On Being Rejected. A Meta-Analysis of Experimental Research on Rejection. Jonathan Gerber and Ladd Wheeler

Transcription

1 PERSPECTIVES ON PSYCHOLOGICAL SCIENCE O Beig Rejected A Meta-Aalysis of Experimetal Research o Rejectio Joatha Gerber ad Ladd Wheeler Macquarie Uiversity, Sydey, New South Wales, Australia ABSTRACT This article presets the first meta-aalysis of experimetal research o rejectio, samplig 88 studies. The results are cosistet with a eeds accout, which states that rejectio frustrates basic psychological eeds, but ot with a umbess accout, which states that rejectio causes physical ad emotioal umbess. Rejectio moderately lowers mood (d ) ad self-esteem (d ), but does ot decrease arousal or flatte affect. Both belogig (d ) ad cotrol (d ) are frustrated by rejectio. Aggressive resposes to rejectio, cosidered paradoxical by some, appear to be due to attempts to gai cotrol; measures that cotrast belogig ad cotrol (d ) cause atisocial respodig, whereas measures that do ot allow for cotrol to be restored cause prosocial respodig (d ). These fidigs suggest that rejectio makes idividuals feel bad ready to act to restore cotrol or belogig ad that they will prioritize restorig cotrol eve if it requires beig atisocial. Rejectio is a acute social experiece. The last 10 years have see the rise of experimetal social psychological approaches to uderstad the experiece of rejectio, ad these studies have revealed may effects. For example, research has show that rejectio ca decrease performace o itelligece tests (Baumeister, Twege, & Nuss, 2002), icrease ocoscious mimicry (Laki & Chartrad, 2005), icrease cosumptio of chocolate chip cookies (Baumeister, DeWall, Ciarocco, & Twege, 2005), lead to harder work o collective creativity tasks (Williams, 2001), ad icrease aggressio (Twege, Baumeister, Tice, & Stucke, 2001). These resposes are ot easily recocilable. For example, both ehaced performace (e.g., better performace o collective creativity tasks) ad impaired performace (e.g., poorer performace o itelligece tests) follow from rejectio. Agai, some resposes seem prosocial (e.g., ocoscious mimicry icreases, which ca lead to likig), Address correspodece to Joatha Gerber, Departmet of Psychology, Macquarie Uiversity, Sydey, New South Wales, 2109 Australia; jgerber@psy.mq.edu.au. whereas others are atisocial (e.g., aggressively blastig oise at iocet victims). Nor do theoretical accouts agree o the reasos for the various empirical effects. Some researchers believe that rejectio causes activatio of the pai system, as evideced by the coceptual overlap of physical pai ad social pai laguage (MacDoald & Leary, 2005) ad the activatio of physical pai systems durig ostracism (Eiseberger, Lieberma, & Williams, 2003). De Wall ad Baumeister (2006), o the other had, argue that rejectio causes umbess, as ca be see i icreased pai thresholds ad pai tolerace followig rejectio. These views do ot seem to be compatible. This article aims to resolve both the basic effects of rejectio ad also to critically assess theoretical accouts of rejectio s effects via meta-aalysis. This meta-aalysis examied three broad issues cocerig rejectio: (a) the effects of rejectio o iteral states such as mood ad self-esteem, (b) the behavioral effects of rejectio (with a particular focus o resolvig pro- ad atisocial resposes to rejectio), ad (c) procedural issues such as scale choice ad differeces betwee laboratories. INTERNAL STATES FOLLOWING REJECTION The first basic questio about rejectio is this: How does rejectio make people feel? To aswer this, we examied three iteral states followig rejectio; mood, arousal, ad selfesteem. Mood There is o cosesus o whether rejectio affects mood. I geeral, researchers believe that mood is uimportat, ad they have bee drive to this coclusio by two fidigs. The first is the repeated failure to fid mood differeces i idividual studies, eve though behavioral effects are cosistetly foud (e.g., DeWall & Baumeister, 2006). Others have foud mood differeces (Zadro, Williams, & Richardso, 2004), but they ote that differeces i mood do ot mediate rejectio s effects. Behavior after rejectio is ot determied by the of the emotioal reactio. 468 Copyright r 2009 Associatio for Psychological Sciece Volume 4 Number 5

2 Joatha Gerber ad Ladd Wheeler The umbess hypothesis (Baumeister, 2005; DeWall & Baumeister, 2006) argues that people have dampeed emotios followig rejectio: They feel either good or bad, they just feel othig. Numbess is thought to cause lack of empathy, icreased pai tolerace, ad tuig toward emotioal positivity as a meas of reducig umbess (Baumeister, Brewer, Tice, & Twege, 2007). Evidece for this comes from dampeed predictios of emotioal reactios to future evets. For example, whe asked how they would feel if their football team wo a game i the future, rejected people report both lower positive affect ad less egative affect, showig that both types of emotio are flatteed (DeWall & Baumeister, 2006). However, this mood flatteig has oly bee foud o measures of future emotio; it has ot bee foud o measures of curret mood, with the exceptio of oe study fidig mood flatteig o a implicit measure (Twege, Cataese, & Baumeister, 2003). The umbess hypothesis predicts that, across all rejectio studies, there will be o mood effect o explicit measures of curret mood. Furthermore, i studies that have separate measures of positive ad egative mood, mood will be flatteed o both. The lack of mood effects followig rejectio is troublig, as most models of motivatio ad behavior stress the importace of emotio i behavior (e.g., Carver & Scheier, 1990; Murray, 1938). I these models, mood chages are sigals that somethig eeds to be atteded to ad that actio may be required. Therefore, mood effects followig rejectio would support motivatioal, or eeds, accouts of rejectio. 1 Oe factor that may cause differeces i mood effects is the type of mood scale used. Some studies may fid o mood differeces due to the use of differet scales (Leary, persoal commuicatio, February 4, 2007). A meta-aalysis of mood effects followig rejectio aswers both basic questios of how rejectio feels ad also tests whether motivatioal or umbess accouts better explai actios followig rejectio. I summary, the mood questios ivestigated i this study were: 1. Does rejectio cause chages i mood, as predicted by motivatioal theories? 