Adding
a
psychological
dimension
to
mass
gatherings
medicine
Nick
Hopkins
a,*,
Stephen
Reicher
baPsychology,SchoolofSocialSciences,UniversityofDundee,DundeeDD14HN,UK
bSchoolofPsychologyandNeuroscience,UniversityofSt.Andrews,St.Andrews,UK
1. Introduction
Mass gatherings medicine (MGM) has two key claims to distinctiveness.Thefirstisoneofscale:Whenthingsgowrongat mass events, emergency and medical services may be over-whelmed.Thatis, massgatherings present uniqueproblems in termsofmedicalprovision.1 Asecondconcernsdiversity:Many
massgatheringsareglobalintermsofwherepeoplecomefrom. Peoplecomefromalmosteverynationonearthtoeventssuchas theOlympics,thefootballWorldCup,ortheHajj.Theycongregate together,oftenin closephysical proximityandfor anextended period.Thentheydispersebacktotheirhomes.Inthisway,thereis auniqueopportunityforinfectionsthatstartoffinonelocationto spreadfarandwide.2
Thesearereasonsenoughforadistinctiveresearchprogramme concerning mass events. However, there is a third form of distinctiveness–afurtherwarrantforadistinctiveMGMresearch agenda.Thisrelatestowhatpeopledowhentheycometogether. Ourargumentisthatonecannottreatmassgatheringssimplyin terms of the agglomeration of very large numbersof different people.Rather,beinggatheredtogetherchangesindividualsand leadsthemtoactinwaysthataredifferentfromtheireveryday
lives.Thesechangesandthebehavioursthatarisefromthemcan impactuponpeople’shealthandwell-beinginavarietyofways. Moreover,thebehavioursadoptedbycrowdmembersmayhave direct relevance for theprocesses of infectiontransmission. In what follows, we explain the need for MGM research to pay attentiontoboth(1)thewaysinwhichpeoplechangewhenthey arepartofacrowd,and(2)thewaysinwhichthesechangesimpact uponhealth-relatedpracticesandwell-being.
2. Thepsychologyofthemass
Thereisnothingnewinsayingthatpeopleandtheirbehaviour changeincrowds:Reiwald(1949)amassedacompendiumofsuch commentariesgoingbacktoHerodotus.3Ofallanalyses,thatofLe
Bon(1895)hasbeenthemostinfluential.4Hearguedthatwhen people are ‘submerged’ in the mass, they lose their sense of individualidentityandrationality,andasaconsequence,simply followanyideaoremotionthatissuggestedtothem.Thatis,crowd members’behaviourbecomeslesscontrolled,moreirrational,and riskierthannormal.Theseassumptionsareparticularlyprominent whencrushingincidentsaredescribed(suchasthatinMinaduring the2015Hajj,whenmanyhundredpilgrimsdiedapproachingthe JamaraatBridge).Here,talkofirrational‘panic’and‘stampedes’is routine.
Recently,thispopularaccounthasbeenchallenged.Certainly, crowdpsychologyisdistinctive,butwenowhaveanalternative
ARTICLE INFO
Articlehistory:
Received2December2015
Receivedinrevisedform23December2015 Accepted23December2015
CorrespondingEditor:EskildPetersen, Aarhus,Denmark.
Keywords: Massgatherings Infectiontransmission Socialidentity Norms
SUMMARY
Massgatheringsposedistinctive challengesformedicine. Oneneglectedaspectofthis is thatthe behaviourofpeopleparticipatinginsucheventsisdifferentfromthebehaviourtheyexhibitintheir everydaylives.Thispaperseekstodescribeasocialpsychologicalperspectiveontheprocessesshaping people’sbehaviouratmassgatheringsandtoexplorehowthesearerelevantforanunderstandingofthe processesimpactingonthetransmissionofinfection.Itisinadequatetoconceptualizemassgatherings assimplyanaggregateofalargenumberofindividuals. Rather,those presentmayconceptualize themselvesintermsofacollectivewithasharedgroupidentity.Thinkingofoneselfandothersas membersofacollectivechangesone’sbehaviour.First,onebehavesintermsofone’sunderstandingof thenormsassociatedwiththegroup.Second,therelationshipsbetweengroupmembersbecomemore trustingandsupportive.Understandingthesetwobehaviouralchangesiskeytounderstandinghowand whymass gatheringparticipantsmay behavein waysthatmake themmoreorlessvulnerableto infectiontransmission.Implicationsforhealtheducationinterventionsarediscussed.
