Elsevier

Neuropsychologia

Volume 50, Issue 14, December 2012, Pages 3600-3611
Neuropsychologia

Evaluative vs. trait representation in intergroup social judgments: Distinct roles of anterior temporal lobe and prefrontal cortex

https://doi.org/10.1016/j.neuropsychologia.2012.09.002Get rights and content

Abstract

When interacting with someone from another social group, one's responses may be influenced by both stereotypes and evaluations. Given behavioral results suggesting that stereotypes and evaluative associations operate independently, we used fMRI to test whether these biases are mediated by distinct brain systems. White participants viewed pairs of Black or White faces and judged them based on an evaluation (who would you befriend?) or a stereotype-relevant trait (who is more likely to enjoy athletic activities?). Multi-voxel pattern analysis revealed that a predominantly occipital network represented race in a context-invariant manner. However, lateral orbitofrontal cortex preferentially represented race during friendship judgments, whereas anterior medial prefrontal cortex preferentially represented race during trait judgments. Furthermore, representation of race in left temporal pole correlated with a behavioral measure of evaluative bias during friendship judgments and, independently, a measure of stereotyping during trait judgments. Whereas early sensory regions represent race in an apparently invariant manner, representations in higher-level regions are multi-componential and context-dependent.

Highlight

► Participants viewed photographs of White and Black faces in two task contexts. ► Brain representations of race were decoded using multi-voxel pattern analysis of fMRI. ► Distinct brain areas encoded race during judgments of value versus trait information. ► In intergroup judgments, separable systems mediate evaluative bias vs. stereotyping.

Introduction

Social relationships are extremely complex, and a major goal of social cognitive neuroscience is to understand the mechanisms through which the human mind navigates the social world. When interacting with a person from a different social group, pre-existing beliefs about the group – referred to as stereotypes – influence our impressions (Allport, 1954). Social stereotypes may be learned through acculturation within one's society and may spring to mind automatically to influence impressions of outgroup members and behavior towards them (Darley and Gross, 1983, Devine, 1989). Although stereotypes may not accurately describe particular individuals, they can exert strong influence on how a perceiver approaches an interaction with a member of an outgroup (Bargh, Chen, & Burrows, 1996).

Social perceptions of outgroup members are also driven by evaluative processes (Fazio, Jackson, Dunton, & Williams, 1995). Like stereotypes, evaluative associations may influence judgments and behaviors without one's intention or awareness. For example, White Americans tend to associate Black people with negative concepts, compared with White people, in implicit behavioral responses (e.g. Fazio et al., 1995, Greenwald et al., 1998). These biases influence our behavior: people who show stronger implicit evaluative bias on behavioral tasks have been shown to respond in a less friendly manner toward a Black person during a real social interaction (Dovidio et al., 2002, Fazio et al., 1995).

Recently, research has suggested that implicit stereotyping and evaluation processes may operate somewhat independently in behavior (Amodio & Devine, 2006), raising the possibility that these different facets of implicit bias reflect different underlying neural mechanisms. If these two forms of bias were found to reflect different underlying mechanisms, this finding might help explain why implicit evaluations and stereotypes appear to predict different forms of behavior. Furthermore, this finding would shed light on the mechanisms through which these two forms of social bias may be learned and unlearned, potentially informing interventions to reduce social prejudices. The present research was designed to test the hypothesis that racial evaluation and stereotypes reflect distinct neural processes.

Although the concepts of evaluation (i.e., attitudes) and stereotyping have long been distinguished in social psychology research (Fiske, 1998), the notion that implicit stereotyping and evaluation processes might be rooted in different underlying neurocognitive systems was proposed more recently by Amodio and Devine (2006). Amodio and Devine (2006) tested this distinction in a series of behavioral experiments. In each experiment, the authors assessed White American participants’ stereotypic and evaluative associations with Black vs. White faces using two different Implicit Association Tests (IATs; Greenwald et al., 1998). One IAT, designed to measure evaluative associations, assessed the speed with which participants identified faces as Black vs. White and words as pleasant vs. unpleasant, when the response keys for these faces and words were paired in either a congruent (i.e., Black-unpleasant and White-pleasant) or incongruent (i.e. Black-pleasant and White-unpleasant) mapping. Used in hundreds of studies, this evaluative IAT has revealed a pervasive response bias among White American participants, such that they respond faster to Black faces paired with unpleasant words relative to pleasant words, in comparison with White faces (Nosek, Greenwald, & Banaji, 2007). This pattern is interpreted as indicating an implicit negative evaluation of Blacks, compared with Whites.

