-generation East Asians. The results provide insight into the role of motivation in face perception as well as cultural differences in the conception of ingroups.

A clash of values: Fear-relevant stimuli can enhance or corrupt adaptive behavior through competition between Pavlovian and instrumental valuation systems.

Humans and nonhuman primates preferentially learn to fear and avoid archetypical fear-relevant stimuli. Yet how these learning biases influence adaptive behavior, the basic mechanistic underpinnings of these biases, and how they interact with learning experiences during the life span of an individual remain unknown. To study this, we investigated how 4 classes of fear-relevant stimuli (snakes, threatening in-group faces, racial out-group faces, and guns) influenced adaptive behavior. We showed that stimulus-driven biases have a dramatic influence that can either promote or corrupt adaptive behavior depending on how a bias relates to the environment. We quantified and compared the effects of different fear-relevant stimuli on instrumental behavior using a computational reinforcement learning model that formalized the idea that the bias reflects competition between an instrumental and a Pavlovian valuation system. These results were further clarified by 2 independent rating studies showing that perceived danger of the stimuli corresponded well with their influence on adaptive behavior.

Intergroup threat gates social attention in humans.

Humans shift their attention to follow another person's gaze direction, a phenomenon called gaze cueing. This study examined whether a particular social factor, intergroup threat, modulates gaze cueing. As expected, stronger responses of a particular in-group to a threatening out-group were observed when the in-group, conditioned to perceive threat from one of two out-groups, was presented with facial stimuli from the threatening and non-threatening out-groups. These results suggest that intergroup threat plays an important role in shaping social attention. Furthermore, larger gaze-cueing effects were found for threatening out-group faces than for in-group faces only at the 200 ms but not the 800 ms stimulus onset asynchrony (SOA); the specificity of the gaze-cueing effects at the short SOA suggests that threat cues modulate the involuntary component of gaze cueing.

Own-race and own-age biases facilitate visual awareness of faces under interocular suppression.

The detection of a face in a visual scene is the first stage in the face processing hierarchy. Although all subsequent, more elaborate face processing depends on the initial detection of a face, surprisingly little is known about the perceptual mechanisms underlying face detection. Recent evidence suggests that relatively hard-wired face detection mechanisms are broadly tuned to all face-like visual patterns as long as they respect the typical spatial configuration of the eyes above the mouth. Here, we qualify this notion by showing that face detection mechanisms are also sensitive to face shape and facial surface reflectance properties. We used continuous flash suppression (CFS) to render faces invisible at the beginning of a trial and measured the time upright and inverted faces needed to break into awareness. Young Caucasian adult observers were presented with faces from their own race or from another race (race experiment) and with faces from their own age group or from another age group (age experiment). Faces matching the observers’ own race and age group were detected more quickly. Moreover, the advantage of upright over inverted faces in overcoming CFS, i.e., the face inversion effect (FIE), was larger for own-race and own-age faces. These results demonstrate that differences in face shape and surface reflectance influence access to awareness and configural face processing at the initial detection stage. Although we did not collect data from observers of another race or age group, these findings are a first indication that face detection mechanisms are shaped by visual experience with faces from one’s own social group. Such experience-based fine-tuning of face detection mechanisms may equip in-group faces with a competitive advantage for access to conscious awareness.

How disgust facilitates avoidance: an ERP study on attention modulation by threats.

This study investigated the attention modulation of disgust in comparison with anger in a dot-probe task. Results indicated a two-stage processing of attention modulation by threats. When participants viewed the cues that were represented by Chinese faces (i.e. the in-group condition), it was found at the early processing stage that an angry face elicited a larger occipital P1 component whereas a disgusted face elicited a smaller P1 for validly than for invalidly cued targets. However, the result pattern was reversed at the later processing stage: the P3 amplitudes were larger for valid disgust cues but were smaller for valid angry cues, when both were compared with invalid cue conditions. In addition, when participants viewed the cues that were represented by foreign faces (i.e. the out-group condition), the attention modulation of disgust/anger diminished at the early stage, whereas enhanced P3 amplitudes were observed in response to validly cued targets in both disgusting and angry conditions at the later stage. The current result implied that although people can perceptually differentiate the emotional categories of out-group faces as accurately as in-group faces, they may still be not able to psychologically understand the subtle differences behind different categories of out-group facial expressions.