ß2016TheAuthors.PublishedbyElsevierLtdonbehalfofInternationalSocietyforInfectiousDiseases. ThisisanopenaccessarticleundertheCCBYlicense(http://creativecommons.org/licenses/by/4.0/).
* Correspondingauthor.
E-mailaddress:n.p.hopkins@dundee.ac.uk(N.Hopkins).
ContentslistsavailableatScienceDirect
International
Journal
of
Infectious
Diseases
j o urn a l hom e pa ge : ww w. e l s e v i e r. c om/ l o ca t e / i j i d
http://dx.doi.org/10.1016/j.ijid.2015.12.017
understandingofjusthowitisdistinctive,5,6whichdrawsonthe
socialidentityperspectivetogroupprocesses.7,8Thesocialidentity approachtogroupprocessesiswell-evidencedandmaintainsthat wheninacrowd,peopledonotloseidentitybutrathershiftfroma sense of personal identity (what makes me, as an individual, distinctive compared to other individuals) to a sense of social identity(whatmakesus,asagroup,distinctivecomparedtoother groups).That is,at mass gatherings (e.g., theHajj, thefootball WorldCup,amusicfestival)onemaystarttothinkofoneselfasa memberofacollective withashared identity(e.g.,asHajjis,as football fans, as festival-goers). The shift from an individual
personalidentificationtoagroup-basedsocialidentificationisnot automaticorguaranteed(andsomeeventsmaybecharacterized by factionalism and an absence of shared identity). Moreover, individualsatthesameeventmayvaryinthedegreetowhichthey conceiveofthemselvesandotherevent-goersintermsofashared groupmembership.However,tothedegreethatanindividualdoes indeedidentifywithothers(includingthosethattheydonotknow personally),there are multipleconsequences,two of whichare particularlyrelevantforpresentpurposes.
First,thereisa‘normativeshift’:Peoplechangefromactingin termsoftheirindividualidiosyncraticbeliefsandvaluesto group-basedbeliefs and values. To continue withtheexamples listed above,theybegintoactonthebasisofwhattheybelieveitmeans tobeaHajji,afan,orafestival-goer.Theprioritiestheysetandthe goalstheypursuedependuponwhatisvaluedbythesevarious groups.Thus,whatpeopledoinanygivencrowddependsonthe groupanditsnorms.
Second, there is a ‘relational shift’: When people define themselvesin terms of a social identityand see each otheras sharingthesamesocialidentity,thesocialrelationsbetweenthem becomemarkedlymoreintimate.Thus,thereisagrowingbodyof evidence to show that group members are more cooperative, respectful,trusting,supportive,andhelpfultowardseachother.9,10
Moreover,peoplewhoshareagroupidentityseekgreaterphysical proximity11 and feel more comfortable with crowding.12 This
sense of intimacy and support contributes to the intensively positiveemotionsthatcharacterizemanycrowdevents.13
3. Crowdsandhealth
These normative and relational processes can impact upon behaviourinavarietyofways.