Amodio and Devine (2006) designed a second IAT to assess stereotypic associations, independently of evaluative associations. This stereotyping IAT was identical in task structure to the evaluative IAT, but it compared the speed with which participants categorized Black (vs. White) faces and athletic- vs. intelligence-related words in congruent vs. incongruent mappings. These word categories were chosen because athleticism and (un)intelligence are the two most common stereotypes of African Americans reported by White Americans (Devine & Elliot, 1995). Importantly, the words used in the stereotyping IAT were selected on the basis of pilot testing so that they were similar in valence. Because these target words were all moderately positive, this task could only be completed on the basis of semantic associations, and not evaluative associations.

In all three studies reported by Amodio and Devine (2006), participants exhibited significant racial bias on both the evaluative and stereotyping IATs. Yet scores on the two measures were uncorrelated (despite a combined sample size of 230), consistent with the idea that these two forms of bias reflect different underlying processes. More importantly, scores on evaluative and stereotyping IATs predicted different behavioral expressions of racial bias. Higher evaluative IAT scores uniquely predicted more negative feelings toward Black people and greater seating distance along a row of chairs from the belongings of their Black study partner. By contrast, higher stereotyping IAT scores uniquely predicted more stereotype-consistent trait impressions of a Black student and lower expectancies for the Black students' performance on a GRE-type academic test. Overall, these results demonstrate that implicit evaluative and stereotyping processes may operate independently at a behavioral level. However, it remains unclear how these behavioral effects relate to underlying neural mechanisms.

Several previous studies have examined the neural correlates of intergroup bias (for reviews, see Amodio, 2008, Eberhardt, 2005). The majority of these studies have investigated differences in brain activity associated with perception of Black versus White faces in White participants. Multiple brain regions have been reported to show such differences, such as amygdala, medial and lateral prefrontal cortex, hippocampus, and fusiform gyrus (Amodio et al., 2003, Golby et al., 2001, Lieberman et al., 2005, Wheeler and Fiske, 2005). The majority of these studies examined neural responses to pictures of White and Black individuals in passive viewing paradigms (Amodio et al., 2003, Cunningham et al., 2004, Phelps et al., 2000) or categorizing target faces (Lieberman et al., 2005, Wheeler and Fiske, 2005). Because these studies were interested in the emotional aspects of implicit prejudice, they focused primarily on amygdala activity in response to faces and, in most cases, observed greater amygdala activity while viewing Black than White faces. However, to date, research has not systematically examined the neural processes involved in conceptual representations of social ingroups vs. outgroups as they relate to evaluative and trait (i.e., stereotype) information.

The current research examined the neural processes involved in conceptual judgments of evaluative and semantic information. There were two broad aims. First, we investigated whether we could find evidence for distinct brain systems mediating evaluative versus semantic representations during social judgments. Whereas brain regions such as orbitofrontal cortex have been linked particularly to value-based assessment of stimuli (Grabenhorst and Rolls, 2008, Rushworth et al., 2011), other regions such as medial prefrontal cortex (Amodio and Frith, 2006, Krueger et al., 2009) and temporal pole (Olson et al., 2007, Zahn et al., 2007) have been suggested to underlie conceptual social representations and their integration with decision making and emotion. However, the precise roles of these brain regions in social judgments are not well understood, despite recent evidence for separable functions (Gozzi, Raymont, Solomon, Koenigs, & Grafman, 2009). A second aim of the present study was to investigate whether neuroimaging results could be linked with behavioral IAT measures of evaluative and stereotyping bias. Insofar as the neuroimaging results can be linked with these behavioral indices, this provides evidence for their relevance to real-life behavior.

