Received: 11 March 2021 Accepted: 4 March 2022 DOI: 10.1002/ejsp.2851 RESEARCH ARTICLE Social norms (not threat) mediate willingness to sacrifice in individuals fused with the nation: Insights from the COVID-19 pandemic Clara Pretus1,2 Óscar Vilarroya1,2 1 Department of Psychiatry and Forensic Medicine, Universitat Autònoma de Barcelona, Abstract Barcelona, Spain Identity fusion with the community has been previously found to mediate altruism in 2 Institut Hospital del Mar d’Investigacions post-disaster settings. However, whether this altruistic response is specifically trig- Mèdiques, Barcelona, Spain gered by ingroup threat, or whether it can also be triggered by global threats remains Correspondence unclear. We evaluated willingness to sacrifice in the context of the COVID-19 pan- Clara Pretus, Department of Psychiatry and Forensic Medicine, Universitat Autònoma de demic across three survey waves. Against expectations, participants fused with the Barcelona, 08193, Barcelona, Spain. nation (vs. non-fused) did not differentially respond to a national versus global threat Email: clara.pretus@gmail.com condition. Conversely, social norms decisively influenced willingness to sacrifice in this sample, with fused individuals with stronger norms about social distancing reporting the highest altruistic response during the first weeks of the pandemic. Longitudinally, after an initial peak in the altruistic response, deteriorating social norms mediated decreases in willingness to sacrifice in individuals fused with the nation (vs. non-fused). Implications of these results for the development of interventions aimed to address global challenges are discussed. KEYWORDS costly sacrifices, COVID-19, identity fusion, prosocial behaviour, social norms 1 INTRODUCTION utopia’ (among others Barton, 1969; Fritz, 1961; Wolfenstein, 1957). Current research is starting to disentangle the psychological underpin- Community-level traumatic events such as catastrophes, natural disas- nings of this phenomenon based on recent sociopsychological models. ters, and acts of terrorism involve shared experiences of pain and suf- Altruistic responses to natural disasters have been shown to be fering that often give rise to periods of solidarity and intense social sup- mediated by an increase in feelings of oneness with the group (Segal port (Kaniasty & Norris, 2004). For instance, several studies report an et al., 2018), also known as identity fusion (Swann et al., 2009). increase in altruistic behaviour directly after or upon recall of natural Identity fusion aims to explain extreme pro-group behaviour and, disasters such as Hurricane Katrina in the United States (Rodríguez according to its proponents, it differs from social identity theory in et al., 2006), prolonged ice storms in Quebec (Lemieux, 2014), and several critical ways. In social identity theory (Turner et al., 1994) major earthquakes in Sichuan (Li et al., 2013) and New Zealand (Segal individuals’ collective identity overshadows their personal identity, et al., 2018). Different authors have referred to this phenomenon as leading to a depersonalization process where they become proto- ‘heroic post-crisis benevolence’, ‘honeymoon phase’ or ‘post-disaster typical group members (Hogg et al., 1993). Through this process, This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. © 2021 The Authors. European Journal of Social Psychology published by John Wiley & Sons Ltd. Eur J Soc Psychol. 2022;1–10. wileyonlinelibrary.com/journal/ejsp 1 2 PRETUS AND VILARROYA people who highly identify with a group diminish their personal this sense, because parochial altruism often serves norm enforcement identity in favour of the group identity. Conversely, identity fusion (Baumgartner et al., 2012; Bernhard et al., 2006), fused individuals characterises individuals who maintain a strong sense of self, so should be more motivated to endure costly sacrifices for the group that both personal and group identities remain active and interact according to what they perceive to be normative. That is, shifting norms synergistically to support social interactions (Swann et al., 2009). It should involve changes in willingness to sacrifice for the issues ampli- is precisely this strong sense of self which allows them to harbour a fied by these norms. Such a finding would contribute to the develop- strong motivation to engage in extreme actions on behalf of other ment of identity fusion theory, revealing social norms as a key media- group members, with whom they establish family-like bonds (Swann tor of costly sacrifices in fused individuals. In addition, it would have et al., 2009). As a result, identity fusion has been found to better interesting implications for norm-based behavioural interventions, for predict extreme pro-group action as compared to group identification instance, paving the way to more effective approaches that could tar- (Swann, Gómez, Dovidio, et al., 2010; Wolfowicz et al., 2021). Indeed, get norms in combination with fusion. identity fusion can be triggered by shared dysphoric experiences (Whitehouse et al., 2017). Thus, the trauma and pain brought about by catastrophic