3.1. Normativeimpacts
Thereareatleastthreewaysinwhichgroupnormsmayimpact healthpracticesandhencehealthandwell-being.Thefirstisthat thegroupsinvolvedinmassgatheringsmayhavenormsthataffect theoverallvalueplacedupongoodhealth.Forinstance,incontexts whereyouthisadefiningfeature(e.g.,musicevents),thenvalues associatedwithbeing‘adventurous’and‘carefree’mayencourage practicesthatexposeonetorisk,e.g.,unprotectedsex.14Atother
events, the norms may be rather different, but also result in lessened concern about protecting oneself. Thus, at the Hindu Magh Mela15 and Kumbh Mela16,17 (Allahabad, north India),
pilgrims strive to transcend the material in order to devote themselvestoaspiritualexistence.Thebodycountsfornothing. Indeed,thebodyisanimpedimenttoachievingastateofgrace.At theextreme,itcanbeviewed asauspicioustodiewhile atthe Mela. Moreover,it is normative totrust tofaith asa protector againstill-health,whichcanleadpilgrimstostoptakingmedicines andabstainfromseekingmedicalhelpincasesofillness.
Asecondwayinwhichgroupnormsmayaffecthealthand well-being concerns the practices that are judged appropriate. For example,attheMaghMela,pilgrimsbatheinandsipwaterfrom
thesacred(yetpolluted)Gangesandtakebackplasticbottlesofit fortheirfamiliesathome.Thiscanhaveseriousconsequencesfor their healthandhasbeenshowntoresultinanincreaseinthe numberofcasesofnon-bloodydiarrhoea.18Atotherevents,the
behavioursadoptedbycrowdmembersmayincreasethechances of spreading infection.For example, blowingvuvuzelas (plastic blowinghornsoftenusedatAfricanandAsiansportingevents)can facilitate thegeneration and disseminationof respiratory aero-sols.19
Third,therearenormsthatdonotdirectlyimpacthealthand well-beingbutthatmayusurpeverydaynormsthatdo.Inmany casesthesehavetodowithperseveranceandendurance.These derive fromthefact that,in many cases,group membership is enhancedorevendependentuponcompletingthecollectiveevent. Atruefootballfanisonewhogoestogamescomerainorshine.20 CompletionoftheMaghMelafor12consecutiveyearsprovides specialstatusandaccordsgracetoHindus.Finishing theHajjat leastonceisacoregoalforeachandeveryfaithfulMuslim.Asa consequence, people are reluctant to give up even if they are unwellorinfectious,andcontinuingconstitutesathreatbothto themselves and to others. Indeed at some events (such as pilgrimages), sufferingill-health canbe partof thepleasure of theeventbecausecompletingone’spilgrimageinthefaceof ill-healthmaybeunderstoodasimplyingthatthedeitiesarepotent andprotective.
Together,thesebriefillustrationshintatthemultiplewaysin whichcollectivenormscanimpactontheindividual’sbehaviourin waysthatmaybeconsequentialfortheirownhealthandindeed thehealthofothers.Thesegroupnormsandtheirconsequences arecomplex.Justassomenormsmayencouragebehavioursthat increase the individual’s vulnerability to the transmission of infection,sosomenormsmayworktoprotecthealth.Forexample, at some events there may benormative prohibitions on some behaviours(e.g.,concerningdruguse),whichthenhaveknock-on effectsofdecreasingthelikelihoodofengaginginotherbehaviours (e.g., unprotected sex) that couldfacilitate the transmission of infection.Moreover,severalhealth-relevantnormsmay simulta-neously beof relevance in any given gathering.Inevitably, the natureofthenormsthatarerelevanttocrowdmembers’ health-relatedbehaviourswillbespecifictotheeventinquestion,which meansthatthewayinwhichnormsoperateinrelationtohealth willbedifferentforeverymassgathering.Inturnthismeansthat anunderstandingofinfectiontransmissionopportunities,etc.,will dependuponasituatedanalysisfortheeventofinterest.
