The implicit affiliation motive moderates cortisol responses to acute psychosocial stress in high school students

The implicit affiliation motive moderates cortisol responses to acute psychosocial stress in high school students

Mirko Wegner

, Julia Schüler

, Henning Budde

aUniversityofBern,InstituteofSportScience,Switzerland

bMedicalSchoolHamburg,FacultyofHumanSciences,DepartmentofPedagogy,Germany

cReykjavikUniversity,SchoolofScienceandEngineering,DepartmentofSportScience,Iceland

KEYWORDS Cortisol;

Affiliationmotive;

Psychosocialstress;

Physicalstress;

Adolescents;

School

Summary Ithasbeenpreviouslyshown thattheimplicitaffiliationmotive— theneedto establishandmaintainfriendlyrelationshipswithothers—leadstochronichealthbenefits.

The underlyingassumptionfor thepresentresearch wasthattheimplicitaffiliation motive alsomoderatesthesalivarycortisolresponsetoacutepsychologicalstresswhensomeaspects ofsocialevaluationanduncontrollability areinvolved.By contrastwe didnotexpectsimi- lareffectsinresponsetoexerciseasaphysicalstressor.Fifty-ninehighschoolstudentsaged M=14.8years wererandomlyassignedto apsychosocialstress (publishingthe resultsofan intelligencetestperformed),aphysicalstress(exerciseintensityof65—75%ofHRmax),anda controlcondition(normalschoollesson)eachlasting15min.Participants’affiliationmotives wereassessedusingtheOperantMotiveTestandsalivarycortisolsamplesweretakenpreand poststressor.Wefoundthatthestrengthoftheaffiliationmotivenegativelypredictedcortisol reactionstoacutepsychosocialbutnottophysicalstresswhencomparedtoacontrolgroup.

Theresultssuggestthattheaffiliationmotivebufferstheeffectofacutepsychosocialstress ontheHPAaxis.

∗Correspondingauthorat:UniversityofBern,InstituteofSportScience,Fabrikstrasse8,3012Bern,Switzerland.Tel.:+41316315659;

fax:+41316314631.

∗∗ Correspondingauthorat:MSHMedicalSchoolHamburg,AmKaiserkai1,20457Hamburg,Germany.

E-mailaddresses:mirko.wegner@ispw.unibe.ch(M.Wegner),henning.budde@medicalschool-hamburg.de,henningb@ru.is (H.Budde).

Konstanzer Online-Publikations-System (KOPS) URL: http://nbn-resolving.de/urn:nbn:de:bsz:352-0-382691

http://dx.doi.org/10.1016/j.psyneuen.2014.06.013

1. Introduction

Both, psychosocial andphysical stress affects theactivity of the hypothalamic—pituitary—adrenal (HPA) axis result- ing in an increased release of cortisol. For chronically increasedactivityof theHPAaxisseveralnegativeeffects havebeenfoundincludingforexampleimpairmentofhealth (DickersonandKemeny,2004).Researchersinthefieldare highlyinterestedinindividualdifferencevariablesthatmod- erate the cortisol response to psychological and physical stress(Kudielkaetal.,2009).Pastresearchsuggestedage, gender,smoking,coffee,oralcoholconsumptionasmodera- torsofthecortisolresponsetostress(Kudielkaetal.,2009).

However,less researchfocused onmoderatingpersonality variables.

One important moderating personality variable is the implicit affiliation motive (need for affiliation, nAff).The implicitaffiliationmotiveisdefinedastheneedtoestablish or maintain friendly, warm, and close interpersonal rela- tionships (Murray, 1938; Atkinson et al., 1954; McAdams, 1980;McAdams andConstantian, 1983).Characteristicsof theimplicitaffiliationmotivearethatitenergizesbehavior towardactivelypursuingaffiliativegoals,itorientsaperson towardaffiliativecuesand itmakesapersonlearn better (e.g., social networks) what is needed to reach an affili- ationgoal(Biernat,1989;KoestnerandMcClelland, 1992).

