Keywords:

In the present paper we tested the hypothesis that the physical presence of other ingroup members may ameliorate Whites' spontaneous affective responses toward Blacks. Results of Study 1 demonstrated that IAT-assessed attitudes toward Blacks were indeed less negative when participants were tested in small groups rather than individually. Study 2 shed light on the underlying processes by demonstrating that respondents at the presence of others displayed increased accessibility to egalitarian-related concepts after Black primes, as compared to respondents tested individually. Overall, results point to the wide malleability of spontaneous affective responses and to the possibility that contextual factors, like the presence of other individuals, might automatically activate egalitarians goals. Results are discussed in relation to current models of automatic intergroup bias and preconscious control over it.

Contextual effects on prejudiced attitudes:

When the presence of others leads to more egalitarian responses.

Over the last decades in Western societies there has been an impressive change in the social norms that sanction discriminatory behaviors toward stigmatized outgroups [START_REF] Dovidio | Aversive racism and selection decisions: 1989 and 1999[END_REF][START_REF] Kluegel | Beliefs about inequality: America's view of what is and what ought to be[END_REF]. Racism is now openly condemned by the majority of the population -especially among specific subgroups like college and university students -and egalitarian principles are increasingly becoming socially shared values. For instance, Crandall and his colleagues [START_REF] Crandall | Social norms and the expression and suppression of prejudice: The struggle for internalization[END_REF] have shown that it is considered appropriate to condemn and sanction racists to an extent similar to that of child molesters or terrorists. The negative perception of racists is even stronger than the negative perception of negligent parents or men who leave their families. Social norms clearly state that race discrimination is not acceptable.

Despite these cultural and social changes, discrimination is still a plague in Western societies. In addition, prejudiced attitudes and negative stereotypes continue to linger at an automatic level (e.g., [START_REF] Devine | Stereotypes and prejudice: Their automatic and controlled components[END_REF][START_REF] Greenwald | Measuring individual differences in implicit cognition: The Implicit Association Test[END_REF]. For instance, Blacks still trigger automatic negative responses among White perceivers. Therefore, spontaneous responses still signal the presence of a large gap between the valence and the mental contents associated to Blacks on one side, and those associated with Whites on the other.

Recent research demonstrates, however, that automatic negative responses are not as ubiquitous and immutable as they were considered until 10 years ago [START_REF] Barden | Contextual moderation of racial bias: The impact of social roles on controlled and automatically activated attitudes[END_REF][START_REF] Blair | Imagining stereotypes away: The moderation of implicit stereotype through mental imagery[END_REF][START_REF] Dasgupta | On the malleability of automatic attitudes: Combating automatic prejudice with images of admired and disliked individuals[END_REF][START_REF] Lowery | Social influence effect on automatic racial prejudice[END_REF][START_REF] Maddux | Saying no to negativity: The effects of context and motivation to control prejudice on automatic evaluative responses[END_REF][START_REF] Sinclair | Social tuning of automatic racial attitudes: The role of affiliative motivation[END_REF][START_REF] Wittenbrink | Evidence for racial prejudice at the implicit level and its relationship with questionnaire measures[END_REF][START_REF] Moskowitz | Preconscious control and compensatory cognition[END_REF]; see [START_REF] Blair | The malleability of automatic stereotypes and prejudice[END_REF] for a review). Indeed the perceiver's characteristics [START_REF] Wittenbrink | Evidence for racial prejudice at the implicit level and its relationship with questionnaire measures[END_REF], how the targets are mentally construed [START_REF] Wittenbrink | Spontaneous prejudice in context: Variability in automatically activated attitudes[END_REF], and the specific characteristics of the setting in which attitudes are assessed [START_REF] Lowery | Social influence effect on automatic racial prejudice[END_REF] all affect the valence of automatic responses toward Blacks. This means that spontaneous responses are also malleable and may undergo positive changes. The challenge is thus to identify the specific factors that might help to achieve such goal. In the current paper we will focus on the effects of the physical presence of other ingroup members where the group holds egalitarian norms and explicitly supports positive intergroup relations. It is hypothesized that the physical presence of ingroup members may ameliorate spontaneous responses toward members of stigmatized outgroups -like Blacks -which are protected by social norms shared within the ingroup.

Contextual influences on intergroup judgments. Current models of stereotyping assume that the context in which intergroup judgments are provided influences the valence of such judgments [START_REF] Bodenhausen | Stereotype activation and inhibition[END_REF][START_REF] Fiske | A continuum of impression formation, from categorybased to individuating processes: Influences of information and motivation on attention and interpretation[END_REF]. Depending on the specific context, different motivations, self-images, and normative rules may become salient. Accordingly, in public settings individuals may feel a stronger pressure toward being fair and, as a consequence, they may be more likely to inhibit prejudiced responses [START_REF] Bodenhausen | Stereotype activation and inhibition[END_REF][START_REF] Plant | Internal and external motivation to respond without prejudice[END_REF]. This reasoning implies that the effects of public contexts are mainly driven by a conscious and strategic desire to appear as non-prejudiced individuals.

However, as noted by Lambert and his colleagues [START_REF] Lambert | Stereotypes as dominant responses: On the "social facilitation" of prejudice in anticipated public context[END_REF], there is still no systematic investigation about the moderating role of private versus public settings on the expression of prejudice, especially in relation to the less controlled forms of prejudice expression. Even though one of the core goals of social psychology is to study processes that occur in public contexts, our knowledge about how spontaneous intergroup attitudes are influenced by the presence of others is still limited. In a thorough series of studies, it has been recently demonstrated that individuals modify their spontaneous responses in order to go along with the perceived expectations of other physically present persons [START_REF] Lowery | Social influence effect on automatic racial prejudice[END_REF][START_REF] Sinclair | Social tuning of automatic racial attitudes: The role of affiliative motivation[END_REF]. For instance, when the experimenter wore a t-shirt with an anti-racist slogan, participants' automatic responses were less prejudiced [START_REF] Sinclair | Social tuning of automatic racial attitudes: The role of affiliative motivation[END_REF]. The underlying theory is that individuals spontaneously tune their attitudes according to the attitudes expressed by physically present and desirable others. In short, this research demonstrates that we are sensitive to persons around us on both controlled and spontaneous responses. In most cases, however, there are no salient cues in the environment -like an anti-racist t-shirt -that imply about a need to be egalitarian. In such cases, it is reasonable to ask whether the perceiver behaves in a social vacuum, and whether the perceiver's attitudes are influenced by the presence of others.