3.2. Relationalimpacts
Themulti-directionalnatureoftheimpactsofcrowdprocesses on health is even more apparent when we consider thesocial relationalchangesincrowds.Asnotedearlier,asharedidentityina group leads to the provision of social support. Indeed, the expectation ofsuchsupport21 canmakepeople feelbetterable
todealwithstressfulsituationsandtherebyimprovetheir well-being. Thus, group membership can improve both mental and physical well-being in stressful situations,22,23can improvethe
functioningoftheelderly,24protectagainstdepression,25andhelp
protectself-esteemamongstyoungpeoplenegotiatingbarriersto individualdevelopment.26
Inourownresearchwehaveextendedthisworkintwoways. First, we investigated whether such effects extend from small groupstomassgatherings.Second,weinvestigatedwhetherany sucheffectsextendedbeyondthegatheringitselftoone’ssenseof physicalandmentalwell-beingbackineverydaylife.
self-assessedhealth.27Althoughtheeventiscrowded(withseveral
millionattendingonthemostauspiciousbathingdaysandmany hundreds of thousands living on the Gangesfloodplain for the wholemonth),participantsinalongitudinalsurveystudy(witha controlsampleofnon-participants) reportedbetterhealthafter theevent thanbefore. Given thedifficultiesposed by thecold weather,28 the basic living conditions and diet, and the noise
throughouttheday,29thisisstriking.Moreover,thereisevidence
thatasenseofsharedidentityattheeventwaskey:Themorethat participantsattheeventreportedfeelingasharedidentitywith theirfellowpilgrims,themoretheyreportedrelationalintimacy withothers,andthegreatertheincreaseinself-assessedhealth frombeforetoaftertheevent.30Basedonoursurveydataandon
ourinterviewswithpilgrims,15webelievethatanyunderstanding
of how the psychology of crowd membership shapes health-related behaviour and practice must pay regard to crowd members’understandingsofboththenormsassociatedwiththeir shared identity and the relational intimacy that is engendered betweencrowdmembers.Thus,evenifitistruethatsomepeople get ill through the harsh, crowded, noisy, and unsanitary conditionsof pilgrimage, the great majority(who do not)may reportimprovedself-assessedhealth.
Yet,thissamesenseofconnectionwithotherscanbringrisks. Takefor exampletheissue of disgust.This is oftenseen asan evolved tendency that keeps us distant fromthe pathogens of others,31particularlythoseofstrangers,towhichwemayhaveless
immunity.32Unsurprisingly,wearelessdisgustedbytheexcretaof
intimates than that of aliens. For instance, our own children’s diapersoffenduslessthanthoseofotherchildren.33Alittlemore
surprisingly,perhaps,wehavefoundthatwearelessdisgustedby asweatyt-shirtbelongingtoastranger,whenthatpersonhappens tobea memberofa groupwithwhichweidentifyourselves(a fellowstudent,say).Such alossofdisgustmaybefunctionalin termsofallowingfamiliestolivetogetherandgroupstocohere. Yet, at the same time, the lessening of disgust may be dysfunctional, leading us to drop our guard against forms of proximity and physical conduct that could facilitate infection transmission.Thisis where thesocial psychologicalanalysis of crowd behaviour is especially relevant to issues of infectious diseases.Wherepeoplearelessdisgustedbythephysicalpresence ofothers,andareevenwillingtotoleratetheirphysicalexcreta, thismaymakepossibleaseriesofpracticesthatexposepeopleto thespreadofdisease.Theymaybeslowertodistancethemselves fromsomeonewhoiscoughingandspluttering.Theymaybemore willing toshare food and drink, to loanhandkerchiefs, and to accept such loans in turn. Moreover, all this sharing may be facilitatedbythesenseofpositiveemotionandenhanced well-beingthatmanyexperienceatmassgatherings.