BaumeisterandLeary(1995)suggestthattheneedtobelong isauniversaldrive forfrequent,affectivelypleasant,sta- bleand enduringrelationships withotherswhich includes concern for each other’s welfare (p. 498). It is also sug- gestedthatthisneedforaffiliationhasanevolutionarybase becauseofitsbenefitsforreproductionandsurvival(e.g., careforoffspring,food,hunting,protection)(Axelrodand Hamilton,1981;Ainsworth,1989).Forthisreasonitisevo- lutionarilyfunctionalthatthesatisfactionoftheaffiliation motivehaspositiveaffectiveconsequencesandthedissat- isfactionresultsinnegativeaffectstates(McClelland,1985;

McAdams and Bryant, 1987; Baumeister and Leary, 1995;

Schüler etal., 2008).In additiontotheseemotional con- sequences,theimplicitaffiliationmotivealsopossessesthe qualities of a fundamental human need becauseit elicits goal-orientedbehaviordirectedatsatisfyingtheaffiliation motive (Boyatzis, 1973) and has been linked toa variety ofsocialbehaviors(LansingandHeyns,1959;Exline,1962;

McAdamsandConstantian,1983).

The affiliationmotive hasbeen associatedwithchronic healthbenefitsincluding,forexample,decreaseddiastolic bloodpressure(McClelland,1979),increasedimmunefunc- tionanddecreasedsusceptibilitytodisease(Jemmottetal., 1990), fewer reported severity of illnesses (Mehta and Josephs,2010)andamorepositiveperceptionofaneutral social interaction leading to increased well-being (Kordik etal.,2012).Otherauthorsadditionallyfocusedonwhether theimplicitaffiliationmotiveisalsoreflectedinself-reports of personal affiliation values and goals (Brunstein et al., 1995; Schüler et al., 2008). They found that a congru- ence between self-reports of affiliation strivings and the implicit affiliation motive affected well-being positively.

Moreover,differentbehaviorassociatedwithadispositional needforaffiliation(e.g.,socialinteractionandsupport)has beenpreviouslyshowntoleadtoprotectivehealtheffects includingdecreasedcortisollevelsinresearchwithprimates

(Abbottetal.,2003)andhumansalike(Thorsteinssonand James, 1999; Heinrichs etal., 2003). The latter research studiessuggested that social affiliation and integrationin asocial group render situations thatinvolve social evalu- ationlessthreateningandmorecontrollable.Summingup, thedispositionaldesiretobelonghasseveralstress-reducing andtherewithhealth-enhancingeffects.

Inpreviousstudiesithasnotbeentestedwhetherthedis- positionalneedforaffiliationalsoresultsinastressreducing effectwithoutactuallyexperiencingsocialinteraction.Thus theaimofthepresentstudywastotestwhethertheimplicit affiliationmotiveasanindividualdifferencevariablemode- ratestheindividual’scortisolresponsetoacutepsychosocial stress. To aim this we compared the cortisol response to psychosocialstress withthe responsetophysical stress — anothertypicalstressorfoundinschool—andtoacontrol condition.Toourknowledge,thestress-reducingeffectof theimplicitaffiliationmotivehasnotyetbeenreportedin anadolescentsample.

2. Materials and methods

2.1. Studydesignanddatacollection

Participantsfilledintheimplicitaffiliationmotivemeasure and completed questionnaires on sociodemographic vari- ablesbefore theyparticipated in thetest. Students were thenrandomly assigned tooneof the threeexperimental groups.Inthepsychosocialstressgroup(PSY,n=19,female:

12)participantsworkedonverbalandmathematicaltasksof anintelligencetest(HAWIK-IV;PetermannandPetermann, 2006)for15min.Inordertoinducepsychosocialstress,stu- dentswere toldbeforethey started workingonthe tasks thattheirIQscorewouldbemadepublicattheendofthe session.Thetasksintheintelligencetestexceededallstu- dents’ capability. The psychosocial stressor thus involved an aspect of social evaluation by peers and the experi- menteraswellasanachievementaspectbecausestudents assumed theycould perform well or poorly. In the physi- calstress group(PHYS, n=18,female:9)participantshad torun in a noncompetitive mode at a moderate exercise intensity of 65—75% of their individual HRmax for 15min.

The control group (CON, n=23, female: 11) took part in a teacher-centered lesson for the same amount of time.

Salivarycortisolsamplesweretakenbefore(pre)andafter (post)beingexposedtothestressor.Participantsweretold nottoeatanddrink1hbeforethetestingtookplace.

