Jennifer A Richeson

Andrew R Todd

Sophie Trawalter

Abigail A Baird

Eye-Gaze Direction Modulates Race-Related Amygdala Activity

Keywords: amygdala activation, eye-gaze, face perception, race

Although previous research has found greater activity in the human amygdala in response to Black male compared with White male targets, the basis of this effect remains unclear. For example, is it race alone that triggers amygdala activity, or do other stimulus cues, in conjunction with racial group membership, also play a critical role in this regard? To address this issue, we used functional magnetic resonance imaging to measure amygdala activity in response to Black and White male targets displaying different eye-gaze directions (i.e. direct or averted gaze), as gaze cues have been shown to infl uence the socio-emotional aspects of person construal. The results revealed that eye-gaze direction signifi cantly moderates race-related amygdala activity. Specifi cally, Black targets only generated greater amygdala activity than White targets when the faces bore direct gaze. This fi nding is noteworthy as it demonstrates the importance of compound stimulus cues in the appraisal of social targets.

Group membership is a fundamental characteristic of person perception. Indeed, in almost every facet of human cognition, affect, and behavior, members of groups to which we belong (ingroup members) are responded to differently than are individuals with whom we do not share meaningful group memberships (outgroup members; Tajfel, Tuner, Austin, & Worchel, 1971). Not only are ingroup members largely favored over outgroup members [START_REF] Brewer | The psychology of prejudice: Ingroup love or outgroup hate?[END_REF], they are also individuated, recognized, and remembered more than outgroup members [START_REF] Brewer | A dual process model of impression formation[END_REF][START_REF] Brigham | The role of experience and contact in the recognition of faces of own-and other-race person[END_REF][START_REF] Fiske | A continuum of impression formation from category-based to individuating processes: Infl uences of information and motivation on attention and interpretation[END_REF][START_REF] Levin | Classifying faces by race: The structure of face categories[END_REF][START_REF] Meissner | Thirty years of investigating the own-race bias in memory for faces: A meta-analytic review[END_REF]. Moreover, people tend to automatically associate ingroup members with positive concepts and outgroup members with negative concepts, even if only at low levels of conscious awareness [START_REF] De Houwer | An affective variant of the Simon paradigm[END_REF][START_REF] Dovidio | On the nature of prejudice: Automatic and controlled processes[END_REF][START_REF] Fazio | Variability in automatic activation as an unobtrusive measure of racial attitudes: A bona fi de pipeline[END_REF][START_REF] Greenwald | Measuring individual differences in implicit cognition: The implicit association test[END_REF].

Consistent with this research, a growing body of work is fi nding that people exhibit different patterns of neural activity in response to ingroup compared with outgroup individuals [START_REF] Golby | Differential fusiform responses to same-and other-race faces[END_REF][START_REF] Hart | Differential response in the human amygdala to racial outgroup vs. ingroup face stimuli[END_REF][START_REF] Phelps | Performance on indirect measures of race evaluation predicts amygdala activation[END_REF][START_REF] Richeson | An fMRI investigation of the impact of interracial contact on executive function[END_REF] for a review, see [START_REF] Eberhardt | Imaging race[END_REF]. Much of this work has found that racial ingroup and outgroup members differentially activate the amygdala (e.g. [START_REF] Hart | Differential response in the human amygdala to racial outgroup vs. ingroup face stimuli[END_REF][START_REF] Phelps | Performance on indirect measures of race evaluation predicts amygdala activation[END_REF][START_REF] Wheeler | Controlling racial prejudice: Social-cognitive goals affect amygdala and stereotype activation[END_REF]. Specially, studies have shown that activity in the amygdala: (i) is greater following the presentation of outgroup than ingroup faces, at least when presented very briefl y (Cunningham, Johnson et al., 2004); (ii) habituates more slowly following the presentation of outgroup than ingroup faces [START_REF] Hart | Differential response in the human amygdala to racial outgroup vs. ingroup face stimuli[END_REF]; see also [START_REF] Olsson | The role of social groups in the persistence of learned fear[END_REF]; and (iii) correlates with an unobtrusive measure of racial prejudice (Cunningham, Johnson et al., 2004;[START_REF] Phelps | Performance on indirect measures of race evaluation predicts amygdala activation[END_REF].

Based on these and related findings, the amygdala has been implicated as being responsive to the potential threat that may be posed by members of other racial groups and, furthermore, that differential amygdalar activity might provide the impetus for intergroup bias. But why is the face of a racial outgroup member construed in a threatening manner? One possibility is that merely categorizing a target as 'not one of us' initiates the activation of the 'universal' outgroup stereotype, which includes traits such as dishonest, competitive, and hostile [START_REF] Campbell | Stereotypes and the perception of group differences[END_REF]. Another interesting possibility is that it is not outgroup status per se that triggers amygdala activation, but rather the presence of stimulus cues that signal threat, danger, or social importance. The current research examines this latter possibility. Specifically, we consider whether a cue that is particularly relevant to socio-emotional processing-namely, eye-gaze direction-modulates the extent to which racial outgroup, compared with ingroup, members activate the amygdala.

Amygdala and socio-emotional processing

The amygdala has consistently been identifi ed as a structure that plays a critical role in emotional learning, memory, and the evaluative appraisal of social stimuli [START_REF] Aggleton | The amygdala: A functional analysis[END_REF][START_REF] Ledoux | The emotional brain[END_REF]. Guiding behavioral generation, its primary function lies in linking perception and action by providing an emotional value or signifi cance to stimulus inputs [START_REF] Adolphs | The neurology of social cognition[END_REF][START_REF] Adolphs | Cognitive neuroscience of human social behavior[END_REF](Adolphs, , 2006)). This function is perhaps most apparent in the area of threat detection, an observation that is supported by both patient and brain imaging data. Damage to the amygdala has been shown to impair people's ability to recognize social emotions from facial expressions [START_REF] Adolphs | Impaired recognition of social emotions following amygdala damage[END_REF]. Compared to normal participants, patients with bilateral amygdala damage reliably overestimate the perceived trustworthiness and approachability of strangers [START_REF] Adolphs | Impaired recognition of emotion in facial expressions following bilateral damage to the human amygdala[END_REF]. This is due in part to their failure to exhibit conditioned fear responses [START_REF] Bechara | Double dissociation of conditioning and declarative knowledge relative to the amygdala and hippocampus in humans[END_REF] as well as their inability to utilize threat-relevant information communicated by the eyes of conspecifi cs [START_REF] Adolphs | A mechanism for impaired fear recognition after amygdala damage[END_REF].

Corroborating these fi ndings, early neuroimaging investigations have demonstrated heightened amygdala activation when healthy participants view faces conveying negative emotions, most notably fear [START_REF] Baird | Functional magnetic resonance imaging of facial affect recognition in children[END_REF][START_REF] Breiter | Response and habituation of the human amygdala during visual processing of facial expression[END_REF][START_REF] Morris | A differential neural response in the human amygdala to fearful and happy facial expressions[END_REF] and, to a lesser extent, anger and surprise [START_REF] Sato | The amygdala processes the emotional signifi cance of facial expressions: An fMRI investigation using the interaction between expression and face direction[END_REF][START_REF] Wright | Enhanced amygdala responses to emotional versus neutral schematic facial expressions[END_REF]; see also [START_REF] Whalen | A functional MRI study of human amygdala responses to facial expressions of fear versus anger[END_REF]. More recently, however, research has demonstrated that it is not the valence of stimuli per se to which the amygdala responds, but rather their emotional intensity (i.e. arousability; [START_REF] Anderson | Dissociated neural representations of intensity and valence in human olfaction[END_REF]Cunningham, Raye, & Johnson, 2004) and, in some cases, the ambiguity of the stimuli (e.g. [START_REF] Adams | Gaze and amygdala sensitivity to anger and fear faces[END_REF][START_REF] Whalen | Fear, vigilance, and ambiguity: Initial neuroimaging studies of the human amygdala[END_REF]. Based on work of this ilk, the amygdala has been characterized as a structure that helps people to navigate their social worlds by facilitating the acquisition of emotional knowledge and the low-level, relatively automatic recognition of stimuli that pose a potential threat.

So, why then would racial outgroups trigger the amygdala more than racial ingroups? This fi nding could be due, at least in part, to the particular ingroup and outgroup targets that have been examined. To date, much of the aforementioned research on heightened amygdala activity to outgroup compared with ingroup members has considered the responses of White perceivers to Black (outgroup) relative to White (ingroup) targets (e.g. Cunningham, Johnson et al., 2004;[START_REF] Wheeler | Controlling racial prejudice: Social-cognitive goals affect amygdala and stereotype activation[END_REF]. Although some work has found evidence for differential amygdala activity among Black perceivers to White, compared with Black, targets [START_REF] Hart | Differential response in the human amygdala to racial outgroup vs. ingroup face stimuli[END_REF], this effect seems to be largely due to differential rates of habituation to ingroup versus outgroup targets, rather than differences in initial activation (see also [START_REF] Olsson | The role of social groups in the persistence of learned fear[END_REF]. Furthermore, some work has found that at least under some processing conditions, Black perceivers also show heightened activity to Black male targets (i.e. racial ingroup members), compared with White male (i.e. racial outgroup members) targets [START_REF] Lieberman | An fMRI investigation of race-related amygdala activity in African-American and Caucasian-American individuals[END_REF], which suggests that the differential amygdala activity that is typically attributed to ingroup versus outgroup status may be better attributed to the particular race (and gender) of the targets that have been examined-Black males. It is possible, in other words, that these fi ndings are driven in part by the differential threat signaled by an outgroup that is stereotypically associated with threat, namely young Black males.

