Profiles of observed infant anger predict preschool behavior problems: Moderation by life stress

ProfilesofO

bservedInfantA

ngerPredictPreschoolBehaviorProblems:

Moderation

byLife

Stress

RebeccaJ.Brooker

Montana

StateUniversity

Kristin

A.Buss

ThePennsylvania

StateUniversity

Kathryn

Lemery-Chalfant

Arizona

StateUniversity

Nazan

Aksan

University

ofIowa

RichardJ.D

avidsonand

H.HillG

oldsmith

University

ofWisconsin—

Madison

Using

bothtraditionalcom

positesandnovelprofilesofanger,w

eexam

inedassociationsbetw

eeninfant

angerandpreschoolbehaviorproblem

sinalarge,longitudinaldataset(N

!966).W

ealsotested

theroleoflife

stressasamoderatorofthe

linkbetw

eenearly

angerandthe

developmentofbehaviorproblem

s.Although

traditionalmeasures

ofanger

were

largelyunrelated

tolater

behaviorproblem

s,profilesof

angerthatdissociatedtypicalfrom

atypicaldevelopmentpredicted

behaviorproblemsduring

preschool.Moreover,the

relationbetw

eeninfantanger

profilesand

preschoolbehaviorproblem

swasmoderated

suchthat,w

henearly

lifestress

waslow

,infantswith

atypicalprofiles

ofearly

angershow

edmore

preschoolbehaviorproblemsthan

didinfants

withnorm

ativeangerprofiles.H

owever,w

henearly

lifestress

washigh,infants

withatypicaland

normative

profilesofinfantangerdid

notdifferinpreschool

behaviorproblem

s.Weconclude

thatadiscrete

emotions

approachincluding

latentprofileanalysis

isusefulforelucidating

biologicalandenvironm

entaldevelopmentalpathw

aystoearly

problembehaviors.

Keywords:infancy,anger,lifestress,behaviorproblem

s

Fromearly

inlife,young

childrenwhorespond

toblocked

goalswith

highlevels

ofanger

arebelieved

tobeatgreater

riskfor

aggressive,delinquent,andgeneralexternalizing

problemsrelative

tochildren

who

showless

anger(Cole,

Teti,&Zahn-W

axler,2003;

Denham

etal.,

2002).Yet,given

normative

increasesin

angeracrossinfancyand

toddlerhood,evenintypically

developingchildren

(Braungart-Rieker,Hill-Soderlund,&

Karrass,2010),itis

difficulttodeterm

inepreciselywhich

childrenareatrisk.Research

inother

domains

hasdelineated

riskstatus

bydifferentiating

typicalfrom

atypicaldevelopm

entearly

inlife

andidentifying

contextualmoderatorsthatexacerbate

orbufferrisk.Wetook

eachofthese

approachesinthe

currentresearch.Wefollow

edasam

pleofinfanttw

inslongitudinally

tocharacterize

normative

andatyp-

icalprofilesofangerand

toexam

ineearly

lifestress

asamoder-

atorofthe

linkbetw

eeninfant

angerand

preschoolbehavior

problems.

EarlyAnger

andthe

Developm

entofBehavior

Problems

Anger

isone

ofthe

earliestdeveloping

emotions

inhum

ans.Evolutionary

andfunctionalist

emotion

theoristshave

describedangerasan

action-orientedresponse

togoalinterference

linkedto

discretepatterns

ofexpressioninthe

faceand

body(Izard,1977;

Lewis,1990).These

expressionsofanger,including

bodilytens-

ing,anarched

back,furrow

edbrow

s,and/or

asquaring

ofthe

mouth,are

reliablyelicited

asearlyas2

monthsofage

byrem

ov-ing

orwithholding

anticipatedpositive

rewards

(Alessandri,Sul-

livan,&Lew

is,1990;Izard,1977).Earlydisplaysofangerin

thiscontextare

consistentwiththe

conceptualizationofangeras

mo-

tivatingthe

persistentpursuitofablocked

goal(Campos,M

umme,

Kerm

oian,&Cam

pos,1994;

Levenson,2003;

Stein&Jew

ett,1986).Som

edissentexistsregardingthepresenceofdiscreteanger

Thisarticle

waspublished

Online

FirstAugust25,2014.

RebeccaJ.Brooker,D

epartmentofPsychology,M

ontanaState

Univer-

sity;Kristin

A.Buss,D

epartmentofPsychology,The

PennsylvaniaState

University;K

athrynLem

ery-Chalfant,Departm

entofPsychology,Arizona

StateUniversity;N

azanAksan,D

epartmentof

Neurology,U

niversityof

Iowa;Richard

J.Davidson

andH.HillG

oldsmith,D

epartmentofPsychol-

ogy,University

ofWisconsin—

Madison.

Data

collectionforthis

projectwassupported

byGrantR01

MH50560

fromthe

National

InstituteofMental

Health

toH.HillGoldsm

ith.Thewriting

ofthisarticlewaspartially

supportedbyGrantsT32

MH018931

toRichard

J.Davidson

andK01MH100240

toRebecca

J.Brookerfromthe

NationalInstitute

ofMentalH

ealth.Infrastructuresupportw

asalso

pro-vided

byGrants

P30HD03352

andP50

MH084051.Salary

supportwas

receivedbyNazan

Aksan

fromthe

ToyotaMotorCom

pany.Wethank

thefam

ilieswho

participatedinthis

studyand

thestaff

members

whohelped

withthe

recruitmentof

studyparticipants

anddata

collection.Correspondence

concerningthis

articleshould

beaddressed

toH.Hill

Goldsm

ith,328Brogden

Hall,1202

WestJohnson

Street,Madison,W

I53706,orto

RebeccaBrooker,MontanaStateU

niversity,Departm

entofPsychology,P.O

.Box

173440,Bozem

an,MT59717.

E-mail:

[email protected]

orrebecca.brooker@

montana.edu

This document is copyrighted by the American Psychological Association or one of its allied publishers.This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.

Developm

entalPsychology©2014

American

PsychologicalAssociation

2014,Vol.50,N

o.10,2343–23520012-1649/14/$12.00

http://dx.doi.org/10.1037/a0037693

2343

earlyinlife,and

perspectivesvary

onthe

degreeofoverlap

thatexists

between

displaysofanger

andother

emotions,

suchas

sadness(Cam

ras,1992;

Izard,1977;

Oster,

2005).However,

nearlyallperspectivesreportobservable

angerby6monthsofage.