We predict that in the presence of other individuals there will be a decrease in prejudiced attitudes due to the operation of egalitarian social norms. These norms are conceived as socially shared sets of prescriptions that indicate that interracial judgments should be characterized by fairness and equality and not by discrimination. Given their socially shared nature, egalitarian norms are particularly relevant in regulating behaviours when the perceiver is in social contexts rather than alone. Therefore, these socially shared sets of prescriptions are expected to be recurrently implicated in regulatory processes that occur in social settings. Beside conscious regulatory attempts, after repeated experiences, individuals may learn to associate specific situations (i.e., public settings) with normatively appropriate responses so that to automatize particular response patterns [START_REF] Aarts | The silence of the library: Environment, situational norm, and social behaviour[END_REF]Chartrand & Bargh, 1996;Mischel & Shoda, 1995). Therefore, even spontaneous intergroup attitudes should become less negative in public contexts as compared to private settings. In Study 1, we will specifically test this hypothesis.

In addition, when individuals consistently try to attain the same goal in a given situation, they may also come to automatically activate this goal any time that situation is encountered [START_REF] Shah | The automatic pursuit and management of goals[END_REF]. As such, the individual will develop what [START_REF] Aarts | The silence of the library: Environment, situational norm, and social behaviour[END_REF] call situational norms which are conceived as socially shared beliefs representing the links between specific situations and appropriate normative behaviours. This implies that the goal of being fair toward outgroup members does not need to be intentionally established, but it may also spontaneously arise from contextual cues by means of associative processes (see [START_REF] Kunda | When do stereotypes come to mind and when do they color judgment? A goal-based theoretical framework for stereotype activation and application[END_REF]. Because (egalitarian) social norms can be considered to be sets of shared knowledge that are maximally relevant to regulate public behaviors, public situations will gradually gain the power to automatically activate those norms, which in turn will automatically modulate spontaneous responses. In other words, the presence of other individuals may automatically trigger relevant norms that are functional in order to regulate social conducts, like the need to be egalitarian toward Blacks (see also [START_REF] Fitzsimons | Thinking of you: Nonconscious pursuit of interpersonal goals associated with relationship partners[END_REF]. This activated goal will then give rise to regulatory processes aimed at attaining the goal which, in this case, means to eliminate, or at least decrease, prejudice-consistent responses. In Study 2 we tested whether the actual presence of other individuals automatically activates the goal of being egalitarian when faced with Blacks. We hypothesized that the actual presence of others increases the accessibility of egalitarian-related concepts after the presentation of a Black prime.

Study 1

The preliminary goal that was pursued in Study 1 was to verify whether the physical presence of peers improves spontaneous affective responses toward Blacks 1 . To this end a race-IAT was employed [START_REF] Greenwald | Measuring individual differences in implicit cognition: The Implicit Association Test[END_REF], and participants performed it either alone or in the same room with two peers.

Method Participants

One-hundred eighty-four students attending secondary schools in Padova participated in the study on a voluntary basis (46 males and 138 females; ages ranged between 16 and 18 years) with the consent of the representatives of the schools. All participants except one were Whites.

Procedure

Participants were tested in a quiet room made available by the schools. Two experimental conditions were created. Some participants were tested alone, whereas other participants performed the very same tasks as the "alone" participants but at the presence of two peers. Therefore, in one experimental condition small groups of three students were created by randomly sampling three students attending the same class. This condition will be labelled "physical presence". Importantly, participants worked alone on their own computer just like participants in the individual condition.

Participants were placed in a way to maximize physical proximity while at the same time preventing that they could see other. Indeed, participants were seated close to each other but they faced their backs.

At their arrival in the laboratory, participants were asked to perform a standard race-IAT. The experimenter first explained the structure and the main characteristics of the task and then all instructions were provided on the computer screen to avoid any discussion during the experiment.

In addition, it was explained that participants could not turn around during the experiment and that everyone had to focus on one's own computer. Ten positive words (e.g., love, peace, paradise, and happiness), ten negative words (e.g., disgust, earthquake, vomit, and betrayal), ten pictures portraying young White males and 10 pictures portraying young Black males were used. In the two critical phases of the test each stimulus item appeared once (i.e., 40 trials in each phase). The relative order of the phases within the test was counterbalanced across participants.

Next, we assessed the perceived normative appropriateness of prejudiced responses.

Participants were asked to imagine two hypothetical situations of discrimination and to judge how much the perpetrator might be justified for his/her action (i.e., "It is understandable if a company decides to hire a White rather than a Black worker even though they have similar curricula"; "It is understandable that a girl on a train prefers to sit beside a White rather than a Black male").

Responses were provided on 5-point Likert scales ranging from "I totally disagree" to "I totally agree". Finally, participants were asked additional questions which were not relevant to the aims of the current work. Participants were then returned to their classes. Debriefing was made collectively at the very end of the data collection within the school.

Results

IAT

Data were treated according to Greenwald et al.'s suggestions [START_REF] Greenwald | Understanding and using the Implicit Association Test: I. An improved scoring algorithm[END_REF], so that a single d score was computed for each participant. Positive values correspond to stronger associations between Blacks and negative words. Data from 8 participants were excluded because they did not properly follow the instruction and made an excessive number of errors (more than 20% of the trials). Data from a group in which a Black participant was present were also excluded from the analyses. One-hundred seventy-three participants remained available for the analyses.

The IAT-score was submitted to a 2 (condition: alone vs. physical presence) X 2 (participants' An explanation of our findings is that the presence of others is effective in activating egalitarian social norms. The goal of being egalitarian consists of both an individual and a more social component [START_REF] Moskowitz | Preconsciously controlling stereotyping: Implicitly activated egalitarian goals prevent the activation of stereotypes[END_REF][START_REF] Plant | Internal and external motivation to respond without prejudice[END_REF]. Individuals differ to the extent to which they chronically endorse egalitarian values [START_REF] Moskowitz | Preconscious control of stereotype activation through chronic egalitarian goals[END_REF]2000). In addition to the degree of this chronic endorsement which is related to stable individual differences, we also expect that social contexts may differentially trigger the goal of being egalitarian. Research on goal activation has shown that different environments and contexts do indeed automatically activate different social norms (see [START_REF] Aarts | The silence of the library: Environment, situational norm, and social behaviour[END_REF]. For instance, [START_REF] Aarts | The silence of the library: Environment, situational norm, and social behaviour[END_REF] have convincingly demonstrated that participants primed with the picture of a library automatically activated the concept of "silence" as revealed by an enhanced accessibility of words like "quiet" or "silent".

Following this line of reasoning, if egalitarian norms are actually becoming socially shared norms within Western societies, we hypothesize that being in the presence of others might spontaneously trigger the activation of egalitarian goals. The automatic activation of egalitarian goals is therefore considered as the candidate process underlying the amelioration of spontaneous affective responses in the social context. Study 1, however, did not provide a direct test of the activation of egalitarian goals. We specifically predict that respondents who are in the physical presence of ingroup peers will be more likely to activate an egalitarian goal in response to Blacks as compared to people tested individually. The following study will address this issue.