2. Does rejectio cause flatteig of affect as predicted by the umbess hypothesis? 3. Does the magitude of the mood effect differ by scale or by the researcher? Arousal Arousal is commoly paired with mood as a measure of affective toe ad predictor of behavior. If people are aroused, they will be eergized for actio. As such, arousal is a secod idicator of how people feel after rejectio. The umbess accout of rejectio (DeWall & Baumeister, 2006) asserts that arousal is decreased by rejectio. I their 1 Mood s presece as a sigal i the motivatioal model eed ot imply that mood mediates the effects of rejectio. Mood ca merely oriet a idividual toward a evirometal threat without determiig the stregth of behavior. experimets, DeWall ad Baumeister foud some idicatios that people respod to rejectio with decreased arousal. For example, rejected people ca be piched with calipers for loger ad with greater itesity. Researchers argue that this is due to decreased arousal i the cetral ervous system. However, the measures of arousal used by DeWall ad Baumeister are cofouded with cotrol. For example, toleratig more pai for loger could idicate lower arousal, but it may also be a way for rejected people to demostrate their stregth ad power (cf. Litt, 1988). This potetial cofoudig of arousal ad motivatioal effects leaves the umbess hypothesis uestablished. I this meta-aalysis, we used ucofouded measures of arousal either physiological measures such as blood pressure or selfreport scales to aswer these questios: 4. Does rejectio cause chages i arousal? I particular, is there a decrease i arousal as predicted from the umbess hypothesis? Self-Esteem Self-esteem is the third basic idicator of how rejectio feels. Self-esteem is a global positive or egative self-evaluatio (Roseberg, 1965) ad idicates whether rejectio makes people feel good or bad about themselves. Self-esteem is a importat marker as it has strog liks to motivatio. Self-esteem is ot a basic eed, as directly pursuig self-esteem is ot beeficial (Crocker & Park, 2004). However, there is evidece that self-esteem may be a idicator of at least three basic eeds. The sociometer hypothesis (Leary, Tambor, Terdal, & Dows, 1995) argues that self-esteem drops sigal a threat to the feelig of belogig. As belogig status icreases ad decreases, so does self-esteem. However, belogig is ot the sole eed that covaries with selfesteem. Cotrol (Judge, Erez, Boo, & Thorese, 2002; Leary, Cottrell, & Phillips, 2001) ad meaigful existece (Greeberg, Solomo, & Pyszczyski, 1997) have also bee show to covary with self-esteem. Give self-esteem covariatio with these three eeds, self-esteem might more geerally idicate a threat to eeds. As such, evidece of drops i self-esteem followig rejectio are importat, as they would suggest that eed states have bee activated by rejectio, with the type of eed activated beig defied by the actios people take followig rejectio. I summary, our questio regardig self-esteem is this: 5. Is self-esteem impaired by rejectio as eeds accouts would suggest? Needs: Belogig, Cotrol, ad Meaigful Existece Needs are hypothetical costructs that help us to classify actios (Murray, 1938). Needs accouts of rejectio argue that rejectio frustrates basic huma eeds, leadig to attempts to satisfy them. These attempts could be actios to satiate the eed, Volume 4 Number 5 469

3 Rejectio Meta-Aalysis chages i cogitio that satisfy the eed (e.g., fatasizig), or other chages that suggest preparedess for eeds satisfactio (e.g., salivatig whe you re hugry; Murray, 1938). May rejectio researchers believe that rejectio affects people s eed states, but the umber ad relative importace of each eed remais disputed. Some theorists, spurred particularly by the ifluetial Baumeister ad Leary (1995) paper o the eed to belog, coted that rejectio primarily or exclusively affects oly oe eed, belogig, ad that ay other eeds are trivial i compariso (e.g., Leary, 2005). Other theorists (Williams, 2001) suggest that oe form of rejectio, ostracism, affects four eeds: belogig, self-esteem, cotrol, ad meaigful existece. Self-esteem, as argued earlier, is a marker for other eeds that may be affected by rejectio, which leaves two eeds to add to the belogig accout: cotrol ad meaigful existece. Threats to cotrol, i particular, may be importat followig rejectio, as the defiitio of feelig rejected teds to etail the idea that a idividual did ot desire the rejectio (e.g., Leary, 2005). It would seem that rejectio is forced o people agaist their will, givig a cetral role to cotrol that has largely bee uderappreciated. Meaigful existece is the eed to believe that oe s life has purpose ad value ad that oe is havig a meaigful iteractio with the world. Meaigful existece may be most strogly affected by oe variety of rejectio ostracism as ostracism may make people feel like they do ot exist (Williams, 2001). There could be other actios ad eeds affected by rejectio but the studies to date have effects that largely deal with belogig, cotrol, ad meaigful existece. Ay exceptios (e.g., attributios) were ot motivatioal i ature, appeared less tha five times i curret research, ad were ot icluded here. The assessmet of eeds is best accomplished by showig chages i behavior, but rejectio research frequetly uses selfreports of eed states. The items i these scales are typically ot about iteded actios directly idicative of eeds (e.g., I wat to throw a rock) but about iteral states (e.g., I felt I had o cotrol) or observatios of the past situatio (e.g., I felt like I could ot cotrol the directio of the game). This ca be a problem if the self-report measures are the oly type of measure showig the eed effect or if self-report measures show cosiderably larger effects tha behavior because there is the possibility that self-report scales overestimate the magitude of rejectio s effect due to demad characteristics or passive observatio of a situatio. This is particularly saliet as may eeds items (e.g., I felt like my actios had some impact o the directio of the game) could be iterpreted as passive observatio of the situatio (i.e., the situatio offered o cotrol) ad ot as eeds-related thoughts (e.g., I was affected by the lack of cotrol). However, if self-reported scales show similar effect s to behavioral measures, the we have a crude demostratio of coverget validity: People ot oly report feelig eed frustratio, but they also act i ways to restore their eeds. The importace