Indeed, the prevailing stereotype of Black men is that they are dangerous and threatening [START_REF] Cottrell | Different emotional reactions to different groups: A sociofunctional threat-based approach to 'prejudice[END_REF]Devine & Elliott, 1995). Furthermore, Black men are strongly associated with violent crime [START_REF] Correll | The police offi cer's dilemma: Using ethnicity to disambiguate potentially threatening individuals[END_REF][START_REF] Eberhardt | Seeing black: Race, crime, and visual processing[END_REF][START_REF] Payne | Prejudice and perception: The role of automatic and controlled processes in perceiving a weapon[END_REF] and angry facial expressions of emotion [START_REF] Ackerman | They all look the same to me (unless they're angry)[END_REF][START_REF] Hugenberg | Ambiguity in social categorization: The role of prejudice and facial affect in race categorization[END_REF]. It follows, therefore, that Black male targets are particularly potent threat signals for White perceivers, compared with White male (i.e. ingroup) targets. Consistent with this reasoning, White perceivers have been found to orient their attention to faces of Black male targets [START_REF] Ito | Race and gender on the brain: Electrocortical measures of attention to the race and gender of multiply categorizable individuals[END_REF][START_REF] Eberhardt | Imaging race[END_REF][START_REF] Richeson | The threat of appearing prejudiced and race-based attentional biases[END_REF][START_REF] Trawalter | Attending to threat: Race, eye-gaze, and selective attention[END_REF], much like individuals selectively attend to cues and stimuli associated with physical threat and danger (e.g. snakes; [START_REF] Öhman | Emotion drives attention: Detecting the snake in the grass[END_REF].

Taken together, this research suggests that for many White individuals, Black men are appraised as a particularly threatening racial outgroup and, thus, capture attention, presumably due to the need for heightened vigilance to the potential threat source. Consequently, this work suggests that the differential amygdala activity in response to Black, compared with White, men is largely due to the differential threat signal (and, thus, functional signifi cance) associated with Black, compared with White, men (see also Kenrick, Delton, Robertson, Becker, & Neuberg, in press).

Threat and eye-gaze direction

Although this research indicates that the cultural stereotype of Black men makes them a particularly threatening outgroup for White perceivers, other cues that are more evolutionarily important should be able to attenuate, if not completely trump, this effect. For instance, eye-gaze direction is one of the most basic social cues that perceivers rely upon (e.g. [START_REF] Hood | Adult's eyes trigger shifts of visual attention in human infants[END_REF]. Almost without exception, the most important social targets are those with whom direct eye contact has been established ( [START_REF] Baron-Cohen | Mindblindness: An essay on autism and theory of mind[END_REF]. Consistent with this idea, recent imaging investigations have found that a person's eye-gaze direction results in differential activity in the amygdala [START_REF] George | Seen gaze-direction modulates fusiform activity and its coupling with other brain areas during face processing[END_REF][START_REF] Kawashima | The human amygdala plays an important role in gaze monitoring[END_REF][START_REF] Ochsner | Current directions in social cognitive neuroscience[END_REF]. Furthermore, patients with amygdala damage have impaired ability to use eye-gaze direction as a cue to direct attention (Akiyama, et al., in press), and they show a severe reduction in direct eye contact during actual interactions [START_REF] Spezio | Amygdala damage impairs eye contact during conversations with real people[END_REF]. Taken together, this work suggests that the amygdala is particularly sensitive to eye-gaze direction, presumably because of its socio-emotional signal value.

Although direct eye-gaze signals that targets are motivated to approach, the meaning of direct gaze can differ signifi cantly. Specifi cally, direct eye-gaze can signal both positive approach tendencies, such as romantic interest [START_REF] Mason | The look of love: Gaze shifts and person perception[END_REF], as well as negative approach tendencies, such as hostility and impending peril [START_REF] Argyle | Gaze and mutual gaze[END_REF]. Hence, direct eye-gaze may be especially signifi cant to perceivers when communicated by a threatening outgroup member. In other words, social cues that are associated with threat, such as racial group membership, may combine with eye-gaze direction to communicate a target's threat potential and, thus, modulate amygdala activity accordingly. Furthermore, given that direct eye-gaze facilitates social categorization [START_REF] Macrae | Are you looking at me? Eye gaze and person perception[END_REF], it is not surprising that exposure to Black male targets displaying direct gaze often results in heightened amygdala activity. Indeed, the race cues associated with threat are facilitated by the compatible signal value of the eye-gaze cues. If the Black male targets were displaying averted eye-gaze, however, the race and gaze cues would be in competition. That is, although the racial (and gender) group membership of the target is associated with threat, it may fail to elicit differential amygdala activity because the gaze information suggests that the target does not pose an immediate threat (cf. [START_REF] Hart | Differential response in the human amygdala to racial outgroup vs. ingroup face stimuli[END_REF][START_REF] Phelps | Performance on indirect measures of race evaluation predicts amygdala activation[END_REF]. In other words, averted gaze may attenuate the threat value associated with Black male targets relative to White male targets.

Overview of the present work

The present work examined explicit threat perceptions (Study 1) and implicit threat perceptions as revealed in neural activity in the amygdala (Study 2) in response to facial photographs of Black, compared with White, male targets who bore direct eye-gaze or indirect gaze (averted or closed eyes). Because of the shared signal value of threat, Black male targets with direct eye-gaze were expected to evoke greater threat perceptions and amygdala activity than White male targets with direct eye-gaze, and compared with Black male targets with either closed eyes or averted eye-gaze. In other words, averted eye-gaze, in particular, was expected to attenuate if not completely undermine the race difference in amygdala activity found in previous research, thus reiterating the role of the amygdala in monitoring for cues of particular socio-emotional relevance.

Study 1

Based on the research presented previously, we conducted a behavioral study in order to test whether Black and White male targets with direct versus indirect (averted, closed eyes) eye-gaze are perceived to differ in threat value. That is, can eye-gaze direction modulate the perception of threat communicated by Black male targets? Method Materials The stimulus materials for both Study 1 and Study 2 were facial photographs of 32 unfamiliar targets (16 Black faces and 16 White faces). Each target was photographed displaying direct eye-gaze. To create faces with averted gaze and closed eyes, the original faces were manipulated using Adobe Photoshop. In total, 96 stimulus faces were created: 16 Black/ direct-gaze (BDG); 16 Black/averted-gaze (BAG); 16 Black/closed-eyes (BCE); 16 White/directgaze (WDG); 16 White/averted-gaze (WAG); and 16 White/closed-eyes (WCE). The faces were digitized color images of young adults in full-frontal pose. Each target conveyed a neutral facial expression. In Study 1, 10 faces of each type (Black or White; direct-gaze, averted-gaze, closed-eyes) were randomly selected to be rated, for a total of 60 faces.

Participants & procedure Twenty White undergraduate students attending a New England college came in to the lab individually to provide behavioral ratings of the faces. In addition to examining systematic differences in how threatening the faces were perceived to be, we also examined whether the manipulation of some of the photographs in Photoshop (i.e. those with averted gaze and closed-eyes) might also infl uence how they were perceived. In order to examine both of these issues, the 60 faces selected at random were rated on how threatening the face was, as well as on how odd or artifi cial the face appeared, both on 7-point Likert-type scales.

Results and discussion

Artifi ciality We fi rst assessed how artifi cial the faces appeared, in order to ensure that any results of eye-gaze that emerge could not be attributed to the manipulation of some of the faces. The mean artifi ciality ratings for each face were calculated and then subjected to 2 (target race: Black, White) × 3 (eye-gaze: direct, averted, closed eyes) analysis of variance (ANOVA). Results revealed a main effect of race (F(1,19) = 6.31, p < .05). White faces (M = 3.00) were rated as being more artificial-looking than the Black faces (M = 2.75). Furthermore, the main effect of eye-gaze was also reliable (F(2,38) = 8.49, p < .001). Faces with closed eyes (M = 3.14) were rated as looking more artifi cial than either faces with averted eye-gaze (M = 2.79) or faces with direct eye-gaze (M = 2.71), which did not differ. The interaction between race and gaze was not statistically reliable (F(2,38) = 1.92, p > .15). Consequently, the results seem to be largely attributable to perceptions of White faces with closed eyes, rather than differences among the Black and White faces with direct or averted eye-gaze, the primary focus of the present work.