Despite

consistencyinitsfunction

acrossthe

lifespan,anger

evincessubstantialchange.N

ormatively,expressed

angerisrela-

tivelylow

inearly

infancy,increaseslate

ininfancy

andthrough

thesecond

yearoflife,

andthen

decreasesacross

toddlerhood.(Braungart-Rieker

etal.,

2010;Denham

,Lehm

an,Moser,

&Reeves,1995).Periods

ofstabilityinearly

angerarealso

presentbetw

een2.5

to5months,5

to7.5

months,and

7.5to22monthsof

age(Malatesta,Culver,Tesm

an,&Shepard,1989).O

verall,then,there

ismixed

evidencefor

mean-level

stabilityand

changein

earlyangerexpressions,suggesting

thepossible

existenceofindi-

vidualdifferencesindevelopm

entalprofiles.Therefore,ourfirst

goalwastodescribe

individualvariabilityindevelopm

entalpro-filesofanger.A

lthoughdecidedly

exploratory,theextantliteraturesuggests

atleastthreedistinctprofiles

ofangerinthe

secondhalf

ofinfancy:aprototypicalprofile

ofangerthatincreasesovertime

andmore

atypicalprofiles

ofgenerally

highand

generallylow

angerreactivity.These

threeprofiles

were

thushypothesized

onthe

basisofprevious

work;how

ever,additionalprofilesare

cer-tainly

plausible(e.g.,decreasing

anger).High,

stablelevels

ofanger

anddifficulties

regulatinganger

duringinfancy

andchildhood

arebelieved

toprecede

thedevel-

opment

ofaggressive

andexternalizing

problems(Cole

etal.,

2003;Denham

etal.,2002;Eisenbergetal.,2001).In

addition,increases

inaggressive

behaviors,which

areseparate

frombut

relatedtoangerrelative

togoalpursuit,m

irrorthoseforobserved

angerbetw

een10

and50

months

ofage,

suggestingpossible

overlapinthe

developmentofangerand

problembehaviors(A

linketal.,2006).In

somecases,high

levelsofanger

havealso

beenassociated

withthe

developmentofinternalizing

problemsin

chil-dren

(Eisenbergetal.,

2001;Lem

ery,Essex,

&Smider,

2002),although

thismaybeatleast

partiallydue

tointernalizing

andexternalizing

symptom

comorbidity

earlyinlife

(Gilliom

&Shaw

,2004).Stably

highlevels

ofangerthereforeappearto

bedysregu-

latedinthatthey

impederatherthan

aidgoalpursuit(Cole,M

ichel,&Teti,1994),placing

individualsatrisk

forsubsequentbehaviorproblem

s.Atypically

lowangerm

ayalso

bedysregulated

inthatit

interfereswith

goalpersistence

(Belsky,Friedm

an,&Hsieh,

2001).These

findingsunderscore

theimportance

ofdistinguishingbe-

tween

normal-range

variationinanger

andnonnorm

ative,more

extremeanger

tendencies,which

mayrepresentfacets

ofrisk

forthe

developmentof

behaviorproblem

s.Therefore,weexam

inedinfantangerin

multiple

contextsatboth

6and

12months

ofageand

itsassociation

withparent-reported

behaviorproblem

sat36

months

ofage.Furtherm

ore,wecharacterized

infantangerusing

bothcontinuous

measures

aswellas

discretelyspecified

develop-mentalprofilesofangerbetw

een6and

12monthsofage.Thisdual

analytictrack

permitted

ustofully

exploreand

betterunderstandadaptive

andmaladaptive

consequencesofinfantangerreactivity.

LifeStress

andRisk

forBehavior

Problems

Thoughsom

edirectlinks

among

emotion

andbehavior

prob-lem

sare

expected,relations

between

emotions

anddeveloping

behavioralproblemsare

oftenmore

complex.Contextualfactors

arecriticalin

shapingdevelopm

entaloutcomes(Cicchetti&

Aber,

1998).Norm

ativelife

stressors(e.g.,death

inthe

family,m

ovingtoanew

home)are

notablecontextualfactors

forearly

develop-ment,given

thattheyare

experiencedbymostchildren.Investi-

gationsofadolescents

reportthatthesetypes

ofnonsevere

stres-sors

arekey

predictorsofincreases

inbehavior

problems(Attar,

Guerra,&

Tolan,1994;Vaux

&Ruggiero,1983).H

ighlevels

oflife

stresspositively

predictexternalizingproblem

s,includingag-

gression,hyperactivity,andconductproblem

s,between

7and

13years

ofage(Jackson

&Warren,2000).

Lifestressors

alsoplace

childrenand

adolescentsatincreased

riskfordeveloping

internalizingproblem

s(Sw

earingen&Cohen,

1985).Atleast

onestudy

suggeststhat

sucheffects

cannotbe

explainedbythepresenceofparentalpsychopathology,w

hichmay

leadtoboth

negative,stressfulexperiencesand

anincreased

riskfor

maladaptive

outcomesinoffspring.

Thiswork

showedthat

when

stressfullife

eventswere

accountedfor,

parents’mental

illnesswasno

longerassociated

with

adolescents’depressive

symptom

s(Gore,A

seltine,&Colten,1992).

Earlylife

stressisalso

associatedwith

angerearly

inlife;

childrenwhoexperience

agreaternum

berofstressfullifeevents

displaymore

angerwhen

goalsare

blocked(Wang,

Trivedi,Treiber,&

Sneider,2005).Lifestress

maygenerally

disrupttheability

ofyoungchildren

toregulate

escalatingnegative

emotions,

includinganger,leading

tothe

developmentofbehaviorproblem

s(Com

pas,Connor-Sm

ith,Saltzm

an,Thom

sen,&Wadsw

orth,2001).

Fromthis

vantagepoint,

earlystress

mayeither

disruptchildren’sability

toup-regulate

angerthatis“toolow

”tomaintain

goalpursuitortodow

n-regulate“too

high”angerthatm

ayinter-

ferewiththe

goalattainment.Em

piricalsupportforthenotion

thatlife

stressmaybedetrim

entalforboth

high-and

low-anger

chil-dren

islacking.Stress

doesexacerbate

riskforbehaviorproblem

sininstances

inwhich

developmentis

alreadynonnorm

ative(i.e.,

profilesofdevelopm

entthat

donot

match

themost

common

patterns;Hauser-Cram

,Warfield,Shonkoff,&

Krauss,2001),and

thereisseparate

evidencethat

preschoolerswho

expressedex-

tremely

highorextrem

elylow

levelsofangerin

responsetogoal

blockagewere

reportedashaving

greaternumbersofexternalizing

problemsthan

were

moderately

expressivepreschoolers

(Cole,Zahn-W

axler,Fox,Usher,&

Welsh,1996).H

ence,itispossible

thatrisk

forbehavior

problemsisthe

productofinteractions

between

earlylife

stressand

atypicalangerprofiles,regardlessof

overallangerlevels.Thispossibilityunderscorestheim

portanceofbetterunderstanding

earlyprofilesofangerin

thecontextoffamily

stress.Thus,

ourfinal

aimwastotest

theinteraction

between

developmentalprofiles

ofinfantangerandfam

ilystress

onfuture

behavioralproblems.