of each eed followig rejectio ca be determied i two ways. 2 First, the most importat eeds will ted to have the largest effect magitudes. Secod, it is possible to show which eed takes precedece ad priority whe two eeds are i coflict (see atisocial resposes below for more detail). The self-regulatio perspective argues that people are uable to self-regulate followig rejectio (Baumeister, 2005). For example, people ofte respod aggressively followig rejectio (Twege et al., 2001), ad this will ot help them be reicluded ad restore their threateed sese of belogig. Ulike the umbess hypothesis, which implicates subcortical fuctioig, the self-regulatio perspective suggests that frotal lobe processes such as executive processig are affected. Loss of self-regulatio is argued to be demostrated by poorer performace o itelligece tests ad by self-cotrol failure. Crucially, the self-regulatio accout argues that eeds are active but that they remai ufulfilled. Demostratig eeds satiatio will thus show that i may istaces self-regulatio is ot impaired by rejectio. If people report havig active eeds followig rejectio ad, with a similar effect, act i ways that are cosistet with those eeds, there is evidece of good self-regulatio: These people had a goal, ad they regulated to achieve the goal. The cofluece of self-reports ad behavior would argue agaist self-regulatio deficits followig rejectio. I this meta-aalysis, we deliberately left aside the few papers dealig with the self-regulatio perspective, as we believe the iterpretatio of self-regulatio research is ambiguous. We believed this because previous self-regulatio research has failed to ivestigate the active eed states of rejected idividuals. For example, eatig chocolate chip cookies is kow to repair mood deficits, but self-regulatio research has assumed (due to the lack of mood effects) that mood-regulatio is ot the priority followig rejectio. As such, eatig chocolate chip cookies is take to be evidece for self-regulatory failure istead of successful mood restoratio. Agai, success at the cold pressor task is kow to be associated with feeligs of cotrol (Litt, 1988). However, as self-regulatio research has assumed that rejectio oly affects belogig, it takes success at the cold pressor task as evidece of self-regulatio failure istead of successful restoratio of cotrol. As such, it seems to assume that selfregulatio is impaired. 3 Istead, we focused o demostratig which eeds are active followig rejectio. Is it merely the eed to belog, or are the eeds for cotrol ad meaigful existece affected too? These 2 Our claims regardig the relative importace of eeds apply oly to the cotext of rejectio. We make o claim for the relative importace of these eeds i other settigs. 3 There were other reasos for excludig self-regulatio research. Most measures did ot have five istaces, which was our cutoff criterio for icludig a measure. Furthermore, most self-regulatio measures would have bee coded as measures of cotrol, bolsterig our effect, but we felt that selfregulatio researchers would cosider this ufair util cotrol effects had first bee demostrated. 470 Volume 4 Number 5

4 Joatha Gerber ad Ladd Wheeler questios ca lay the groudwork for future self-regulatio research. Furthermore, we also focused o testig whether selfreport ad behavioral measures of eeds match, which would suggest that effective self-regulatio occurs at least some of the time. I summary, our basic eeds questios are as follows: 6. Is there evidece for activatio of eeds for belogig, cotrol, ad meaigful existece followig rejectio? 7. Do behavioral measures ad self-report scales show equivalet effect s? 8. Which eeds are most importat followig rejectio? 4 The europhysiological evidece is icoclusive by itself, as the same regios of the brai active durig social pai are also active durig opaiful stressors, such as solvig difficult math problems (Wag, Ulbert, Schomer, Marikovic, & Halgre, 2005). Prosocial ad Atisocial Resposes to Rejectio Possibly the biggest puzzle i the rejectio literature is that rejectio makes people act prosocially some of the time ad atisocially at other times. The puzzle is that a belogig accout caot explai atisocial resposes. For example, rejectio ca cause aggressio directed agaist iocet third parties (Warburto, Williams, & Cairs, 2006), which may i tur cause further exclusio for the rejected idividual, as is ofte the case with bullies (Juvoe & Gross, 2005). Researchers therefore cosider the aggressio effect to be paradoxical. A host of reasos have bee offered for atisocial resposes. Some have suggested that it may be due to the rejectio iductio techique (Williams, Forgas, & vo Hippel, 2005). Others show that the status of the aggressio target (Twege et al., 2001) is importat; people may be less willig to puish iocet third parties ad more likely to puish perpetrators of rejectio. Both rejectio paradigm ad the status of the aggressio target were tested as moderators of atisocial respodig i this meta-aalysis. The umbess accout suggests that the atisocial respose comes from lack of empathy ad icreased pai tolerace. The self-regulatio perspective suggests that atisocial behavior stems from loss of self-cotrol. Aside from these possibilities, oe recet review (Leary, Twege, & Quiliva, 2006) offered ie explaatios of aggressio followig rejectio. These reasos ca largely be classified as either pai reflexes or as ways of regaiig cotrol. Pai accouts argue that aggressio is a reflex caused by pai. Physical pai ca cause aggressio (Berkowitz, 1993). As similar eural regios are activated by physical ad social pai, social pai may cause reflexive aggressio. This may be true, 4 but it ca oly offer a partial explaatio of aggressio followig rejectio as it fails to explai why participats oly aggress at some times ad ot others. Agai, sometimes the aggressio followig rejectio is ot reflexive; hot-sauce aggressio (assigig a high level of hot sauce to be eate by a future experimetal participat ) ca occur eve with time delays of several miutes ad iterveig maipulatios; hardly the most reflexive of timigs (Warburto, Williams, & Cairs, 2006). The other explaatios of aggressio after rejectio suggest that people aggress to regai some sese of cotrol (or the power to cotrol). For example, some people i souther U.S. culture aggress as a badge of hoor ad to maitai their status ad power (Nisbett & Cohe, 1996). Agai, rejectio