events may provide the grounds for individuals to 2 THE CURRENT STUDY strengthen their ties with the community with which their share these grievances. The current COVID-19 pandemic has been pointed out as an excel- Of note, identity fusion has been extensively studied in the context lent opportunity to study processes related to altruism and identity of intergroup conflict (Buhrmester & Swann, 2015; Jong et al., 2015; fusion, according to proponents of this same theory (Gómez, 2020). Whitehouse et al., 2014) and it typically involves relatively narrow During the first year of the pandemic, we have witnessed extraordi- well-defined reference groups such as nations and moral communities nary efforts in national and international cooperation to counteract (religious or other) that can be distinguished from rival outgroups. In the devastating effects of the virus, including the mobilisation of thou- this context, willingness to sacrifice for the group in fused individuals sands of millions in public spending to guarantee medical supply pro- can be understood as a form of parochial altruism (Sheikh et al., 2014). visions and support employment and businesses within and across dif- This framework, however, does not necessarily apply to catastrophes ferent countries (European Council, 2020). At an individual level, exam- and natural disasters, where the enemy is not clearly defined. Thus, ples of cooperation and solidarity among neighbours and anonymous the question remains as to whether the observed altruism in fused citizens, especially during the first few months of the pandemic, are individuals after a natural disaster specifically responds to ingroup also abundant. Both national and community identification have been threat, or instead, whether it can also be triggered by global threats pointed out as valuable predictors of, respectively, engagement in pub- that challenge humanity as a whole. This question is especially rele- lic health behaviours (Van Bavel et al., 2022) and increased well-being vant in an increasingly inter-dependent world that inevitably faces (Bowe et al., 2021) during the COVID-19 pandemic. Because we were striking global challenges such as recurrent pandemics and climate interested in potential differences between national and global threats, change. we focused on identify fusion with the nation and its relationship with Ultimately, identity fusion leads to greater willingness to sacrifice altruistic behaviour. for the group, an outcome that can be beneficial for groups facing an In the present study, we investigated altruistic behaviour during the existential threat (Atran et al., 2014; Gómez et al., 2017). Indeed, exis- first 6 months of the COVID-19 pandemic. Departing from the identity tential threat has been shown to exacerbate the effects of fusion on fusion framework, we operationalised altruism as willingness to sacri- pro-group behaviour (Gómez, Morales, et al., 2011; Swann et al., 2009), fice for others in the context of the pandemic, which involved a clear whereas autonomic arousal in fused participants increases willingness risk to one’s own life. Specifically, we evaluated whether individuals to sacrifice in defence of the group (Swann, Gómez, Huici, et al., 2010). fused with the nation showed a higher altruistic response to COVID- Aside from perceived threat, a rather unexplored mediator of pro- 19, particularly after a national threat versus a global threat experi- group behaviour in fused individuals are social norms. Although social mental condition, and whether social norms mediated such increase. norms have been extensively studied in relationship to group identifi- For this purpose, an online survey including a national threat versus cation (Terry & Hogg, 1996), whether fused individuals are also more global threat experimental manipulation was launched in three waves responsive to in-group social norms as compared to non-fused individ- and completed by a large sample in Spain. Spain is one of the Euro- uals remains unanswered. As group members who experience a ‘sense pean countries most affected by COVID-19 to date, and one of the of oneness with the group’, fused individuals should be particularly Western countries that suffered the devastating consequences of the attuned to social norms and adjust their behaviour accordingly. In fact, disease earlier in the pandemic, when the uncertainty about this new parochial altruism, or the willingness to undertake risks in favour of the pathogen was at its highest in the West. At the time of the first sur- in-group, is intimately related to social norms (Bernhard et al., 2006). vey wave (March 2020), Spain had one of the highest numbers of con- For instance, individuals are more likely to respond with costly punish- firmed deaths in the world, only after Italy, and the highest number of ments to the violation of egalitarian sharing norms when the recipient deaths per million (‘Worldometer’, 2020). Participants were randomly is an in-group (Bernhard et al., 2006), and costly punishment increased assigned to two experimental conditions at the start of the first wave: the more the norm was transgressed (Fehr & Fischbacher, 2004). In half of them were presented with a graph of the evolution of confirmed SOCIAL NORMS (NOT THREAT) MEDIATE WILLINGNESS TO SACRIFICE IN INDIVIDUALS FUSED WITH THE NATION 3 COVID-19 cases in Spain (national threat) and half of them a map repre- 3.2 Participants senting worldwide confirmed cases (global threat). We predicted that participants fused with the nation would show Thousand and fifty-seven participants from the general population higher willingness to sacrifice in response to the national threat were recruited by means of an online panel using quotas representative (versus global threat) experimental condition employed in the first of gender, age, and province. Eight-hundred and eighteen of these par- survey wave. Moreover, we expected both perceived threat and social ticipants completed the second wave and 680 also completed the third norms to mediate changes in willingness to sacrifice, particularly in wave. Compared to participants who completed all three survey waves, participants fused with the nation. That is, even though perceptions dropout participants were younger (B = –2.97, 95% CI [–4.75, –1.21], of norms or threat may change in time across the whole sample, the t(1055) = –3.03, p < .001) and had been assigned to the global threat impact of such shift on willingness to sacrifice should be larger in fused condition with greater frequency than participants in the final sample versus non-fused participants. Because injunctive social norms, or (χ𝜒 2 (1) = 4.32, p = .04), but did not differ in any other demographic shared expectations about how someone ought to behave, may lead variable or variable of interest (p > .19). Dropout participants were to conflicting conformity decisions (Mcdonald & Crandall, 2015), we excluded from the analyses, providing a final sample of 680 participants chose to employ descriptive norms, which could potentially be more with somewhat greater frequency of respondents in the national threat influential in response to changing conditions (Melnyk et al., 2013). condition than in the global threat condition (54% national threat vs. In addition, because descriptive norms about people’s willingness 46% global threat condition, χ2 (1) = 3.97, p = .046). The final sam- to sacrifice could potentially backfire (if many people are willing to ple comprised 49.4% women, M = 46.9 years old, SD = 13.5, of whom sacrifice, fused individuals may be less motivated to do so), we chose to 49.7% had completed a higher education degree, and 19.9% lived in measure more mundane norms that still tap into how the group relates high-income households (>3.000 euros monthly). Participants in each to the pandemic, that is, norms about social distancing. Finally, per- condition did not differ in any of the main demographic variables. sonal compliance with social distancing was included as an exploratory measure. 3.3 Measures 3 METHODS The three survey waves included the same scales, except for identity fusion, which was measured only at Waves 1 and 3. The exclusion of the This research was approved by an ethical review board in Spain accord- fusion measure in Wave 2 was due to an initial assumption that fusion, ing to the Declaration of Helsinki guidelines. The study materials, code similarly to other aspects of identity, would not change in such a short and data are available following this link. period of time (Buhrmester & Swann, 2015). However, because of the exceptionality of the pandemic at all levels, we decided to put this mea- sure back in Wave 3, a choice that provided interesting insights (see 3.1 Study design Section 4). A longitudinal survey was launched at three time points during the COVID-19 pandemic in Spain: at the time of highest case growth rate, 3.3.1 Identity fusion just before adopting the toughest lockdown measures (26–31 March 2020), as lockdown measures were being lifted (5–11 May 2020), Identity fusion with the nation (Spain) was measured by means of the and at the start of the second epidemic wave (4–10 August 2020). A identity fusion pictorial measure (Swann et al., 2009), which includes between-subjects experimental condition was included at the start of two circles, a larger one representing the group and a smaller one rep- the first survey wave: half of the participants were randomly assigned resenting the respondent, with different degrees of overlapping from to a national threat condition (a graph of the evolution of confirmed A (no overlapping) to E (the small circle is at the centre of the larger COVID-19 cases in Spain) and the other half to a global threat condi- circle). tion (a map representing worldwide confirmed cases). Based on previ- ous literature, we estimated that around one third of the sample would be fused with the nation (Gómez, Brooks, et al., 2011). 