Once again, the process of lowered disgust may be general wherepeopleshareidentityinamassgathering,buttheimpact willbespecific,dependingonwhatbehavioursarerelevantinthe particulargatheringofinterest.Sharingbottlesofbeerorkissing strangersmayberelevantatmusicfestivalssuchasGlastonbury (UK), but not at the Hajj. Conversely, handling discarded face masksmayberelevantattheHajj,butnotatGlastonbury.Whatis neededisamappingofthedifferentsharingpracticesatdifferent massgatherings,followedbyananalysisoftheirincidence.Such datacouldbeincorporatedintotheanalysisofpeople’scontactsin mass gatherings and so add a neglected dimension to current modelsofinfectiontransmission,whichtendtofocusoncontact frequency.34Atthesametime,inthesamewaythatitisnowwell
recognizedhowcentralsuchsimplepracticesashand-washingcan betothespreadofdiseaseinhospitalsandelsewhere35andthat observanceofsuchpracticescanbeshapedbyfocused interven-tions,36so,wesuggestthat(1)practicesofsharingmaybecentral
tothespreadofdiseaseatmassgatherings,(2)reducingthedanger
ofdiseasebeingspreadatsuchgatheringsiscriticallydependent uponinfluencingpracticesofsharing,and(3)theabilitytoachieve influenceisdependentonunderstandingthecollectivepsychology thatunderpinspracticesofsharing.
4. Usingmasspsychologytomakeadifference
Thus far we have sought to demonstrate, first, that mass psychologyiscriticaltounderstandingthehealthimpactofmass gatheringsand,second,thatthedistinctivenessofmass psycholo-gycontributestothedistinctivenessofMGM.Peoplethinkandact differentlyinmasseventstothewaystheythinkandactinmuchof day-to-daylife.Asaconsequence,theirhealthpracticesdifferfrom everydaypractices.Thisinturnshapesthewaysinwhichpeople’s healthisaffectedandthewaysinwhichill-healthspreads.Ifthe sheernumberanddiversityofpeoplewhoattendmassgatherings isrelevanttothepotentialcreationofnon-local(orevenglobal) pandemics,soisthewaythatsocialrelationsbetweenpeopleare transformedinthemass.Inshort,wehopetohaveshownthatthe additionofa psychologicaldimensioniscrucialforappreciating thedistinctivenessofthechallengesposedbymassgatherings.
Theimportanceofaddressingthepsychologicaldimensionin mass gatherings researchis sometimesnoted. However, in the absenceofa clearempiricallybasedtheoreticalframework,the approachtakentoconceptualizingmassgatheringpsychologyhas beenlimited. Typically it hasinvolved a taxonomyof different crowd ‘moods’ and their associated risks.37 Moreover, and as
hinted at earlier, it is often assumed that crowd psychology underminesjudgementandleadsindividualstobehaveinways that makemass gatheringsinherentlyrisky.Thisis particularly clear when the concept of ‘panic’ is used to describe crowd behaviour in disasters and emergencies.38 Certainly there are
accidentsatmassgatherings(indeed,atthe2015Hajj,notonly wasthereamajorcrushingincident,butearlieracranehadcome tumblingdownontotheMasjidal-Haramresultinginmorethana hundreddeaths).However,itismisguidedtocharacterizecrowd members’behaviourinsuchscenariosintermsofirrationalpanic. Wherecrushingoccursitistypicallyduetoovercrowdingcaused bypoor managementratherthancrowdmembers’irrationality, andindisasterscrowdmembersroutinelysupportandhelpeach other.39
Thesocialidentityperspectiveoffersanalternative conceptu-alizationofthebasesforcrowdmembers’behaviourthatavoids suchtalkofirrationality.Itexplainshowsocialidentityprocesses leadtomeaningfulbehaviourthatdiffersfromthatfoundwhen individuals conceptualize themselves in terms of their diverse personalidentities.Moreover,itcontributesinsightswithregards tointerventionsdesignedtoimprovemassgatheringsafety.For example,researchatmusicfestivalshighlightstheimportanceof socialidentityprocessesforcrowdmembers’resilienceintheface ofrisk,andmakesthepointthatmassgatheringorganizersand staffshouldseektousetheseprocesses(ratherthanactinways that intentionallyor unintentionallysubvert them).40 Indeed,a
social identity approachemphasizes theimportance ofofficials having a real appreciation of the particular social identities associatedwiththemassgatheringtheyarechargedwithplanning and controlling: Without this they will forever misunderstand participants’behaviourandactinwaysthatalienatethosethey mustworkwith.38Needlesstosay,suchunderstandingsmustalso
inclusionwithinMGMinformourinterventions?Willthenormal techniquesofhealthcommunicationworkincrowds?Or,doesa distinctive crowd psychology point to the need for distinctive techniques?
