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Social Networks

j ou rn a l h o m e pa ge :w w w . e l s e v i e r . c o m / l o c a t e / s o c n e t

A relationship between verbal aggression and personal network size

Koen Vanbrabant

^a^,∗

, Peter Kuppens

^a

, Johan Braeken

^b

, Evelien Demaerschalk

^a

, An Boeren

^a

, Francis Tuerlinckx

^a

aDepartmentofPsychology,UniversityofLeuven,Leuven,Belgium

bDepartmentofMethodologyandStatistics,TilburgUniversity,Tilburg,TheNetherlands

a r t i c l e i n f o

Keywords:

Personalnetworksize Overtaggression Verbalaggression

a b s t r a c t

Aggressionhasbeenassociatedwithnegativesocialconsequences.Yet,moreadaptiveviewsofaggres- sionholdthatitcanhavebeneﬁcialcorrelatesaswell.Infourstudies,weexaminedtherelationship betweenaggressionandpersonalnetworksize,apropertyassociatedwithimportantsocialbeneﬁts.The resultspointedtoaconsistentpositiverelationshipbetweenverbalaggressionandsocialnetworksize.

Thisrelationshipremainedaftercontrollingforthirdvariableslikeextraversionandwhenusingdiffer- entmeasuresofnetworksize.Thefourthstudysoughttoexplaintherelationshipsintermsofmutual relationshipswithstatusandpower,butfoundnosupportformediation.

Aggression is an integral part of human nature. Due to its harmfulconsequencesmuchresearchisdevotedtoitscausesand control. Yet, the fact that aggression has persisted throughout humanhistorysuggeststhatitmayhaveanadaptivesideaswell.

Inthispaper,weexaminetheadaptiveversusmaladaptivenature ofaggressionbyexamininghowitisassociatedwithanimportant socialasset,namelypersonalnetworksize.

1. Aggression:adaptiveormaladaptive?

Alongstandingtraditioninpsychologicalresearchviewsaggres- sionassociallymaladaptive(Smith,2007).Forinstance,Hawley (2003)providesa reviewof researchthat associatesaggression with,among others,peerrejection(CoieandDodge,1998),low educationalachievement(BrooksandNewcomb,1995),andunem- ployment(Caspietal.,1987).Consequently,severaldevelopmental theoriesfocusonthemaladaptivesideofaggressionandexclude theideathataggressioncanbeassociatedwithsocialadaptation (Hawley,2003).

Ontheotherhand,itisnotparticularlydifﬁculttoﬁndpeo- plewhobehaveaggressivelybutarewelladapted.Wemaythink ofinstancesofaggressioninlargecompanymanagers(e.g.,Steve Jobsallegedaggressivemanagementstyle,seee.g.,Colvin,2007), politics(e.g.,politicianNeilFaragewhoinsultseuropresidentHer- manVanRompuyonFebruary24,2010),orsports(e.g.,theHaka

∗ Correspondingauthorat:CenterforthePsychologyofLearningandExperimen- talPsychopathology,FacultyofPsychologyandEducationalSciences,Universityof Leuven,Tiensestraat102,3000Leuven,Belgium.Tel.:+3216326117;

fax:+3216326099.

E-mailaddress:Koen.Vanbrabant@ppw.kuleuven.be(K.Vanbrabant).

wardanceinrugby).Mostevolutionarytheoriesendorsetheidea thataggressivebehaviourmustbeadaptive(Smith,2007)other- wiseitwouldnothavebeensuchaprominentfeatureofhuman evolutionaryhistory(Buss,2005).Inlinewithanadaptiveviewon aggression,researchbyTiedensandcolleaguesshowedthatthe overtexpressionofaggressionisassociatedwiththeperceptionof statusandsocialpower(Tiedensetal.,2000).Alsootherresearch hasshownthataggressioncanyieldimportantsocialbeneﬁts,such as positive friendshipqualitiesand personal disclosure (Averill, 1983;GrotpeterandCrick,1996)andsocialstatus(Tiedens,2001).

Inthispaper,wefocusontherelationshipbetweenaggressionand aparticularsocialoutcome,namelyaperson’spersonalnetwork size(PNS).