may cause a ego threat that people try to ward off. People may use aggressio to get revege, a way of regaiig power over past wrogs (Leary, Twege, & Quiliva, 2006). If aggressive resposes may be attempts to gai cotrol, the may resposes classified as beig atisocial should also be opportuities to regai cotrol. For example, oe measure of prosocial behavior is observig whether participats help a experimeter pick up a box of spilled pecils. However, the experimeter is the oe who has just told the participat that they will be aloe i later life, ad thus ot pickig up the pecils could be a subtle meas of retaliatio agaist the experimeter, leadig to feeligs of icreased cotrol (Tedeschi & Felto, 1994). The situatio offers a choice betwee restorig cotrol or restorig belogig: Will people be prosocial ad pick up the pecils, thus restorig a sese of belogig, or will they be atisocial ad refuse to help but restore a sese of cotrol? Atisocial resposes may be due to people tryig to restore cotrol at the expese of belogig. This hypothesis ca be tested by comparig these coflicted situatios with situatios where belogig ad cotrol are ot mutually exclusive. For example, rejected people ucosciously mimic other s behavior more tha do orejected idividuals. This situatio is ulikely to allow a idividual to gai cotrol ad is a more pure measure of belogig. Thus, comparig measures that allow cotrol via atisocial respodig to measures that do ot allow for cotrol to be pursued may help reveal if cotrol eeds are at the source of the aggressio paradox. Our predictio is that prosocial resposes should be evidet whe the possibility of restorig cotrol is ot preset, whereas atisocial resposes occur whe people have the chace to regai cotrol. These istaces where oe eed must be chose over aother also show which eed is stroger after rejectio. If cotrol is more importat tha belogig after rejectio, people should prioritize regaiig cotrol over restorig belogig. Oe of the questios our meta-aalysis poses is this: Will people choose belogig or cotrol? A fial potetial explaatio of pro- ad atisocial resposes is that there is either a geeral pro- or atisocial respose but that the published studies are extreme positive ad egative tails of a largely upublished zero-cetered distributio. Thus, upublished studies of pro- ad atisocial resposes are importat for this meta-aalysis. If there are few upublished ull results (ad most upublished studies show a effect), the possibility of a file drawer effect ca be elimiated (Johso & Eagly, 2000). Volume 4 Number 5 471

5 Rejectio Meta-Aalysis I summary, the questios relatig to atisocial respodig to rejectio are as follows: 9. Do belogig measures that allow restoratio of cotrol by beig atisocial show egative effect s, whereas belogig measures that do ot allow for cotrol to be restored show positive effect s? 10. Does the status of the target moderate atisocial tedecies? 11. Does the rejectio paradigm moderate atisocial tedecies? 12. Is there evidece of publicatio bias i pro- ad/or atisocial studies? EXPERIMENTAL DESIGN ISSUES Aside from the precedig questios of primary iterest, there are a umber of methodological questios i the rejectio literature ad also may potetial moderators of rejectio s effects that warrat exploratio. I particular, differeces i research methods have bee suggested to be causes of the apparet disagreemet i the literature. As such, ivestigatio of these moderators was importat. Rejectio Paradigms ad Iductio Techiques At the Sydey Symposium of Social Psychology i 2004, a hot topic was whether differet iductio techiques might cause some of the differeces i experimetal results, particularly the differeces i pro- ad atisocial respodig to rejectio. Does the experimetal paradigm act as a moderator of ay depedet variables? Four geeral rejectio paradigms may be distiguished: ostracism, demarcated rejectio, future rejectio, ad relivig rejectio. The first two paradigms use a i vivo iductio of rejectio, whereas the latter two do ot provide a direct experiece of rejectio but iduce expectatios, associatios, or past memories of rejectio. Ostracism is usually defied as igorig ad excludig (Williams, 2001). However, this is isufficiet to describe the key feature of experimetal maipulatios of ostracism: the rejectio occurs without metio it is ot sigaled or demarcated. For example, i Cyberball (Williams & Jarvis, 2006), researchers throw the ball to participats for a while ad the do ot throw them the ball. The excluded participats are ot told that they are beig excluded, this is left for them to ifer; the rejectio is ot explicitly metioed. Similarly, i the trai ride paradigm (Zadro, Williams, & Richardso, 2005) participats are igored ad excluded durig a role-play coversatio without ay sigal that the others are itedig to igore them. Ostracism is sometimes see as the most potet form of rejectio because the iitial reactio to ostracism is automatic ad idiscrimiate (Williams & Gerber, 2005). The lack of demarcatio betwee iclusio ad exclusio may cause ostracism to have a higher impact tha other rejectio paradigms. As such, this meta-aalysis examied whether ostracism has stroger effects o depedet variables tha other rejectio paradigms. Demarcated rejectio comprises those paradigms i which the participat is clearly told they are beig rejected. For example, group-work rejectio (Nezlek, Kowalski, Leary, Blevis, & Holgate, 1997) egages participats i some form of iformatio exchage, either via questioaire or face-to-face iteractio, prior to selectig other group members for future iteractios. The rejected participat is the told that o oe chose to work with them. As aother example, Buckley, Wikel, ad Leary (2004) use a paradigm i which participats speak ito a microphoe about themselves ad receive feedback o their performace from a evaluator, actually a computer, i aother room via a series of lights that idicate whether the evaluator wats to iteract with them or ot. Rejected participats were give clear idicatio o this scale that the evaluator did ot wish to iteract with them. I this meta-aalysis, paradigms were icluded i the demarcated rejectio category if they used a live iductio ad if the rejectio was clearly metioed to the participat. Future rejectio, also called aticipated aloeess, comes from the life-aloe paradigm (Twege et al., 2001). I this paradigm, participats complete a bogus persoality test ad