Ouranswertothelatterquestionis‘yes,itdoes’.Toexplain,we needtoaddonemoreelementtooursketchofmasspsychology, above.Ifitistruethat,ingroupsandcrowds,peopleshiftfrom personaltosocialidentity,andthattheyseektoactonthebasisof groupnorms,groupvalues,andgroupgoals,sosocialinfluenceisa functionofbeingabletocouchparticularmessages–inthepresent context, health-related messages – so that they are seen as a reflectionofthesenormvaluesandgoals.42,43Thisdependsupon
twofactors.Theonerelatestothesourceofthemessage:Themore thissourceis seenaspartof thegroupheor sheisseeking to influence, the greater the potential influence. The other factor relatestothecontentofthemessage:Themorethismessageis couchedinidentity-relatedterms,themoreinfluenceitislikelyto achieve.Canone,forinstance,drawongroupnormstopersuade peoplenottoperseverewhenill,orelsenottoshareresourcesthat might put others at risk? Again, the answer lies in a deep knowledgeofgroupculturealongsideaknowledgeofmedicine(to understand what practices put people most at risk) and a knowledgeofgrouppsychology(tounderstandthesocialidentity processes that encourage such practices).44 A successful MGM
needstobetrulymulti-disciplinary.Ifwehavespentmostofour time arguing for the relevance of psychology, this psychology furthersuggeststheimportanceofhistorians,social anthropolo-gists,andotherculturalexperts.
Insummary,theprinciplesofgroupinfluencesuggestthatthe way that health messages are communicated, even where the message is constant, will need to be culturally sensitive and thereforeadaptedaccordingtothespecificaudiencethatisbeing targeted.Withthisinmind,wearenowinapositiontofinishwith twosimplesummarypoints.Understandingtheoperationofsocial identityprocessesinthecrowdisthekeytounderstanding the psychological dimension of health and well-being in mass gatherings, includinginfection transmission.Understanding the socialidentityofthoseattendinganygivenmassgatheringisthe keytounderstandinghowtocommunicatewiththeminorderto protecttheirhealth.
Conflictofinterest:Theauthorshavenoconflictsofinterestto declare.TheresearchreportedherewasfundedbytheESRC(UK) researchgrant‘Collectiveparticipationandsocialidentification:A studyoftheindividual,interpersonalandcollectivedimensionsof attendanceattheMaghMela’(RES-062-23-1449).Thefundershad noroleinthedesignoranalysisofourresearch.Allresearchwas conductedinaccordancewiththeethicalpoliciesoftheBritish PsychologicalSocietyandapprovedbytheethicalreviewboardsof theuniversitiesofAllahabadandDundee.
References
1.WorldHealthOrganization(WHO).Communicablediseasealertandresponse formassgatherings.Geneva,Switzerland:WHO;2008.
2.BenkouitenS,CharrelR, BelhouchatT,DrakiT,SalezA,Nougairede.etal. Circulationofrespiratoryvirusesamongpilgrimsduringthe2012Hajj pilgrim-age.ClinInfectDis2013;57:992–1000.
3.ReiwaldP.Del’espritdesmasses.Neuchatel:DelachaixandNiestle;1949. 4.LeBonG.Thecrowd:astudyofthepopularmind.London:ErnestBenn;1895/
1947.
5.ReicherSD.Thepsychologyofcrowddynamics. In:HoggM,TindaleS,editors.
Blackwellhandbookofsocialpsychology:groupprocesses..Oxford:Blackwell; 2001.p.182–208.
6.ReicherSD.Massactionandmundanereality:anargumentforputtingcrowd analysisat thecentreof thesocial sciences.Contemporary Social Sciences
2011;6:433–49.