2. Personalnetworksize

Inhumans,personalnetworksseemtobeconstitutedoutofa seriesofhierarchicallevels(Zhouetal.,2005).Thisrangesfrom thesupportclique,fromwhomonewouldseekadviceandemo- tionalsupportintimesofdistress,overthesympathygroup,which consistsofpersonswithwhomonehadcontactthelastmonth,to theactivenetwork.Thislastlevelconsistsofallindividualswith whomonehasapersonalrelationship,andfeelstheneedtokeep incontactwith(DunbarandSpoors,1995;Killworthetal.,1998).

Theactivenetworkconsistsofnotonlypersonsyoufeelclose with,butalsomoredistantacquaintances.Yet,theseweakerties stillhaveimportantbeneﬁts,becausetheyarecrucialinproviding accesstoinformation,ideasandexperiences.Weaktiesaremore numerous,moreheterogeneousandarelesslikelytobeconnected witheachotherthanstrongties(Granovetter,1983).Theseweaker connections play an important role in the life of individuals 0378-8733/$–seefrontmatter © 2011 Elsevier B.V. All rights reserved.

doi:10.1016/j.socnet.2011.10.008

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(Christiakisand Fowler,2009).Forexample,researchpointsout thatpeoplewitha largepersonalnetworkhavemorequalityof lifethanpeoplewithasmallpersonalnetwork(Stokes,1983).In conclusion,havingalargepersonal networkisconsideredtobe beneﬁcial.

3. Thisstudy

Thepresentstudyexaminestheadaptiveversusmaladaptive natureofaggressionfromanovelperspectivebyexaminingthe relationshipbetweenindividualdifferencesinaggressionandPNS.

Nopreviousresearchhasdirectlyexaminedthisrelationship,and weadopted aprimarilyexplorative approach (seeRozin, 2009) inwhichwesoughttoexaminewhetheraggressionandPNSare interrelatedandwhich directionthis relationshiptakes. Onthe onehand,themaladaptiveviewofaggressionwouldarguethat highlevelsofaggressionshouldbeassociatedwithnegativesocial consequencesleadingtosmallerPNS.Ontheotherhand,ifaggres- sionservesanadaptivesocialfunctiononecouldexpectapositive associationbetweenaggressionandPNS.

Several techniques have been developed to measure PNS.

Throughoutthefourstudies,wereliedontwoindirectnetwork estimators,thescale-upmethod(Studies1,2and4;Killworthetal., 1998)andthenamegeneratoroverlaptechnique(Study3;Agresti, 1994).

4. Study1

Theaimoftheﬁrststudywasasimpleexplorationoftherela- tionshipbetweenaggressionandPNS.

4.1. Method 4.1.1. Participants

Asampleof178ﬁrstyearpsychologystudents(150women;age M=19;SD=2;agerangefrom18to44)participatedinreturnfor coursecredits.

4.1.2. Materialsandprocedure

Aggression.The(Dutchtranslationofthe)Buss–PerryAggression Questionnaire(BPAQ;BussandPerry,1992)hasbeenusedexten- sivelyasameasureofaggressioninpreviousresearch.Itmeasures physicalaggression,verbalaggression,anger,andhostilityvia29 items.Asourfocusisonaggression,weonlyconsideredscoreson theverbalandphysicalaggressionsubscales.

Personalnetworksize.PNSor“degree”wasestimatedforevery participantusingthescale-upmethod(Killworthetal.,1998).A personalnetworkisdefinedasthesetofpeoplethatoneknows (e.g.,Bernardetal.,1989).In ordertodefineandexplaintothe participantswhatismeantbyknowingsomeone,wefollowthe definitionofBernardandcolleagues:personAknowspersonBifA knowsBbynameorbyface;AcancontactBbymailorphone;and AandBhadcontactatleastoncethelasttwoyears.

Thescale-upmethodusesquestionsoftheform“Howmany peopleof[acertainsubpopulationofpeople]doyouknow?”An exampleofsuchaquestionis:“Howmanypeopledoyouknow whogotmarriedinthelast12months?”Ifoneknowsthesizeofthe subpopulation,thisinformationcanbeusedtoestimatethePNSof aparticipant.Forinstance,whenthissurveywasconducted,89,700 Belgianpeoplegotmarriedinthelast12monthswhilethesizeof theentireBelgianpopulationwas10,666,866inhabitants.Ifapar- ticipantknowsﬁveindividualsthatgotmarriedinthelasttwelve months,thePNSforanindividualcanbeestimatedasfollows:

5

89,700·10,666,866≈714

10 15 20

34567

Verbal aggression

log Personal Network Size (PNS)

Fig.1.Scatterplotdisplayingtherelationbetweenpersonalnetworksize(onthe abscissa)andverbalaggression(ontheordinate).Thefulllineisalinearregression line;thedottedlineisalowesssemi-parametricregressionline(Study1).