the receive feedback that their persoality idicates they will be aloe i later life. The rejectio is ot directly experieced durig the experimetal sessio, but the potetial for future rejectio is experieced. It has bee suggested that this paradigm may have stroger effects o executive fuctioig (Williams, Forgas, & vo Hippel, 2005) tha do other rejectio paradigms. Relivig rejectio ivolves either primig feeligs of rejectio or askig participats to write a story about a time they were rejected. Both situatios ask participats to thik about past rejectio experieces. I primig paradigms (Sommer & Baumeister, 2002), participats are sublimially primed with words relatig to rejectio. Primig calls up past associatios with rejectio. I story-writig paradigms (Garder, Pickett, & Brewer, 2000), participats write a story about a time they felt rejected. Writig a story ivokes the thoughts ad feeligs related to previous rejectio episodes. I both of these paradigms, rejectio is iduced through past, ot curret, experiece. Laboratories ad Authors A geeral meta-aalytic procedure is to check whether some authors report uusually large effects. It may be the case that some research groups are better at rejectig participats tha are others. Of course, the author effects are ofte cofouded with the rejectio paradigm, as some authors use maily oe iductio techique. I this aalysis, priority was give to the experimetal paradigm results because they were more meaigful ad iterpretable. 472 Volume 4 Number 5

6 Joatha Gerber ad Ladd Wheeler Valece of Compariso Group Most rejectio paradigms compare a excluded group with a icluded group, ot with a eutral compariso group. For example, i the Cyberball paradigm, participats are either icluded or excluded from further participatio there is o true cotrol coditio (Baumeister et al., 2005). It is possible that may rejectio studies actually ivestigate the effect of iclusio, ot the effect of rejectio. Furthermore, there is some evidece that iclusio cotrol groups are ot eutral. DeWall ad Baumeister (2006) foud that, after the life-aloe paradigm, participats i the future belogig group showed ehaced mood, whereas the future aloe (rejectio coditio) participats were eutral. Agai, iclusio decreases axiety to the same extet that exclusio icreases axiety (Williams, 2001). We thus tested each type of cotrol group typically used i rejectio studies (iclusioary groups, eutral groups, ad misfortue/egative orejectio groups) to determie how or if the rejectio effects differ for each of them. Measure/Scale Type The previously discussed differece betwee self-report ad behavioral measures is part of a larger geeral questio of whether some measures are more sesitive tha others. Some self-report measures are developed by the researchers specifically for the research situatio. This may be good for tailorig them to the situatio, but these scales ofte have utested psychometric properties. Therefore, we ivestigated whether scales developed by the researcher showed differet, specifically larger, effect s to exterally validated scales. I particular, Williams ad colleagues regularly use a 12-item questioaire to assess eeds we will refer to this scale as the stadard 12 (S-12). This scale has utested psychometric properties. Assessmet of Suspicio ad Maipulatio Checks Two idicators of experimetal rigor are the use of suspicio checks ad maipulatio checks. We checked whether rejectio studies geerally assess how suspicious ad egaged the participats are i the study ad whether appropriate maipulatio checks are used. Summary of Meta-Aalysis This meta-aalysis seeks to summarize experimetal rejectio research to date; aalyze the iteral ad behavioral effects of rejectio, critically assess theoretical accouts of rejectio, ad explore some methodological issues ad potetial moderators of these effects. We will address the 12 questios detailed earlier i this article. METHOD Study Selectio Studies were located by PSYCIfo search, curriculum vitae searches of kow rejectio researchers, ad requests to the Society for Persoality ad Social Psychology discussio list for upublished papers ad dissertatios. The PSYCIfo search was a broad search lookig for all syoyms of rejectio, 5 ad we matched these to both experimetal desig ad keywords related to our depedet variables. We excluded field studies from the developmetal literature as we were iterested i experimetal lab maipulatios of rejectio. Upublished theses ad other upublished data were set by researchers i respose to requests or purchased from ProQuest Iformatio Services. We icluded oly origial studies that used a experimetal maipulatio of rejectio. We also required that there be o iterveig maipulatios betwee the rejectio iductio ad the assessmet of depedet variables. A complete list of studies with coded characteristics is preseted i Appedix 1. Oe study (Oate, Williams, Joes, & Zadro, 2007) had eed effect s that were clear outliers (effect s were 5 7 stadard deviatios above the meas). The eed effect s are icluded i Appedix 1, but were excluded from ay aalyses. Codig The characteristics of the coded data were sample, experimetal paradigm, amout of iclusio before rejectio, type of compariso group, types of measures used (mood, self-esteem, arousal, belogig, cotrol, ad meaigful existece), the effect (for each measure), the iverse weight of the effect (for each measure), suspicio ad maipulatio checks, items to assess feeligs of rejectio, researcher, aggressio target, ad whether the same respose allowed both cotrol ad belogig to be satisfied simultaeously. These are expaded o i the codig defiitios ad examples below. The iteral states were coded so that positive effect s idicated more positive mood ad greater arousal ad self-esteem. Needs effect s were coded so that positive sigs idicated greater frustratio ad presece of the eed. Joatha Gerber coded the data. A secod rater coded 10% of the studies, ad iterrater reliability was reasoable (average k across all categories). 5 The complete list of rejectio terms was as follows: exile, elimiatio, separatio, disjoiig, severace, sever, partig, part, ucouplig, divorce, exclusio, exclude, preclusio, preclude, exteriority, reject, rejectio, oacceptace, oapproval, disapproval, seclude, seclusio, social isolatio, isolate, isolated, leave over, leave out, left out, throw out, uchose, ot accept, rebuff, repulse, spur, dismiss out of had, say o to, declie, draw the lie at, be usatisfied, rubbish, dislike, object of scor, reproach, reproached, byword, cotempt, outcast, despise, cotem, disapprove, thik little of, codem, sub, brush off, repel, eject, ejectio, throw out, bum s rush, dismiss, disset, egatio, uwilligess, loath, avoid, avoidace, shu, shued, shuig, ot go ear, keep away, bypass, circumvet, refusal, oacceptace, turig dow, tur dow, thumbs dow, declie, decliig, rejectig, outcast, pariah, leper, outsider, utouchable, harija, expatriate, alie, outcaste, ostracism, ostracize, ostracized, excluded, igore, igored, igorig, bar, be blid, be iattetive, ot otice, ot atted, pay o attetio, pay o heed, ot liste, disregard, igore, pass over, dodge, avoid, abado, desert, make uwelcome, frow o, cold shoulder, sed to Covetry, boycott, blackball, blacklist, excommuicate, ad baish. Volume 4 Number 5 473