7.TajfelH,TurnerJ.Thesocialidentitytheoryofintergroupbehaviour. In: WorchelS,AustinWG,editors.Psychologyonintergrouprelations.. 2nd
ed., Chicago:Nelson-Hall;1986.p.7–24.
8.TurnerJC,HoggMA,OakesPJ,ReicherSD,WetherellMC.Rediscoveringthe socialgroup:aself-categorisationtheory.Oxford:BasilBlackwell;1987. 9.LevineM,ProsserA,EvansD,ReicherS.Identityandemergencyintervention:
howsocialgroupmembershipandinclusivenessofgroupboundariesshape helpingbehaviour.PersSocPsycholBull2005;31:443–53.
10.WakefieldJR,HopkinsN,CockburnC,ShekKM,MuirheadA,ReicherS,van RijswijkW.Theimpactofadoptingethnicorcivicconceptionsofnational belongingforothers’treatment.PersSocPsycholBull2011;37:1599–610. 11.NovelliD,DruryJ,ReicherS.Cometogether:twostudiesconcerningtheimpact
ofgrouprelationson‘personalspace’.BrJSocPsychol2010;49:223–36. 12.AlnabusiH,DruryJ.Socialidentificationmoderatestheeffectofcrowddensity
onsafetyattheHajj.ProcNatlAcadSciUSA2014;111:9091–6.
13.HopkinsNP,ReicherSD,KhanSS,TewariS,SrinivasanN,StevensonC. Explain-ingeffervescence:investigatingtherelationshipbetweensharedsocialidentity andpositiveexperienceincrowds.CognEmot2016;30:20–32.
14.BriggsD,TutengesS.Riskandtransgressiononholiday:‘newexperiences’andthe piedpiperofexcessiveconsumption.IntJTourismAnthropol2014;3:275–98. 15.HopkinsN,StevensonC,ShankarS,PandeyK,KhanSS,TewariS.Beingtogether
attheMaghMela:thesocialpsychologyofcrowdsandcollectivity.In:GaleT, MaddrellA,TerryA,editors.Sacredmobilities.Farnham,UK:Ashgate;2015.p. 19–39.
16.MacleanK.Pilgrimageandpower:theKumnhMelainAllahabad,1765-1954. Oxford:OxfordUniversityPress;2008.
17.SridharS,GautretP,BrouquiP.AcomprehensivereviewoftheKumbhMela: identifying risks for spread of infectious diseases. Clin Microbiol Infect
2015;21:128–33.
18.TheKumbhMelaPublicHealth(KMPH)team.PublichealthattheKumbhMela. HarvardSchoolofPublicHealth.Availableat: http://fxbkumbh.wordpress.-com/.(accessedApril29,2015).
19.LaiKM,BottomleyC,McNerneyR.Propagationofrespiratoryaerosolsbythe vuvuzela.PLoSOne2011;6:e20086.
20.NevilleFG.Theexperienceofparticipatingincrowds.UnpublishedPhDThesis. UniversityofSt.Andrews;2012.
21.HaslamSA,ReicherSD,LevineM.Whenotherpeopleareheaven,whenother peoplearehell:howsocialidentitydeterminesthenatureandimpactofsocial support. In:JettenJ,HaslamC,HaslamSA,editors.Thesocialcure.London: PsychologyPress;2012.p.157–74.
22.HaslamSA,O’BrienA,JettenJ,VormedalK,PennaS.Takingthestrain:social identity, social support, and the experience of stress. Br J Soc Psychol
2005;44:355–70.
23.GallagherS,MeaneyS,MuldoonOT.Socialidentityinfluencesstressappraisals and cardiovascularreactions toacutestress exposure. BrJHealthPsychol
2014;19:566–79.