Close contact with racial outgroup members moderates attentional allocation towards outgroup versus ingroup faces

Some research has demonstrated that White perceivers direct more initial attention to Black relative to White target faces, while other work has failed to show this relationship. Several variables have been identified that moderate early attention to racial outgroup versus racial ingroup faces. In the current paper, two studies sought to extend this work by testing whether close contact with racial outgroup members moderates the amount of initial attention directed towards racial outgroup members relative to ingroup members using a dot-probe task. In Study 1, Whites’ attentional allocation to Black versus White faces was moderated by the amount of close and meaningful contact with Blacks. Study 2 extended these findings by demonstrating that Whites’ attentional allocation to Asian relative to White faces was moderated by close contact with Asians. These findings identify close outgroup contact as an additional moderating variable in the attentional capture of racial outgroup versus ingroup faces, for groups both associated and not associated with threat.

Visualizing minimal ingroup and outgroup faces: implications for impressions, attitudes, and behavior.

More than 40 years of research have shown that people favor members of their ingroup in their impressions, attitudes, and behaviors. Here, we propose that people also form different mental images of minimal ingroup and outgroup members, and we test the hypothesis that differences in these mental images contribute to the well-established biases that arise from minimal group categorization. In Study 1, participants were assigned to 1 of 2 groups using a classic minimal group paradigm. Next, a reverse correlation image classification procedure was used to create visual renderings of ingroup and outgroup face representations. Subsequently, a 2nd sample naive to the face generation stage rated these faces on a series of trait dimensions. The results indicated that the ingroup face was significantly more likely than the outgroup face to elicit favorable impressions (e.g., trusting, caring, intelligent, attractive). Extending this finding, Study 2 revealed that ingroup face representations elicited more favorable implicitly measured attitudes than did outgroup representations, and Study 3 showed that ingroup faces were trusted more than outgroup faces during an economic game. Finally, Study 4 demonstrated that facial physiognomy associated with trustworthiness more closely resembled the facial structure of the average ingroup than outgroup face representation. Together, these studies suggest that minimal group distinctions can elicit different mental representations, and that this visual bias is sufficient to elicit ingroup favoritism in impressions, attitudes and behaviors.

Neural Correlates of the In-Group Memory Advantage on the Encoding and Recognition of Faces

People have a memory advantage for faces that belong to the same group, for example, that attend the same university or have the same personality type. Faces from such in-group members are assumed to receive more attention during memory encoding and are therefore recognized more accurately. Here we use event-related potentials related to memory encoding and retrieval to investigate the neural correlates of the in-group memory advantage. Using the minimal group procedure, subjects were classified based on a bogus personality test as belonging to one of two personality types. While the electroencephalogram was recorded, subjects studied and recognized faces supposedly belonging to the subject’s own and the other personality type. Subjects recognized in-group faces more accurately than out-group faces but the effect size was small. Using the individual behavioral in-group memory advantage in multivariate analyses of covariance, we determined neural correlates of the in-group advantage. During memory encoding (300 to 1000 ms after stimulus onset), subjects with a high in-group memory advantage elicited more positive amplitudes for subsequently remembered in-group than out-group faces, showing that in-group faces received more attention and elicited more neural activity during initial encoding. Early during memory retrieval (300 to 500 ms), frontal brain areas were more activated for remembered in-group faces indicating an early detection of group membership. Surprisingly, the parietal old/new effect (600 to 900 ms) thought to indicate recollection processes differed between in-group and out-group faces independent from the behavioral in-group memory advantage. This finding suggests that group membership affects memory retrieval independent of memory performance. Comparisons with a previous study on the other-race effect, another memory phenomenon influenced by social classification of faces, suggested that the in-group memory advantage is dominated by top-down processing whereas the other-race effect is also influenced by extensive perceptual experience.

Group membership alters the threshold for mind perception: The role of social identity, collective identification, and intergroup threat

Human faces are used as cues to the presence of social agents, and the ability to detect minds and mental states in others occupies a central role in social interaction. In the current research, we present evidence that the human propensity for mind perception is bound by social group membership. Specifically, we show how identification with different social groups influences the threshold for mind perception. In three experiments, participants assessed a continuum of face morphs that ranged from human to doll faces. These faces were described as in-group or out-group members. Participants had higher (i.e., more stringent) thresholds for perceiving minds behind out-group faces, both in minimal (Experiment 1) and real-world groups (Experiment 2). In other words, out-group members required more humanness than in-group members to be perceived as having minds. This intergroup bias in mind perception was moderated by collective identification, such that highly identified group members had the highest threshold for perceiving minds behind out-group relative to in-group faces. In contrast, Democrats and Republicans who perceived the other party as threatening had lower thresholds for perceiving minds behind out-group faces (Experiment 3). These experiments suggest that mind perception is a dynamic process in which relevant contextual information such as social identity and out-group threat change the interpretation of physical features that signal the presence of another mind. Implications for mind perception, dehumanization, and intergroup relations are discussed. (229 words)