3.3.2 Willingness to sacrifice A power analysis conducted with the R package ‘simr’ (Green et al., 2016) revealed that recruiting 800 participants would allow to detect Willingness to sacrifice was measured with the item ‘I am willing to be even small effects (e.g., 0.1) for the interaction between time, condition, at the front line to protect the most vulnerable from COVID-19’ using and fusion with a statistical power of 80% (95% CI [70.8, 87.3]) based a scale from 1 (‘Totally disagree’) to 5 (‘Totally agree’). In addition, an on 1000 simulations, an α = .05, and three observations per respon- extended 4-item sacrifice scale was added in Wave 3 to confer internal dent. validity to the 1-item sacrifice measure we used across all three waves. Informed consent was obtained from all participants at the start of The extended sacrifice scale was adapted from Day and Impett (2018), the survey. including four items capturing participants willingness to engage in 4 PRETUS AND VILARROYA different behaviours (‘I would be willing to invest time that I could have elled the variance of the endogenous variables of the model (the medi- spent elsewhere’, ‘I would be willing to invest money that I could have ator and the dependent variable) at the between-subjects level (level spent elsewhere’, ‘I would be willing to spend less time with friends 2) following Rosseel (2012). In the moderated mediation, we tested the and family’, and ‘I would be willing to miss the opportunity to engage conditional effect of identity fusion on the indirect effect of both social in a more pleasurable activity’) to help society against the coronavirus. norms and perceived threat on change in willingness to sacrifice by fit- Responses ranged from 1 (‘Totally disagree’) to 5 (‘Totally agree’). ting two linear models with 2000 bootstrapped samples, following the procedure in Hayes (2018). For that, we created a dummy variable for identity fusion (1 = fused, 0 = non-fused) and mean centred both fusion 3.3.3 Social norms and the mediator (social norms or perceived threat). The effect of a mediator M (social norms or perceived threat) on an outcome variable Y Social norms about social distancing were measured with the item (willingness to sacrifices) as moderated by W (identity fusion) was esti- ‘Spaniards are complying with social distancing measures against mated using Hayes’ Model 14 equations (1 and 2): COVID-19’ using a scale from 1 (‘Totally disagree’) to 5 (‘Totally agree’). M = iM + aX (1) 3.3.4 Perceived threat Ŷ = iY + c′ X + b1 M + b2 W + b3 MW (2) Perceived threat was measured with the item ‘I feel that COVID-19 is a threat to me and my family’ using a scale from 1 (‘At a very low degree’) Thus, the indirect effect of X (time) on Y was computed as the prod- to 5 (‘At a very high degree’), including an option to skip the question (‘I uct of the effect of X on M and the conditional effect of M on Y (3): prefer not to answer’). a (b1 + b3 W) = ab1 + ab3 W (3) 3.3.5 Personal compliance with social distancing Adoption of social distancing measures was measured with the item ‘I 4 RESULTS am adopting all social distancing measures in my reach against COVID- 19’ using a scale from 1 (‘Totally disagree’) to 5 (‘Totally agree’). The three survey waves were conducted during two key periods within the first 6 months of the pandemic in Spain, which we here refer to as ‘recovery’ period (March to May) and ‘relapse’ period (May to August). 3.4 Analyses The ‘recovery’ period (Survey 1 to Survey 2) spans from the peak of the first COVID-19 wave up until the first lockdown, and most severe To evaluate relationships at each timepoint, we calculated Pearson’s of all, was lifted. Conversely, the second period captures a ‘relapse’ in correlations for each survey wave. Within-participant changes in per- COVID-19 cases (Survey 2 to 3), which led to the start of the second ceived threat, adoption of social distancing measures, social norms COVID-19 wave. about social distancing and willingness to sacrifice were assessed by Group averages of the variables of interest across survey waves are means of a series of mixed effect models with random intercepts for presented in Table 1 and correlations between the variables of interest participants, a fixed effect for time (Waves 1, 2 and 3) using REML (afex at each timepoint are presented in Figures 2a and b. package in R; Singmann, Bolker, Westfall, & Aust, 2016). In this section, we will first present longitudinal changes for each To test the effects of the experimental manipulation, we exam- variable over time, then proceed to test the effects of the experimental ined the effects of the experimental condition on willingness to sac- manipulation and finalise by presenting the results on the mediation of rifice in fused versus non-fused participants at baseline by means of social norms on changes in willingness to sacrifice. an OLS regression testing the interaction between the two condi- tions (national vs. global threat) and fusion (participants fused with the nation vs. non-fused). Of note, the employed identity fusion pictorial 4.1 Longitudinal changes measure (Swann et al., 2009) is typically analysed as a dichotomous variable, where the maximal score is coded as ‘fused’ and the rest of Within-participant changes in the variables of interest across the three responses as ‘non-fused’. To test hypotheses specific to groups (e.g., survey waves are presented in Figure 1. fused participants), we examined the group-specific parameter esti- mates (simple effects). Moderated