CurrentStudy

Insum

,weaddressseveralgapsin

theliterature

regardingearly

angerdevelopmentby

characterizingtypicaland

atypicalprofilesofangerduring

infancyand

testingthe

roleofearly

lifestress

asamoderator

ofthe

linkbetw

eeninfant

angerand

preschoolbe-

haviorproblems.A

lthoughsom

eofouranalysesw

ereexploratory

innature,hypothesesforeach

ofouraimscan

bederived

fromthe

literature.Aspreviously

stated,weexpected

thatatleast

threeprofilesofangerw

ouldbediscernible

duringinfancy.In

addition,weanticipated

thatearlyangerw

ouldbepositively

associatedwith


2344BRO

OKER

ETAL.

behaviorproblemsin

preschoolbutthatlevelsoflifestressw

ouldmoderate

thisrelation.Namely,w

eexpected

thatgreaterearlylife

stresswould

exacerbaterisk

forbehavior

problemslinked

toatypicalinfantangerreactivity.

Method

Participants

Thesam

plewasdraw

nfrom

alongitudinaltw

instudy

examin-

inggenetic

andenvironm

entalinfluencesonemotionaldevelop-

mentacross

infancyand

earlychildhood

(Schmidtetal.,2013).

Participantsfor

theparentstudy

were

recruitedfrom

thegreater

Madison,W

isconsin,areathrough

avariety

ofmethods,including

statebirth

records,mothers-of-tw

insclubs,

televisionpublicity,

birthannouncem

entsinnew

spapers,flyersindoctors’offices,the

Internet,andreferrals

fromparticipants.Forthe

parentstudy,989fam

ilieswere

contactedfor

recruitment,

which

was

ongoingthroughout

thestudy.O

nehundred

andforty

onefam

ilieswere

enrolledbutdid

notparticipateinany

phaseofthe

study.Infantscom

pletedlaboratory

assessments

at6months

and12months

ofage.A

tthetimeofthe

6-month

assessment,56

familieschose

nottoparticipate,3

families

hadwithdraw

nfrom

thestudy,and

495fam

ilieswere

notyetenrolled.Thusthe

6-month

sample

included294

families;566

infantsprovided

usabledata

(292girls).A

tthetimeofthe

12-month

assessment,115

families

chosenotto

par-ticipate,a

totalof17fam

ilieshad

withdraw

nfrom

thestudy,and

160fam

ilieswere

notyet

enrolled.Thus,the12-m

onthsam

pleincluded

456fam

ilies;881infantsprovided

usabledata(451girls).

Nearly

500infants

(n!481)

providedobservational

datafrom

laboratoryepisodes

atboth

6and

12months

ofage.

Smaller

numbersofinfantshad

datafrom

onlythe

6-month

(n!85)orthe

12-month

assessment(n

!400).Thesam

pleincludesthoseinfantswith

observationaldata

fromanger

episodesateither

the6-or

12-month

assessment 1

(N!966;51.1%

girls).Consistentw

ithlocaldem

ographics,mostm

othersself-reportedtheir

raceasCaucasian

(95%,African

American

!1.7%

,Asian

American

!0.9%

,American

Indian!0.4%

,Hispanic

!1.4%

,OtherRace

!0.6%

)asdid

fathers(92.8%

,African

American

!2.7%

,Asian

American

!0.9%

,American

Indian!0.3%

,His-

panic!2.1%

,Other

!1.2%

).Thelargest

number

ofmothers

(31.4%)reported

acollege

degreeastheirhighestlevelofeduca-

tion(grade

school!0.1%

,somehigh

school!1.3%

,highschool

graduate!14.5%

,somecollege,29.6%

,somegraduatetraining

!14.1%

,graduatedegree

!9.0%

).Thelargestnum

beroffathers

reportedeithersom

ecollege

(27.5%)ora

collegedegree

(27.6%)

astheir

highestlevel

ofeducation

(gradeschool

!0.3%

,some

highschool

!2.4%

,highschoolgraduate

!19.1%

,somegrad-

uatetraining

!11.5%

,graduate

degree!11.6%

).Ofthose

families

who

chosetoreport

theirannual

income,the

greatestnum

ber(43.1%

)reported

grosshousehold

incomes

ofover

$60,000(2.3%

earned$15,000

orless,

3.5%earned

$16,000–$20,000,8.4%

earned$21,000–$30,000,13.3%

earned$31,000–

40,000,13.8%

earned$41,000–$50,000,

and15.5%

earned$51,000–$60,000).O

nehundred

andone

families

didnotreport

onfam

ilycom

position:Ofthose

who

did,94.9%

reportedthat

childrenlived

withboth

biologicalparents.

ProcedureLaboratory

assessments

occurredwhen

infantswere

6(M

!5.83,SD

!0.60)and

12(M

!11.89,SD

!1.42)m

onthsofage;infants

participatedinanum

berofepisodes

designedtoelicit

discreteemotions.W

efocused

onepisodesdesigned

toelicitanger

ininfants.Follow

ingassessm

ents,mothers

andfathers

completed

apacketofquestionnairesand

mailed

themback

tothe

laboratory.Parents

alsocom

pletedmailed

questionnaireswhen

childrenwere

36months

ofage.Table1provides

anoutline

ofdatacollection,

procedures,assessments,and

measures.

BehavioralAssessm

entGentle

armrestraint.

Atboth

6and

12monthsofage,infant

angerwasassessed

duringthe

gentlearm

restraintepisodefrom

theLaboratory

Temperam

entAssessm

entBattery

(Lab–TAB;

Goldsm

ith&Rothbart,1996).Forthis,the

infantwasseated

ina

highchairand

presentedwithanoveltoy

withwhich

heorshewas

allowedtoplay

for15–30s.The

parent,havingreceived

instruc-tionsfrom

theexperim

enter,thenstood

behindthe

infantandheld

theinfant’s

forearmstohis

orher

sidetoprevent

engagement

withthe

toyfor30

s.Theinfantw

asthenallow

edtoreengage

with

thetoy

for30sbefore

asecond

restrainttrialbegan.Thesecond

trialproceededsim

ilarly,endingwiththe

infantbeingallow

edto

playwiththe

toy.Carseat.

Angerw

asalso

assessedat6

and12months

ofageduring

thecarseatLab–TA

Bepisode.Forthis,the

parentbuckledthe

infantintoastandard

butrestrictivecar

seatandthen

stoodoutside

ofthechild’sview

.Theparentw

asinstructedtoleave

theinfant

inthe

carseat

for30

sand

refrainfrom

speakingtoor

comforting

himorher.Episodes

endedwith

theparent

moving

backinto

theinfant’sdirectline

ofsightandcom

fortinghim

orherasneeded.Behavioral

codingprocedures.