24.GleibsIH,HaslamC,JonesJ,HaslamSA,McNeillJ,ConnollyH.Nocountryforold men?Theroleofa‘‘Gentlemen’sClub’’inpromotingsocialengagementand psychologicalwell-beinginresidentialcare.AgingMentHealth2011;15:456–67. 25.CruwysT,HaslamSA,DingleGA,HaslamC,JettenJ.Depressionandsocial
identity:anintegrativereview.PersSocPsycholRev2014;18:215–38. 26.BakouriM,Staerkle´ C.Copingwithstructuraldisadvantage:overcoming
nega-tiveeffectsofperceivedbarriersthroughbondingidentities.BrJSocPsychol 2015.http://dx.doi.org/10.1111/bjso.12102
27.TewariS,KhanSS,HopkinsNP,SrinivasanN,ReicherSD.Participationinmass gatheringscanbenefitwell-being:longitudinalandcontroldatafromaNorth IndianHindupilgrimageevent.PLoSOne2012;7:e47291.
28.PandeyK,StevensonC,ShankarS,HopkinsN,ReicherS.Coldcomfortatthe MaghMela:socialidentityprocessesandphysicalhardship.BrJSocPsychol
2014;53:675–90.
29.ShankarS,StevensonC,PandeyK,TewariS,HopkinsN,ReicherSD.Acalming cacophony:socialidentitycanshapetheexperienceofloudnoise.JEnviron Psychol2013;36:87–95.
30.KhanSS,HopkinsN,ReicherSD,TewariS,SrinivasanN,StevensonC.Shared identitypredictsenhancedhealthatamassgathering.GroupProcessIntergroup Relat2016;inpress.http://dx.doi.org/10.1177/1368430214556703. 31.CurtisV,deBarraM,AungerR.Disgustasanadaptivesystemfordisease
avoidancebehaviour.PhilosTransRSocLondBBiolSci2011;366:389–401. 32.FaulknerJ,SchallerM,ParkJH,DuncanLA.Evolveddisease-avoidance
mecha-nismsandcontemporaryxenophobicattitudes.GroupProcessIntergroupRelat
2004;7:333–53.
33.CaseT,RepacholiB,StevensonR.Mybabydoesn’tsmellasbadasyours:the plasticityofdisgust.EvolHumanBehav2006;27:357–65.
34.ChowellG,NishiuraH,ViboudC.Modelingrapidlydisseminatinginfectious disease during mass gatherings. BMC Med2012;10:159. http://dx.doi.org/ 10.1186/1741-7015-10-159
35.Gould D, DreyN. Typesof interventions usedto improve hand hygiene compliance and prevent healthcare associated infection. J Infect Prev
2013;14:88–93.
36.BiranA,SchmidtWP,VaradharajanKS,RajaramanD,KumarR,GrenlandK,etal. Effectofabehaviour-changeinterventiononhandwashingwithsoapinIndia (SeuperAmma):acluster-randomisedtrial.LancetGlobalHealth2014;2:e145–54. 37.HuttonA,ZeitzK,BrownS,ArbonP.Assessingthepsychosocialelementsof
crowdsatmassgatherings.PrehospDisasterMed2011;6:414–21.
38.DruryJ,NovelliD,StottCJ.Psychologicaldisastermythsintheperceptionand managementofmassemergencies.JAppliedSocPsych2013;43:2259–70. 39.DruryJ. Collective resilienceinmass emergenciesand disasters:a social
40.DruryJ,NovelliD,StottC.Managingtoavertdisaster:explainingcollective resilienceatanoutdoormusicevent.EurJSocPsych2016;inpress.http://dx. doi.org/10.1002/ejsp.2108.
41.TempletonA,DruryJ,PhilippidesA.Frommindlessmassestosmallgroups: conceptualizing collective behavior in crowd modeling. Rev Gen Psychol
2015;19:215–29.
42.HaslamSA,ReicherSD,PlatowMJ.Thenewpsychologyofleadership:identity, influenceandpower.London:PsychologyPress;2011.
43.TurnerJC.Socialinfluence.MiltonKeynes,UK:OpenUniversityPress;1991. 44.HopkinsN,ReicherSD.Thepsychologyofhealthandwell-beinginmass