mediation analyses were conducted by means of the R 4.1.1 Identity fusion package ‘lavaan’ (Rosseel, 2012). Because we had repeated measures for each participant, we conducted a multilevel structural equation While 49% of the sample was fused with the nation at survey wave 1, model with participant ID as the clustering factor. We modelled the this percentage dropped to 39% in survey wave 3, c2 (1) = 12.60, p < moderated mediation at the within-subjects level (level 1) and mod- .001 (see Figure 1e). SOCIAL NORMS (NOT THREAT) MEDIATE WILLINGNESS TO SACRIFICE IN INDIVIDUALS FUSED WITH THE NATION 5 TA B L E 1 Averages of the variables of interest across the three survey waves Survey wave 1: Survey wave 2: Survey wave 3: 26––30 March 2020 5–11 May 2020 4–10 August 2020 mean(sd) mean(sd) mean(sd) 7-day moving average of daily new cases* 6860 603.7 4016.7 Fused with nation (N) 333 (49%) n/a 267 (39%) Willingness to sacrifice (1 = low, 5 = high) 3.47 (1.14) 3.28 (1.06) 3.24 (1.11) Adoption of social distancing measures (1 = 4.51 (0.91) 4.42 (0.85) 4.21 (1.00) low, 5 = high) Perceived normativeness of social 3.22 (0.99) 2.80 (1.05) 2.58 (0.99) distancing (1 = low, 5 = high) Perceived threat (1 = low, 5 = high) 3.94 (1.06) 3.44 (1.21) 3.58 (1.14) *according to worldometers.info. F I G U R E 1 Longitudinal changes across the three survey waves, including perceived threat (a), adoption of social distancing measures (b), social norms about social distancing (c), willingness to sacrifice (d) and identity fusion with the nation (e). Only two timepoints were available for identity fusion (Mar-20 and Aug-20). The dashed line in Figures a–d show the 7-day average of national daily new cases across the three timepoints for visual reference (the number of cases has been divided by 2000 to fit the y-axis) 6 PRETUS AND VILARROYA 4.1.2 Willingness to sacrifice 4.3 The relevance of norms in fused individuals In parallel to social norms, willingness to sacrifice for others decreased Norms about social distancing were also particularly relevant for fused during the recovery period, Mw2-w1 = –0.20, 95% CI [–0.30, –0.09], participants in the longitudinal analyses. Specifically, norms about t(1358) = –4.46, p < .001, Cohen’s d = 0.18, stabilising in the relapse social distancing mediated change in willingness to sacrifice, but only period (p = .66) (see Figure 1d). in individuals fused with the nation. The moderated mediation model testing the indirect effects of social norms on change in willingness to sacrifice in fused versus non-fused participants (see Figure 2d) 4.1.3 Social norms revealed that, in fused participants, 48% of the effect of time on will- ingness to sacrifice was mediated by social norms about social distanc- During the recovery period, perceived social norms about social dis- ing (Est. = 0.48, 95% CI [0.23, 0.72], p < .001), while indirect effects tancing dropped, Mw2-w1 = –0.42, 95% CI [–0.53, –0.32], t(1358) = – of norms in non-fused participants were less pronounced (Est. = 0.30, 9.3, p < .001, Cohen’s d = –0.42, a tendency that continued during the 95% CI [0.01, 0.58], p = .04). Direct comparison of the indirect effects of relapse period, Mw3-w2 = –0.22, 95% CI [–0.32, –0.11], t(1358) = –4.72, social norms revealed significant differences between fused and non- p < .001, Cohen’s d = –0.21 (see Figure 1c). fused participants (Est. = –0.09, 95% CI [–0.16, –0.02], p = .011). The detailed results of this moderated mediation are presented in Table 2. In parallel to the experimental manipulation results, perceptions of 4.1.4 Adoption of social distancing measures threat did not particularly influence longitudinal change in willingness to sacrifice. To test this idea, a second moderated mediation analysis Adoption of social distancing measures remained stable during the was conducted evaluating the mediating effects of perceived threat on recovery period (p = .10), but experienced a drop during relapse, change in willingness to sacrifice in fused and non-fused participants. Mw3-w2 = –0.22, 95% CI [–0.32, –0.12], t(1358) = –5.23, p < .001, This model failed to detect a mediation effect of perceived threat both Cohen’s d = –0.26 (see Figure 1b). in fused (Est. = –0.03, 95% CI [–0.17, 0.12], p = .71) and non-fused par- ticipants (Est. = 0.07, 95% CI [–0.06, 0.20], p =.30). The 1-item sacrifice scale correlated with the extended 4-item sac- 4.1.5 Perceived threat rifice scale introduced at Wave 3 (r = .40, 95% CI [0.34, 0.47], p < .001). Perceived threat decreased during the recovery period, Mw2-w1 = – 0.50, 95% CI [–0.61, –0.39], t(1341) = –10.81, p < .001, Cohen’s d = 5 DISCUSSION –0.47, and increased again during the relapse period, Mw3-w2 = 0.15, 95% CI [0.04, 0.26], t(1342) = 3.20, p < .001, Cohen’s d = 0.12, with- The aftermath of a catastrophe is typically characterised by a surge out ever reaching initial levels, Mw3-w1 = –0.35, 95% CI [–0.46, –0.24], in social support and solidarity, a phenomenon some authors refer to t(1342) = –7.61, p < .001, Cohen’s d = –0.33 (see Figure 1a). as ‘honeymoon period’ or ‘post-disaster utopia’. Identity fusion with the community has been previously found to mediate