Consistentwith

Lab–TAB

scoringprocedures

(Goldsm

ith&Rothbart,1996),trained

codersassigned

ratingsofanger

andsadness

foreach

infantinthe

armrestraint

andcar

seatepisodes.

Ratingswere

assignedin5-s

epochs,duringwhich

themaxim

umintensity

wasscored

forthe

following:observed

facialanger(0!noanger;3

!angerofthe

highestintensity),bodilyanger(0

!nostruggle

orresistance;4!

continuoushigh-intensitystruggle),and

distressvocalizations(0!

novocal

distress;5

!full

intensitycry/scream

).Latency

(inseconds)to

thefirstangerbehaviorw

asalso

recorded.The

following

sadnessbehaviors

were

similarly

scored:maxi-

mum

intensityoffacialsadness

(0!no

sadness;3!sadness

ofthe

highestintensity),bodilysadness

(0!absent,1

!present),

andlatency

(inseconds)

tothe

firstsadness

behaviorinthe

episode.Anger

andsadness

variableswere

codedseparately

toallow

forthe

possibilitythatinfants

mayhave

shownboth

angerand

sadnessinthe

same5-s

epoch.Allcoders

were

requiredto

achieveaminim

umreliability

("!0.70)

with

amaster

coderbefore

codingindependently.

Roughly10%

ofepisodes

were

double-codedtoestablish

reliabilityand

preventcoding

drift.Mean

intercoderreliabilityforangervariablesw

as"

!0.78.M

eanintercoderreliability

forsadnessvariables

was

"!0.75.

1Resultsare

unchangedwhen

limited

tothose

individualswithdata

atboth

6and

12months.


2345INFANTANGER,LIFE

STRESS,ANDBEH

AVIORPRO

BLEMS

Latencyscores

were

reversedtoparallel

thedirectionality

ofother

behaviors;greaterscores

reflectedamore

rapiddisplay

ofangerorsadness.W

ithin-episodeaverage

compositesw

ereform

edacross

epochsfor

eachofthe

remaining

behaviors.Speedscores

andaverage

composites

were

thenz-scored

andcom

binedinto

singlemeasures 2

ofanger

(mean

r!.59)

andsadness

foreach

episode(mean

r!.45).N

otethatthis

procedureresults

intwo

composites

ofanger:(i.e.,carseatand

armrestraint)ateach

ageand

twocom

positesofsadness

ateach

age.Anger

andsadness

compositesw

eremoderately

correlatedatboth

6months(carseat:

r!.53,arm

restraint:r!.43)and

12months(carseat:r

!.50,

armrestraint:r

!.40).

QuestionnairesEarly

lifestress.

Given

ourinterestinthe

roleofnonsevere,

ormore

“typical”early

lifestressors,the

lifeeventsdom

ainofthe

ParentingStressIndex

(PSI;Loyd&Abidin,1985)w

asselectedas

ameasure

ofearlylife

stress.When

childrenwere

6months

old,the

primary

caregiverreportedwhetherthe

familyhad

experiencedeach

of20possible

stressfullifeevents

thatrangedfrom

regularhassles

(e.g.,encountering

more

stressorsthan

anticipated)to

major

lifeevents

(e.g.,death

ofamember

ofthe

immediate

family).Item

swere

weighted

bythe

severityofthe

lifestressor;

forexam

ple,endorsing

anitem

askingabout

anillness

inthe

immediate

family

(thechild

alongwith

hisorher

parentsand

siblings)receivedascore

of1,andendorsing

anitem

askingabout

divorcereceived

ascore

of7.Item

scoreswere

thensum

medto

createanoverallscale

score.Endorsingallitem

swould

resultina

scoreof80.A

saparentreportm

easure,thePSIisgenerally

more

sensitivetothe

perceptionsandmemoriesofparentsthan

tothose

ofchildren.However,by

focusingonthe

lifeevents

domain,w

ecaptured

objective,discretelife

eventsthataffectallmembersofa

family(e.g.,children

move

when

parentsmove).Thus,this

scaleisafam

ily-levelmeasure

ofcumulative

lifestress.

Behaviorproblem

s.Behaviorproblem

swere

assessedatage

36months

viathe

ChildBehavior

Checklist(Achenbach

&Re-

scorla,2000).Theprim

arycaregiverreported

thedegree

towhich

variousstatem

ents(e.g.,“show

spanic

fornogood

reason”)were

trueoftheirchild’sbehaviorona3-pointscale(0

!notatalltrue;

2!

verytrue

oroften

true).Ascale

scoreofinternalizing

problems(nitem

s!32;

#!.82)and

ascale

scoreofexternal-

izingproblem

s(nitem

s!34;#

!.90)w

asformedforeach

child.Given

thatscoresfor

internalizingand

externalizingscales

were

highlycorrelated

(r!.58)and

thatinternalizingand

externalizingbehaviors

arehighly

correlatedearly

inlife

(Gilliom

&Shaw

,

2004),theTotalProblemsscalescorew

asused(nitem

s!98,#

!.94).The

TotalProblemsscale

includedallitem

sfrom

theinter-

nalizingand

externalizingscales

alongwithitem

sfrom

theother

problemsscale

(nitem

s!32,

#!.79).The

mean

correlationamong

thethree

scaleswasr

!.68.

Missing

data.Because

recruitment

wasongoing

throughoutthe

durationofthe

study(i.e.,

someparticipants

joinedat12

months),a

greaternumberofchildren

participatedinthe

12-month

thaninthe

6-month

laboratoryassessm

ent(Table1).A

nanalysis

ofpatterns

ofmissing

datasuggested

thatdata

were

missing

completely

atrandom

,Little’s

Missing

Completely

atRandom

(MCAR)test,

$2(131)

!148.23,p

%.10.

Profileswere

createdusing

astatistical

procedure(described

below)thatincludesfull-inform

ationmaxim

umlikelihood

(FIML)

estimation.Thatis,allavailable

datawere

usedtoderive

individ-uallikelihoods

ofprofile

groupmembership.Because

ofthis,all

individualswith

lifestress

measures

hadan

availableprofile

assignment,

andacom

plete-casesanalysis

strategywasused.

Additionally,

multilevel

analyseswere

usedtoaccount

forthe

correlatednature

ofthedata

(i.e.,twins

within

families).

Results

Analyses

were

conductedinaccordance

with

studyaim

sand

hypotheses.After

weexam

ineddescriptive

statisticsfor

allvari-ables,profiles

ofinfantangerwere

derivedfrom

6-and12-m

onthobservations

ofanger

andvalidated

bytesting

forprofile-based

differencesincom

positemeasures.Bivariate

associationsbetween


sand

measures

ofanger

were

exam-

inedforboth

traditional(i.e.,levelsofobservedangerquantified

ascom

posites)and

novel(i.e.,

angerprofiles)

measures

ofinfant

angerpriortomultivariate

analyses.Finally,lifestress

wastested

asamoderatorofthe

relationbetw

eeninfantangerand


s.