2.2. Studygroup

Fifty-nine adolescents (32 female) aged M=14.8 years (SD=0.5) from a high school in Berlin, Germany, partici- patedinthestudy.Participantsandtheirparentssignedan informedconsentformpriortoparticipation.The present study was approved by the relevant ethics committee of the German Psychological Society (DGPs) and performed in accordance with the declaration of Helsinki. Exclusion criteriaforthestudy were:dyslexia (verifiedby teachers’

statements),obesity,physicalor mentalimpairments,and theuseof psychoactivesubstances (e.g.Ritalin).Findings ofthisstudy,butnotrelatedtotheaffiliationmotivewere

previouslyreported(Wegneretal.,2014).Noneofthepar- ticipants indicated that they were smokers or used oral contraceptives.

2.3. Assessments

2.3.1. Cortisol

Twosalivasamples(pre,post)weretakenusingSalivettes withthebluecap(Sarstedt,Nümbrecht,Germany).Partic- ipantschewed ona synthetic swab for 1min. Afterwards theswabswereplacedintheplastictubeoftheSalivettes.

Participants provided their first sample after the fourth schoollessonat1200handthesecondsample30minlater.

Sampleswere stored at −20^◦C until theywere analyzed.

Biochemical analyses were performed at the Charité- Universitätsmedizin,Berlin,Germany.Achemiluminescence immunoassayprocedure(IBL,Hamburg,Germany)wasused toassesscortisollevelsinthesamplestaken.Theintra-and inter-assaycoefficientswerebelow8%.

2.3.2. Implicitaffiliationmotive

Tomeasuretheimplicitaffiliationmotive(nAff)theOperant Motive Test (OMT; Kuhl and Scheffer, 1999) was adminis- tered. The test consists of 15 pictures showing sketches of peoplee.g. talking toeach other.Participants have to choose oneof thepeople depicted asa protagonist first.

Subsequently,theyhave toanswer fourquestionssponta- neously innote form. These fourquestions are:(1) What isimportant for the person in this situation and what is thepersondoing?,(2)Howdoesthepersonfeel?,(3)Why doesthepersonfeelthisway?and(4)Howdoesthestory end?Participants’responseswerecodedusingthestandard- izedaffiliationscoringrulesoftheOMT(KuhlandScheffer, 1999).Accordingtothemanual,theaffiliation motivewas codedwheneverparticipantswroteabout(A)friendly,intu- itiveandintimateexchangebetweenfriends,(B)havingfun withothers, (C)solvingproblems inaffiliativeor intimate relationshipswithothers, (D)seekingsecurityinthe rela- tionshipwithothersor (E) feelings ofbeing alone.Whole pictureswereeithercodedornotcodedfortheaffiliation motive.Twoexperiencedcodersreachedsatisfactoryinter- and intra-rater reliabilities of .85 and .88, respectively.

Affiliation scores ranged from0 to7 (M=3.48, SD=1.31).

Forsubsequentdataanalysestheaffiliationscoreswerez- standardized.Theimplicitaffiliationmotiveassessedusing the OMT has been previously linked to right hemispheric activity(KuhlandKazén,2008)andfriendlybehaviortoward customers(Schefferetal.,2007).

2.4. Statisticalanalysis

Aseriesofhierarchicalregressionanalyseswereconducted tocontrolforlowerordereffectsbeforetestingforhigher order effects. The motive measure (OMT) was used as thequantitativecontinuous independentvariablemeasur- ingindividualdifferencesinparticipants’implicitaffiliation motive.Experimentalgroupallocationswereusedascate- goricalindependentvariablesandcombinedtointeraction termswiththeaffiliationmotive.Thepost-stressorsalivary cortisollevelservedasthedependentvariable.Pre-stressor cortisolandgenderwereenteredascovariates(seeTable2).

Table1 Cortisolrawscores(ng/ml)ofthepre-andpost- measuresforthephysicalstress,thepsychosocialstress,and thecontrolgroup.

Cortisol

Pre Post

M SD M SD

Physicalstress 1.74 0.66 2.15 1.57

Psychosocialstress 1.89 0.86 2.24 1.10

Control 1.45 0.78 1.80 0.72

Allcortisolmeasures werelog-transformeddue toskewed distribution.Thestatisticalanalysisprocedureusedherehas beenpreviouslyapplied(e.g.,Schultheissetal.,2014).