altruism in post- disaster settings. Our longitudinal three-wave study evaluated the 4.2 Effects of the experimental threat relationship between identity fusion, social norms, and willingness to manipulation sacrifice throughout the first 6 months of the COVID-19 pandemic in Spain, one of the European countries most affected by this disease. The national threat (vs. global threat) condition elicited higher willing- While the altruistic response in fused individuals was not particularly ness to sacrifice across the sample in Wave 1 (Mdiff = 0.20, 95% CI [0.03, influenced by the national (vs. universal) threat experimental condition, 0.37], t(678) = 2.32, p = .021), though fused participants did not dif- social norms were decisive in shaping fused individual’s willingness to ferentially respond to the experimental condition (B = 0.15, 95% CI [– sacrifice. At baseline, fused (vs. non-fused) participants with stronger 0.19, 0.48], t(678) = 0.84, p = .40). Participants fused with the nation (vs. weaker) norms about social distancing reported the highest levels did also not particularly exhibit increased willingness to sacrifice com- of willingness to sacrifice. Longitudinally, a moderated mediation model pared to non-fused participants across conditions (Mdiff = 0.16, 95% CI revealed that, specifically in fused individuals, decreasing social norms [0.01, 0.33], t(678) = 1.88, p = .061). However, individuals fused with about social distancing rather than changes in perceived threat medi- the nation with stronger norms about social distancing did show con- ated 48% of the drop in willingness to sacrifice. siderably higher willingness to sacrifice both compared to fused partic- Our findings contribute to identity fusion theory by underlining the ipants with weaker norms (Mdiff = 1.12, 95% CI [0.63, 1.61], t(676) = role of norms rather than perceived threat in mediating willingness 4.46, p < .001), and compared to non-fused participants with stronger to engage in extraordinary actions on behalf of the group in fused norms (Mdiff = 0.49, 95% CI [0.14, 0.84], t(676) = 2.75, p = .006, see individuals. While the influence of social norms on people’s choices Figure 2c). and behaviour is a well-established phenomenon (Cialdini & Goldstein, SOCIAL NORMS (NOT THREAT) MEDIATE WILLINGNESS TO SACRIFICE IN INDIVIDUALS FUSED WITH THE NATION 7 F I G U R E 2 The key role of social norms in participants fused with the nation. (a) Chart of the number of confirmed COVID-19 cases in Spain as presented to participants in the national threat condition, (b) World map representing the number of COVID-19 cases confirmed globally as shown to participants in the global threat condition (extracted from John Hopkins University, 2020). (c) Norms about social distancing correlated with willingness to sacrifice across the three timepoints in participants fused with the nation (p < .04) but not in non-fused participants (p > .28). (d) Perceived threat did not correlate with willingness to sacrifice in participants fused with the nation at any of the three timepoints (p > .26), and only in the second wave in non-fused participants (p = .001), (e) Individuals fused with the nation with stronger norms were more willing to sacrifice for others compared to those with weaker norms, a difference that was not observed in non-fused participants, (f) Conceptual model of the tested moderated mediation, with identity fusion moderating the indirect effect of social norms on change in willingness to sacrifice 2004; Morris et al., 2015; Paluck, 2009), social norms so far have Our findings may also be relevant for the development of norm- been excluded from collective action models (Tausch et al., 2011; van based behavioural interventions, which could benefit from targeting Zomeren, 2013; van Zomeren et al., 2011, 2018) and identity fusion norms in combination with fusion. Because our data suggests that literature (Gómez, Brooks, et al., 2011; Swann et al., 2009, 2014). fused individuals are more responsive to norms than non-fused indi- Previous studies with very limited samples (N = 40) have found that viduals, norm-based interventions may be especially effective in mobil- social influence regulates extreme pro-group action in fused individu- ising particular behaviours in emergency settings, where we find a tem- als (Hamid et al., 2019). In the present study (N = 680), we found that (a) porary surge in identity fusion. More generally, promoting norms in change in perceived social norms account for almost 50% of the change combination with an appeal to shared identities, may be more effective in disposition to sacrifice in fused individuals, (b) norms correlated with than targeting either of these separately. willingness to sacrifice at each timepoint in fused (but not in non-fused) Of note, fused individuals in our sample did not differentially individuals and (c) fused individuals with strong norms were more will- respond to ingroup compared to global threat conditions. In line with ing to sacrifice both compared to fused participants with weak norms this, self-reported perceived threat at each timepoint was unrelated to and non-fused participants