7 Rejectio Meta-Aalysis Codig Defiitios, Decisios, ad Examples Sample Size Sample was calculated from reported sample s. I the case that idividual cell s were ot reported, the sample was split evely ito as may groups as ecessary, eve if this resulted i fractioal sample s. Experimetal Paradigm The codig of the experimetal paradigm was guided by the coceptual aalysis reported earlier. Thus, the studies were coded ito ostracism, demarcated rejectio, future rejectio, ad relivig rejectio. There were a umber of variatios withi the four classes of rejectio iductio procedures. We origially coded the iductios to take small variatios ito accout, but this left most categories with less tha five istaces. Thus, the paradigms were grouped ito the four major classes outlied above. Compariso Group We coded three types of compariso groups: iclusio, eutral, ad egative. The egative cotrol groups icluded misfortue feedback (from the life-aloe paradigm) ad also argumet groups. May rejectio paradigms had more tha oe compariso group. For example, future rejectio typically compares the lifealoe group to two groups: the future belogig group ad a misfortue cotrol. I most results sectios of this meta-aalysis, multiple compariso groups were averaged ad compared with the rejectio group. This retaied data idepedece ad also maximized the power of the meta-aalysis. However, whe aalyzig compariso groups we compared each compariso group idividually with the rejectio group. This made effect s oidepedet but allowed for a better overall aalysis of compariso groups. Mood Mood was coded from recogized mood scales ad other questios o emotioal toe that were related to how people were feelig. These were all self-report scales, icludig the Positive ad Negative Affect Schedule (PANAS; Watso, Clark, & Tellege, 1988), the Brief Mood Itrospectio Scale (BMIS; Mayer & Gaschke, 1988), the Heatherto Sesatio Questioaire (Heatherto, Striepe, & Witteberg, 1998), ad some scales developed by the researchers themselves. The PANAS scale was sometimes reported as a combied measure ad at other times as two separate scales. Where possible, we averaged together the positive ad egative scales for use i the composite effect. This was ot always possible, ad hece there were fewer PANAS overall results tha idividual subscale results. Arousal Arousal is defied as a state of alertess & readiess for actio, 2. pervasive cortical resposiveess (paraphrase), ad 3. a state of excitemet or eergy expediture liked to a emotio (VadeBos, 2006, p. 71). We measured arousal with the BMIS arousal subscale ad with questios about how excited or uexcited ad alert or bored people were. Measures of physiological arousal such as blood pressure ad cortisol were also coded here. Self-Esteem Self-esteem chages were coded from scales that measured state levels of self-esteem. The scales used icluded McFarlad ad Ross s (1982) self-esteem scale, ad Heatherto ad Polivy s (1991) state self-esteem scale. Belogig The eed to belog has bee defied as the eed to have frequet, carig iteractios with other people (Baumeister & Leary, 1995). Items that related to belogig were items that ivolved other people, items i which there was potetial for some further iteractio, or behaviors that would facilitate iteractio. For example, coformity o Asch s lie task was coded as belogig, as coformig to the group cosesus would ecourage reiclusio. Rememberig social iformatio was coded as belogig, as it would facilitate future iteractio. Cotrol Cotrol is defied as authority, power or ifluece over evets, behaviors, situatios or people (VadeBos, 2006, p. 228). This defiitio was exteded to ecompass aspects of persoal power that might be idicative of people feelig powerful but ot yet exercisig that power. Some examples of measures coded for cotrol were the prisoer s dilemma game, i which the moves to puish the other player by makig ucooperative turs were istaces of cotrol. Pai tolerace ad pai threshold were also couted as measures of cotrol, as participats could use loger times i the cold water or ski piches as demostratios that they are strog ad powerful (Litt, 1988). 6 Meaigful Existece Meaigful existece is the eed to feel that oe s life is worthwhile ad meaigful. This eed is coceptually related to terror maagemet theory (Roseblatt, Greeberg, Solomo, Pyszczyski, & Lyo, 1989). It was coded from self-report scales that metioed aspects of meaigful existece ad other measures derived from terror maagemet theory. Suspicio Thirty-six studies reported measurig suspicio. Of these, 14 merely oted that some (2 or less) participats were removed due to suspicio but gave o details of the method used to assess suspicio. 6 We arbitrarily chose pai threshold over pai tolerace as their effect s were almost idetical. 474 Volume 4 Number 5