Threat perceptions To test our primary predictions, the mean threat ratings for each face were calculated and subjected to the same 2 (target race: Black, White) × 3 (eye-gaze: direct, averted, closed eyes) ANOVA. The means are presented in Table 1. Consistent with predictions, results revealed a main effect of race (F(1,19) = 5.53, p < .03), as well as a main effect of eye-gaze (F(2,38) = 27.6, p < .0001). Both of these effects, however, were moderated by a signifi cant race by gaze interaction (F(2,38) = 18.1, p < .0001). Because we were most interested in the relative threat of faces with direct compared with averted eye-gaze, we conducted a second ANOVA, excluding the faces with closed eyes. Results revealed the same main effects of race (F(1,19) = 7.18, p < .05) and gaze (F(1,19) = 21.4, p < .0002), as well as the signifi cant interaction (F(1,19) = 35.5, p < .0001). Examination of the means revealed that Black faces with direct gaze were rated as more threatening than Black faces with averted gaze (respective Ms = 3.43 & 2.54; t(19) = 5.81, p < .0001). By contrast, White faces with direct and averted gaze were perceived to be equally threatening (respective Ms = 2.58 & 2.63; t(19) = .67, p = ns). Furthermore, whereas Black faces with direct gaze were perceived as more threatening that White faces with direct gaze (t(19) = 4.9, p < .0001), Black and White faces with averted gaze were perceived to be equally (non)threatening (t(19) = .60, p = ns). These results suggest that, indeed, White perceivers are likely to fi nd faces of Black male individuals with direct eye-gaze to be more threatening than Black male individuals with averted gaze, or compared to White male individuals irrespective of gaze. In other words, these behavioral ratings provide initial evidence for the claim that eyegaze moderates the effect of race on perceptions of threat.

Study 2

Considered in tandem with the research reviewed previously, the results of Study 1 suggest that averted eye-gaze direction can attenuate the extent to which Black male targets are perceived to be more threatening than White male targets. Although the results of Study 1 are promising, they emerged from explicit judgments of threat, which are likely to be infl uenced by both low level activity in the amygdala and higher level cognitive processing in frontal areas (e.g. Cunningham, Johnson et al., 2004). Hence, a strong test of the extent to which eye-gaze direction moderates threat perception requires an examination of neural activity in the amygdala while participants are engaged in an unrelated task. Consequently, in Study 2 we examined the veracity of the hypothesis that eye-gaze direction moderates the effect of race on more implicit threat responses-neural activity in the amygdala.

Method

Participants Nine paid student volunteers from a New England college (6 female; 19-23 years of age) participated in the experiment. All participants were White, right-handed, native English speakers with no history of neurological problems. All gave informed written consent according to the procedures approved by the Committee for the Protection of Human Participants at the college.

Materials

The stimulus materials were identical to those described in Study 1; however, the full set of 96 faces was used in Study 2. In the magnetic resonance imaging (MRI) scanner, stimuli were generated using an Apple G3 Laptop computer running PsyScope software.

Stimuli were projected to participants with an Epson (model ELP-7000) LCD projector onto a screen positioned at the head end of the bore. Participants viewed the screen by use of a mirror placed at a 45° angle on top of the head coil.

A fi ber optic, light sensitive key press interfaced with the PsyScope Button Box (New Micros, Dallas, Texas) was used to record participants' behavioral responses.

Procedure Scanning involved a blockedpresentation of the stimuli, with the blocks alternating between Black and White faces.

Stimulus presentation of the experimental blocks (12 blocks) alternated with baseline blocks, which comprised a blank screen with a central fi xation cross. Both the presentation blocks and the baseline blocks were 20 s in duration. During each presentation block, 8 faces (e.g. Black targets displaying direct gaze) were presented to participants. Each face remained on the screen for 2.5 s and was located either to the right or left of the fi xation cross. The location of the faces on the screen was counterbalanced across participants and the order of presentation of the faces was randomized. Participants were instructed to focus on the fi xation cross. When a face appeared on the screen, they were requested to report, by means of a key press, whether the face appeared to the left or right of the fi xation cross. Gradient-echo echoplanar MR images were acquired using a 1.5 Tesla GE Signa System (General Electric, Milwaukee, WI, USA). A quadrature birdcage head coil was used for RF transmission and reception. In each of 25 noncontiguous planes parallel to the anteriorposterior commissure, 112 T2*-weighted MR images depicting BOLD contrast were acquired with TE 35 ms, TR 2500 ms, fl ip angle 90°, slice thickness 4.5 mm, and skip slice 1 mm. Head movement was limited by foam padding within the head coil. For each participant, 3-D MRI anatomical data were also obtained using the Spoiled Grass (SPGR) technique. T1-weighted images (TR 7.7 ms, TE 3 ms, fl ip angle 15°, slice thickness 1.2 mm) were obtained in the AC-PC orientation. BOLD images were realigned to correct for interscan movements and coregistered to the participant's anatomical image using SPM99 (Wellcome Department of Cognitive Neurology, London). The resulting matching brain images were spatially normalized with a cubic (3×3×3 mm) voxel size. BOLD images were further smoothed using an isotropic Gaussian fi lter of 6 mm FWHM and corrected for global activity by proportional scaling.

Data analysis fi rst removed low-frequency drifts in the signal plus global changes in activity. The six different stimulation conditions (Black or White faces, direct-gaze, averted-gaze, or closed-eyes) were then modeled as boxcar functions, convolved with a hemodynamic response function. Based on previous fi ndings, our hypothesis was that the combination of direct gaze and ingroup-outgroup status would modulate activation in the amygdala. Accordingly, region-of-interest (ROI) analyses were restricted to the right and left amygdala. We performed two types of ROI analyses on our data. The fi rst relied on a functional defi nition, while the second relied on an anatomical defi nition.

A functional ROI was defi ned using the contrast most central to our hypotheses, that Black faces displaying direct gaze would produce increased amygdala activity relative to White faces displaying direct gaze. This methodology has been used widely as a means by which to discern functional regions of interest (see [START_REF] Kanwisher | The fusiform face area: A module in human extrastriate specialized for the perception of faces[END_REF]. In order to identify specific amygdala regions showing significant BOLD changes, statistics were computed on a voxel-by-voxel basis using the general linear model. Specifi c effects were tested by applying appropriate linear contrasts for each condition, resulting in a t statistic for each ROI. These individual contrast images were then submitted to a second-level, random-effects analysis to create mean t images (thresholded at P = 0.005, uncorrected; minimal cluster size = 20 mm 3 ). An automated peak-search algorithm identifi ed the location of peak activations and deactivations based on z value and cluster size.

A second ROI analysis was performed based on neuroanatomy. To ensure neuroanatomical specificity, coordinates from the [START_REF] Talairach | Co-planar stereotaxic atlas of the human brain[END_REF] atlas were used to place spherical regions of interest, with a 5 mm radius (524mm 3 ), in the right (center point: x = 15, y = -6, z = -21) and left amygdala (center point: x = -15, y = -6, z = -21). Data were extracted from this region on a subject-by-subject basis, and direct tests of our hypotheses were performed off line. Signifi cance levels are reported for the critical comparisons within the right and left amygdala.

Results and Discussion

The behavioral data (response accuracy and latencies) were submitted to a 2 (race: Black or White) × 3 (eye-gaze: direct, averted, eyes closed) repeated-measures ANOVA. This revealed no effects of the experimental manipulations on either the accuracy or latency of participants' responses.

Our prediction was that the amygdala response to racial targets would be modulated by gaze direction. Results from our functional ROI revealed a region in the right amygdala (x = 15, y = -6, z = 24; extent = 12 voxels) for which BOLD signal intensities were significantly greater in response to Black faces than to White faces (t(8) = 6.06, corrected p < .01) for the direct gaze (BDG > WDG) condition only (see Figure 1). No signifi cant effect of race was observed in the right or left amygdala when targets displayed averted gaze or had their eyes closed (BAG > WAG; BCE > WCE). No signifi cant differences within either the right or left amygdala were observed with regard to the main effect of race (BDG+BAG+BCE > WDG+WAG+WCE) or gaze (BDG+WDG > BAG+WAG; BDG+WDG > BCE+WCE).