The present study used the technique of multi-voxel pattern analysis (MVPA; Haynes and Rees, 2006, Norman et al., 2006). Whereas previous studies have adopted standard univariate fMRI methodologies to investigate differential regional brain activity between perception of Black versus White faces, MVPA provides a finer-grained approach to distinguishing patterns of neural activity that is well suited for testing our hypotheses regarding neurocognitive representations. In studies using MVPA, fMRI data is typically investigated on a participant-by-participant basis, often using unsmoothed, unnormalized data. Two or more conditions are compared, and a pattern classifier is trained to distinguish voxel-by-voxel patterns of brain activity between those two conditions. Insofar as the classifier is able to distinguish these patterns, in a manner that generalizes to novel exemplars, this indicates that the brain region under investigation contains a representation that distinguishes these patterns. Thus, MVPA can be used to decode the representations contained within certain brain regions. This can apply to relatively low-level perceptual features, for example decoding the orientation of visually-presented lines by examining patterns of activity in primary visual cortex (Kamitani & Tong, 2005). It can also apply to higher-order brain regions, such as prefrontal cortex, and higher-level representations, such as the content of participants' delayed intentions (Gilbert, 2011, Gilbert et al., 2012, Haynes et al., 2007). MVPA is an attractive technique to apply to social cognitive neuroscience, seeing as a major aim of this field is to investigate the nature of representations underlying social behavior. However, with few exceptions (e.g. Gilbert et al., 2009, Natu et al., 2011; Ratner, Kaul, & Van Bavel, in press) this approach has not yet been applied to the study of social processes.

To elicit the activation of either trait-based or evaluative representations of ingroup and outgroup members, participants viewed pairs of White or Black faces and either made a trait judgment related to an implicit stereotype (which person is more likely to enjoy athletic activities?) or an evaluative judgment (which person would you be more likely to befriend?). We then used MVPA in an attempt to decode whether participants were viewing White versus Black faces by looking at patterns of brain activity in these two judgment conditions. Insofar as race can be decoded by looking at brain activity across both conditions, this is consistent with a relatively invariant representation of race in the relevant brain region. However, if race can only be decoded from a particular brain region when participants are making one or the other type of judgment, this would suggest a preferential role of that brain region in maintaining or expressing either evaluative or stereotype-based representations, providing evidence of distinct brain systems mediating these two types of representation.

We also collected IAT measures of both evaluative bias and implicit stereotyping. In past research, these two measures were shown to index independent representations of intergroup social information, such that association strength scores on the two measures were uncorrelated with each other, and predicted unique behavioral outcomes (Amodio & Devine, 2006). In the present study, we tested whether scores on the behavioral measures of implicit racial evaluation and stereotyping would uniquely correlate with MVPA race decoding accuracy associated with friendship and trait judgments, respectively. This methodological design provides a highly specific test of our hypothesis while also establishing a meaningful connection between brain activity and behavior. Thus, we hypothesized that (a) race would be decoded in regions linked to visual processing independent of the type of conceptual associations activated for a particular judgment, but that (b) judgments based on evaluative and stereotype associations would recruit distinct patterns of activity in brain regions linked to evaluative processing and social cognition, and (c) these patterns would be uniquely associated with behavioral measures of implicit racial evaluation and stereotyping, respectively.

To test these hypotheses, it was critical to create an engaging and ecologically valid task that could be completed in the MRI scanner. To this end, we used an elaborate cover story. Participants were told that the study examined people's ability to infer information about others based solely on a picture of their face. Specifically, participants were told they would infer the types of activities a person might enjoy and whether a person is someone the participant might befriend. These two judgments were designed to rely on trait-related semantic versus affective processing, respectively. To bolster the cover story, participants completed questionnaires assessing their own preferences for various hobbies and interests and for the qualities that they value most in a potential friend. They were told that they would make judgments of other people who had completed the same set of questionnaires so that we could verify the accuracy of their inferences about each target person on these dimensions.

White American participants learned that, while in the scanner, they would see pairs of faces and would decide which of the two pictured individuals was more likely to (a) possess a particular trait or (b) be a friend, in a hypothetical circumstance (see Fig. 1). Participants were told that for the trait judgments, each participant would focus on just one particular trait. They were asked to select a piece of paper from a jar that indicated the activity they would judge. This choice was rigged so that every slip of paper indicated “athletic” as the trait. Athletic was used because it is a central African American stereotype that does not have strong evaluative associations, unlike many other stereotypes that hold negative value.