Byaveragingtheresponsesofarespondentformanysubgroupsthe accuracyoftheestimatecanbeincreased.Themultipleresponses needtobecombined:

ˆdi=

K k=1yik

K k=1Nk

·N (1)

wherey_ikisthenumberofpeoplethatpersoniknowsinsubpopu- lationk,N_krepresentsthesizeofthesubpopulationk,andNisthe sizeofthewholepopulation.

In this study a questionnaire with 32 subpopulations was administered.Thesubpopulationconsistedof12ﬁrstnamesand 20othersubpopulations(seeAppendix).

4.2. Results

Theaveragesizeof theparticipant’sPNSwas290(SD=241) degrees. Thedistribution ofPNS waspositivelyskewedsothat thesizeofnetworksoftwoindividualscandifferbyanorderof magnitude.Asourstatisticaltoolsassumelinearityandadditivity and these assumptions are not ﬁt for data on a multiplica- tivescale, PNSwas log-transformed(hereafter named logPNS).

There was a positive correlation between logPNS and verbal aggression (r(178)=0.26, p<0.0002). Fig. 1 graphically displays this relationship. The correlationbetween logPNSand physical aggressionwasnon-signiﬁcant(r(178)=0.09,p=0.12)(verbaland physical aggression correlated 0.47, p<0.0001). In a regression analyses, verbal aggression remained a signiﬁcant predictor of logPNS(t(174)=3.02,p=0.003,ˇ=0.05)whencontrollingforphys- ical aggression (t(174)=−0.79, p=0.43, ˇ=−0.008) and gender (t(174)=−1.69,p=0.094,ˇ=−0.27).

4.3. Discussion

Study1providedﬁrstevidencethatverbalaggressionisposi- tivelyassociatedwithPNS.Theﬁndingsfurthersuggestthatthereis noassociationbetweenphysicalaggressionandPNSandthatgen- derdoesnotseemtoplayaroleinthefoundrelationship.However, aweaknessofStudy1isthatitdidnotcontrolforothervariables

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Table1

CorrelationsofallvariablesinStudy2.

1. 2. 3. 4. 5. 6. 7. 8. 9.

1.PNS 1.00^**

2.logPNS 0.93^** 1.00^**

3.Verbalaggression 0.25^** 0.26^** 1.00^**

4.Physicalaggression 0.10 0.07 0.24^** 1.00^**

5.Neuroticsm −0.01 0.00 −0.11 0.13^* 1.00^**

6.Extraversion 0.16^* 0.21^** 0.20^** 0.00 −0.47^** 1.00^**

7.Openness 0.15^* 0.11 0.10 −0.17^* −0.10 0.00 1.00^**

8.Agreeableness −0.06 −0.07 −0.31^** −0.40^** −0.18^* 0.27^** 0.26^** 1.00^**

9.Conscientiousness 0.02 0.01 0.00 −0.18^** −0.21^** 0.14^* 0.13^* 0.31^** 1.00^**

*p<0.05.

**p<0.01.

thatmightpossiblyexplaintherelationbetweenverbalaggression andPNS.ThiswillbeaddressedinStudy2.

5. Study2

Extraversionispositivelyrelatedtoaggressionandtheovert expressionofanger(e.g.,BödekkerandStemmler,2000),andhas beenassociatedwiththepropensitytoconnectwithothers(e.g., Totterdeletal.,2008).

TherelationshipbetweenverbalaggressionandPNSmaythere- foresimplybeduetotheirmutualassociationwithextraversion.In Study2weexaminedtheassociationbetweenaggressionandPNS inadifferentsample,whilecontrollingforextraversion.Wealso controlledfortheotherFiveFactorpersonalitytraits,someofwhich alsodemonstraterelationshipswiththevariablesunderstudy(for instanceagreeablenessandaggression;Burtonetal.,2007).

Asampleof187ﬁrstyearpsychologystudents(157women;age M=19;SD=2,agerangefrom17to36)participatedinreturnfor coursecredits.

10 15 20 25

4.04.55.05.56.06.57.0

Verbal aggression

Fig.2.Scatterplotdisplayingtherelationbetweenpersonalnetworksize(onthe abscissa)andverbalaggression(ontheordinate).Thefulllineisalinearregression line;thedottedlineisalowesssemi-parametricregressionline(Study2).