Table 2 displays the results of whole brain voxel-wise analyses for the two most relevant contrasts stemming from our hypotheses regarding the effects of eye-gaze direction: (1) BDG > BAG and (2) WDG > WAG. Because we were primarily interested in the relative threat of faces with direct compared with averted eyegaze, however, we extracted individual data from the functionally derived ROI and conducted a 2 (race) × 2 (eye-gaze) ANOVA, excluding the faces with closed eyes. Results revealed neither main effects of race (F(1,8) = .65, p = .44) nor eye-gaze (F(1,8) = .07, p =.80); however, the interaction between race and gaze was reliable (F(1,8) = 4.98, p = .056) Examination of the means revealed that Black faces with direct eyegaze produced signifi cantly greater amygdala activity than Black faces with averted eye-gaze (respective Ms = 0.077 & -.041; t(8) = 2.31, p = .05). By contrast, White faces with direct and averted eye-gaze produced similar levels of amygdala activity (respective Ms = -.004 & .056; t(8) = -1.08, p = .31). Consistent with the results of the analyses reported previously, Black faces with direct eye-gaze produced signifi cantly greater amygdala activity than White faces with direct eye-gaze (respective Ms = .077 & -.004; t(8) = 2.26, p = .05), whereas the amygdala activity associated with Black and White faces with averted eye-gaze did not differ reliably(respective Ms = -.041 & .056; t(8) = -1.58, p = .15). In fact, the means were in the opposite direction; White faces with averted eye-gaze were associated with marginally more amygdala activity than Black faces with averted eye-gaze.

Our second set of analyses, based on anatomical localization, yielded results that converge quite nicely with those obtained from the functional ROI analyses presented previously. A 2 (race: Black, White) × 2 (eye-gaze: direct, averted) ANOVA on neural activity in the right amygdala anatomical ROI revealed neither main effects of race nor eye-gaze, but a signifi cant interaction effect (F(1,8) = 7.22, p < .05). As depicted in Figure 2, Black faces with direct gaze produced greater amygdala activity than White faces with direct gaze (t(8) = 3.25, p < .01); but, the amygdala activity associated with exposure to Black and White faces with averted gaze did not differ (t(8) = -1.36, p = ns). Furthermore, Black faces with direct gaze produced signifi cantly more amygdala activity than Black faces with averted gaze (t(8) = 2.42 , p < .05). By contrast, White faces with direct gaze produced marginally less amygdala activity than White faces with averted gaze (t(8) = -1.85, p = .10).

Analyses of the mean percent signal change within the anatomically derived ROI placed in the left amygdala revealed similar effects for race and eye-gaze. Similar to the ANOVA results for the functional ROI and anatomically derived right amygdala ROI presented previously, only a signifi cant interaction between race and gaze emerged from the 2 (race) × 2 (eye-gaze) ANOVA (F(1,8) = 15.20, p < .01). As shown in the right

General discussion

The present findings corroborate previous research that has observed differential activity in the amygdala after exposure to Black, compared with, White faces (Cunningham, Johnson et al., 2004;[START_REF] Hart | Differential response in the human amygdala to racial outgroup vs. ingroup face stimuli[END_REF][START_REF] Lieberman | An fMRI investigation of race-related amygdala activity in African-American and Caucasian-American individuals[END_REF][START_REF] Wheeler | Controlling racial prejudice: Social-cognitive goals affect amygdala and stereotype activation[END_REF]. Extending previous research, however, race per se was not suffi cient to trigger amygdala response; rather, race and eye-gaze cues worked in concert to modulate activity in this neural structure. Confi rming our prediction, Black targets elicited greater amygdala activity compared with White targets (i.e. Black > White) only when the targets displayed direct gaze. When gaze was averted or the eyes were closed, no signifi cant increase in amygdala activity was observed in response to Black targets, and, if anything, results suggested that averted eye-gaze might amplify the threat or uncertainty associated with ingroup (i.e. White) targets. These fi ndings further demonstrate the importance of gaze cues in social cognition [START_REF] Adams | Gaze and amygdala sensitivity to anger and fear faces[END_REF][START_REF] Baron-Cohen | Mindblindness: An essay on autism and theory of mind[END_REF][START_REF] Emery | The eyes have it: The neuroethology, function and evolution of social gaze[END_REF][START_REF] Macrae | Are you looking at me? Eye gaze and person perception[END_REF]. Signaling the emotional status or behavioral intentions of conspecifi cs, gaze cues alert perceivers to possible threat or danger, particularly when the self is the object of others' attention. But why do outgroup targets displaying direct gaze trigger an elevated amygdala response? One candidate explanation is that the amygdala is signaling the presence of an unfamiliar stimulus that has acquired additional emotional signifi cance through prior learning or experience (e.g. [START_REF] Olsson | The role of social groups in the persistence of learned fear[END_REF]. That is, the amygdala is tagging a potentially important emotional stimulus in the environment, a stimulus that is made salient through cultural forces that refl ect the current status of intergroup relations. That eyegaze cues should modulate amygdala activity in this way is consistent with evidence from a variety of sources. Neurophysiological investigations in monkeys have identifi ed cells in the medial and lateral nuclei of the amygdala that are sensitive to eye-gaze direction [START_REF] Brothers | Response of neurons in the macaque amygdala to complex social stimuli[END_REF]. Similarly, human lesion studies have revealed impairments in the interpretation of gaze-related, emotional information following amygdalotomy [START_REF] Adolphs | Impaired recognition of emotion in facial expressions following bilateral damage to the human amygdala[END_REF][START_REF] Young | Face processing impairments after amygdalectomy[END_REF]. In particular, recent research suggests that whereas normal individuals (i.e. those not suffering from amygdala damage) tend to spontaneously attend to the eye region of targets as a means of fear-relevant information gathering, those individuals suffering from amygdala damage fail to do so, leaving them unable to recognize fearful expressions [START_REF] Adolphs | A mechanism for impaired fear recognition after amygdala damage[END_REF]. Interestingly, simply instructing these patients to focus on the eyes of targets is suffi cient to reverse-albeit only temporarilythe previously obtained decrements in emotion recognition [START_REF] Adolphs | A mechanism for impaired fear recognition after amygdala damage[END_REF].

Of potential theoretical interest in the present study is the laterality of the observed effect; the functional analyses revealed differential activity to Black versus White faces with direct gaze, in the right, but not the left, amygdala and the anatomical analyses revealed greater reactivity overall in the right compared with the left amygdala. [START_REF] Whalen | Fear, vigilance, and ambiguity: Initial neuroimaging studies of the human amygdala[END_REF]colleagues (1998, 2001) have suggested that one function of the amygdala is to modulate the vigilance level of an organism. In pursuit of this objective, the right amygdala is thought to play a critical role in the detection of emotionally arousing or potentially threatening stimuli. Consistent with this perspective, [START_REF] Kawashima | The human amygdala plays an important role in gaze monitoring[END_REF] found that the right, but not left, amygdala was sensitive to eye contact. Furthermore, a recent examination of neural activity as a function of skin tone revealed that the right amygdala was more active for light and darker skinned Black targets as well as for darker skinned White targets, relative to light-skinned White targets [START_REF] Ronquillo | The effects of skin tone on race-related amygdala activity: An fMRI investigation[END_REF]. The present study, therefore, corroborates this work, fi nding that differential amygdala activity to outgroup, compared with ingroup, targets is more robust in the right amygdala.

The ability to negotiate a complex world may require neural systems that are specialized in the task of social information processing [START_REF] Adolphs | The neurology of social cognition[END_REF][START_REF] Adolphs | Cognitive neuroscience of human social behavior[END_REF]. As other people are some of the most important objects we encounter, socialcognitive functioning may recruit operations that are fi nely tuned to discerning the signal value of these targets (see [START_REF] Ochsner | Current directions in social cognitive neuroscience[END_REF] for a similar argument). In recent years, researchers have begun to explore the neural processes that underlie social cognition, particularly the operations that support emotional appraisal, person perception, and the ability to discern the intentions of others (for a review, see [START_REF] Lieberman | Social cognitive neuroscience: A review of core processes[END_REF]. In each of these tasks, eye-gaze cues have been shown to modulate the inferences that people make as they strive to understand other social agents [START_REF] Baron-Cohen | Mindblindness: An essay on autism and theory of mind[END_REF][START_REF] Emery | The eyes have it: The neuroethology, function and evolution of social gaze[END_REF]. Extending this line of inquiry, the present results revealed that eye-gaze cues also shape people's emotional reactions to members of different racial groups. In so doing, the current work highlights the importance of compound stimulus cues in the cognitive neuroscience of person perception.

Figure 1 .

 1 Figure 1. Coronal section through the right amygdala (15, -6, -24; 12 voxels), showing the functional region of interest derived from the contrast BDG >WDG

Figure 2 .

 2 Figure 2. Mean percent signal change within the anatomically selected regions of interest placed in the right and left amygdala

Table 1 .

 1 Mean threat judgments for Black and White targets by eye-gaze direction

		Direct	Averted	Closed
	Black targets	3.43 (0.91)	2.54 (0.86)	2.44 (0.88)
	White targets	2.58 (0.99)	2.63 (0.82)	2.19 (0.93)

Note: Standard deviations are in parentheses.

Table 2 .

 2 Whole brain analysis for the comparisons of interest BA, approximate Broadmann's area location. L, left; R, right; Talairach coordinates of locations based on center of mass. Size, number of 3 × 3 × 3 mm voxels. panel of Figure2, Black faces with direct gaze produced more activity in the left amygdala than White faces with direct gaze (t(8) = 2.74, p < .05). Interestingly, neural activity in this region in response to White faces with averted eye-gaze was signifi cantly greater than activity to Black faces with averted gaze (t(8) = -2.47, p < .05). Moreover, Black faces with direct gaze produced signifi cantly more activity in this left amygdala ROI than Black faces with averted gaze (t(8) = 2.65, p < .05). By contrast, neural activity to White faces with direct and averted gaze did not differ signifi cantly (t(8) = -1.04, p = ns). Considered in tandem, these results are consistent with predictions, suggesting that eye-gaze direction moderates the effect of race on neural activity in the amygdala.