Descriptive

Statisticsand

Age-Based

Change

inVariables

Descriptive

statisticsareshow

ninTable

2.Substantialvariabil-itywasobserved

forallm

easuresacross

assessments,indicating

thepresence

ofbroad

individualdifferences.

T-testscom

paredcotw

insonallstudy

variablestoensure

randomlabeling

oftwins

(i.e.,TwinAvs.Tw

inB)within

family;

allcotw

indifferences

were

nonsignificant.Additionalttestscom

paredboysand

girlsonallvariables.G

irls(M

!&0.02,SD

!0.60)

showedless

angerthan

boys(M

!0.05,SD

!0.53)

atthe

12-month

assessment,

t(879)!

&1.93,p

!.05,d

!0.12.N

oothersex

differenceswere

present.Apaired

samples

ttest

suggestedthat

observationsofanger,

t(480)!0.23,p

%.10,evinced

mean

levelstabilitybetw

een6and

12months

ofage.Additionally,bivariate

correlationssuggested

asmallam

ountofrank-orderstabilityinangerovertim

e(r

!.16,

p'.01).

2Theform

ationofeach

composite

wasalso

supportedbyaprincipal

components

analysis(PCA

).Additionaldetails

ofeachPCA

areavailable

fromauthors.

Table1

Outline

ofData

Collection

Procedures

Age

Assessm

enttypeContexts/m

easuresConstructs

6months

BehavioralvisitArmrestraint

Anger,sadness

CarseatAnger,sadness

Questionnaires

ParentingStress

IndexLife

stress

12months

BehavioralvisitArmrestraint

Anger,sadness

CarseatAnger,sadness

36months

Questionnaires

ChildBehavior

ChecklistChild

behaviorproblem

s


2346BRO

OKER

ETAL.

Heterogeneity

inProfiles

ofAnger

Developm

entWetested

forheterogeneous

profilesofanger

duringinfancy

usinglatentprofile

analysis(LPA

).LPAidentifies

latentprofilesofindividuals

whodiffer

fromthe

overallgroupbyrelaxing

theassum

ptionthatallindividualsare

drawnfrom

asingle

population.Relaxing

assumptions

inthis

wayallow

smean

levelsofangerto

varyaround

separatemeans

andenables

identificationofprofiles

reflectinguniquepatternsofobserved

angeracrossepisodes.Anal-

ysesbegan

with

asingle-profile

solutionand

progresseduntil

addingadditionalprofilesno

longerimproved

fitovertheprevious

model(totalm

odelsrun

!4).Because

theLPA

procedurewas

intendedtodescribe

behavioralvariability

bothacross

contexts(arm

restraintand

carseat)

andacross

time(6-

and12-m

onthassessm

ents),com

positescores

fromindividual

episodeswere

used.Hence,

eachanalysis

includedfour

variables,reflecting

multiple

indicesofangerovertim

e,onwhich

profilegroups

were

based:armrestraintangerat6

months

ofage,carseatangerat6

months

ofage,armrestraintangerat12

months

ofage,andcar

seatangerat12monthsofage.A

multilevelfram

ework

wasused

toaccountforthe

nonindependenceofthe

twindata.

Examination

offitstatistics

(Table3)suggested

thatathree-

profilesolution

fitthedata

best.Thefirstprofile

includedchildren

withlow

scoresinboth

anger-elicitingepisodesat6

and12months

ofage(n

!96).W

elabeled

thisthelow

angerprofile.Thesecond

profileincluded

childrenwithdecreasing

scoresofangerfrom6to

12months

ofagebutw

hosescores

remained

highrelative

tothe

scoresofotherchildren

(n!83).W

elabeled

thisthe

highanger

profile.Themostcom

monprofile

includedchildren

whoshow

edmoderate

levelsofangeracrossallepisodes.However,children

inthis

groupshow

edrelative

increasesindisplays

ofanger

inboth

episodesbetween

the6-and

12-month

assessments(n

!787).W

enam

edthis

classthe

increasingprofile.G

enderwasunrelated

toprofile

membership,

$2(2)

!1.60,p

%.10.Forsubsequentanal -

ysesusing

angerprofiles,

childrenwere

assignedtothe

profile

groupfor

which

theyhad

thehighestprobability

ofmembership

(Mprobability

ofmembership

inassigned

group!0.82).

Internalvalidationofthe

latentprofiles.

Weconducted

atestofinternalvalidation

ofprofilegroup

differencesinobserved

angerineach

ofthelaboratory

episodesateach

assessment.O

uranalysis

was

conductedas

atwo-level

linearmixed

model

(Level1:fam

ily,Level2:twins

within

families)

toaccount

fornonindependence

inthe

twindesign.

Thefirstanalysisshowedthat,assuggested

byFigure1,profiles

differedinlevels

ofanger

observedinthe

carseat,F(2,503)

!25.43,p

'.01,(

p 2!.09,and

armrestraint,F(2,536)

!330.22,

p'.01,(

p 2!.55,episodesat6

months.Follow

-upcontrastsw

ithBonferroni

correctionsuggested

that,inboth

episodes,thehigh

angerprofileshow

edthe

highestlevelsofangerw

hereasthe

lowanger

profileshow

edthe

lowestlevels

ofanger.Sim

ilarly,at12months,profiles

significantlydiffered

inlevels

ofangerobservedinboth

thecarseat,F(2,774)

!15.14,p

'.01,(

p 2!.04,and

armrestraint,F(2,832)

!356.21,p

'.01,(

p 2!.46,episodes.Follow

upcontrasts

with

Bonferronicorrection

suggestedthat,for

bothepisodes,the

lowanger

profileshow

edless

angerthan

boththe

highangerprofile

andthe

increasingangerprofile.The

highand

increasingangerprofiles

were

notsignificantlydifferent.

Anger

and36-M

onthBehavior

Problems

Correlationsincluding

traditional(continuous)measures

ofan-gerrevealed

thatgreaterangerat6(r

!.38,p

'.01)butnot12

Table2

Descriptive

Statisticsfor

Primary

Variables

Variable

Units

nMinim

umMaxim

umM

SDt

6-month

observedanger

zscore

566&1.82

2.070.02

0.62&0.40

12-month

observedanger

zscore

881&1.98

1.450.01

0.570.57

36-month

behaviorproblems

Rawscore

2190.00

0.750.23

0.160.92

Lifestress

Rawscore

4550.00

29.009.66

5.93&0.13

Note.t

!productofa

t-testcomparison

oftwins.

Table3

FitIndicesfor

LatentProfilesofAnger

Number

ofprofilesinmodel

AIC

BIC$2

Entropy

Average

classassignm

entprobability

25,705.17

5,770.5290.80

!!

