223 that anomie.social fragmentation.and lack of community identities are less likely to develop depression in the context associated with th of life events that present severe challenges to well-being. More ive still are the ntal data shov ,2011. that manipulations targeting individuals social identifica Speaking further about the importance of the psychologi ) ship for health,evidenc example.in an im estudy.Reicher ows t ers or guards in a simulated prison(revisiting the of the Stanford Prison Experiment;Haney,Banks,& Zimbardo 1973).Over the course of th 9-day experime which hey be nged (rath than one or three)perfor pressor tas more quickl 1070 increase the sense of shared social identity among the prison- Finally Cruwys et al (2013)report findings from an epi demiological study with a repr ntative sample of more ipants that explore ated by the of on-site clinicians the n group of social In a further example,Gleibs,Haslam,Jones,et al.(2011) which respondents belonged was a strong predictor of invited care hom re gender-based socia dep concurrently and ngitudin ally in f 4 year oreove this e ntoms deere Depressed resp ndents with no shins who at a 12-week follow -up.A significant improvement was seen joined one group reduced their risk of depression relapse by among men who ha higher levels of cial isolation and 4 610 hey joined thre e groups their risk re ce b owing ial and that have pn e properti in times of psychological vulne rability o in th depre ssion (C.Ha 3015 t the cally entails ha and there of the findings.Nevertheless,our confidence in H1 is rein fore.conveys greater resilience. ored by the fact Eviden ce for H3:The benefit of group but also to be both reliable and robust mbe depressior will be moderated by relevant normative content Evidence for H2:Social identification witha e a great deal of information to greate of med ingful groups will predict their members about appropriate ways to think,feel,and act lower levels of depression Such information(in the form of"norms";Cialdini&Trost me has be o influ Existing literatur laim tha and varied self-con cept (i.e.,those who are high in self-complexity:Linville, (2012)found that women were influenced to eat either more ile.I987 Ale group me er set a norm con ualized in terms of a person's possession of multiple sumption (Johnston White.2003:Reed.Lange social identities,several authors have argued that these con Ketchie,&Clapp,2007)and smoking (Schofield et al are compatibl Ha am et al.,20 lyer et a Even simply reminding people o hat rt has s he Ithy beha 304 Cruwys et al. 223 that anomie, social fragmentation, and lack of community are associated with the increased prevalence of suicide (Durkheim, 1897/1951; Hawton, Harriss, Hodder, Simkin, & Gunnell, 2001). More persuasive still are the experimental data showing that manipulations targeting individuals’ social identifica￾tion have consequent effects on depression symptoms. For example, in an immersive study, Reicher and Haslam (2006) randomly assigned 15 well-adjusted men to be either prison￾ers or guards in a simulated prison (revisiting the paradigm of the Stanford Prison Experiment; Haney, Banks, & Zimbardo, 1973). Over the course of the 9-day experiment, manipulations (in particular, of group boundary permeabil￾ity; Tajfel & Turner, 1979, see also Ellemers, 1993) served to increase the sense of shared social identity among the prison￾ers and this led to a gradual reduction in depression symp￾toms. However, guards’ sense of shared social identity declined and this led to a significant increase in depression (corroborated by the observations of on-site clinicians). In a further example, Gleibs, Haslam, Jones, et al. (2011) invited care home residents to join gender-based social groups (gentlemen’s and ladies’ clubs) that took part in fort￾nightly social activities. Compared with baseline, social identification increased and depression symptoms decreased at a 12-week follow-up. A significant improvement was seen among men, who had higher levels of social isolation and depression at baseline. Importantly, these experimental studies provide initial evidence for the causal role of social identification in shap￾ing mood and clinical outcomes in vulnerable populations. As with most of the correlational studies in this area, depres￾sion was not the researchers’ primary focus and hence, there are residual questions about the precise clinical implications of the findings. Nevertheless, our confidence in H1 is rein￾forced by the fact that across both surveys and experimental studies, the negative association between social identifica￾tion and depression appears not only to be moderately strong but also to be both reliable and robust. Evidence for H2: Social identification with a greater number of meaningful groups will predict lower levels of depression. Existing literature provides reliable support for the claim that individuals who have a more complex and varied self-con￾cept (i.e., those who are high in self-complexity; Linville, 1987) are buffered against failure in any one domain and are less likely to become depressed (Koch & Shepperd, 2004; Linville, 1987). Although self-complexity was not originally conceptualized in terms of a person’s possession of multiple social identities, several authors have argued that these con￾cepts are compatible (C. Haslam et al., 2008; Iyer et al., 2009). Consistent with this claim, recent studies have found that individuals who report having a greater number of social identities are less likely to develop depression in the context of life events that present severe challenges to well-being, such as starting university (Iyer et al., 2009), having a stroke (C. Haslam et al., 2008), or experiencing brain trauma (Jones et al., 2011). Speaking further about the importance of the psychologi￾cal dimensions of group membership for health, evidence shows that individuals’ objectively measured resilience is increased by experimental manipulations that make multiple group memberships salient. In one study (Jones & Jetten, 2011), participants who were asked to list five groups to which they belonged (rather than one or three) performed better on a cold-pressor task and recovered more quickly from strenuous exercise. Finally, Cruwys et al. (2013) report findings from an epi￾demiological study with a representative sample of more than 4,000 British participants that explored (among other things) the relationship between group memberships and mental health. In this study, the number of social groups to which respondents belonged was a strong predictor of depression symptoms both concurrently and longitudinally (4 years later). Moreover, this effect was more than 3 times as strong among respondents with a history of depression. Depressed respondents with no group memberships who joined one group reduced their risk of depression relapse by 24%; if they joined three groups their risk of relapse reduced by 63%. Such research is part of a growing body of evidence that supports H2 and suggests that social identities are resources that individuals can draw on—and that have pro￾tective properties—in times of psychological vulnerability of the form typically associated with depression (C. Haslam, Jetten, & Haslam, 2012). In these contexts, having more identities typically entails having more resources and there￾fore, conveys greater resilience. Evidence for H3: The benefit of group membership for depression symptoms will be moderated by relevant normative content. Social groups communicate a great deal of information to their members about appropriate ways to think, feel, and act. Such information (in the form of “norms”; Cialdini & Trost, 1998; Turner, 1991) has been shown to influence health via at least two routes. First, behavioral conformity can have sig￾nificant implications for health. For instance, Cruwys et al. (2012) found that women were influenced to eat either more or less popcorn than those in a control condition when an in￾group member set a norm for high or low popcorn consump￾tion, respectively. Similar effects have been found for alcohol consumption (Johnston & White, 2003; Reed, Lange, Ketchie, & Clapp, 2007) and smoking (Schofield et al., 2001). Even simply reminding people of a particular social identity that they hold (i.e., making it salient) is enough for them to endorse less healthy behaviors that are in line with Downloaded from psr.sagepub.com at Remen University of China on September 6, 2015