8 Joatha Gerber ad Ladd Wheeler Maipulatio Checks Twety-eight studies reported usig appropriate maipulatio checks, ad these were spread fairly evely across authors. Most studies by Williams ad colleagues (e.g., Williams, Cheug, & Choi, 2000; Zadro, Williams, & Richardso, 2005) reported feeligs of exclusio ad iclusio as maipulatio checks, but these are better classified as effects of the maipulatio, ot maipulatio checks per se. As such they were coded uder feeligs of exclusio. Feeligs of Rejectio Feeligs of rejectio were coded as either self-report items or items i the debrief relatig to how rejected they felt. Thirty-five studies assessed feeligs of rejectio, ad these were spread across most authors ad paradigms. The exceptio is the life-aloe paradigm, which ever appears to have assessed how rejected participats felt. Researcher We coded studies by the key supervisors. For example, Garder, Pickett, ad Brewer (2000) was coded as a study by Brewer ad colleagues. The sole exceptio was Jea Twege, who started research uder Roy Baumeister but has eough idepedet studies to justify a separate author category. Aggressio Target Aggressio target was coded as either the rejecter or a iocet third party. Belogig ad Cotrol Results For all belogig measures, the presece (or absece) of cotrol was assessed. Measures were coded for the absece of cotrol opportuities, the presece of a choice betwee cotrol or belogig, or the ability to satisfy both belogig ad cotrol i the same actio. The latter category was ot represeted i the literature. Other Codig Decisios Measures were classified by the category defiitios listed above, ot by the iterpretatio of the origial paper. For example, may aggressive acts (e.g., white oise to a participat i the ext room) fit the defiitio of a lost opportuity to regai belogig, so these situatios were coded as belogig measures as well as cotrol measures. 7 If measures fitted coceptually with two eed categories, we placed them i both categories. For example, both the prisoer s dilemma ad the white-oise task would qualify as a chace to regai either belogig or cotrol, so they were coded i both categories. Although this meat some measures appeared twice 7 We are ot sayig that these acts are ot aggressive; rather, we are otig that aggressive acts ca fit withi a motivatioal framework ad serve to meet eeds such as belogig ad cotrol (see Kelter, Gruefeld, & Aderso, 2003). (e.g., i both cotrol ad belogig), the assumptio of idepedece ecessary for a composite effect withi each depedet variable was still met, as each measure was oly icluded oce withi a category. If a study had depedet variables from more tha oe category, we icluded all depedet variables i the meta-aalysis. For example, all four subscales of the S-12 were icluded i this aalysis, each subscale i its appropriate category. Oce agai, the assumptio of idepedece ecessary to produce a composite effect withi each depedet variable was satisfied. To retai idepedece withi each effect, a differet approach was required whe studies had multiple measures of a idividual depedet variable. Oe ecessity for calculatig a composite effect (i.e., the weighted average of the idividual effect s) is that each effect is idepedet. To achieve idepedece for studies that had more tha oe measure of a depedet variable, we coded all measures but the selected oe measure to use i calculatig the composite effect. Behavioral measures took first priority whe calculatig the composite effect, whereas measures with some reported validity had secod priority, ad measures used i multiple studies took third priority. Whe we switched to testig the effects of measure type or compariso group, we icluded oidepedet effect s (i.e., both scales if two were used, both compariso groups if two were used) to icrease the power of our aalysis (Lipsey & Wilso, 2001). To give a cocrete example, if a study had both a behavioral ad self-report measure of belogig, the we used oly the behavioral measure i the composite effect of belogig. However, whe testig differeces betwee types of belogig measures, we used both the behavioral ad self-report measures. Effect s were calculated from meas ad stadard deviatios or proportios. Effect s were recalculated eve if they were reported i the origial paper to esure cosistecy i the data. There were some forms of aalysis ad reportig that were ot sufficiet or appropriate for the meta-aalysis, icludig regressio coefficiets, factorial desigs i which ot all factors were reported, ad multiple aalysis of variace (ANOVA) desigs i which ot all cells were reported. Whe researchers reported oly p values, we estimated the maximum possible effect if the directio of the meas was reported or we left them out. There were oly 10 effect s estimated i this maer. If cell s were ot reported, we divided the total sample ito equal groups. We used a Excel calculatio program to verify the first 10% of effect s computed by had ad the calculated the rest i Excel. As most studies used uder 200 participats, we reduced the iverse variace weights for our two largest samples of 750 ad 390 to 250. This reduced the impact of these two studies o the overall results (Wilso, Lipsey, & Derzo, 2003). Effect s were corrected for small sample bias, usig the Hedges ad Olki (1985) method. Volume 4 Number 5 475

9 Rejectio Meta-Aalysis Aalytic Strategy We aalyzed the data usig methods recommeded by both Johso ad Eagly (2000) ad Lipsey ad Wilso (2001). The strategy was first to look for publicatio bias by examiig a scatterplot of effect s by sample. The scatterplots all revealed o publicatio bias. This was usurprisig give that may rejectio studies iclude ull results (e.g., mood) alog with other sigificat depedet measures. The oly scatterplot that showed mior cocer was the belogig scatterplot. It revealed a gap betwee 0.6 ad 0, possibly idicatig that some osigificat atisocial studies were ot reported. However, it is ulikely that the published results are due to a moutai of upublished ull results as the primary researchers ivestigatig atisocial resposes supplied this meta-aalysis with several upublished studies with ozero effect s. After this, we computed a composite effect, ad the we tested whether the coded moderators iflueced the effect. Statistics were computed usig SPSS macros published by Lipsey ad Wilso (2001). As most idepedet variables were categorical, we used a ANOVA aalog ad ot multiple regressio to avoid the use of umerous dummy variables with a low value for each predictor. We used a mixed-effects model, as this was a relatively small sample of studies with potetial radom factors. RESULTS Composite Effect Sizes of All Depedet Measures After ispectig the effect- ad sample- scatterplots, which we will discuss further with each depedet variable (DV), we used a radom effects model to compute composite effect s for all DVs. These are preseted i Table 1. No effect s were homogeeous (all Q statistics were sigificat), thus justifyig the use of the radom effects model. Table 1 shows that rejectio sigificatly affected all variables except for arousal but that o effect was homogeeous. As TABLE 1 Summary of Effect Sizes of All Depedet