0.720.80

35,646.57

5,734.2970.60

!!

0.580.81

45,633.77

5,754.8622.80

0.550.86

Note.$2isderived

fromthe

Vuong-Lo-M

endell-RubinLikelihood

RatioTest.The

three-profilemodelw

asdeterm

inedtohave

thebestfit.A

IC!

Akaike

information

criterion;BIC!Bayesian

information

criterion.!!p

'.01.

-1.5 -1

-0.5 0

0.5 1

1.5

6 mo. A

rm Restraint

6 mo. Car Seat

12 mo. A

rm Restraint

12 mo. Car Seat

Observed Anger Composite (z-score)

Low AngerIncreasing AngerHigh AngerFigure

1.Cross-situational,cross-age

latentprofiles

ofinfant

anger.The

errorbars

reflectthestandard

errorofthe

mean.



STRESS,ANDBEH

AVIORPRO

BLEMS

(r!.05,p

%.10)m

onthswaslinked

tomore

behaviorproblems

at36months

ofage.To

ensurethat

associationstruly

reflectedlinks

toobserved

angerand

notmore

generallevelsofnegative

emotionality,w

ecreated

adirectionality

composite

thataccountedfor

levelsofsadness

observedduring

thetwoanger

episodes.Sadness

andangerw

eresignificantly

correlatedatboth

6months

(r!.39,

p'.01)

and12months

ofage

(r!.35,

p'.01).

Modeled

aftertheproceduresofEssex

etal.(2011),directionalitycom

positeswere

formedbyhalving

thedifference

between

thestandardized

angerand

sadnesscom

posites.Given

thatcoding

proceduresdid

notrequire

sadnessand

angertobe

mutually

exclusive,childrenwhoexpressed

highlevelsofnegative

emotion

overall(i.e.,bothangerand

sadness)ratherthanonly

angerwould

receiveadirectionality

scorenearzero.In

contrast,childrenwho

displayedgreaterrelativeangerw

ouldreceivepositivescores,w

ithmore

positivevalues

indicatinggreater

anger;childrenwhodis-

playedgreaterrelative

sadnesswould

receivenegative

scores,with

more

negativevalues

indicatinggreater

sadness.Thus,direction-ality

compositesreflectpropensitiesforanger(relative

tosadness)

thatare

independentfrom

overalllevels

ofnegative

emotion

(sadnessplus

anger).Mostim

portant,theyallow

atestof

addi-tional

confidencethat

findingsare

linkedspecifically

toinfant

anger.Substitutingthe

directionalitycom

positeinto

bivariateanal-

ysesrevealedthataccounting

forlevelsofsadnessleftassociationsbetw

eenangerand

behaviorproblemsunchanged

(6months:r

!.24,p

'.01;12

months:r

!–.00,p

%.10).Thatis,itrem

ainedthe

casethatonly

greaterlevelsof6-month

angerwere

associatedwithmore

36-month

behaviorproblems.

Angerprofiles

were

alsosignificantly

associatedwithbehavior

problemsat36

monthsofage,F(2,218)!

3.23,p'.05,(

p 2!.03.

Childreninthe

normative,increasing

angergroup

showedfew

erbehaviorproblem

satage

36months

thandid

childreninthe

highanger

group(t

!&8.38,

p'.05,

d!0.60).

Thisdifference

remained

significantupon

correctionfor

multiple

comparisons

(Bonferroni).

LifeStress

asaModerator

oftheLink

Between

EarlyAnger

andProblem

BehaviorsInour

finalset

ofanalyses,

wetested

earlylife

stressasa

moderator

ofthe

associationbetw

eenobserved

angerininfancy

andbehaviorproblem

sduringthe

preschoolyears.Traditionalandprofile

measures

ofanger

were

testedinseparate

analyses.A

two-levelm

ixedmodelw

asused

toaccountforthe

nestednature

ofthedata

(twins

within

families).

First,wetested

themodelthatincluded

traditionalmeasures

ofobserved

angerat6

and12months

ofage.A

t6months

ofage,

greateranger

wasassociated

withmore

behaviorproblem

sat36

months

ofage,B!0.10,SE(B)

!0.03,p

'.01.Life

stressdid

notpredict

preschoolbehavior

problems,B

!&0.01,

SE(B)!

0.00,p%.05,and

therewasnosignificant

interactionbetw

eenanger

andlife

stress,B!–0.01,SE(B)

!0.01,p

%.05.A

t12months

ofage,neitheranger,B!–0.01,SE(B)

!0.03,p

%.10,

norlife

stress,B

!&0.00,

SE(B)!0.00,

p%.10,

predictedbehaviorproblem

sduring

preschoolandnosignificantinteraction

waspresent,B

!&0.01,SE(B)

!0.01,p

%.10.

Asecond

two-levellinearm

ixedmodeltested

whetherearly

lifestress

moderated

linksbetw

eenprofiles

ofinfantanger

andpre-

schoolbehavior

problems. 3

Consistentwith

thesuggestions

of

Aiken

andWest(1991),anger

profileswere

dummycoded

suchthat

theincreasing

group,the

normative

developmental

profilebased

onitsfrequency

inthe

currentsample

andconsistency

with

expectationsbased

onthe

extantliterature,servedasthe

referentgroup.Continuousvariablesw

erecentered

priortothe

creationof

interactionterm

s.Asshow

ninTable4,therew

asasignificantinteractionbetw

eenlifestressand

bothofthedum

myvariables()R

2!.10). 4To

probethe

natureofthis

moderation,

weexam

inedthe

associationbe-

tween

earlyangerprofiles

andlaterbehaviorproblem

swhen

lifestress

wasrecentered

atlow

(–1SD)and

high(*1SD)levels

(Aiken

&West,1991;Cohen

&Cohen,1983).Recentering

thelifestress

variableallow

edustoexam

ineitseffecton

theassociation

between

angerprofiles

andbehavior

problemsasacontinuous

variablewhileelim

inatingtheneed

tocreatearbitrary

“highstress”

and“low

stress”groups.Results

showedthatatlow

levelsoflife

stress,childreninboth

thelowanger,B

!0.34,SE(B)

!0.09,p

'.01,and

thehigh

angerprofiles,B!0.20,SE(B)

!0.06,p

'.01,

showedgreaterbehaviorproblem

sthandid

childreninthe

increas-ing

angerprofile(Figure2).Incontrast,athigh

levelsoflifestress,neitherthe

low,B

!&0.18,SE(B)