A critical feature of this design is that face pairs were always of the same race, such that participants always made trait or friendship judgments between two Black or two White faces. (Additionally, Asian faces were included in the stimulus set in order to aid the cover story, but were not analyzed.) This design precluded participants' concerns about showing explicit racial prejudice or the engagement of control in order to respond without prejudice. Thus, any patterns of activity distinguishing judgments on Black versus White faces could not be attributed to explicit prejudice or self-regulatory efforts. The object of the experimental task was not to engender bias towards one or the other of the faces presented on a single trial, but rather to compare brain activity on separate trials in response to pairs of Black versus White faces. This comparison was made in two conditions designed to encourage participants to think about people either in terms of evaluations or trait judgments.

Section snippets

Participants and procedure

Twenty volunteers (14 male; age 18–22 years, mean 19) were recruited through flyers placed around the New York University campus. Participants completed the study individually in exchange for $40. All participants were right-handed, White, native-English speakers with no history of neurological illness. All experimental sessions were run by White experimenters. Upon arrival, participants provided informed consent and were screened for contraindications for MRI scanning. Participants were then

Results

Four participants were excluded due to excessive movement (three participants) or poor task compliance (falling asleep during the experiment; one participant), yielding a final sample of 16 participants.

Discussion

Knowledge about a person's social group, such as trait attributes or a global evaluation, can have a profound influence on how we perceive and act toward that person. An understanding of the neural structures that represent this knowledge is crucial to theories of how this knowledge is acquired, activated, and expressed. In this study, we used multi-voxel pattern analysis (MVPA) to investigate regional brain activity that distinguished presentation of White versus Black faces during two

Conclusion

The present results suggest that the representation of race is multi-componential and potentially mutable. Our findings suggest that two distinct aspects of race bias—implicit stereotyping and implicit evaluation—are mediated by distinct brain mechanisms. By learning more about the way in which different aspects of bias are represented within the brain, and potentially expressed via distinct brain pathways, this raises the hope of developing more sophisticated and effective interventions by

Acknowledgments

This research was supported by a grant from the National Science Foundation to D.M.A. (BCS 0847350). S.J.G. was supported by a Royal Society University Research Fellowship and a Royal Society International Travel Grant.

References (64)

  • R. Saxe et al.

    Making sense of another mind: The role of the right temporo-parietal junction

    Neuropsychologia

    (2005)
  • M.E. Walton et al.

    Separable learning systems in the macaque brain and the role of orbitofrontal cortex in contingent learning

    Neuron

    (2010)
  • G.W. Allport

    The nature of prejudice

    (1954)
  • D.M. Amodio

    The social neuroscience of intergroup relations

    European Review of Social Psychology

    (2008)
  • D.M. Amodio

    Coordinated roles of motivation and perception in the regulation of intergroup responses: Frontal cortical asymmetry effects on the P2 event-related potential and behavior

    Journal of Cognitive Neuroscience

    (2010)
  • D.M. Amodio et al.

    Stereotyping and evaluation in implicit race bias: Evidence for independent constructs and unique effects on behavior

    Journal of Personality and Social Psychology

    (2006)
  • D.M. Amodio et al.

    A dynamic model of guilt: implications for motivation and self-regulation in the context of prejudice

    Psychological Science

    (2007)
  • D.M. Amodio et al.

    Individual differences in the regulation of intergroup bias: The role of conflict monitoring and neural signals for control

    Journal of Personality and Social Psychology

    (2008)
  • D.M. Amodio et al.

    Meeting of minds: The medial frontal cortex and social cognition

    (2006)

    Nature Reviews Neuroscience

    (2006)
  • D.M. Amodio et al.

    Individual differences in the activation and control of affective race bias as assessed by startle eyeblink response and self-report

    Journal of Personality and Social Psychology

    (2003)
  • D.M. Amodio et al.

    Neural signals for the detection of unintentional race bias

    Psychological Science

    (2004)
  • D.M. Amodio et al.

    Implicit intergroup bias: Cognitive, affective, and motivational underpinnings

  • D.M. Amodio et al.

    A memory systems model of implicit social cognition

    Current Directions in Psychological Science

    (2011)
  • J.A. Bargh et al.