Variables i This Study Depedet variable k Total sample Effect 95% cofidece iterval Q statistic Mood 51 3, , Arousal , Self-esteem 36 2, , Belogig 39 2, , Cotrol 53 3, , Meaigful existece 24 1, , Note. A positive effect for belogig, cotrol, ad meaigful existece idicates greater eeds frustratio. Care should be take iterpretig these effects, as o effects are homogeeous. p p p < o effect was homogeeous, a mixed effects ANOVA aalog was used to examie potetial moderator variables for each depedet variable (Lipsey & Wilso, 2001). Iteral States: Results Mood There was a moderate (d , p <.05, 95% CI , 0.35), ohomogeeous effect of rejectio o mood. Despite the claims of may researchers that mood is ot iflueced by rejectio, rejectio does appear to affect people s mood: it makes people feel worse. As the effect was ohomogeeous, we examied whether the mood effects were depedet o the measure used to assess mood. A mixed-effects ANOVA aalog (show i Table 2) showed that there were differeces by scale type, Qb(3) , p 5.05 (where Qb represets heterogeeity betwee groups), ad that each scale type was homogeeous, Qw(47) , p 5.36 (where Qw represets heterogeeity withi groups). The PANAS scale ad items developed by the researchers picked up mood chages, whereas the BMIS ad Heatherto scales did ot show mood chages. The items developed by researchers ted to have fewer items tha the BMIS, sometimes beig as short as oe or two items (e.g., happy sad, good bad), ad these shorter scales appear to pick up the emotioal impact of rejectio more strogly. As the PANAS cotais positive ad egative affect subscales, we used these subscales to ivestigate the possibility of mood flatteig. The results (preseted i Table 3) suggest that rejectio lowers positive mood slightly more tha it ehaces egative mood, although both types of mood are affected. Neither group was homogeeous. There were o effects due to experimetal paradigm, Qb(3) , p 5.50, or researcher, Qb(5)5 6.16, p Arousal Results After removig two outliers, we foud 11 studies measurig arousal. Both outliers were from Zadro et al. (2005), who used a TABLE 2 Mood Effect Sizes by Scale Type Scale type k Effect 95% cofidece iterval Qw statistic PANAS/PANAS-X , BMIS , Short items developed , by researcher Heatherto , Note. PANAS 5 Positive ad Negative Affect Schedule; BMIS 5 Brief Mood Itrospectio Scale. p p < Volume 4 Number 5

10 Joatha Gerber ad Ladd Wheeler TABLE 3 Mood Effect Sizes by Positive ad Negative Scales Scale type k Effect 95% cofidece iterval Qw statistic Negative emotio , Positive emotio , p p p TABLE 5 Self-Esteem Effect Sizes by Experimetal Paradigm Rejectio paradigm k Effect 95% cofidece iterval Qw statistic Ostracism , Demarcated rejectio , Life-aloe , Recall/primig , p p p < argumet compariso coditio that led to highly elevated levels of arousal i the compariso group. The overall radomeffects effect for this sample was ot sigificat (d150.27, p 5.10, 95% CI , 0.60). However, the arousal results were ohomogeeous, Q(11) , p 5.001, so we ivestigated potetial moderators of arousal. The sample was split by experimetal paradigm. A mixed-effects ANOVA aalog was sigificat, Qb(2) , p 5.03, ad made each group homogeeous, Qw(9) , p CIs suggested that oly ostracism had a discerible effect o arousal (see Table 4). Ostracism paradigms led to a moderate icrease i arousal. The other types of rejectio had o ifluece o arousal, ad their CIs icluded zero. Cotrary to a self-regulatio accout, o experimetal rejectio paradigms led to decreased arousal. This suggests that people do ot become umb followig rejectio. A split of arousal by research group yielded the same results as a paradigm split, as researcher ad paradigm were cofouded. The effects did ot differ by scale type, Qb(1) , p 5.65; the physiological effect s are the same as self-report. Self-Esteem Results Rejectio had a moderate effect o self-esteem (d , p <.00005, 95% CI , 0.84). This effect had a much tighter cofidece iterval tha the other DVs, but was still ot homogeeous, Q(35) , p Therefore, we searched for potetial moderators of the effect. A radom-effects ANOVA aalog by experimetal paradigm (see Table 5) produced sigificat results, Qb(3) , p 5.004, ad made all but oe group homogeeous, Qw(32) , p Ostracism had the largest effect o self-esteem, whereas the life-aloe paradigm had a moderate effect o selfesteem. Primig ad recall studies were ohomogeeous but TABLE 4 Arousal Effect Sizes by Experimetal Paradigm Rejectio paradigm k Effect 95% cofidece iterval Qw statistic Ostracism , Demarcated rejectio , Life-aloe , p <.001. were ot able to be split ay further. This suggests that ostracism is more damagig to self-esteem tha are other experimetal maipulatios. As ostracism studies typically use the S-12 scale, we tested whether the ostracism results were due to the scale ad foud that they were ot. The S-12 scale was o more effective tha other scale types, Qb(3) , p 5.24, at capturig self-esteem. A split by research group yielded the same results as experimetal iductio due to cofoudig of paradigm ad researcher. A split by scale type did ot yield sigificat results, Qb(2) , p 5.43, although it did make the groups homogeeous, Qw(40) , p Iterim Summary Take together, these results suggest that rejectio causes a state of alertess to evirometal threat. Rejectio makes people feel worse ad, i the case of ostracism, aroused. Lowered self-esteem followig rejectio suggests a readiess for actio, potetially to satisfy the eed for belogig, cotrol, or meaigful existece. The type of chage ad actio aroused by rejectio were assessed ext by examiig measures of eeds. Actios Followig Rejectio: Results Belogig Rejectio had a moderate effect o belogig (d150.69, p , 95% CI , 1.09), ad the effect was ohomogeeous, Q(38) , p < There were several fidigs that reflected the complexity of the literature o pro- ad atisocial resposes to rejectio. The belogig results were sigificatly differet by measure type, Qb(2) , p <.0005, but o group was homogeeous, Qw(50) , p < The experimetal paradigms were also sigificatly differet, Qb(3) , p <.0005, but o group was homogeeous, Qw(35) , p < Similarly, the researcher split was sigificat, Qb(4) , p <.0005, but ot homogeeous, Qw(33) , p <.0005 (oe researcher was left out as he oly had oe study). However, three research groups did have homogeeous effects, Leary ad colleagues (d , Qw , p 5.17), Volume 4 Number 5 477