Study 2

In accordance to the proposed hypothesis, the egalitarian concept should be more accessible after seeing a Black person when respondents are in a physical presence setting rather than alone. In this study, participants were asked to perform a Lexical Decision Task (LDT) in which both Black and White faces were used as primes and egalitarian and control words were used as targets. As before, some participants were tested individually, whereas other participants were tested in a small group (i.e., 3 to 4 participants in the same room). As stated, in the physical presence condition we predicted an increase in the accessibility of egalitarian words after Black faces.

Method Participants

Two-hundred sixty-eight first year psychology students at the University of Padova participated in the study to accomplish partial course requirements (51 males and 217 females).

Two participants were not Italian and their data were discarded as well as the data of two Italian respondents who were in a group with a foreign participant.

Materials

ACCEPTED MANUSCRIPT

Equality in the presence of others 11 Photographs (5.2 cm × 7.8 cm) portraying head-and-shoulder images of 24 White and 24

Black male adults were used as primes. There were 24 target words: Six words related to egalitarianism (e.g., equality, tolerance, justice), six positive words irrelevant to egalitarianism (e.g., humility, kindness, responsibility) and twelve non sense words. Words were derived from [START_REF] Moskowitz | Preconsciously controlling stereotyping: Implicitly activated egalitarian goals prevent the activation of stereotypes[END_REF], whereas non words were pronounceable anagrams of the 12 meaningful words.

Procedure

As in the previous study, two experimental conditions were created. In the alone condition participants were tested alone whereas in the physical presence condition participants were tested in a small group in the presence of two or three other students.

Once participants arrived in the laboratory, they were welcomed and placed in front of a computer. As in the previous study, participants in the physical presence condition were placed in a way to maximize physical proximity and to avoid eye gaze. In both experimental conditions, the instructions for the task were provided on the computer screen and participants had some practice trials, in order to familiarize with the task, before starting with the experimental trials.

Each trial began with a 200 ms presentation of the prime picture that was followed, after a 100 ms of blank screen, by the target word. Participants were instructed to look carefully at the pictures since they would be later asked to perform a memory task, but no response was required at this stage. Indeed the primary task involved the target words. Participants were asked to perform a lexical decision task in which they had to judge as fast and accurately as possible whether the target word was a meaningful or non sense word by pressing one of the two labelled keys on the computer keyboard. Overall, participants went through a series of 144 trials, so that each prime face was presented three times. On half of the trials, the target was a meaningful word, whereas on the other half of the trials it was a non sense word. The pairings between a specific prime and a given target were randomly determined for each participant by the software. The presentation order of the trials was also randomized (ITI = 2 seconds).

Finally, participants were thanked and the debriefing was given collectively at the end of the data collection.

Results

Seven participants were excluded from the analyses either because of an excessive number of errors in the LDT (more than 20% of the trials) or because they did not properly follow the instructions. This left the data from two-hundred fifty-seven respondents available for the analyses.

Overall, the error rate in the responses to meaningful words was very low (2.68 % of the trials) and these trials were removed. Response latencies to correct trials were log-transformed.

Next, for each participant the mean response latencies to egalitarian and control words after Black and White faces were computed. These four indices were then submitted to a 2 (Words: Egalitarian vs. control) X 2 (Prime: Black vs. White) X 2 (Condition: alone vs. physical presence) X 2 (participant's gender) mixed-model analysis of variance, with the first two factors withinparticipants and the last two factors between participants. A significant main effect of the type of word emerged, F(1,253) = 12.09, p=.001, 2 = .046. Responses to egalitarian words were faster than responses to control words. No other main effect or two-way interaction was significant. As expected, however, a significant three-way interaction emerged, F(1,253) = 8.97, p=.003, 2 = .034. 4 In order to better understand the meaning of this interaction, two separate analyses of variance were carried out within the two experimental conditions. As for the alone condition, there was only a significant main effect of the type of word, F(1,65) = 3.97, p =.05, 2 = .058, indicating faster responses to egalitarian words. The interaction effect was not significant (p=.146), and, if anything, it suggested that egalitarian words were more easily processed after a White prime. In the group condition, in addition to the aforementioned main effect of the type of word, F(1,190) = 18.90, p<.001, 2 = .090, there was also a significant interaction effect, F(1,190) = 11.38, p=.001, 2 = .057. As can be seen in Figure 1, responses to egalitarian and control words were very similar after White primes. The planned comparison between the two means was not significant (p=.52). In contrast, following a Black face participants were faster in processing egalitarian words rather than control words (planned comparison, p<.001). Therefore, in the physical presence condition there was a selective increase in the accessibility of egalitarian words only after Black primes.

Additional 2 (Words: Egalitarian vs. control) X 2 (Condition: Alone vs. physical presence)

analyses of variance were performed separately on trials in which a White or Black face appeared as a prime. When a White face was primed, there was no interaction between the two factors (p= .128)

suggesting that the condition did not modify the accessibility of egalitarian words. In contrast, a significant interaction emerged after a Black face was primed, F(1,255) = 6.09, p=.014, 2 = .023, demonstrating again an increased accessibility of egalitarian words once in the presence of others.

General discussion

Results from Study 1 clearly demonstrate that in a social context spontaneous affective responses toward Blacks tend to be less negative. The actual presence of other individuals significantly modified spontaneous responses demonstrating that changes in the surrounding social environment were effective in producing a positive shift in automatic intergroup attitudes [START_REF] Blair | The malleability of automatic stereotypes and prejudice[END_REF][START_REF] Lowery | Social influence effect on automatic racial prejudice[END_REF]. Importantly, results from Study 2 do specifically indicate one plausible mechanism that may account for the observed changes. Indeed, participants in the social context activated different mental constructs as compared to participants who were tested alone. In the presence of other persons, egalitarian-related concepts were more easily accessed after the presentation of Black faces demonstrating that the group context triggered the goal of not being prejudiced and behaving fairly toward Blacks.