Personality.TheDutchversionoftheNEO-FFI(Hoekstraetal., 1996)wasusedtoassesneuroticism,extraversion,opennessto experience,agreeablenessandconscientiousness.Eachscalecon- sistsof12items.

Aggression.TheBPAVwasusedsimilartoStudy1.

Personalnetworksize.LikeStudy1,Study2reliedonthescale- upmethodtoestimatepersonalnetworksize.Thesurveyagain consisted of32 items,however usingdifferentﬁrst names(see Appendix).

5.2. Results

Thesizeoftheparticipant’spersonalnetworkwas253(SD=149) degrees on average, and was positively skewed. There was a positive correlation between logPNS and verbal aggression (r(187)=0.26,p=0.0002;seeFig.2),whilethecorrelationbetween logPNSandphysicalaggressionwasnon-signiﬁcant(r(187)=0.07, p=0.46).Onlyextraversionwasasigniﬁcantpersonalitycorrelate of logPNS(r(164)=0.19, p<0.005) (see Table 1 for correlations betweenallvariables).

Inaregressionmodel,weincludedverbalaggressionandphys- icalaggressionaspredictorsoflogPNS,whilecontrollingforthe fivepersonalitydimensionsandgender.Thefindingsshowedthat logPNSremainedassociatedwithverbalaggression(t(133)=2.40, p=0.03, ˇ=0.03), while there was again no significant rela- tionwithphysicalaggression(t(133)=−0.49,p=0.62,ˇ=−0.003).

Extraversion (t(133)=3.86, p<0.0001, ˇ=0.03) and neuroticism(t(133)=2.11,p=0.04, ˇ=0.01)and gender(t(133)=−2.82, p=0.006,ˇ=−0.35),weretheonlyothersigniﬁcantcovariatesin themodel.

5.3. Discussion

TheresultsofthissecondstudyreplicatedtheﬁndingsofStudy 1, even whencontrolling forextraversion(aswell astheother BigFivepersonalityfactors).Weconcludethatwhenthescale-up methodisusedtoestimatesocialnetworksize,thereisastable associationbetweenverbalaggressionandPNS.

Wefoundamaineffectofgenderinthisstudy,withmalesbeing moreaggressivethanfemales,althoughwewouldadvisecaution toover-interpretthereliabilityof thisﬁnding,duetothesmall numberofmaleparticipants.Thusfar,however,itcannotberuled outthatthefoundrelationshipisspeciﬁctotheusedmethodto estimatePNSinbothstudies.

6. Study3

Study3usedadifferentmeasuretoestimatePNS,namelythe

“namegeneratoroverlap”technique(Killworthetal.,1984).We alsoaimedatreplicatingtheﬁndingthattherelationshipbetween

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PNSandverbalaggressionwasnotduetosharedvariancewith personality.

6.1. Method

6.1.1. Participants

Asampleof74ﬁrstyearpsychologystudents(62women,age M=19;SD=2,range17–36)participatedinreturnforcoursecred- its.

Personality.PersonalitywasmeasuredwiththeNEO-FFI.

Aggression.Verbalandphysicalaggressionweremeasuredwith thesameinstrumentasinStudies1and2.

Personal network size. Following the “name generator over- lap” technique, an estimate can be made of the size of the (sub)population on the basis of counting individuals who are namedinmorethanonesample.Forthistechnique,thePetersen estimator(Agresti,1994;Petersen,1896)isthemoststraightfor- wardestimator.ConsidersampleAandsampleB,havingsample sizesn_Aandn_Beachwithanumberofindividualsthatareacquain- tancesofanindividual.Thenumberofindividualsthatappearin bothsamplesareenumerated,n_AB.Underindependence,itholds that

nAB

N = nA

N ·nB

N

SolvingfortheunknownNgivesthePetersenestimator ˆNofthe totalnumberofacquaintances:

Nˆ= nA·nB

nAB

ThismethodcanbeappliedtothestudyofPNSasfollows.To generatea first sample of acquaintances(called List A)we, for example,usethereversedsmall-worldtechnique(Bernardetal., 1982)andask“Whichacquaintancescangetyouincontactwiththe primeministerofBelgium?”Theparticipantforexampleresponds withfournames(n_A=4;e.g.,MarkB.,MichelleO.,GeorgeL.and MarieV.)inthisfirstnamegeneratormoment.Togenerateasec- ondsampleofacquaintances(calledListB)we,forexampleuse thephonebooktechnique(PoolandKochen,1978).Thepartici- pantreceivesfiverandomchosensurnamesoutofaphonebook, andreports allacquaintanceswiththesesurnames.Inthis sec- ondnamegeneratormoment,theparticipantrecalledforexample sevennamesofacquaintances(n_B=7;e.g.,KarelB.,Anne-MarieM., GeorgeL.,BartV.,MarieV., PieterB.,DriesL.and ElsL.).When wecomparethesetwonamegeneratormoments,weseethattwo namesappearinbothlists(n_AB=2).Basedonthisoverlapinname

1.5 2.0 2.5 3.0 3.5 4.0 4.5

1.82.02.22.42.62.8

Verbal aggression

Fig.3.Scatterplotdisplayingtherelationbetweenpersonalnetworksize(onthe abscissa)andverbalaggression(ontheordinate).Thedottedlineisalinearregres- sionline;thefulllineisalowesssemi-parametricregressionline(Study3).

generatormomentswecanmakeanestimateoftheparticipant’s PNSbyusingtheabovementionedformula:

N =ˆ nA·nB

nAB =4·7 2 =14

The instrument for this study consisted of ﬁve naming moments:thephonebooktechniquewith100surnames,thephone booktechniquewith100ﬁrstnames,thesmallworldtechnique wasusedtwotimeswithdifferentquestions,andallparticipants hadtolistallofthepersonstheyconsideredtobeintheirsup- portgroup.Withtheoverlapinnamesbetweenthesemoments, wewereabletoestimatethePNSforeveryparticipant.

6.2. Results

Thesizeoftheparticipant’spersonalnetworkwasonaverage 229 (SD=170) degrees, and was positively skewed. After log- transformationtherewasapositivecorrelationbetweenlogPNS andverbalaggression(r(74)=0.32,p=0.003;seeFig.3).logPNSwas notcorrelatedwithphysicalaggression(r(74)=0.08,p=0.249)but waspositivelyrelatedtoextraversion(r(74)=0.34,p=0.002;see Table2forthecorrelationsbetweenallvariables).

A regression analysis was performed that included verbal aggression and physical aggressionas predictors of PNS, while controllingfortheﬁvepersonalitydimensionsandgender.Verbal aggressionremainedasigniﬁcantpredictoroflogPNS(t(65)=2.62,

Table2

CorrelationsbetweenmeasuresofStudy3.

1. 2. 3. 4. 5. 6. 7. 8. 9.

1.PNS 1

2.logPNS 0.94^** 1

3.Verbalaggression 0.27^* 0.32^** 1

4.Physicalaggression 0.09 0.08 0.33^** 1

5.Neuroticism −0.01 0.00 −0.06 0.11 1

6.Extraversion 0.26^* 0.34^** −0.06 −0.23 −0.15 1

7.Openness 0.01 −0.04 0.31^** 0.10 0.18 −0.21 1

8.Agreeableness −0.19 −0.18 −0.26^* −0.55^** −0.09 0.34^** 0.00 1

9.Conscientiousness −0.20 −0.19 −0.15 −0.27^* −0.26^* 0.29^* −0.06 0.36^** 1

*p<0.05.

**p<0.01.

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p=0.011, ˇ=0.30), after controlling for physical aggression (t(65)=−1.15,p=0.255,ˇ=−0.14),gender(t(65)=−1.85,p=0.069, ˇ=−0.22),andtheBigFivepersonalitydimensions.Onlyextraver- sionwasasigniﬁcantpersonalitycovariate(t(65)=4.35,p<0.0001, ˇ=0.47).

6.3. Discussion

Study3againprovidedevidencethatverbalaggressionisposi- tivelyassociatedwithPNS,evenwhenusingadifferentestimator ofPNS.Thisagainheldaftercontrollingforthemajorpersonal- itydimensionsincludingextraversionandgender.Throughoutthe previousstudies,wehavedemonstratedaconsistentpositiverela- tionbetweenverbalaggressionandPNS.Anattempttoexplainthis relationshipwasmadeinStudy4.