	Coordinates

Acknowledgements

The authors are grateful to Jennifer Eberhardt for providing the stimulus materials, to Heather Gordon and Malia Mason for assistance with data collection, as well as to C. Neil Macrae, Todd Heatherton, and Elizabeth Phelps for comments on previous versions of this manuscript. The authors would also like to acknowledge the support of the John D. & Catherine T. MacArthur Foundation to the fi rst author, NICHD grant #1F32HD055772 to the third author, and NICHD grant #5R03HD045742-02 to the fourth author.

These data were presented at the 2003 Meeting of the Society for Personality and Social Psychology.


Michael T Schmitt
email: mschmitt@sfu.ca]

Simon Fraser

Daniel A Miller

Nyla R Branscombe

Jack W Brehm

The Diffi culty of Making Reparations Affects the Intensity of Collective Guilt

Keywords: collective guilt, emotion, emotional intensity, guilt, intergroup emotion

We examined how the diffi culty of making reparations for the harm done to another group affects the intensity of collective guilt. Men were confronted with information documenting male privilege and were told that they would have a chance to help women and reduce patriarchy by collecting signatures on a petition. We manipulated the diffi culty of making reparations by asking participants to collect 5, 50, or 100 signatures. As predicted by Brehm's (1999) theory of emotional intensity, collective guilt was a non-monotonic function of the diffi culty of making reparations. Men in the moderate diffi culty (50 signatures) condition expressed greater collective guilt than participants in the low (5) or high (100) diffi culty conditions. Results are discussed in terms of the implications for the theory of emotional intensity, collective guilt, and collective emotions more generally.

When our ingroup commits unjust acts of harm against another group, we can experience collective guilt (for a review see Branscombe & Doosje, 2004). Research suggests that collective guilt has a motivational quality. The more that people feel collective guilt, the more they support reparations for the harm done to the outgroup [START_REF] Branscombe | The measurement of collective guilt: What it is and what it is not[END_REF][START_REF] Iyer | Racial wrongs and restitutions: The role of guilt and other group-based emotions[END_REF][START_REF] Swim | White guilt: Its antecedents and consequences for attitudes toward affi rmative action[END_REF] and reject ideologies that reinforce an exploitative relationship with the outgroup [START_REF] Powell | Inequality as ingroup privilege or outgroup disadvantage: The impact of group focus on collective guilt and interracial attitudes[END_REF]. Using [START_REF] Brehm | The intensity of emotion[END_REF] theory of emotional intensity, we predict that the perceived diffi culty of making reparations infl uences the intensity with which collective guilt is felt in a non-monotonic fashion. Assuming that collective guilt represents the motivation to restore a just relationship with a harmed outgroup, we argue that the intensity of that motivational state will increase to match the diffi culty of achieving reparations. When reparations appear easy to achieve, collective guilt should be relatively low. As the diffi culty of reparations increases, the intensity of guilt should increase as well, because more motivation is required to make reparations. At some point, however, the diffi culty of achieving reparations will exceed the importance of achieving them, and increased diffi culty will lead to a decrease in guilt.

What is collective guilt?

How is it that people can feel guilt on behalf of their ingroup, even when they do not perceive themselves as personally responsible for the ingroup's harmful actions? According to selfcategorization theory [START_REF] Turner | Rediscovering the social group: A self-categorization theory[END_REF], the self can be experienced at different levels of inclusiveness. When people categorize themselves as individuals, they tend to focus on their unique qualities that differentiate them from other individuals. In contrast, when people self-categorize in terms of a social category, they tend to depersonalize the self and view themselves as more similar to other ingroup members. Accordingly, the ingroup's successes, failures, and wrongdoings are 'shared' by individual group members as representatives of a common category membership. By defi ning the self at a more inclusive level, the group and its relationships to outgroups acquire emotional signifi cance [START_REF] Smith | Social identity and social emotions: Toward new conceptualizations of prejudice[END_REF].

Through depersonalization, people who self-categorize as members of a group that is responsible for illegitimate harm to another group will feel 'guilt by association', even in the absence of a sense of personal responsibility [START_REF] Branscombe | Antecedents and consequences of collective guilt[END_REF]. Among high-status groups, the appraisal of the ingroup's advantage as illegitimate correlates with feelings of guilt [START_REF] Montada | Justice and emotional reactions to the disadvantaged[END_REF][START_REF] Schmitt | Gender, ethnicity, and education as privileges: Exploring the generalizability of the existential guilt reaction[END_REF]. Experimental evidence suggests that the experience of collective guilt is more likely when justifi cations for the ingroup's high-status are undermined, compared to when those justifi cations are reinforced [START_REF] Miron | Collective guilt as distress over illegitimate ingroup inequality[END_REF]. Similarly, when the ingroup is implicated in an unjust intergroup relationship, people feel more guilt compared to when attention is focused solely on the outgroup's plight [START_REF] Powell | Inequality as ingroup privilege or outgroup disadvantage: The impact of group focus on collective guilt and interracial attitudes[END_REF].

In order for a person to experience feelings of collective guilt they must be willing to accept responsibility for the ingroup actions, even if they themselves had no part in the event.

To the extent that people deny any form of collective responsibility and claim that only the individuals who perpetrated the harm directly can be assigned responsibility, then the experience of collective guilt is likely to be minimal. [START_REF] Branscombe | The measurement of collective guilt: What it is and what it is not[END_REF] refer to the belief that groups can be held accountable for the actions of its members as 'whole group accountability', and fi nd that agreement with this belief is positively correlated with the extent to which people report feeling collective guilt. Thus, one way for people to avoid the negative feeling of collective guilt is to take an ideological position that rejects the idea that whole groups can be assigned blame for the actions of some of their members.

Thus, collective guilt arises when people accept the notion of group accountability and they see the ingroup as responsible for perpetrating injustice against another group. In turn, collective guilt functions to urge reparations-meaning the creation or restoration of a just relationship with the harmed outgroup [START_REF] Schmitt | Gender inequality and the intensity of men's collective guilt[END_REF]. Reparations can include behaviors aimed at making up for past injustices committed by the ingroup, and behaviors aimed at creating a new intergroup relationship that eliminates current injustices. Research on guilt resulting from the ingroup's actions suggests that collective guilt does have these motivational characteristics. Dutch students who experienced guilt about their country's exploitation of Indonesia were more likely than those who did not feel guilty to support fi nancial compensation to the Indonesian government [START_REF] Doosje | Guilty by association: When one's group has a negative history[END_REF]. Guilt induced by perceptions of racial inequality motivates European Americans to reject racist ideologies [START_REF] Powell | Inequality as ingroup privilege or outgroup disadvantage: The impact of group focus on collective guilt and interracial attitudes[END_REF] and support compensatory affi rmative action policies [START_REF] Branscombe | The measurement of collective guilt: What it is and what it is not[END_REF][START_REF] Iyer | Racial wrongs and restitutions: The role of guilt and other group-based emotions[END_REF][START_REF] Swim | White guilt: Its antecedents and consequences for attitudes toward affi rmative action[END_REF]. Similarly, guilt resulting from an individual's wrongdoings (when acting alone, not as a group member) appears to motivate people to repair the harm done [START_REF] Baumeister | Guilt: An interpersonal approach[END_REF][START_REF] Frijda | The emotions[END_REF], apologize, and accept punishment [START_REF] Roseman | Phenomenology, behaviors, and goals differentiate discrete emotions[END_REF]).

Brehm's theory of emotional intensity

To explore the implications of collective guilt's motivational character we relied on [START_REF] Brehm | The intensity of emotion[END_REF] theory of emotional intensity. Like other theories of emotion [START_REF] Arnold | Human emotion and action[END_REF][START_REF] Duffy | An explanation of 'emotional' phenomena without the use of the concept 'emotion[END_REF][START_REF] Frijda | The emotions[END_REF][START_REF] Lazurus | Emotion and adaptation[END_REF], this theory of emotional intensity begins with the assumption that emotions are states of motivational arousal-they 'urge behavior designed to promote or prevent important outcomes or urge adaptation to important outcomes that have already occurred' (Brehm, 1999, p. 4). Emotions can be 'defi ned by an intentional structure: that of maintaining or changing a given situation' (Frijda, 1986, p. 98). That is, they are motivational states that organize and control behavior (e.g. [START_REF] Brehm | The emotional control of behavior[END_REF]. All emotions are assumed to have motivational properties, even if the function of the emotion is to discourage action, or if the function is not particularly clear [START_REF] Brehm | The intensity of emotion[END_REF].