3. Results

3.1. Descriptivestatistics

In preliminary analyses we found that the three experi- mentalgroups didnotdifferregardingage,F(2,56)=0.71, p=.50,or gender, ²(2)=1.10,p=.58.Descriptivedata of thepre-andpost-stressorcortisolrawscorescanbefound in Table1.According toVanCauter andRefetoff (1985) a cortisolresponse ispresent whenthe cortisolpre-value is exceededbymorethan10%.Inouradolescentsamplethe averagecortisolresponsefrompretopost-testisapproxi- mately20%,F(1,58)=3.80,p=.05,²_p=.06.

3.2. Regressionanalysesonthemoderatingeffect oftheaffiliationmotiveoncortisolchanges

Inordertotestthemoderatingeffectoftheimplicitaffilia- tionmotiveoncortisolresponsesinthethreeexperimental groups, we conducted fourhierarchicalregression models (seeTable2).Post-stressorcortisolscoreswereresidualized forgenderandpre-stressorcortisollevelsinthefirstblock (Model 1). This model revealed low regression weights betweenpre-andpost-stressorlevelsofcortisol(B=−0.18) andnogendereffectsonthecortisolresponse(B=−0.07), asillustratedinTable2.Consequently,theremainingthree models now tested the effects of the affiliation motive (Model 2), the experimental groups (Model 3), and the interaction of implicit affiliation motive×experimental groups (Model 4) onthecortisol responseresidualizedfor pre-stressorcortisolscores.Thus,inModel2wetestedthe maineffectoftheimplicitaffiliationmotiveonthecortisol response. Although the whole model was not significant including the implicit affiliation motive improved the regression modelsignificantly, R²=.069,F(1,55)=4.22, p=.045,meaningadolescentswithahighimplicitaffiliation motive showedlowercortisollevelsafter 30min indepen- dentofthekindofstressor,B=−0.098,SE=0.047,t=−2.05, p=.045.InModel3weaddedtheexperimentalconditions into the regression analysis, resulting in no improvement of the model. Finally(Model 4),including theinteraction terms (multiplicative term of z-transformed variables) of the implicit affiliation motive (nAff)×experimental

Table2Predictorsoftheresidualizedpost-stressorcortisolscores. VariablePost-stressorcortisol Model1Model2Model3Model4 BSEtpBSEtpBSEtpBSEtp Constant1.2490.1707.330.0001.1610.1716.79.0001.1470.1736.65.0001.1790.1647.19.000 Pre-stressorC−0.1750.160−1.090.280−0.0750.163−0.46.647−0.1150.172−0.67.506−0.1770.165−1.08.287 Gendera−0.0730.093−0.780.437−0.0760.091−0.84.403−0.0620.092−0.68.500−0.0810.088−0.92.360 nAffiliation−0.0980.047−2.05.045−0.0950.049−1.94.058−0.0940.049−1.92.060 Psychosocialb0.1250.1131.11.2730.1790.1091.64.108 Physicalc0.0230.1130.20.8410.0440.1090.40.690 nAff×Psy−0.2680.101−2.66.010 nAff×Phys−0.2380.117−2.03.047 R2.027.096.119.239 F0.771.951.432.28* df(2,56)(3,55)(5,53)(7,51) R2.069.023.120 F4.22*0.684.02* df(1,55)(2,53)(2,51) a1:male,0:female. b1:psychosocialstress,0:control. c1:physicalstress,0:control. *p<.05.

Figure1 Associationbetweentheimplicitaffiliationmotive andsalivary cortisol responses(log-transformed)inthe three experimental conditions (psychosocial stress - dashed line, physicalstress-solidline,control-thindashedline).

conditionsrenderedthewholemodelsignificant,R²=.239, F(7,51)=2.28, p=.042 (see Table 2). This means that students’cortisolresponsestotheexperimentalconditions weredependentontheirlevelsofimplicitaffiliationmotive.

Follow-up regression analyses revealed that corti- sol responses of participants in the psychosocial stress group were significantly negatively associated with the implicitaffiliationmotive,B=−0.531,SE=0.156,pr=−.65, t(17)=−3.40,p=.004(seeFig.1).Thismeansthatpartic- ipantshigh inthe affiliationmotive showedlowercortisol levelsinresponsetothepsychosocialstressorused.Inthe physicalstresscondition,B=−0.463,SE=0.156,pr=−.35, t(17)=−1.47, p=.161, and the control condition cortisol responses were not significantly related to the affiliation motive,B=0.096,SE=0.136,pr=.15,t(22)=0.71,p=.488.