    Automaticity of social behavior: Direct effects of trait construct and stereotype-activation on action

    Journal of Personality and Social Psychology

    (1996)
  • S.J. Breckler

    Empirical validation of affect, behavior, and cognition as distinct components of attitude

    Journal of Personality and Social Psychology

    (1984)
  • M.W. Chee et al.

    Dorsolateral prefrontal cortex and the implicit association of concepts and attributes

    Neuroreport

    (2000)
  • Contreras, J.M., Banaji, M.R., & Mitchell, J.P. Dissociable neural correlates of stereotypes and other forms of...
  • W.A. Cunningham et al.

    Separable neural components in the processing of black and white faces

    Psychological Science

    (2004)
  • A.R. Damasio et al.

    Face agnosia and the neural substrates of memory

    Annual Review of Neuroscience

    (1990)
  • J.M. Darley et al.

    A hypothesis-confirming bias in labeling effects

    Journal of Personality and Social Psychology

    (1983)
  • P.G. Devine

    Prejudice and stereotypes: Their automatic and controlled components

    Journal of Personality and Social Psychology

    (1989)
  • P.G. Devine et al.

    Are racial stereotypes really fading? The Princeton trilogy revisited

    Personality and Social Psychology Bulletin

    (1995)
  • Cited by (64)

    • Neural Basis of Prejudice and Prejudice Reduction

      2022, Biological Psychiatry: Cognitive Neuroscience and Neuroimaging
      Citation Excerpt :

      Regardless of whether participants were instructed to classify faces by gender or race, ERP measures revealed larger responses to outgroup Black than ingroup White faces in the N100 (or N1), an ERP component observed over occipitoparietal regions which reflects early orienting and bottom-up attention processing (11). Functional magnetic resonance imaging (fMRI) studies corroborate this bottom-up interpretation, such that race can be decoded from patterns of activity in early visual cortex in the occipital lobe as participants view Black and White faces (12,13). Goal-directed, top-down processing of social identity occurs ∼180 to 200 ms following face presentation, as indicated by the P200 (or P2) ERP component (14,15).

    • Ethnicity bias

      2021, Encyclopedia of Behavioral Neuroscience: Second Edition
    • Measuring implicit mental representations related to ethnic stereotypes with ERPs: An exploratory study

      2021, Neuropsychologia
      Citation Excerpt :

      Indeed, the second most powerful source (in order of magnitude) in our study was the right Medial Frontal Gyrus (BA 10) that, as part of the mentalizing network together with the TPJ, STS, precuneus and ATL (Saxe, 2006), is known to be involved in processes of attributing personal traits, mental states and intentions to others (Proverbio et al., 2016, 2018; Mitchell et al., 2006; Mahy et al., 2014; Milne et al., 2001). Moreover, this brain region has been implicated specifically in studies on gender and racial stereotyping, for example when inferring personal traits of people belonging to a minority group (Freeman et al., 2010), making stereotype-based judgements (Gilbert et al., 2012), representing social information that refers to others such as outgroup stereotyping (Mitchell et al., 2006) and representing negative gender biases related to the processing social attributes and occupational stereotypes (Proverbio et al., 2017, 2018). For instance, Mitchell et al. (2006) used functional neuroimaging while participants were required to make inferences about others mental states when the “other” was similar or dissimilar to oneself on regard of socio-political views.

    • Functional neuroanatomy of racial categorization from visual perception: A meta-analytic study

      2020, NeuroImage
      Citation Excerpt :

      Indeed, brain regions such as IOG, MOG and FG are typically associated with representation of facial features, including facial parts (e.g. eyes, nose, mouth), lower level aspects of face processing (e.g. physical variations) and invariant visual traits (e.g. identity, gender and race) (Bernstein and Yovel, 2015; Kanwisher et al., 1997; Pitcher et al., 2011). Instead, STG and ITG, located in the anterior temporal lobe, have been shown to be involved in storing social knowledge about faces based on prior semantic associations (Eifuku et al., 2010; Ross and Olson, 2012) and specifically in expressing racial and gender stereotypes (Gallate et al., 2011; Gilbert et al., 2012). Beside communalities, the three clusters were characterized by regions reflecting different processes through which same-group and other-group faces are categorized and represented.

    View all citing articles on Scopus
    View full text