The presence of others as a cue for preconscious control. The proposed regulatory mechanism is assumed to operate outside of conscious awareness and would thus appear to be an instance of preconscious control [START_REF] Moskowitz | Preconscious control and compensatory cognition[END_REF]; see also [START_REF] Moskowitz | The implicit volition model: On preconscious regulation of temporarily adopted goals[END_REF]. In an interesting line of research, Moskowitz and colleagues have put forward the idea that individuals may differ in their ability to automatically suppress negative responses toward Blacks [START_REF] Moskowitz | Preconscious control of stereotype activation through chronic egalitarian goals[END_REF]2000). For instance, they demonstrated that individuals with a chronic egalitarian goal did not automatically activate stereotypes after being primed with the category "Blacks" whereas non-chronics did (Moskowitz et al., 1999, Study 3). Despite the fact that these two groups of respondents -chronics and non-chronics -had a similar knowledge about cultural stereotypes, they activated different mental contents (see also [START_REF] Lepore | Category and stereotype activation: Is prejudice inevitable[END_REF]. Indeed, chronic egalitarians were assumed to hold internalized egalitarian goals and, as a consequence, they developed efficient strategies that prevent stereotype activation even without conscious effort. On one hand, chronicegalitarians did not show any evidence of stereotype activation, but on the other they were also significantly faster in processing egalitarian-related words following pictures of African Americans (Moskowitz et al., 2000 study 2). According to Moskowitz's model, it is this automatic activation of egalitarian goals that inhibits the activation of prejudiced responses.

This point is crucial for the aims of the present paper because it implies that spontaneous prejudiced responses are not inevitable but that they can be avoided -or at least reduced-any time the individual is led to activate egalitarian goals. Moskowitz and colleagues (1999;2000) focused on dispositional and stable differences among individuals, but the same reasoning may also apply for situationally-activated goals (see [START_REF] Moskowitz | Preconscious effects of temporary goals on attention[END_REF]. In order to efficiently achieve preconscious forms of control, an adaptive cognitive system should be able to first automate the activation of specific goals in a given social context and then to provide those sets of responses that allow the achievement of the activated goal [START_REF] Bargh | Auto-motives: Preconscious determinants of social interaction[END_REF]. The results from the current studies demonstrate that situational cues, like the presence of other persons, may automatically trigger both egalitarian normative imperatives (Study 2), and spontaneous responses in line with this goal (Study 1).

Therefore, the goal of being fair toward Blacks does not need to be intentionally established, but it may also spontaneously arise from contextual cues by means of associative processes [START_REF] Aarts | The silence of the library: Environment, situational norm, and social behaviour[END_REF][START_REF] Kunda | When do stereotypes come to mind and when do they color judgment? A goal-based theoretical framework for stereotype activation and application[END_REF]. The physical presence of other individuals may by itself activate those social norms that are shared within the group and establish specific behavioural goals. These activated goals will then automatically guide regulatory processes aimed at attaining the goals which, in our case, may lead to a significant decrease in prejudice-consistent responses.

Do group contexts always ameliorate spontaneous responses toward Blacks?

The described processes are likely to hold true only in social contexts in which egalitarian norms are indeed shared within the group. In cases in which such norms are not widespread, the individual is not expected to build up any associative link between the public context and egalitarian responses. Only wellestablished situational norms can automatically influence social behaviours [START_REF] Aarts | The silence of the library: Environment, situational norm, and social behaviour[END_REF]. In addition, where social norms prescribe discrimination rather than condemning it, as in the case of neo-Nazi groups, group contexts may lead to increased prejudice in comparison to individual settings [START_REF] Crandall | Social norms and the expression and suppression of prejudice: The struggle for internalization[END_REF]. In other words, in social settings there might be a generalized spontaneous assimilation toward whatever norm is perceived as socially shared within the group (see also [START_REF] Sechrist | Perceived consensus influences intergroup behavior and stereotype accessibility[END_REF]. This conceptualization is largely different from the framework provided by the social facilitation literature (e.g., [START_REF] Zajonc | Social facilitation[END_REF]. Indeed, social facilitation effects are expected to be quite independent from the social membership of the audience and from normative concerns. In contrast, we expect that the presence of others individuals might have opposite effects depending of the specific characteristics of such individuals, so that prejudice responses could either decrease or increase as a function of the norms that are shared among the various individuals in that specific setting.

Importantly, the changes in the social milieu that have occurred in the last decades in relation to prejudice expression have modified what is perceived as the default social norm.

Currently, egalitarianism is becoming a core value of normatively prescribed social conduct and this represents the first building block for the implementation of preconscious forms of control over prejudiced responses. This reasoning strongly supports the importance of any intervention, cultural or legislative, aimed at sustaining the diffusion of egalitarian social norms. It is sometimes argued that social norms sanctioning discrimination and favouring political correctness have a limited influence because they only impact controlled responses and may even lead to rebound effects [START_REF] Macrae | Out of mind but back in sight: Stereotypes on the rebound[END_REF][START_REF] Plant | Responses to other-imposed pro-Black pressure: Acceptance or backlash[END_REF]. In contrast, we contend here that the diffusion of egalitarian social norms may represent the first step toward the development of automatized regulatory processes that, at least in group contexts, may reduce prejudiced responses without any need for conscious control. As stated by [START_REF] Allport | The nature of prejudice[END_REF], legal norms create a public conscience and behavioural models that may decrease blatant forms of discrimination, and next «when expression changes, thoughts too, in the long run, are likely to fall into line» (p. 437).

Conclusion

The present work took up recent appeals to devote more attention to interpersonal factors and social context effects when studying intergroup attitudes [START_REF] Devine | Stereotypes and prejudice: Their automatic and controlled components[END_REF][START_REF] Lambert | Stereotypes as dominant responses: On the "social facilitation" of prejudice in anticipated public context[END_REF][START_REF] Mcguire | The morphing of attitude-change into social-cognition research[END_REF]. Along this line, we found evidence that the mere presence of other people may modify spontaneous affective responses as well as the activation of egalitarian goals. This demonstrates the relevance of social settings in the modulation of individual cognitive processes. In particular we have shown that at the actual presence of others individuals tend to reduce their spontaneous negative responses toward Blacks.