AllinteractioneffectsareillustratedinFig.1.

4. Discussion

According to our hypothesis in the present study adoles- cents’cortisolresponsestopsychosocialstressinaschool settingdependedontheirimplicitaffiliationmotive.How- ever, the affiliation motive did not moderate the effects of physical stress. Due to theseresults it seemsthat the affiliationmotiveisnotimportantuntilthestresssituation involvessomeaspectofsocialevaluation.Althoughneither thepsychosocialnorthephysicalstressoralonewereableto significantlypredictcortisolresponses(Model3,Table2)the regressioncoefficientofthepsychosocialstressor(B=0.125) washigherthanthecoefficientforphysicalstress(B=0.023) suggestingastrongereffectoncortisolresponses.

One reason why the affiliation motive may be able to moderate the psychosocial but not the physical stress response is given by Abbott et al. (2003). In their study withprimatestheyarguethatindividualsdifferintheirpsy- chological stress response if they lack information about timing, severity,or duration of thepsychological stressor.

Inthisworkthepsychologicalstressresponseisattributed torank-relatedstress.Aprimatethathastofearrejection within agroup will experienceless psychological stress if it iswell rootedinthe group’s socialnetwork, whichalso functionsasacopingoutletforexperiencedstress.Psycho- logicalstressresultingfromin-grouprejectionwillthenbe morepredictableforanindividualwhoknowshowtoestab- lishstableandpredictablesocialrelations;orishighinits

‘‘affiliationmotive’’(cf.Abbottetal.,2003).Similarresults couldbepreviouslyfoundinhumans(Heinrichsetal.,2003).

Inthisstudy,socialsupportledtoadecreasedcortisolreac- tiontoacutepsychologicalstress.Heinrichsandcolleagues alsoattributedtheirfindingstoparticipants’appraisalofthe acutestresssituationaslessthreateningandmorecontrol- lable.Differenttoourpresentstudytheylookedatactual social supportbut notatthe affiliationmotive asanindi- vidual difference variable.Formere physical stressors an affiliativecompetencedoesnothelptoobtaininformation aboutthecontrollabilityofthestressor.

Still little is known about how social support actually reducescortisolonaneurophysiologicallevel.Fromanimal andhumanresearchitisknownthatbeyonditscentralrole as social attachmentregulator oxytocin (Heinrichset al., 2003) butalsoprogesterone (Wirthand Schultheiss, 2006) inhibit theactivity oftheHPA axisresponsiveness.Future studiesmaybenefitfromincludingoxytocinorprogesterone measuresinthestudydesign.However,theadministration of oxytocin remains problematic becauseof ethicalques- tions about potentially persisting behavioral effects since therearereportsofoxytocinlevelsremainingincreasedfor atleast7h(vanIJzendoornetal.,2012).

Inourpresentanalysiswealsofoundthatmerelyinclud- ing the implicit affiliation motive (Model 2) significantly improvedtheregressionmodel(Table2),additionallypoint- ingtotherelevanceof theaffiliationmotive independent ofthetypeofstressor.Thisisinlinewithpreviousresearch findingsrelatingcortisollevelstopsychometricandbehav- ioralmeasuresofaffiliation,butprimarilyinwomen.Wirth andSchultheiss(2006)forexamplerelatedwomen’simplicit affiliationmotivetocortisollevels.However,inthepresent studytheaffiliationmotivewasrelatedtoadolescents’cor- tisollevelsindependentofgender.

Our results suggest that a high implicit affiliation motiveisassociatedwithreducedacutestressresponsesas expressedinstudents’cortisollevels.Thisisimportantespe- ciallyinthelightofpreviousfindingsonthechronichealth benefitsoftheaffiliationmotive(e.g.,Jemmottetal.,1990;

MehtaandJosephs,2010).However,itcouldalsobeargued thatthereducedcortisolresponsetotheintelligencetest- ing in our data represents a maladaptive response to an achievementsituation(Ericksonetal.,2003).Forexample it hasbeen previouslyshown thatcortisol elevationcould benefitperformancesinareaslikeperception(Seckletal., 1991;McGaugh,2000;BuchananandLovallo,2001),reward- related learning, or psychomotor activity (Piazza and Le Loal,1996).