!0.10,p

%.05,northe

high,B

!0.04,

SE(B)!0.06,

p%.05,

angergroups

significantlydiffered

fromthe

increasinggroup

inlevelsofbehaviorproblem

s. 5

Discussion

Ouroverarching

goalwastorefine

existingknow

ledgeabout

earlyangerdevelopm

entandthe

ways

thatangerininfancy

may

serveasarisk

factorfor


s.Weiden-

tifiedthree

uniqueprofiles

ofanger

duringinfancy:

highanger,

lowanger,

andincreasing

anger.Wefound

thatdifferences

inpreschool

behaviorproblem

scould

bepredicted

bynovel

angerprofiles

andearly

lifestress;

preschoolbehavior

problemswere

inconsistentlylinked

totraditionalm

easuresofanger.Remarkably

forsuchalarge

sample,observationsofm

oreextrem

e,highlevels

ofinfant

angerwere

notconsistent

predictorsoflater

behaviorproblem

s.However,findings

showedthatearly

lifestress

moder-

3Forcom

pleteness,and

toensure

thatanalyses

were

notbiased

bygloballevelsofnegative

affect,wealso

testedamodelthatsubstituted

thedirectionality

compositesfortraditionalm

easuresofanger.Similarto

what

wasfound

inanalysesusing

traditionalmeasures,greaterangerat6

months

ofagewasassociated

withmore

behaviorproblemsat36

months

ofage,B

!0.18,SE(B)

!0.08,p

'.05.Life

stressdid

notpredictpreschoolbehaviorproblem

s,B!

&0.00,SE(B)

!0.00,p

%.10,and

therewasno

significantinteractionbetw

eenthe

directionalitycom

positeand

lifestress,

B!

&0.02,SE(B)

!0.01,p

%.10.A

t12months

ofage,neither

thedirectionality

composite,

B!

&0.09,

SE(B)!0.07,

p%.10,

norlife

stress,B!

&0.00,SE(B)

!0.00,p

%.10,predicted

behaviorproblem

sduring

preschool,andnosignificantinteraction

waspresent,B

!&0.01,

SE(B)!0.01,p

%.10.

4AnR2calculation

isnota

partoftheestim

ationprocedure

formixed

models;therefore,w

ecalculated

R2asthe

decreaseinthe

proportionof

errorvariance

between

models

thatdid

anddid

notinclude

theLife

Stress+AngerClassinteractions.A

lternatively,rerunningthe

analysesasaStepw

iseregression,w

hichdoes

notaccount

fortwinrelatedness

butallow

sforthe

estimation

ofR2,returns

anidenticalestim

ateof

)R2and

aprobability

levelofp'.01.

5Recodingthe

dummyvariable

totestdifferencesbetw

eenlow

andhigh

angerprofilesrevealednodifferencesin

behaviorproblemsatlow

levelsofstress,

B!

&0.14,

SE(B)!0.10,

p%.10,

andatrend

toward

more

behaviorproblemsin

thehigh

angerprofilethan

inthe

lowangerprofile

athigh

levelsoflife

stress,B!0.22,SE(B)

!0.11,p

!.05.


2348BRO

OKER

ETAL.

atedpreschoolbehaviorproblem

swhen

angermeasures

reflectedcross-contextand

cross-timevariability.W

henearly

lifestressw

aslow

,infantswithatypicalprofilesofangerin

infancyshow

edmore

preschoolbehaviorproblemsthan

didtypically

developinginfants.

Athigh

levelsofearly

lifestress,infants

withatypicalprofiles

ofanger

showedlevels

ofpreschool

behaviorproblem

ssim

ilarto

typicallydeveloping

infants.Notably,

thesefindings

were

notpresentin

analysesusing

traditionalmeasures

ofanger,which

didnotdifferentiate

typicalandatypicaldevelopm

entalprofiles.

IndividualDifferences

inContinuous

andCategorical

Measures

ofAnger

Consistentwithhypotheses,w

efound

evidencefor

threepro-

filesduring

infancy.Profiles

were

formed

frommultim

easurecom

positesofangerintwocontextsat6

and12monthsofage.A

substantialproportionofinfants(19%

)showedatypicalprofilesof

angerduringthis

period.Atypicalprofiles

ofangerdevelopment,

which

donotadhereto

thetypicaldevelopmentalcourseasdefined

inthe

literature,have

largelygone

unnoticed,and

highlightingthese

atypicalprofilesisamajorcontribution

ofthiswork.

Characterizingindividualdifferences

inprofiles

ofearly

angeralso

helpedclarify

theimportance

ofearlyangerforlaterbehavior

problems.Wefound

thatoverall

levelsofearly

anger,when

quantifiedusing

traditionalcom

positemeasures,did

notconsis-

tentlypredictparent-reported

behaviorproblemsatage

36months.

Incontrast,

more

novelprofiles

ofanger

thatdescribed

cross-contextand

cross-timevariability

didshow

groupdifferences

inbehaviorproblem

s.Childrenwithtypicalprofilesofangershow

edfew

erbehavior

problemsthan

didchildren

with

atypicalanger

profilesbetw

een6and

12months

ofage,

althoughsubsequent

analysesshow

edthat

thisassociation

wasfurther

moderated

byearly

lifestress.

Weemphasize

thatexpressionsofanger,especially

duringin-

fancy,donot

necessarilyreflect

maladaptive

tendencies.Anger

typicallyincreases

duringthe

6–12-month

period(Braungart-

Riekeretal.,2010),suggestingthatincreases

inangerare

norma-

tiveratherthan

problematic

earlyinlife.O

urfindingsare

consis-tentw

iththesestudies.W

efoundthatthem

ajorityofinfants(81%

)show

edincreasesin

displaysofangerbetween

6and

12monthsof

ageintwolaboratory

contextsand,atthe

12-month

assessment,

theseinfants

were

indistinguishablefrom

otherinfantswhowere

classifiedasstably

highinanger.This

overlapbetw

een“typical”

andputatively-at-risk

infantswasprecisely

thetype

ofunderlyingprocess

thatwesuggested

might

beobscuring

therelationship

between

levelsofanger

at12months

andbehavior

problems2

yearslater.Stated

differently,highlevels

ofanger

at12months

may

notbe

predictiveoflater

outcomesbecause,

atthis

age,putatively

at-riskand

typicallydeveloping

childrendisplay

similar

levelsofanger.

ProfilesofInfantA

nger,EarlyLife

Stress,and

BehaviorProblem

sConsistentw

ithexpectations,w

efound

thatlevelsofstress

inthe

earlyenvironm

entmoderated

theassociation

between

angerininfancy

andpreschool

behaviorproblem

s.Given

lowlevels

ofearly

stress,themostim

portantriskfactorforpreschoolbehavior

problemswasnotlevels

ofangerduringinfancy

butwhetherthe

developmentalprofile

ofanger

wasnorm

ativeoratypical.Chil-

drenwithnonnorm

ativeprofiles

ofanger

ininfancy

hadgreater

behaviorproblem

sat36

months

compared

withthose

withmore

typicalprofiles

ofinfant

anger.This

risk-relateddistinction

be-tween

normative

andatypicalprofiles

ofearlyangerw

asnotseen

athigh

levelsofearly

family

stress.Sim

ilarly,this

moderated

effectwasnotevidentin

analysesthatused

continuousmeasures

ofanger,underscoringthe

importance

ofdifferentiatingindividual

differencesinearly

emotion,particularly

asitrelatestonorm

ativeand

atypicaldevelopment.