7. Study4

Tiedensetal.(2000)arguethathighstatusisassociatedwith emotionsincludinganger and pride whilelow status is associ- atedwithsadnessandguilt.Theauthorsconcludethatemotions areinferredfromstatus andthat statusinturncanbeinferred fromtheexpressionofthecorrespondingemotions.Also,research byCillessenandMayeux(2004)foundthatadolescentaggression canleadtohigherpeerstatus.Insum,thedisplayofaggressionis relatedtostatus.Highstatus,inturn,maybeassociatedwithan increaseinPNS(Belle,1983).Notonlymightapositionofstatus bringapersonintouchwithmorepeople(Keltneretal.,2003), otherpeoplearealsomotivatedtoincludeapersoninhighstatus positionsintotheirpersonal network,giventheexpectedsocial advantages.

Theabovesuggeststhatthenotionofstatuscouldhelptoexplain therelationshipbetweenPNSandverbalaggression.Specifically, perceivedpowerorstatusmayfunctionasamediatoroftherela- tionshipbetweenverbalaggressionandPNS.Weaimedtoexamine thispossibilityinafourthstudy.Weincludedtwodifferentmea- suresreflectingstatus: onedesigned tomeasure thesubjective senseof personal power and the other reflectingself-reported sociometricstatus.

Asampleof52undergraduatepsychologystudents(32women, ageM=21;SD=1,range19–24)participatedinreturnforcourse credit.Oneparticipantwasexcludedfromtheanalysesbecause theparticipant’sPNSestimatewasclearlyanoutlier(>3000).

Extraversion.TheextraversionscaleoftheDutchversionofthe NEO-FFIwasused.Onlyextraversionwasusedbecausetheother threestudiespointedoutthatthiswastheonlysigniﬁcantperson- alitycovariate.

Aggression.TheBPAVwasusedtomeasureverbalandphysical aggression.

Personalnetworksize.PNS wasestimatedusing thescale-up method,identicaltoStudy2(seeAppendix).

Subjective power. Subjective power was measured with a DutchtranslationoftheSubjectiveSenseofPowerQuestionnaire (AndersonandGalinsky,2006).Thequestionnaireconsistsofeight questionsallratedonaﬁvepointLikertscale(e.g.,“IthinkIhavea greatdealofpower”).

Self-reported sociometric status. Sociometric status is usually measuredusingpeer ratingsin a so-calledroundrobindesign, whichwaspracticallyunfeasibleinoursample.For thatreason

12 14 16 18 20 22

4.55.05.56.06.5

Verbal aggression

Fig.4.Scatterplotkdisplayingtherelationbetweenpersonalnetworksize(onthe abscissa)andverbalaggression(ontheordinate).Thefulllineisalinearregression line;thedottedlineisalowesssemi-parametricregressionline(Study4).

the existing peerrating questionnaire wasconvertedto a self- reportquestionnaire.Thequestionnaireconsistedofnineitemsall ratedonafivepointLikertscale.Thefirstfiveitemswereinspired byAndersonetal.(2006);theotherfouritemswereinspiredby CillessenandMayeux(2004).WeperformedaPrincipalComponent Analysis(PCA)withcomponent1explaining40%ofthevariance.

Consequently,scoresontheﬁrstprincipalcomponentwereused asameasureofself-reportedsociometricstatus.

7.2. Results

Asin Study2,thesizeoftheparticipant’spersonalnetwork was249(SD=133)andpositivelyskewed.Afterlog-transformation therewasapositivecorrelationbetweenestimatedPNSandver- balaggression(r(51)=0.37,p=0.004;seeFig.4).Inthisstudythe correlationbetweenPNSandphysicalaggressionwasalsosigniﬁ- cant(r(51)=0.35,p=0.005;seeTable3forcorrelationsbetweenall variables).

Thedatawerefurtheranalysedtotestforthemediationmodel describedabove.Inthismediationmodel,sociometricstatusand subjectivepowerweretreatedaspotentialmediatorsfortherela- tionshipbetweenPNSandverbalaggression.Similartotheother studies, extraversion was included as a covariate. The media- tionanalyseswereconductedaccordingtothemethodproposed by Baron and Kenny (1986).The first step showed that verbal aggression,t(49)=2.80,p=0.007,ˇ=0.06,isasignificantpredic- toroflogPNS,evenwhencontrollingforextraversion,t(49)=1.52, p=0.14, ˇ=0.02. Analyses in a secondstep showedthat verbal aggression, t(49)=2.50, p=0.016, ˇ=0.31, is a significant predictor for subjective power after controlling for extraversion, t(49)=2.24, p=0.03, ˇ=0.14;and verbalaggression,t(49)=2.85, p<0.01,ˇ=0.23isasignificantpredictorofsociometricstatus,after controlling for extraversion, t(49)=3.30, p=0.002, ˇ=0.13. The laststep,however,showedthatsociometricpower,t(47)=−0.722, p=0.47,ˇ=−0.02andstatus,t(47)=0.35,p=0.35,ˇ=0.013arenot significantpredictorsoflogPNSaftercontrollingforextraversion, t(47)=1.40, p=0.17, ˇ=0.02 and verbal aggression, t(47)=2.59, p=0.013,ˇ=0.059.Inthis last model,therelationshipbetween verbalaggressionandlogPNSremainedsignificant,evenaftercon- trollingforstatus,powerandextraversion.SeeFig.5foravisual