Emotions control behavior by organizing events in the environment in terms of their subjective importance at the time, and by maintaining behaviors necessary for coping with the most important event at a given moment. As argued by Levenson (1994, p. 123), Emotions are short-lived psychological-physiological phenomena that represent efficient modes of adaptation to changing environmental demands. Psychologically, emotions alter attention, shift certain behaviors upward in response hierarchies, and activate relevant associative networks in memory. Physiologically, emotions rapidly organize the responses of disparate biological systems including facial expression, somatic muscular tonus, voice tone, autonomic nervous system activity, and endocrine activity to produce a bodily milieu that is optimal for effective response. Emotions serve to establish our position vis-a-vis our environment, pulling us toward certain people, objects, actions and ideas, and pushing us away from others'.

One way for a person to respond to an important event is to increase the intensity of the emotion aroused in response to that event [START_REF] Brehm | The intensity of emotion[END_REF][START_REF] Silvia | Exploring alternative deterrents to emotional intensity: Anticipated happiness, distraction, and sadness[END_REF]. Thus, the emotion focuses attention on the event, and directs resources toward achievement of the function of that emotion (e.g. reparations in the case of guilt) while ignoring other signals.

The more important the event, the greater the potential intensity. Generalizing from previous work on motivational arousal [START_REF] Brehm | The intensity of motivation[END_REF], the theory of emotional intensity assumes that the intensity of a given emotion is a nonmonotonic function of the perceived magnitude of deterrence to attaining the function of the emotion. A deterrent is 'any factor that resists or opposes the function of the emotion' (Brehm, 1999, p. 5). Such factors include those that deter feeling the emotion, and those that deter behaviors urged by the emotion. The fi rst class of factors can be thought of as reasons for not feeling the emotion, or reasons for feeling a different emotion. For example, reasons to feel happy can act as deterrents to sadness, and vice versa. Less obviously, distraction and demands on attention can act as deterrents to emotional experience, as these draw attention away from factors that instigated the emotion and alert the organism to other aspects of the environment that might call for different emotional responses.

The second class of deterrents can be thought of as reasons for not engaging in behaviors urged by the emotion, such as the effort required to engage in the behavior. For example, in the case of collective guilt, the diffi culty of making reparations could serve as a deterrent. This second class of factors-those dealing with reasons for not engaging in the behavior urged by the emotion-has not yet been examined in tests of Brehm's theory of emotional intensity. Research on motivational intensity (without regard to specific emotions) has relied on manipulations of task diffi culty, but most tests of the emotion theory have operationalized deterrents as reasons for feeling a different emotion than the person is currently feeling. One unique contribution of the present study is that we operationalize deterrents in terms of the diffi culty of completing a behavior that would fulfi ll the function of the emotion.

How do deterrents affect emotional intensity? Theoretically, the maximum potential intensity of an emotion is determined by the importance of attaining the function of that emotion. When the level of deterrence is unknown, emotional intensity should rise to this maximum level as set by the importance of achieving the function of the emotion. A high level of intensity prepares a person for as yet unknown deterrents to the emotion-reasons for not engaging in the behavior urged by the emotion. The level of deterrence is likely to be unknown in situations where a person might know that something can be done to achieve the function of the emotion, but they do not know what deterrents might arise or what their magnitudes might be. In an experimental context, the level of deterrence is assumed to be unknown in control conditions that provide no information about deterrents.

In the absence of deterrents, emotional intensity is a function of the importance of achieving the function of the emotion. When, however, deterrents are known, a different process occurs, and emotional intensity varies non-monotonically as a function of the level of deterrence. When the level of deterrence is perceived to be low, emotional intensity should also be low, because little motivation is required to achieve the function of the emotion. As the perceived magnitude of deterrence increases, so too will emotional intensity, up to the point set by the importance of attaining the function of the emotion. If the perceived level of deterrence increases beyond that point, emotional intensity should drop substantially.

A number of experiments have offered evidence supporting this approach to emotional intensity-even with emotions with less obvious motivational properties. For example, [START_REF] Miron | Does happiness function like a motivational state?[END_REF] found that the intensity of happiness varied as a function of deterrents to happiness. Happy participants were presented with reasons for not feeling happy (increases in graduation requirements) that varied in magnitude. Participants presented with a minor reason for not feeling happy (a small increase in graduation requirements) felt less happy than participants who were not presented with any deterrents. A moderate reason for not feeling happy led to relatively greater happiness. At a higher level of deterrence (a large increase in graduation requirements), however, happiness dropped to a relatively low level of intensity. The resulting cubic pattern of emotional intensity has also been found in studies of sadness [START_REF] Silvia | Exploring alternative deterrents to emotional intensity: Anticipated happiness, distraction, and sadness[END_REF], anger, and sympathy (for a review see [START_REF] Brehm | The intensity of emotion[END_REF].

In the case of collective guilt, an obvious deterrent is the diffi culty of making reparations for the harm done. When reparations are perceived as fairly easy to achieve, the intensity of collective guilt should be relatively low. As perceived diffi culty of making reparations increases, so too should the intensity of collective guilt, up to the point at which guilt reaches its maximal level set by the importance of making reparations. When the diffi culty of reparations increases beyond this point, collective guilt should drop to a low level of intensity. One of the interesting implications of this theory is that emotional intensity will be lowest when reparations appear rather easy or very diffi cult. Conversely, the intensity of collective guilt should be highest when the difficulty of reparations is either moderate or unknown.

Overview of the experiment

We tested our hypotheses regarding the effect of diffi culty of reparations by examining men's experiences of collective guilt in response to their collective advantages relative to women. Inequality favoring men over women exists to some degree in essentially all contemporary societies [START_REF] Abel | Circles of care: Work and identity in women's lives[END_REF][START_REF] Keegen | The history of warfare[END_REF][START_REF] Peterson | Global gender issues[END_REF][START_REF] Wood | A cross-cultural analysis of the behavior of women and men: Implications for the origins of sex differences[END_REF]. Women are disadvantaged in the labor force compared to men [START_REF] Bartol | Gender infl uences on performance evaluations[END_REF][START_REF] Reskin | Women and men at work[END_REF], are more likely than men to be poor [START_REF] Mclanahan | The feminization of poverty: Past and future[END_REF], and are the primary victims of sexual assault [START_REF] Rozee | Rape: A century of resistance[END_REF]. Although the form and extent of male privilege varies depending on social class, ethnicity, age, and sexual orientation [START_REF] Connell | Gender and power: Society, the person and sexual politics[END_REF], gender inequality clearly benefi ts men as a group at the expense of women as a group.

To invoke collective guilt, we presented men with detailed information regarding the ways in which gender inequality benefi ts their group and harms women (see [START_REF] Miron | Collective guilt as distress over illegitimate ingroup inequality[END_REF], for the use of a similar manipulation to invoke collective guilt in men). We then told them that we would give them an opportunity to reduce gender inequality by collecting signatures on a petition. To manipulate the diffi culty of making reparations, we told participants that they would need to collect 5, 50, or 100 signatures (a control condition did not mention the petition). After participants learned about the petition, we measured collective guilt. We predicted that the intensity of collective guilt felt by men would be infl uenced by the diffi culty of reparations as postulated by the theory of emotional intensity [START_REF] Brehm | The intensity of emotion[END_REF]. More specifi cally, we expected that when the diffi culty of making reparations is low (5 signatures), guilt should also be low as compared to the control condition because little motivation should be required to complete the inequality-reducing behavior. However, when diffi culty increases to a moderate level (50 signatures), we predicted that guilt should also increase compared to the low diffi culty condition, because more effort would be required to carry out reparations. As diffi culty further increases (100 signatures), we predicted that the intensity of guilt should decrease as compared to the moderate condition, because the diffi culty of making reparations in this condition would outweigh the importance of doing so.

Method

Participants and procedure

Eighty men participated in partial fulfi llment of a research requirement for an introductory psychology course. Participants were randomly assigned to one of four conditions: low, moderate, and high reparations diffi culty, or a noinformation control condition.

In order to test our hypotheses, we had to be confi dent that participants would feel guilt, and thus be motivated to support reparations.

If participants on the whole did not experience guilt in any of the conditions, or were opposed to making reparations, then we would not expect deterrents to guilt to infl uence its intensity. Therefore, as described below, we created a context in which participants overall would experience guilt and be supportive of making reparations, at least at low and moderate levels of diffi culty.

Furthermore, because the level at which the diffi culty of making reparations will outweigh the importance of reparations needed to be determined a priori, we conducted a pretest to establish the levels of diffi culty to use in our experiment. Men from the same population as our participants were asked the maximum number of signatures they would be willing to collect for the described petition. Because the average maximum was close to 50, we chose that level for the moderate diffi culty condition, and then chose numbers well above and below that for the high and low diffi culty conditions respectively.