with strong norms. Thus, our results stress willingness to sacrifice in fused individuals. Thus, our results suggest the need to include social norms as a key factor in psychological models that fused participants in our sample were not particularly mobilised that aim to explain extreme pro-group action. by perceptions of threat. This finding adds some nuance to previous 8 PRETUS AND VILARROYA TA B L E 2 Results of the mediation effect of social norms conditional on identity fusion with the nation 95% CI 95% CI Estimate SE z-value p-value lower higher a –0.64 0.05 –13.76 <.001 –0.73 –0.55 b1 0.14 0.03 4.04 <.001 0.07 0.20 b2 0.13 0.09 1.53 .126 –0.03 0.30 b3 0.14 0.05 2.60 .009 0.04 0.25 c’ –0.13 0.05 –2.60 .009 –0.23 –0.03 High identity fusion Indirect effect –0.12 0.03 –4.53 <.001 –0.17 –0.07 Direct effect –0.13 0.05 –2.60 .009 –0.23 –0.03 Total effect –0.25 0.05 –5.19 <.001 –0.35 –0.16 Proportion mediated 0.48 0.13 3.77 <.001 0.23 0.72 Low identity fusion Indirect effect –0.06 0.03 –2.20 .028 –0.11 –0.01 Direct effect –0.13 0.05 –2.60 .009 –0.23 –0.03 Total effect –0.19 0.05 –3.89 <.001 –0.28 –0.09 Proportion mediated 0.30 0.14 2.06 .040 0.01 0.58 claims that individual effects of identity fusion are stronger under con- our data, the surge in the altruistic response that characterises the ditions of threat (Gómez, Brooks, et al., 2011; Gómez, Morales, et al., ‘post-disaster utopian’ phase also seems to be accompanied by a peak 2011; Swann et al., 2009). These claims are often based on Gómez et al. in identity fusion, which later dissolves. While a recent study by Segal (2011), who found that ostracism, which the authors describe as form et al. (2018) already described increased identity fusion upon recall of social threat, increases endorsement of extreme pro-group action in of a major earthquake in Christchurch, New Zealand, we were able to fused individuals. Whereas ostracism may be a social threat, the desire detect real-time changes in identity fusion within the same individuals to fit in could lead to increased salience of social norms. Thus, this study throughout the first months of the COVID-19 pandemic. This was does not allow us to make a clear distinction between the effects of relatively unexpected, due to the high stability of this construct in social norms and perceptions of threat. ordinary contexts. Interestingly, perceived threat followed a U-shape, Our study raises the possibility that (non-social) threat may be irrel- as cases dropped and increased again at the end of the summer. evant in fused individuals’ disposition to engage in pro-group action, However, this relapse in cases and perceived threat did not trigger a offering a unique contribution to identity fusion theory. Our results second ‘honeymoon’ period, and willingness to sacrifice and feelings of suggest that fused individuals are unresponsive to perceptions of oneness with the group kept deteriorating (and normalising), stressing threat when it comes to engaging in extreme pro-group action. Rather, the relative disconnect between actual threat and willingness to it seems that fused individuals’ behavioral dispositions mirror social sacrifice. norms, or what the group deems relevant at each moment in time. The present study has several limitations. Owing to timing con- In terms of changes in identity fusion over time, we observed a straints, we ran short surveys with few items, which limited our ability trajectory similar to that described by Kaniasty and Norris (2004) in to run internal validity checks. Scales with multiple items, compared to catastrophe settings. A couple of weeks into the pandemic (March one-item scales, allow internal consistency testing and the minimisa- 2020) we registered notably high scores in willingness to sacrifice tion of random measurement error, ensuring greater reliability regard- and identity fusion with the nation. For instance, while previous ing the measurement of the concept of interest. However, the observed studies typically find one third of the general population in Spain to relationships between our 1-item measures are well aligned with exist- be fused with the nation (Gómez, Brooks, et al., 2011), we detected an ing literature and shed light on a historical event that offered a unique overwhelming 49% of fused participants. However, 6 months into the opportunity to study human cooperation during a pandemic. More- pandemic, only 39% of the same individuals reported being fused with over, the employed experimental stimuli were chosen mainly because Spain, closer assimilating observations in pre-pandemic studies. This of their ecological validity: common graphs to which news consumers unexpected finding suggests a process of de-fusion that is compatible were exposed at the time of the first survey wave. Yet, choosing ecolog- with previous psychosocial models that describe a transition from a ical stimuli often comes at a cost. For instance, our design did not con- ‘post-disaster utopian’ phase, characterised by high levels of mutual trol for salience of the nation (present only in the national threat con- helping, to a phase of deterioration of social support that comes