  gender) X 2 (IAT version) analysis of variance with all factors between participants. A main effect of the version of the IAT was found, F(1,165) = 10.84, p=.001, 2 = .062, indicating that the IATscore was larger when participants performed the prejudice-consistent phase first. Most importantly, a significant main effect of the condition emerged, F(1,165) = 4.21, p=.042, 2 = .025. As expected, participants who performed the task alone showed significantly more negative responses toward Blacks (d= .46, SD = .064) as compared to participants in the physical presence condition (d= .29, SD = .056). Being in the presence of others significantly reduced the negativity of spontaneous responses toward Blacks. No other main or interaction effect was significant. In both conditions, participants showed a significant preference for Whites over Blacks, t(60) = 6.79, p<.001 and t(111) = 6.04, p<.001 in the alone and physical presence condition, respectively.Norm perception and spontaneous affective responsesWe first tested whether participants in the two experimental conditions had a different perception about the justifiability of discriminatory behaviours. Responses to the two items were moderately correlated, r(171) = .332, p<.001, and they were combined in order to create a single index of norm perception. A 2 (condition: individual vs. group) X 2 (participants' gender) analyses of variance, with both factors between participants, was carried out. The gender effect was statistically non-significant, p = .065, 2 as well as all other effects (all ps> .38), demonstrating that participants in the two conditions had a similar perception of the norm. In general, the mean value was quite low (M = 1.91, SD = .81) indicating that participants perceived discrimination as normatively inappropriate.Next, we separately correlated the index of norm perception and responses on the IAT within the two conditions. Results showed that within the individual condition the perception of social norms was not related to responses on the IAT, r(61) = .087, p=.506. In contrast, a significant correlation emerged in the physical presence condition, r(119) = .295, p=.002, demonstrating that, in a social context, the more participants perceived discrimination as inappropriate, the less they had spontaneous negative responses toward Blacks 3 . Discussion Results clearly show that spontaneous affective responses toward Blacks were less negative in the social setting in comparison to the individual setting. The physical presence of other persons significantly reduced the automatic preference for Whites over Blacks. More specifically, in the presence of others, spontaneous affective responses were more in line with perceived social norms. Indeed, norm perception was not related to responses on the IAT in the individual condition, whereas a significant relation was observed in the physical presence condition. This finding suggests that in the presence of others spontaneous responses were more in line with perceived normative values.

Figure 1 .

 1 Figure 1. Untransformed response latencies in the individual and physical presence condition

Footnotes 1 It should be recalled that in the context where data were collected Black individuals are mainly immigrants from Central Africa.

2 The analysis of the means indicated that indicated that male respondents were slightly more prone to justify discriminatory behaviours in comparison to female respondents, M = 2.09, SD = .93 and M = 1.86, SD = .73, respectively 3 We also compared the two correlation coefficients but they were not significantly different from each other, Z = 1.35, p = .08, one-tailed. It has to be noted, however, that results were far clearer when computing the correlation between norm perception and an IAT score computed in accordance with [START_REF] Greenwald | Measuring individual differences in implicit cognition: The Implicit Association Test[END_REF]. The observed correlation in the individual condition was equal to zero, r(61) = .035, p = .79, whereas it was significant in the physical presence condition, r(61) = .331, p < .001, and the two coefficients were also significantly different from each other. Z = 1.94, p = .05, two-tailed. 4 A similar analysis was performed introducing the mean latency in responding to non-words as a covariate. Even after controlling for individual differences in response speed, results were identical to those reported in the text.


Michel Chambon

Sylvie Droit-Volet

Paula M Niedenthal

Embodying Effects 1 Running head : EMBODYING EFFECTS ON TIME PERCEPTION The Effect of Embodying the Elderly on Time Perception

Keywords: Time perception, Embodiment, Elderly stereotype

The present study investigated the perception of stimulus durations represented by elderly faces or by young faces. In a temporal bisection task, participants classified intermediate durations as more similar to a short or a long reference duration. The results showed that the durations represented by elderly faces were less often classified as "long" than the durations represented by young faces. According to internal clock models of time perception, this shortening effect is due to a slowing down of the speed of the internal clock during the perception of elderly faces. Analyses also revealed an interaction between sex of face and sex of participant such that this shortening effect occurred only when the participants share the same sex than the stimulus faces. As discussed, this finding is quite consistent with embodied cognition approaches to information processing, but alternatives accounts are also considered.

A C C E P T E D

M A N U S C R I P T

Embodying Effects 3

When individuals judge the passage of time, their judgments can be biased in a number of ways. For example, the presentation of a face on a computer screen is perceived to last longer when the face expresses anger than when it expresses a neutral emotion [START_REF] Droit-Volet | Perception of the duration of emotional events[END_REF]Gil, Niedenthal, & Droit-Volet, in press). This extending effect has been interpreted in the theoretical framework of internal clock models [START_REF] Gibbon | Scalar expectancy theory and Weber's law in animal timing[END_REF][START_REF] Gibbon | Scalar timing in memory[END_REF]. Specifically, the perception of anger increases arousal and this in turn increases the number of pulses emitted by the internal clock. Given that the pulses compose the raw material for time perception, an increase in the number of pulses yields to an increase in the perceived duration of the angry face. Recently, [START_REF] Effron | Embodied temporal perception of emotion[END_REF] further demonstrated that for the perception of an emotional expression to influence temporal perception at all, imitation of the expression must occur. In their study, participants in whom imitation of the expressions was prevented were not influenced in their temporal judgment by the facial expressions of anger or happiness presented on a computer screen. Such an effect was interpreted in terms of embodiment theories of cognition. These theories hold that the encoding of incoming emotional information involves an internal simulation of the perceived entity (e.g., imitation of a facial expression), with all of its physiological implications, such as a matching of emotional state (e.g., [START_REF] Adolphs | Neural systems for recognizing emotion[END_REF][START_REF] Niedenthal | Embodiment in attitudes, social perception, and emotion[END_REF]. Thus participants in the study by Effron and colleagues who could imitate the facial expression, but not those who were prevented from imitating the expressions, experienced changes in arousal that affected their temporal perception.

Embodied cognition accounts are general models of information processing, and the simulation of "being there" with perceived entities is assumed to occur quite broadly and to include systems that underlie perception in all of the sense modalities, as well as the motor

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systems that support responding and introspective systems that support conscious experience [START_REF] Barsalou | Perceptual symbol systems[END_REF][START_REF] Barsalou | Abstraction in perceptual symbol systems[END_REF][START_REF] Barsalou | Situating abstract concepts[END_REF][START_REF] Blakemore | From the perception of action to the understanding of intention[END_REF][START_REF] Gallese | The roots of empathy: The shared manifold hypothesis and the neural basis of intersubjectivity[END_REF]. The present research was designed to test the prediction that durations represented by exemplars from the category of elderly people are perceived shorter than durations represented by exemplars from the category of young people. This effect should occur if perceivers produce internal simulations of the (slow) motor behavior of the elderly, as suggested in recent work by Bargh and colleagues for other types of behavior (e.g., [START_REF] Bargh | Automaticity of social behavior: Direct effects of trait construct and stereotype activation on action[END_REF], because one effect of such an embodiment is a decrease in arousal.