All participants read an essay that made them aware of the disadvantages suffered by women in the USA (following [START_REF] Schmitt | Women's emotional responses to the pervasiveness of gender discrimination[END_REF]. Among other things, the essay described the gender wage gap, gender stereotypes about women's lack of competence, and the frequency of sexual assault against women. In part, the essay read 'Equal pay has been the law since 1963, however, women are still paid less than men-even when they have similar educational backgrounds, skills and experience'. In addition, participants read that Men rarely worry about sexual assault, but women frequently think about the possibility of sexual assault when they go out at night alone, when they walk from a building to their car in an isolated parking lot, or when stranded in a broken down car.

We included this form of privilege not because it represents the most pervasive difference in the treatment of men and women, but because previous research [START_REF] Branscombe | Thinking about one's gender-group's privileges or disadvantages: Consequences for well-being in women and men[END_REF] found that college men report freedom from fear of sexual assault as a major privilege of being a man. Thus, much of the essay focused on how women often fear going out alone at night, but men rarely worry about sexual assault.

We assumed that sexual assault would be a relatively diffi cult form of inequality for men to justify; consequently, including information about this particular form of disadvantage helped ensure that inequality between women and men would be seen as illegitimate, a necessary precondition for inducing collective guilt.

Manipulation of reparation diffi culty

After reading the essay on gender inequality, participants in the three experimental conditions went on to read about an ostensible opportunity to reduce inequality between women and men at their university. Participants read about a student-sponsored petition supporting improved lighting at the university and a free accompaniment service to walk both women and men between buildings or between buildings and parking lots at night. Participants read that after completing the questionnaire, they would have an opportunity to take a copy of the petition and collect signatures. The collection of signatures was presented explicitly as an opportunity to help reduce women's disadvantages at the university. In order to manipulate the diffi culty of making reparations, we varied the number of signatures the participants would be asked to collect before they could return the petition. Participants read that they would need to collect 5, 50, or 100 signatures in the low, moderate, and high diffi culty conditions, respectively. Participants in the control condition read nothing about the petition, thus, the diffi culty of making reparations in this condition was ambiguous. The dependent measures described below followed the manipulation of reparation diffi culty. At no point in the study were participants asked directly to collect signatures; participants were only told they would be given an opportunity to do so after their participation in the study was complete. Participants were not asked to indicate their willingness, intent, or commitment to collect signatures.

Collective guilt

Collective guilt was measured in two ways. First, participants responded to four items adapted from Branscombe et al.'s (2004) measure of collective guilt acceptance using a 1 (strongly disagree) to 7 (strongly agree) scale: 'I feel guilty about men's harmful actions toward women', 'I feel guilty about the negative things other men have done to women', 'I can easily feel guilty for bad outcomes brought about by members of my gender group', and 'I feel guilty when I think about the unfair disadvantages women suffer'. Second, participants also responded to a measure of currently felt guilt by indicating the extent to which they felt guilty at the present time on a 1 (not at all) to 7 (very much) scale. We factor analyzed these fi ve collective guilt items. The fi rst two eigenvalues were 13.58 and 0.74 respectively. Furthermore, all fi ve items loaded highly on the fi rst factor, suggesting a clear single-factor solution. Thus, the fi ve items were combined into a single measure of collective guilt (α = .88).

Whole group accountability

The extent to which participants were willing to accept collective responsibility for the actions or inactions of their group was accessed with fi ve items (e.g. 'If a group harms members of another group, the whole group should feel guilty' and 'Whole groups, like individuals, ought to be held accountable for their actions'; α = .89) adapted from [START_REF] Branscombe | The measurement of collective guilt: What it is and what it is not[END_REF]. These items were measured on a 7-point scale (strongly disagree, strongly agree). Because willingness to accept ingroup responsibility is a necessary condition for feeling collective guilt, we measured this variable to use as a covariate in analyses of the intensity of collective guilt feelings.

Legitimacy of gender inequality

Beliefs about the legitimacy of discrimination against women were assessed on a 7-point scale (strongly disagree, strongly agree) with two items (i.e. 'I fi nd it perfectly legitimate to discriminate against women', 'Treating women negatively based on their gender is justifi able'). These two items were averaged to create a single index of legitimacy (α = .89). This measure was included to rule out alternative explanations for our predicted fi ndings, by demonstrating that the perceived legitimacy of gender inequality was not affected by our manipulation of reparations diffi culty.

Results

Preliminary analyses

As intended, the men in this sample viewed gender inequality as low in legitimacy (M = 1.65 on a 1-7 scale). Thus, one of the necessary conditions was met for collective guilt to be experienced: men appraised their relationship with the outgroup as illegitimate. Perceptions of legitimacy did not differ by condition (F(3, 76) = .38 p = .77), and were not signifi cantly related to collective guilt (r = -.13, p = .24). 1 We found that the whole group accountability measure was positively related to participants' reports of how guilty they felt (r = 0.47, p < .001). However, participants' reports of whole group accountability did not differ by condition (F(3, 75) = 1.17, p = .33). Thus, to control for individual differences in whole group accountability, a known necessary condition for the experience of collective guilt, this effect was added as covariate in all additional analyses. Using this covariate increases statistical power for detecting an effect of the experimental manipulation by partialling out variance in collective guilt that is not related to experimental condition [START_REF] Frigon | Analysis of covariance: A proposed algorithm[END_REF].

Effects of condition on collective guilt

Assuming that the function of collective guilt is to urge members of dominant groups to create a more just relationship with the outgroup, we predicted that guilt would be low in intensity when the diffi cultly of reparations was low or high, and relatively more intense when the diffi culty of reparations was unknown or at a relatively moderate level. In order to test these predictions we submitted the collective guilt index to the following cubic contrast: control condition (1), low diffi culty condition (-1), moderate diffi culty condition (1), high diffi culty condition (-1). The predicted contrast was signifi cant (F(1,74) = 6.79, p = .01), demonstrating that guilt was reliably higher in the control and moderate diffi culty conditions than in the low and high diffi culty conditions. 2 As shown in Figure 1, guilt was lower in the low diffi culty condition compared to the control condition (t(37) = 1.98, p = .025, onetailed). In addition, guilt was higher in the moderate difficulty condition compared to both the low diffi culty condition (t(38) = -1.71, p = .046, one-tailed) and high diffi culty condition (t(38) = -1.68, p = .048, one tailed). Thus, these results confi rmed our hypotheses. 3

Discussion

Supporting the theory of emotional intensity [START_REF] Brehm | The intensity of emotion[END_REF], we found that the intensity of collective guilt was infl uenced in a non-monotonic fashion by the diffi culty of reparations. The observed variation in the intensity of collective guilt is consistent with predictions derived from the assumption that collective guilt is a motivational state, and a refl ection of the differential levels of motivation required to enact reparations. This pattern of results is diffi cult to explain without assuming that collective guilt functions as a motivational state. For instance, one might suggest that the perceived diffi culty of making reparations affected perceptions of the degree of injustice, and levels of guilt increased as the perceived degree of unjust harm increased. However, this notion would predict a continued linear increase in guilt as diffi culty increased, and thus, cannot explain why guilt would be lower in the high diffi culty condition relative to the moderate diffi culty condition. Moreover, we measured perceptions of the illegitimacy of gender inequality and found that it did not reliably differ by condition.

Another alternative account of these fi ndings might argue that participants' self-reported guilt represents dissonance reduction through effort justification-making one's reported emotion consistent with one's anticipated behavior. If participants plan to engage in reparation behavior in the low and moderate diffi culty conditions (as we assume they would based on pretesting), guilt might be expected to be relatively high in the moderate diffi culty condition, as more guilt would be consistent with the extra work required to complete reparations. In the high diffi culty condition, assuming participants are not planning on engaging in reparations behavior, low guilt would be consistent with one's inaction. However, the cornerstone of a dissonance interpretation is commitment to one side or the other, in this case, to collect the signatures or not. Festinger's 1964 book made clear (as did [START_REF] Brehm | Explorations in cognitive dissonance[END_REF] that commitment is a necessary condition for dissonance reduction processes to occur. Experiments reported in the 1964 book invariably demonstrated that there are no dissonance-like evaluation changes prior to commitment to one behavioral alternative or the other. As participants in the present study provided no clear commitment to engage (or not) in reparations behavior, dissonance theory cannot account for any changes in reported guilt. Indeed, even the alternative account described above reads much like the emotional intensity interpretation, as the intensity of emotion precedes behavior, readying the individual for action or inaction. Moreover, other studies testing the theory of emotional intensity are immune to the effort-justification account [START_REF] Miron | Does happiness function like a motivational state?[END_REF][START_REF] Silvia | Exploring alternative deterrents to emotional intensity: Anticipated happiness, distraction, and sadness[END_REF]. In prior tests of the theory, participants are not presented with any particular behavioral option to fulfi ll the function of the instigated emotion. In those studies it seems implausible to assume that participants' responses were attempts to rationalize anticipated behavior.