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Table3

CorrelationsbetweenmeasuresofStudy4.

1. 2. 3. 4. 5. 6. 7.

1.PNS 1.00^**

2.logPNS 0.93^** 1.00^**

3.Verbalaggression 0.32^* 0.37^** 1.00^**

4.Physicalaggression 0.33^** 0.31^* 0.35^** 1.00^**

5.Extraversion 0.26^* 0.21 0.03 0.14 1.00

6.Power 0.07 0.10 0.33^** 0.25^* 0.30^* 1.00^**

7.Status 0.20 0.23 0.35^** 0.11 0.41^** 0.45^** 1.00^**

*p<0.05.

**p<0.01.

Fig.5. ThemediationmodeltestedinStudy4withcorresponding regression weights.Extraversionwasincludedasacovariatewhentestingthewholemodel (**p<0.01).

overviewofthemediationanalyseswiththecorrespondingstan- dardisedregressionweights.

7.3. Discussion

VerbalaggressionandPNSwereagainpositivelyassociated,also whencontrollingforextraversion.Anattempttoexplainthefound linkbyincludingmeasuresof powerand statusin a mediation modelfailed:powerandstatusdidnotseemtobeassociatedwith PNS.

8. Generaldiscussion

Findingsfromfourstudiesconsistentlyprovidedsupportfora positiverelationshipbetweenPNSandverbalaggression.Thisrela- tionshipwasobservedwhenusingdifferentmethodstoestimate PNS,and couldnot beexplained throughshared variancewith personalityfactorslikeextraversion.Our ﬁndingsindicatedalso thatsubjectivepowerandstatusdonotmediatetherelationship.

Indeed,astrikingobservationwasthatevenafterincludingpower, statusandextraversionintheassociation,astronglinkbetween verbalaggressionandPNSremains.

Threeofthestudiesreliedonthenetworkscale-upmethodfor estimatingPNS.Thesimilaritiesoftheaveragenetworksizes(290, 253,249)tothe290fromtheoriginalscale-upstudieswerestrik- ing,aswasthesimilaritybetweentheseestimatesandtheestimate obtainedthroughadifferentmethod,the“namegeneratoroverlap”

(249).

The previously undocumented relationship between verbal aggressionandPNSraisesseveralinterestingissues.First,itdemon- stratesthataggressionhasadaptivesocialcorrelates.Althoughwe donotclaimacausaldirectionunderlyingtheassociationbetween VAandPNS(whereaswemayhavetacitlyassumedinplacesthat PNSisasocialconsequenceofverbalaggression,ofcourse,ourdata donotruleoutthepossibilitythathavingalargerorsmallerPNS makespeoplemoreorlessverballyaggressive)wecanonlyremark thatifthedisplayofaggressionwasonlydetrimentalforone’ssocial world,verbalaggressionwouldnotbepositivelyrelatedtothesize

ofone’spersonalnetwork.Itispossible,however,thataggression hasotherdetrimentalconsequencesforone’snetworkotherthan onitssize.Forinstance,aggressioncouldaffectthequalityofone’s personalrelationships.Itwouldbeinterestinginfutureresearchto examinealsothequalitynexttothequantityofone’ssocialnetwork intheirrelationshipwithaggression.

Second,itwasonlythemilder,verbalformofaggressionthat yieldsanassociationwithPNS.Itmaybethattheadaptive cor- relatesofaggressionthereforeonlyholdforthismilderformand thatphysicalaggressiondoesnothavethesamesocialimplica- tions.Alternatively,itcannotberuledoutthatarestrictedrange ofphysicalaggressioninoursamplescouldaffecttheassociation withphysicalaggression.