Embodying Temporal Perception

Temporal processing is assumed to rely on a central mechanism -usually referred as the internal clock -that produces pulses with a given rate thereby providing a temporal basis both for motor sequences (e.g., finger tapping, walking) and for temporal judgments [START_REF] Ivry | Perception and production of temporal intervals across a range of durations: Evidence for a common timing mechanism[END_REF][START_REF] Keele | Do perception and motor production share common timing mechanisms: A correlational analysis[END_REF][START_REF] Treisman | Temporal discrimination and the indifference interval: Implications for a model of the "internal clock[END_REF]. According to the internal-clock model of time processing [START_REF] Gibbon | Scalar expectancy theory and Weber's law in animal timing[END_REF][START_REF] Gibbon | Scalar timing in memory[END_REF], the raw material for subjective time comes from the number of pulses emitted by a pacemaker and accumulated in a timer during the event to be judged. Subjective time thus depends on the number of pulses accumulated during the duration to be judged: The more pulses accumulated, the longer the duration is judged to be (for a review, see [START_REF] Meck | Functional and neural mechanisms of interval timing[END_REF]. In studies of temporal perception, there is now ample evidence that subjective time varies as a function of the speeding up or the slowing down of the pacemaker in certain circumstances, when, for example the participants are under stress [START_REF] Meck | Selective adjustement of the speed of the clock and memory processes[END_REF], receive arousal drugs such as methamphetamine [START_REF] Drew | Effects of dopamine antagonists on the timing of two intervals[END_REF]Maricq, Roberts & Church, 1981;[START_REF] Rammsayer | Are there dissociable roles of the mesostriatal and mesolimbocortical dopamine systems on temporal information processing in humans ?[END_REF][START_REF] Rammsayer | Neuropharmacological evidence for different timing mechanisms in humans[END_REF], or are exposed to rhythmical stimuli [START_REF] Droit-Volet | Speeding up an internal clock in children? Effects of visual flicker on subjective duration[END_REF][START_REF] Penton-Voak | Speeding up an internal clock in human? Effects of click trains on subjective duration[END_REF]. As noted, the

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pacemaker is also accelerated during the perception of highly arousing emotional expressions [START_REF] Angrelli | The influence of affective factors in time perception[END_REF][START_REF] Chambon | Social psychology and time perception: The temporal estimation of social and emotional stimuli[END_REF][START_REF] Droit-Volet | Perception of the duration of emotional events[END_REF].

When combined with predictions from embodied cognition models, temporal processing models predict that representing duration with exemplars of the category "elderly people" will bias judgments of duration. In particular, if perceivers reproduce the sensorymotor states of "being there" with elderly people, arousal should decrease [START_REF] Jennings | Cardiac timing and the central regulation of action[END_REF]. This should slow the speed of the pacemaker, fewer pulses should accumulate, and time should appear shorter rather than longer.

Constraints on Embodiment

An embodiment account would also make another prediction. Studies of the imitation and internal simulation of others' gestures and expressions have demonstrated that the behavior of all perceived individuals is not inevitably and automatically reproduced. For example, individuals are more likely to imitate behaviors of in-group members, suggesting that people tend to imitate the gestures of people with whom they are identified or wish to empathize (e.g., [START_REF] Elfenbein | Is ther an in-group advantage in emotion recognition[END_REF][START_REF] Lafrance | Posture mirroring and interactional involvment: Sex and sex typing effects[END_REF]Mondillon, Niedenthal, Gil, & Droit-Volet, in press;Zajonc, Adelmann, Murphy, & Niedenthal, 1987).

The implication of these past demonstrations is that processes of identification and motivation to empathize impose limits on the extent to which the behaviors of other people are embodied (Decety & Jackson, 2004;Jackson & Decety, 2004). Futhermore, as noted by [START_REF] Blakemore | From the perception of action to the understanding of intention[END_REF], the perception and simulation of human movement is influenced by a perceiver's knowledge of and experience with his or her own movement constraints [START_REF] Viviani | Motor competence in the perception of dynamic events: a tutorial[END_REF]. This reasoning suggests a refinement of the present prediction regarding the perception of duration represented by the elderly. Specifically, a same-sex effect could be expected to

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occur because the participants may not be sufficiently identified with the elderly of the opposite sex to internally simulate their motor behavior.

Present Experiment

In the present experiment we employed the temporal bisection task, a frequently used task developed to test the predictions of the clock-based models (e.g., [START_REF] Allan | Human bisection at the geometric mean[END_REF][START_REF] Droit-Volet | Sensory modality effect and time perception in children and adults[END_REF][START_REF] Wearden | Human performance on an analogue of an interval bisection task[END_REF]. In the bisection task, participants are women and men being equally represented in the two age categories. The faces had been selected from a larger set of 58 faces on the basis of a pretest. Eighteen additional undergraduates (9 female, 9 male) participated in the pretest and rated each face on perceived age and emotional expression (anger, sadness, and happiness). Faces perceived to express a marked emotional expression were not selected for use in the main experiment. The mean perceived age was 23.2 years (SD = 1.1) for the resulting young faces sample, and 72.3 years (SD = 5.1) for the elderly one. For the two samples, the mean perceived age of women and men faces sub-samples did not differ significantly (ps > .10).

The faces in the elderly sample were perceived as significantly more sad and more happy than the faces in the young one, t(22) = 2.96 and 2.22, respectively, ps < .01. Because, as noted, the duration (from 400 to 1600 ms) of the presentation duration of faces with an emotional expression (angry, happy, and sad faces) are typically perceived longer than the presentation duration of neutral ones [START_REF] Droit-Volet | Perception of the duration of emotional events[END_REF][START_REF] Effron | Embodied temporal perception of emotion[END_REF], the presence of slight emotional expression should serve to work against the current hypothesis.

Procedure. The standard durations used in the bisection task was 400 ms for the short standard and 1600 ms for the long standard, and the comparison durations 400, 600, 800, 1000, 1200, 1400 and 1600 ms. In the training phase, participants were shown the short and the long standard stimulus durations, presented in the form of a neutral stimulus (a pink oval).

Each standard was presented five times in a random order. Next, they completed eight trials with the neutral stimulus in order to learn to press one key after the short and the other key after the long standard. The key-response match was counterbalanced across participants.

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In the testing phase, the participants were presented with the young and elderly faces that now represented the seven comparison durations. Their task was to judge whether the duration of each presented face was closer to the short or to the long standard duration. There were six blocks of 28 trials, 14 for the faces of elderly people (7 women and 7 men) and 14

for the faces of young people (7 women and 7 men), 7 for the 7 comparison durations. There was thus a total of 168 trials. The face was randomly chosen on each trial from the panel of different faces. The trials were presented in a random order within each bock, and the intertrial interval randomly chosen between 1 and 3 s.

Results

Figure 1 shows the mean proportion of "long" responses plotted against the comparison durations for the elderly and young women's faces as well as for the elderly and young men's faces in the two groups of participants, i.e., male (top panel) and female participants (bottom panel). Inspection of Figure 1 shows that the psychophysical functions for the elderly faces were shifted to the right compared to those for the young faces. Due to a lesser proportion of "long" responses, this rightward shift indicates that the presentation durations of elderly faces were perceived as shorter than those of young faces. However, as expected, the rightward shift of the psychophysical functions is mainly observed when the sex face and the sex participant are the same.