The present study focused onan adolescent sample in ordertoincreasetheknowledgebaseonstressresponsesin thisage group. Itis well knownthatage, pubertal stage, andemotionalfunctioningcanaffectcortisolactivityinthis agegroupandthattheHPAaxisissubjecttodevelopmental change(Adam,2006).Thus,resultsfromourstudymaybe generalizedonlywithcautiontosimilaragegroupsoradult samples.

In our study typical modifiers like age or gender had no effect on the results. Gender was also not found to significantlyaffect cortisollevelsinother studiesexamin- ing similarsamples (Adam,2006; Budde etal., 2010a,b).

Moreover, although one might expect that women would score higher in their implicit affiliation motive, research regardingthistopicdidnotdrawaconsistentpicturewith some authors (Exline, 1960) reporting gender differences regardingtheimplicitaffiliationmotiveandothersdidnot (McAdamsandConstantian,1983;KoestnerandMcClelland, 1992).Inoursamplegirls’implicitaffiliationmotiveswere nothigherthanboys’affiliationmotives.

4.1. Limitationsandfuturedirections

Thepresent studyissubjecttosomelimitations.Onelim- itationisthatonlytwosalivacortisolsamplesweretaken.

Thesamplesweretakenbeforeandafterthepresentation ofthepsychosocialandthephysicalstressor.Inotherstudies uptoeightcortisolsampleswereassessedtobeingableto analyzethecortisolreactionpattern(e.g.,Heinrichsetal., 2003).However,frompreviousstudiesonthekineticsofcor- tisolweconcludedthatthepost-testperformed30minpast theonsetofthestressorwouldbeanadequatetimeinter- valtoapproximatelymeasurecortisolpeaks.Additionally, overallcortisollevelsofthisadolescentsample arerather low.Nevertheless,thesevaluesarecomparablewithother researchstudiesexaminingadolescents’cortisollevelsina similaragegroup(Buddeetal.,2010a,b).

Moreover,withinthepresent studywe didnotask par- ticipantsfortheirperceivedsocialsupportorhowsatisfied theywerewiththeireveryday socialrelationships.Future studiesshouldinclude implicitaffiliation motivemeasures andmeasures ofperceived social supportespeciallywhen interestedin chronicdifferencesbetween individualshigh andlowintheimplicitaffiliationmotive.Moreover,future researchshouldalsoincludeameasureofthepsychological stressreactionfor exampleasreportedin aself-reportof affectorself-perceivedstress.

Takentogether,ourresultssuggestthattheimplicitaffil- iationmotive is an importantmoderating variablefor the cortisolresponsetopsychosocialstress.Bothstressorsused inthepresentstudy,psychosocialandphysical,arerelevant stressorsfoundinaschoolsetting.

Combining our results with previous findings (e.g., Heinrichsetal.,2003)suggeststhatsocialsupportandthe implicitaffiliationmotive—astheneedforsocialinterac- tion—maycontributetobufferingstudents’stressresponses inschool.

Contributors

MWandHBdesignedthestudyandwrotetheprotocol.MW managedthe literaturesearchesandanalyses.MW andJS

undertook the statistical analysis, andauthorHB andMW wrote the first draft of the manuscript. All authors con- tributedtoandhaveapprovedthefinalmanuscript.

Role of the funding source

ThisworkwassupportedbyfundsfromtheReykjavikUniver- sity,Iceland,whichhadnofurtherroleinthestudydesign;

collection,analysis,and interpretationof data;in writing of the report;or in the decision to submitthe paper for publication.

Conflicts of interest

The authors have no conflicts of interest and declare no financialinterests.Allauthorsdiscloseanyactualorpoten- tialconflictofinterestincludinganyfinancial,personalor otherrelationshipswithotherpeopleororganizationswithin threeyearsofbeginningtheworksubmittedthatcouldinap- propriatelyinfluence, or be perceived to influence, their work.

Acknowledgements

Henning Budde is supported by the German Research Foundation (DFG, Deutsche Forschungsgemeinschaft); BU 1837/5-1. We would like to thank AnnemarieMac Dowall (Department of Psychology, Medical School Hamburg) for proofreading.

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