Implications for the study of emotional intensity

This study offers support for the applicability of the theory of emotional intensity to a wide variety of emotions [START_REF] Brehm | The intensity of emotion[END_REF]. Past empirical support has come from studies of happiness, sadness, and anger. However, this study is the fi rst to confi rm that the predictions of emotional intensity theory also hold for guilt. Second, support for the theory of emotional intensity typically comes from studies fi nding that emotions with opposing valences can deter one another (e.g. reasons for feeling happy can deter sadness; Brehm, Brummet, & Harvey, 1999). However, this is the fi rst work to support the theory of emotional intensity by directly manipulating the diffi culty of implementing an action tendency associated with a particular emotion. Third, these data are the fi rst to test the theory of emotional intensity using an emotion based on a collective representation of self and not the personal self. Not only do these results further confi rm the general applicability of the theory of emotional intensity, but they also confi rm that collective emotions, like emotions more generally, have motivational properties. Thus, this research is consistent with the notion that emotions felt on behalf of an ingroup are just as 'real' as emotions tied to the individual self. Regardless of the level of self-defi nition (i.e. individual or group) involved in instigating the emotion, emotions seem to function similarly-as motivations urging and guiding behavior.

One interesting implication of the theory of emotional intensity is that it predicts low levels of emotional arousal when deterrents are relatively low or relatively high. Despite resulting from different levels of deterrents, similar levels of emotional intensity represent similar levels of motivational arousal, and thus will result in similar levels of effort spent attempting to fulfi ll the function of the emotion. One difference between the low emotional intensity experienced under low and high deterrence is worth noting-a person experiencing low guilt because deterrents are low has potential for a greater intensity of guilt if new deterrents are encountered. In contrast, a person experiencing low guilt because deterrence requires a level of emotional intensity that surpasses its potential would continue to feel little guilt if additional deterrents are encountered.

Along the same lines, the theory predicts similar levels of high emotional intensity when deterrents are unknown, and when deterrence reaches the point at which additional deterrence would outweigh the importance of the function of the emotion. Future research could explore whether participants who are not presented with information about deterrence do feel a relative sense of uncertainty regarding aspects of the environment that might deter the function of the emotion. Such evidence would add additional support to the assumption that high emotional intensity when deterrence is operationalized as 'unknown' does arise from a sense of 'not knowing' what the level of deterrence will be.

Implications for the study of collective guilt

Deterrents to collective guilt are not limited to the diffi culty of reparations. Other deterrents to collective guilt (i.e. reasons for not engaging in reparations) might include the costs that reparations incur in terms of the social identity of dominant group members. Establishing egalitarian intergroup relations is likely to result in real material costs (in terms of resources and power) to high-status groups, and reductions in the privileges and status that some groups hold over others are likely to result in costs to the social identities of high-status groups. Establishing intergroup equality is not just a matter of increasing the collective power and resources of disadvantaged groups, but also reducing (at least, in a relative sense) the collective power and resources of dominant groups. Social identity theory [START_REF] Tajfel | The social identity theory of intergroup behavior[END_REF] suggests that when a dominant group's social position is threatened, group members will be motivated to protect the group's collective interests. For example, [START_REF] Branscombe | Racial attitudes in response to thoughts of white privilege[END_REF] found that highly identifi ed White Americans expressed increased racism when forced to confront the advantages of their ethnic group membership, but that low identifi ers expressed decreased racism, potentially refl ecting increased collective guilt. Future research could investigate whether such threats to the social identity of dominant groups function as deterrents to collective guilt.

In addition, future work on collective guilt could fruitfully examine an assumption of the theory of emotional intensity that we have not fully explored-that the importance of achieving the function of an emotion determines its maximum intensity. When the goal of creating just relationships with harmed outgroups is relatively high in importance, the maximum potential intensity of collective guilt should be also high. Therefore, assigning importance to reparations as a goal increases the costs dominant group members are willing to incur before costs to the ingroup outweigh the importance of reparations. The present results suggest that a full understanding of collective guilt requires a consideration of factors that make just, fair relationships with lower status outgroups an important goal-one that can stand up against deterrents like the material and symbolic costs to the ingroup that would likely result from social change. Prior work suggests that perceived illegitimacy of the intergroup relationship is a predictor of collective guilt [START_REF] Miron | Does happiness function like a motivational state?[END_REF]; perhaps the greater the moral transgressions of the ingroup, the more important it is to make reparations. In addition, [START_REF] Wohl | Collective guilt: Emotional reactions when one's group has done wrong or been wronged[END_REF] have argued that people feel greater collective guilt for harming groups with which they share a meaningful superordinate identity (e.g. nationality or humankind). By applying a similar standard of justice to both the and outgroup, a common superordinate category might increase the importance of reparations.

This perspective also leads us to consider general beliefs, ideologies and lay theories relevant to intergroup relations in terms of their implicit level of deterrence to collective guilt. Interestingly, the theory of emotional intensity suggests that belief systems which have opposite meanings can have similar implications for collective guilt. For instance, the theory suggests that collective guilt should be low if one's theory of intergroup relations suggests that establishing more egalitarian relations requires very little effort or cost, and if one's theory of intergroup relations suggests that egalitarian relations are impossible to achieve. Thus, the theory of emotional intensity may offer some insights into the ways in which apparently contradictory social beliefs can result in similar psychological (and political) ends. Political discourse regarding contemporary intergroup relations often contains implicit or explicit deterrents to collective guilt (e.g. 'We can't turn back the clock', 'If we apologize, they'll want fi nancial reparations'; see [START_REF] Augoustinos | On whether to apologize to Indigenous Australians: The denial of white guilt[END_REF]. Reparations might be appraised as more diffi cult for a number of reasons, including a long period of time passing since the harm was done, or because the magnitude of harm is so great that justice requires reparations of a similar magnitude. More generally, a number of variables central to intergroup theorizing (e.g. the stability of intergroup status discrepancies, appraisals of ingroup strength, group identifi cation) might be fruitfully conceptualized as deterrents to collective emotions.

The theory or emotional intensity also points to other deterrents to collective guilt that are irrelevant to the factors that give rise to collective guilt. Emotions refl ect momentary adaptations to the environment, and thus must be responsive to new events that occur. Collective guilt could be deterred by any number of other events or situations and the emotions they give rise tohappiness resulting from seeing a good friend, frustration with a dead-end job, or sadness that occurs from watching depressing news reports.

With such a wide range of deterrents competing for the direction of emotional experience, will collective guilt ever make a difference? Whether these deterrents increase or decrease the intensity of guilt depends on the importance assigned to creating a just relationship with the outgroup. The greater the importance, the greater is the potential for guilt to rise in intensity in response to these other aspects of the environment.

Future research could expand on the present fi ndings by including additional measures of collective guilt. People may be reluctant to report feeling guilt because it implicates their ingroup, and thus levels of reported guilt might underestimate the intensity of the experience. Perhaps this explains the moderate levels of guilt reported by our participants overall. More subtle, covert, or sensitive measures of guilt might better capture fl uctuations in emotional intensity. In addition future research could measure the extent to which actual reparations behavior varies as a function of the perceived diffi culty of making reparations. Measures of other emotions such as contempt, shame, or moral outgrage could determine whether people with a low level of guilt intensity are simply indifferent, or if they experience another emotion in place of guilt. This work could also be expanded to other intergroup contexts (e.g. race/ethnic relations) to test its generalizabilty. Assuming the conditions for the instigation of collective guilt are met, we see no reason why collective guilt would not respond similarly in other contexts.

In conclusion, the current research illustrates the empirical and theoretical benefi ts of considering the implications of collective guilt's motivational properties. We have demonstrated that the diffi culty of making reparations acts as a deterrent to the experience of collective guilt, and affects the intensity of collective guilt in a non-monotonic fashion as predicted by the theory of emotional intensity [START_REF] Brehm | The intensity of emotion[END_REF]. We hope that these fi ndings will motivate additional research that examines other possible deterrents to guilt so that we may better understand this social emotion.

Notes

1. The lack of a signifi cant correlation between legitimacy and guilt is somewhat surprising theoretically and in comparison to past research fi ndings [START_REF] Miron | Collective guilt as distress over illegitimate ingroup inequality[END_REF]. However, there are two plausible reasons for not replicating this relationship. First, there was little variance in participants' responses to the legitimacy items, with participants using the extreme end of the scale to indicate that gender discrimination is illegitimate. Therefore, there was little variance to correlate with guilt. Second, the variability in guilt intensity in this study comes not from variability in legitimacy, but from the experimental manipulation of the diffi culty of making reparations. The important point is although judgments of illegitimacy are a precondition for guilt, variation in illegitimacy judgments does not explain the variability in guilt in this particular sample. 2. The result of the cubic contrast for collective guilt without whole group accountability included as a covariate was similar (F(1, 76) = 5.70, p = .02). 3. Participants also completed single item measures of anger, fear, and sadness. For each of these emotions, we examined the omnibus F test and the cubic contrast. In no case were results signifi cant, indicating that the effects we observed were specifi c to guilt.

Figure 1 .

 1 Figure 1. Men's experience of collective guilt as a function of the diffi culty of making reparations for gender inequality.