To explore the magnitude of the differences in temporal perception between the elderly and the young faces, the proportions of "long" responses for each participant were transformed to z-scores. Then, an index of difference (d') was calculated by substracting the z-score for the young faces from the z-score for the elderly faces [START_REF] Macmillan | Detection Theory: A user's guide[END_REF]. For the seven stimulus durations and two sexes (men's and women's faces) this yielded 14 d' scores for each participant. These d' values are positive if the temporal stimulus was judged to match the longer standard more often when elderly faces were seen compared In a second analysis, we conducted an overall analysis of variance (ANOVA) on the d' scores with one between-subjects factor (participant sex) and two within-subject factors (comparison duration, and sex of face). The ANOVA revealed a significant interaction between participant sex and face sex, F(1, 32) = 59.47, p < .01. Consistent with the findings reported above, relative to the young faces, the durations of elderly faces were perceived as shorter by females when duration was represented by women's faces t(32) = 3.20, p < .01, and inversely, by males when duration was represented by men's faces, t(32) = 5.54, p < .01.

Furthermore, in each group of participants, the difference in temporal judgment of the faces of the different sexes reached significance both for the female participants, t(15) = 4.80, p < .01, and for the male participants, t(17) = 6.29, p < .01.

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The ANOVA also revealed a significant effect of stimulus duration, F(6, 192) = 3.24, p < .01, as well as a three-way interaction between stimulus duration, sex of face and sex of participant, F(6, 192) = 3.06, p < .01. Analysis of the d' scores in each condition taken separately showed no effect of stimulus duration when opposite sex faces were compared to the standard durations. However, and consistent with the arousal hypothesis, the effect of stimulus duration reached significance both when females judged duration represented by women's faces, F(6, 90) = 2.79, p < .05, and when males judged duration represented by men's faces, F(6, 102) = 5.14, p < .01. The interpretation of the changes in perceived duration as due to changes in arousal is supported by this interaction because effects of arousal increase at longer durations (for a discussion, see [START_REF] Burle | Dissociation between activation and attention effects in time estimation: Implication for internal clock models[END_REF]. These findings provide further evidence that a decrease in arousal is responsible for the biased temporal perception observed here.

Discussion

The present experiment showed that female participants classified stimulus durations as "long" less often when the durations were represented by an elderly woman's face than by a young woman's face. This effect was not observed when durations were represented by men's faces. In addition, male participants classified stimulus durations as "long" less often when the durations were represented by an elderly man's face than by a young man's face. This effect was not observed when durations were represented by women's faces. According to internal-clock models of time processing, and specifics of our pattern of results, this effect suggests a decrease in arousal when faces of same sex elderly people are perceived. The present interpretation holds social perception involves embodiment of the perceived persons (particularly when the perceiver is motivated to do so; e.g., Mondillon et al., in press). This embodiment reoccurs on perception of a member of the category. In the case of "elderly people," because elderly individuals tend to produce slower motor movements, one aspect of

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embodying the elderly is a decrease in arousal. A decrease in arousal is known to introduce a bias in temporal perception, and that is just the effect observed here. The bias itself could be seen as counter-intuitive because if elderly people are typically slow, one might expect that the duration of an image of an elderly face on a computer screen would be perceived by young adults as longer than it is. That is, the slowness of crossing the street or performing any motor behavior might be metaphorically transferred to (longer) duration.

The advantage of the present method is that it allows us to test an embodiment hypothesis in a task that is sensitive to automatic changes in arousal as a function of embodiment, but that is not likely to be influenced by conscious considerations or selfpresentation concerns. In addition, since thoughts about the elderly are sometimes associated with feelings of sadness, or are considered as threatening reminders of our own inevitable mortality which, in turn, may induce feelings of intense anxiety [START_REF] Martens | A terror management perspective on ageism[END_REF], influences of the concept of the elderly on temporal perception could be mediated by changes in emotional state. Little is known about the effect of anxiety on the judgment of a stimulus duration, but other findings suggest that death anxiety does not impact on time perception [START_REF] Joubert | Subjective acceleration of time: Death anxiety and sex differences[END_REF]. Moreover, Droit-Volet and colleagues (2004) showed that the duration of sad faces was perceived as slightly longer than the duration of neutral faces.

For these reasons, we believe that the present finding is not due to emotional processes. In fact, the obtained effect appeared strong enough to overcome the opposing influences of possible feelings of sadness.

An important consideration is the relationship between the present findings and other demonstrations held to be effects of the activation of the elderly stereotype on behavior. As cited in the introduction, related research has demonstrated that the presentation of elderlystereotypic traits elderly causes individuals to automatically produce stereotype-consistent behavior (e.g., reduced motor speed). Bargh and colleagues (1996), for example, showed that

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Embodying Effects 12 university students primed with the elderly category walked more slowly when leaving the laboratory than non primed students. The interpretation of the behavioral effects of category activation on motor behavior developed by Bargh and his colleagues relies both on semantic network models of memory and on the principles of ideomotor action offered by James (1890). Thus, these automatic behavior effects have largely been interpreted as indicating that the priming task activated the stereotypical traits of the category (e.g., slow) which, in turn, activated behavioral representations associated with each trait (e.g., walking slowly) and thereby increased the tendency to perform these behaviors (see also [START_REF] Dijksterhuis | The perception-behavior expressway: Automatic effects of social perception on social behavior[END_REF][START_REF] Kawakami | Automatic stereotyping: Category, trait and behavioral activations[END_REF].

The embodied cognition account of the present findings can also be used to interpret these previous findings. The difference is not in the precise predictions so much as in the assumptions about the underlying process. Most semantic models assume that traits and stereotypes are represented by amodal symbols that are not linked to the perceptual (input) or motor (output) systems [START_REF] Niedenthal | Embodiment in attitudes, social perception, and emotion[END_REF]. They further assume that these abstract symbols are the core of the traits and stereotypes, and that embodiment is a consequence of the activation of the core construct. In an embodiment account, the core knowledge or the content of the stereotype is the multimodal simulation itself. As the core knowledge, the simulation is what is activated upon presentation of word (e.g., stereotypic traits) or images (e.g., pictures of faces) that are used as primes to the stereotype knowledge. As [START_REF] Barsalou | Social embodiment[END_REF] have written, "Consider the trait of slow movement in the elderly stereotype. On the embodied view, slow movement is not represented by an amodal redescription which in turn implements associated movements in the motor system.

Instead, knowledge of slow movement resides in simulations of seeing and executing slow movement [of elderly people]…" (p. 73).