Wedidnotﬁndaconsistenteffectofgender.Theliteratureon genderdifferencesinaggressionisratherambiguous(e.g.,Crickand Grotpeter,1995;DavidandKistner,2000).Theseambiguitiesseem inparttobeafunctionofthetypeofaggressionthatisbeingcon- sidered,particularlyovertversuscovertforms(Archer,2004).To explorethegendereffectinfutureresearchitcouldbeinteresting toincludeother,morecovertformsofaggression.

9. Limitationsandfutureresearch

Theﬁndingofthefourstudiesislimitedinasensethattheyall relyonself-reportmeasures.Byusingdifferentmethodsforesti- matingPNSwewereabletoexcludethepossibilitythatourPNS estimation issomehowbiased byself-reportormethodeffects.

Yet,forverbalaggression,thecurrentﬁndingscouldbestrongly corroboratedbyalsolookingatnonself-reportmeasuresofverbal aggressionsuchaspeerreportsorbehaviouralmeasures.Asecond limitationisthatweonlyexploredtherelationshipbetweenPNS andverbalaggressioncross-sectionally.Experimentalorlongitudi- nalstudiesmayhelptoestablishpossiblecausalpathwaysbetween thesetwovariablesandassuchprovideimportantcluestothepro- cessormechanismunderlyingtherelationshipanditsdirection.An exampleofanexperimentalstudycouldbethat(theexpressionof) verbalaggressionismanipulatedandthatproximityseeking(both byandtowardsthatperson)ismeasuredasadependentvariable.

Longitudinalresearchcouldtaketheformofmeasuringbothverbal aggressionandPNSatdifferentmomentsintimeduringaperiod whereapersonalnetworkisexpectedtochangedramatically(e.g., adolescentsmakingtheswitchfromhighschooltocollege).And examiningthebidirectionallinksbetweenbothvariables.

10. Conclusion

Verballyaggressiveindividuals knowmorepeoplethantheir less verbally aggressive counterparts. This consistent ﬁnding clearlyrevealsanadaptivecorrelateofaggression,andidentiﬁes verbalaggressionasanimportantfactorinpersonalnetworks.In linewithWallbott andScherer (1986),weconcludethatverbal aggressionistheexpressionofasocialemotioninwhichpersonal relationswithotherpersonsplayanimportantrole.

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Acknowledgements

Thisresearchwas supportedby KULeuvenResearch Council GrantGOA/05/04.WewouldliketothankJeroenStoutenandStijn Decosterfortheirusefulcommentsandpracticalhelp.

Appendix1.

Thequestionedsubpopulationsofthescale-upquestionnaire.

Questionnaire1isusedinStudy1;Questionnaire2inStudies1 and4.

Questionnaire1 Questionnaire2

Mailman Mailman

Centenarians Centenarians

Divorcedindividuals(thepastyear) Divorcedindividuals(thepastyear) Womenwhogavebirth(thelastyear) Womenwhogavebirth(thelast

year)

Individualswhomarriedthelastyear Individualswhomarriedthelastyear

Nurses Nurses

Individualswithlastname“Maes” Individualswithlastname“Maes”

Individualswhohadadeadlyaccident lastyear

Individualswhohadadeadly accidentlastyear

Architects Architects

Individualswithlastname“DeSmet” Individualswithlastname“DeSmet”

Soldiers Soldiers

Prisoners Prisoners

Depressedindividuals Depressedindividuals

Cooks Cooks

Restaurantmanagers Restaurantmanagers

IndividualswithlastnameGoossens IndividualswithlastnameGoossens

Hairdressers Hairdressers

IndividualswithlastnamePeeters IndividualswithlastnamePeeters IndividualswithfirstnameJulia IndividualswithfirstnameJan IndividualswithfirstnameKatrien IndividualswithfirstnameEric/Erik IndividualswithfirstnameGuido Individualswithfirstname

Isabelle/Isabel

IndividualswithfirstnameChristine IndividualswithfirstnameAn/Ann IndividualswithfirstnameAlain Individualswithfirstname

Frederick/Frederik

IndividualswithfirstnameChristophe IndividualswithfirstnameGeert IndividualswithfirstnameNicole Individualswithfirstname

Katrien/Catherine IndividualswithﬁrstnameSimon Individualswithﬁrstname

Filip/Philippe

IndividualswithﬁrstnameKarel Individualswithﬁrstname Kathleen/Katleen

IndividualswithfirstnameRosa IndividualswithfirstnameClaire IndividualswithfirstnameSteven IndividualswithfirstnameJonas IndividualswithfirstnameLinda IndividualswithfirstnameElke

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