dition). However, our experimental stimuli did elicit differences in will- with a long burdensome recovery (Kaniasty & Norris, 2004). As per ingness to sacrifice across the whole sample in line with our predictions SOCIAL NORMS (NOT THREAT) MEDIATE WILLINGNESS TO SACRIFICE IN INDIVIDUALS FUSED WITH THE NATION 9 (i.e., greater willingness to sacrifice in response to national vs. global enforcement. Human Brain Mapping, 33(6), 1452–1469. https://doi.org/ threat), offering some validation to our stimuli. Furthermore, our study 10.1002/hbm.21298 Bernhard, H., Fischbacher, U., & Fehr, E. (2006). Parochial altruism leveraged a real-world event, the COVID-19 pandemic, which affected in humans. Nature, 442(7105), 912–915. https://doi.org/10.1038/ virtually everyone. Therefore, a control group of people who were not nature04981 exposed to the pandemic was unavailable and, thus, we cannot rule out Bowe, M., Wakefield, J. R. H., Kellezi, B., Stevenson, C., McNamara, N., Jones, time-related confounds in our longitudinal analyses (e.g., seasonality or B. A., Sumich, A., & Heym, N. (2021). The mental health benefits of com- munity helping during crisis: Coordinated helping, community identifica- other global and national events that potentially affected responses). tion and sense of unity during the COVID-19 pandemic. Journal of Com- Finally, our survey was conducted with an online sample, which may munity and Applied Social Psychology, https://doi.org/10.1002/casp.2520 have introduced biases related to the respondents’ ability or willing- Buhrmester, M. D., & Swann, W. B. (2015). Identity fusion. Emerging trends ness to take surveys online (Vaske, 2011). in the social and behavioral sciences (pp. 1–15). Wiley. https://doi.org/10. 1002/9781118900772.etrds0172 In sum, we present evidence that willingness to sacrifice for oth- Cialdini, R. B., & Goldstein, N. J. (2004). Social influence: Compliance ers in times of the COVID-19 pandemic is intimately related to social and conformity (1974), 55, 591–621. https://doi.org/10.1146/annurev. norms rather than perceived threat, especially in participants who feel psych.55.090902.142015 viscerally connected with the nation. Our results are particularly rel- Day, L. C., & Impett, E. A. (2018). Giving when it costs: How interdependent evant in an increasingly inter-dependent world that inevitably faces self-construal shapes willingness to sacrifice and satisfaction with sacri- fice in romantic relationships. Journal of Social and Personal Relationships, striking global challenges. In line with our findings, policies demanding 35(5), 722–742. https://doi.org/10.1177/0265407517694965 a certain level of sacrifice from citizens in the face of global challenges European Council. (2020). European solidarity in action. https: (e.g., reducing greenhouse gas emissions) may benefit from implement- //www.consilium.europa.eu/en/policies/coronavirus/european- ing combined approaches by appealing to both social norms and shared solidarity-in-action/ Fehr, E., & Fischbacher, U. (2004). Third-party punishment and social norms. identities, as well as emphasizing the national or local relevance of the Evolution and Human Behavior, 25(2), 63–87. https://doi.org/10.1016/ problem at stake. S1090-5138(04)00005-4 Fritz, C. E. (1961). Disasters. In R. K. Merton & R. A. Nis- ACKNOWLEDGEMENT bet (Eds.), Contemporary social problems (pp. 651–694). New York: Harcourt, Brace and World. https://www.google.com/ This research was supported by the I+D grant RTI2018-093952-B-I00 search?q=Fritz%2C+C.+E.+(1961).+Disasters.+In+Contemporary+S (Ministerio de Ciencia, Innovación y Universidades). ocial+Problems%2C+ed.+R.+K.Merton+and+R.+A.Nisbet%2C+pp.+ 651–694.+New+York%3A+Harcourt.&rlz=1C1GCEA_enES877ES877 CONFLICT OF INTEREST &oq=Fritz%2C+C.+E.+(1961).+Disasters.+In+Contemporary+Social Gómez, Á. (2020). What doesn’t kill us makes us stronger: the COVID-19 The authors declare no conflict of interest. pandemic transforms anonymous citizens into devoted actors (Lo que no nos mata nos hace más fuertes: la pandemia de COVID-19 trans- ETHICS STATEMENT forma a los ciudadanos anónimos en actores devotos). International Jour- This research was approved by the ethical review board of the Univer- nal of Social Psychology, 611–617. https://doi.org/10.1080/02134748. 2020.1783838 sitat Autònoma de Barcelona (Ref. 5114) according to the Declaration Gómez, Á., Brooks, M. L., Buhrmester, M. D., Vázquez, A., Jetten, J., & Swann, of Helsinki guidelines. W. B. (2011a). On the nature of identity fusion: Insights into the con- struct and a new measure. Journal of Personality and Social Psychology, PATIENT CONSENT STATEMENT 100(5), 918–933. https://doi.org/10.1037/a0022642 Informed consent was obtained from all participants at the start of the Gómez, Á., López-Rodríguez, L., Sheikh, H., Ginges, J., Wilson, L., Waziri, H., Vázquez, A., Davis, R., & Atran, S. (2017). The devoted actor’s will to fight survey. and the spiritual dimension of human conflict. Nature Human Behaviour, 1(9), 673–679. https://doi.org/10.1038/s41562-017-0193-3 DATA AVAILABILITY STATEMENT Gómez, Á., Morales, J. 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