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In fact, it is unclear exactly how the traits contained in an amodal representation of the elderly would affect temporal perception upon its activation by the presentation of images of elderly people. As we suggested earlier, one possibility is that the stereotypic trait "slow" would function as a framework guiding that colors the interpretation of the stimulus to be estimated [START_REF] Higgins | Knowledge activation: Accessibility, applicability, and salience[END_REF]. This influence on information processing during time estimation could result in a judgmental assimilation, time being judged as slower when represented by exemplars of the elderly category. Thus, the slow movement part of the elderly stereotype would be used to judge a duration as long just because the elderly are slow (i.e., take a long time). Yet we found a quite different pattern of results: an opposite effect when durations were represented by same-sex elderly faces and no effect in the case of opposite-sex elderly faces. We do not interpret this as a contrast effect. Contrast effects have been found to be elicited by extreme and well-known primed exemplars (e.g., Dijsksterhuis, Spears, Postmes, Stapel, Koomen, van Knippenberg, & Scheepers, 1998), characteristics the exemplars used in the present experiment did not possess.

Another possibility is that there is a stereotypic belief that the elderly perceive time with a particular bias and that this bias is used in estimating durations that are represented by faces of the elderly. We are not aware that the elderly are held to perceive time in a particular way and research on the content of elderly stereotype does not mention any characteristic related to time perception [START_REF] Hummert | Stereotypes of the elderly held by young, middle-aged, and elderly adults[END_REF][START_REF] Schmidt | Structure of perceptions of older adults: Evidence for multiple stereotypes[END_REF].

Additionally, research on aging has shown that the elderly do not show biases relative to younger individuals in their performance on the bisection task, even if the elderly are more variable in their responses [START_REF] Mccormack | Developmental changes in time estimation: Comparing childhood and old age[END_REF]Wearden, Wearden, & Rabbitt, 1997).

Therefore, in our view, the observed effect of the elderly on temporal perception as well as the other demonstrations of the influence of words and pictures representing the elderly on

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motor behavior may all be demonstrations of a single underlying process. In each case, the incoming prime selects a specific embodied simulation that is used as the means of encoding the information. The embodied simulation has the effect of temporarily influencing cognition, such as temporal perception, and behavior such as walking. The embodiment account also has the advantage of developing the ability to predict limitations of embodiment in information processing. Both motivational and task concerns will predict whether incoming information is embodied or not (e.g., [START_REF] Mondillon | Embodiment of emotion concepts: Evidence from EMG measures[END_REF][START_REF] Solomon | Perceptual simulation in property verification[END_REF]). In the present case we expected and observed that younger women would be more likely to embody a same-sex older person than an opposite-sex older person for both reasons of increased motivation and identification with the former. We did not predict that we would also observe any change in the perceived duration of same-sex younger faces because those younger faces were the same age as the participants.

Embodying the younger person would thus yield the same state as their resting state, not an increase in arousal. On the other hand, one might predict an increase in arousal and the attendant increase in the perceived duration if the stimulus faces of young individuals were those of children rather than young adults. This prediction would make sense if it were independently shown that children typically produce speedier behaviors than young adults.

This point raises a limitation of the present study, namely the absence of neutral stimuli providing baseline data against which elderly faces and young faces effects could be respectively compared. Such a condition would have been useful, but we still feel confident interpreting our results to mean that embodying the same-sex elderly individuals decreased arousal rather than that embodying all of the other types of individuals increased arousal. It would indeed be difficult to explain why elderly faces of opposite sex prompted the same level of arousal as young faces of both sexes. In future studies an associated direct measure of In conclusion, the present findings add to the growing body of evidence that knowledge is constituted by the reenactment of the bodily states that are activated in interaction with entities in the world. Knowledge so define can be predicted to have fascinating and unexpected effects on basic processes of perception, such as the perception of time, especially in the context of social interaction.

  presented with two standard durations, one short and one long, in an initial training phase. In a test phase, they are presented with comparison stimulus durations (i.e., intermediate duration values and standard values). The task is to classify each comparison duration as more similar to either the short or to the long standard duration. In the present version of the task the comparison stimulus durations in the test phase were represented by pictures of faces of elderly and younger males and females (expressing neutral emotion). If individuals simulate the motor behavior of the elderly when exposed to exemplars of the category, this should have the effect of slowing down the pacemaker rate and, subsequently lead them to less often classify the comparison duration as similar to the long standard duration than when exposed to young faces. This should largely be true for same-sex faces, with which the perceivers are likely to be more identified. Method Participants. Sixty-six first-year undergraduates (33 females) from Blaise Pascal University participated in the experiment. Apparatus. The participants were tested individually in a quiet laboratory room. The procedure was controlled by a computer program supported by PsyScope software (Cohen, MacWhinney, Flatt, & Provost, 1993), which presented the stimuli and recorded the participants' responses. Participants made their responses by pressing the "d" and "k" keys on A C C E P T E D M A N U S C R I P T the computer keyboard. The stimuli to be timed were presented in the center of the computer screen. Pink ovals were used to represent standard durations in the training phase, and photos of the faces of women or men, with a neutral facial expression, in the testing phase. The stimulus set consisted of 24 photographs of faces 1 (12 elderly and 12 young people) with

  . Positive d' values thus indicate that stimulus duration was perceived as longer when represented by elderly faces than by young faces. Conversely, d' values are negative if the temporal stimulus was judged to match the longer standard less often when elderly faces were seen compared to young faces. Negative d' values thus indicate that stimulus durationwas perceived as shorter when represented by elderly faces than by young faces. Figure2shows the d' for each stimulus duration and sex of face for the male and female participants separately. Inspection of Figure2provides support for our prediction that the relative shortening of perceived durations represented by elderly faces would occur only for same-sex faces. For each sex of face, we averaged the d' scores across duration, and tested whether this average d' was greater than 0. This was the case when females compared the duration of women's faces to the standard durations (M = -0.23), t(15) = -4.41, p < .01, and when males compared the duration of men's faces, (M = -0.28), t(17) = -6.61, p < .01, but not for opposite-sex judgments, i.e., when females judged men's faces (M = 0.03), t(15) = 0.94, p = .36, and when males judged women's faces (M = -0.02), t(17) = -0.59, p = .57.

  would serve also to provide further evidence of the role of arousal in the obtained effects.

Figure 1 .

 1 Figure Captions

Figure 2 .

 2 Figure 2. Values for d' as a function of the gender of face (WF: women's faces; MF: men's faces) and the gender of participant. Higher values reflect a greater tendency to match the stimulus to the long standard for older faces than for young faces.

Carnot, 63000 Clermont-Ferrand, France. E-mail: michel.chambon@univ-bpclermont.fr, sylvie.droit@univ-bpclermont.fr, or paula.niedenthal@univ-bpclermont.fr.

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