Itisasom

ewhatsurprising

findingthatearly

lifestress

didnot

directlypredictincreased

behaviorproblemsinyoung

children.Itispossible

that,inatypically

developingsam

pleofyoung

chil-dren,there

isdim

inishedoverallvariability

inbehaviorproblem

s,which

makes

significanteffectsmore

difficulttodetect.Itis

alsopossible

thatourmeasure

oflifestressisone

thatisdistalfromthe

truemechanism

linkinglife

stresswithbehaviorproblem

s,making

main

effectsmore

difficulttoobserve.

However,

thislack

ofa

significantmain

effectmaybebetterexplained

bythe

presenceof

thesignificantinteraction

between

earlylife

stressand

behaviorproblem

s.Thatis,theinteraction

suggeststhatthedevelopm

entofbehaviorproblem

sisdependentnotonly

onlife

stressbutalso

onearly

anger.Statistically,

thepresence

ofmoderation

hasbeen

Table4

TestofLifeStress

asaModerator

oftheRelation

BetweenAnger

Profileand

BehaviorProblem

s

Variable

BSE(B)

,t

)R2

Step1

0.12!!

Lowanger a

0.100.05

0.192.00

!

High

anger b0.12

0.040.28

2.91!!

Lifestress

&0.01

0.00&0.17

&1.73

†

Step2

0.10!!

Lowanger a

0.080.05

0.151.57

High

anger b0.12

0.040.27

2.98!!

Lifestress

&0.00

0.00&0.03

&0.28

LowAnger a

+Life

stress&0.04

0.01&0.28

&3.02

!!

High

Anger b

+Life

stress&0.01

0.01&0.20

&2.04

!

aDummyvariable

testslow

angerprofile

relativetoincreasing

angerprofile

referencegroup.

bDummyvariable

testshigh

angerprofilerela -

tivetoincreasing

angerprofilereference

group.†p

'.10.one-tailed.

!p'.05.tw

o-tailed.!!p

'.01.tw

o-tailed.

Figure2.

Atypicalangerprofilesshow

heightened36-m

onthbehaviorprob-

lemsatlow

levelsoflife

stressrelative

totypicalangerprofiles.

!!p

'.01.



STRESS,ANDBEH

AVIORPRO

BLEMS

knowntoobscure

thepresence

ofmain

effectsand

make

themmore

difficulttointerpret

(Aiken

&West,

1991).This

maybe

particularlytrue

incasesin

which

effectsarenonlinear,suggesting

thatmoderate

levelsofstress

areadaptive

whereas

abnormally

loworabnorm

allyhigh

exposuretostress

may

inhibitthe

development

ofregulatory

mechanism

sthat

helptokeep

be-havior

problemsatbay.

Ourresults

suggestthat

riskfactors

fordeveloping

behaviorproblem

sare

distinctatdifferent

levelsoflife

stress.Previous

work

hasshow

nthat

thepresence

ofrisk

factorssuch

aslow

socioeconomicstatus,

parentmental

illness,ormarital

discordincrease

riskfor

behaviorproblem

s(Sam

eroff,Seifer,

Barocas,Zax,&

Greenspan,1987).Each

oftheserisk

factorsiscapturedto

someextentin

ourmeasure

ofstressfullifeevents.W

epointout

thatthe

PSI(Loyd

&Abidin,

1985)taps

nonsevere,relatively

commonlife

stressorsratherthan

extremeorsevere

conditionsof

stress(e.g.,maltreatm

ent).Thus,acontribution

ofthiswork

isthefinding

thatatypicalangerprofilesmayalso

serveasrisk

factorsfor—

andalternate

pathways

toward—

negativeoutcom

es.When

levelsoflife

stresswere

low,the

riskassociated

with

atypicalprofiles

ofdevelopm

entwasmore

tightlylinked

tochildhood

outcomes.H

owever,atypicalprofilesdid

notappeartoexacerbate

theeffects

ofhighstress.

Themechanism

sby

which

earlylife

stressorsmight

affectchildren’s

functioningduring

infancyare

thesubject

ofawide

rangeofinvestigations

acrossnum

erousfields

ofpsychology.

Anim

aland

humanmodels

positthat

stressmay“get

underthe

skin”inearly

development

bydisrupting

thedevelopm

entof

physiologicalsystems,contributing

tooverallw

earandtearon

thebody,altering

thedevelopm

entofneuralcircuitry,and

program-

ming

individual-leveltendencies

forhypo-

orhyperactive

stressresponses

(McEw

en,2012;Shirtcliff&Ruttle,2010).A

ddition-ally,an

environmentofearly

stressmayindirectly

affectchildrenby

impeding

parents’abilities

tointeract

with

theirchildren

inwaysthatcontribute

tothe

developmentofindependentregulation.

Namely,greaterpoverty

inthe

earlyenvironm

enthasbeen

linkedtogreaterstress

andless

maternalsensitivity

duringparent–child

interactions(NationalInstitute

ofChildHealth

andHumanDevel-

opmentEarly

ChildCare

ResearchNetwork,2005);less

sensitiveparentsm

aybelesslikely

toprovide

thescaffold

thatisnecessaryfor

childrentolearn

toappropriately

regulatenegative

emotions

suchasanger(K

opp,1982).While

thesemechanism

sarelikely

toplay

importantroles

inthe

linkbetw

eenangerand

earlybehavior

problems,directtests

ofthese

possibilitieswillbe

importantfor

futureresearch.Sim

ilarly,theidentification

ofmore

refinedbio-

logicalandsocialm

echanismsofearly

riskrem

ainsacriticalaim

fordevelopmentalresearch.

Tothe

extentthat

stressand

atypicaldevelopm

entrepresent

independentrisk

factors,alack

ofassociation

between

angerprofiles

andbehaviorproblem

sathigh

levelsofstress

wassom

e-whatsurprising.Conceivably,facets

ofearly

lifethatw

edid

notstudy,

suchasparent

sensitivityand

responsiveness(Cam

pbell,Shaw

,&Gilliom

,2000;Zeanah,Boris,&Larrieu,1997)

might

furthermoderate

theimpactof

earlystressors

onchildren’s

out-com

es.Forexample,despite

continuedadversity

andstress

inthe

family,youthsw

ithhighly

responsiveparentsduring

infancyare

atdecreased

riskfordisruptive

behaviordisordersrelative

toyouths

with

unresponsivemothers

(Wakschlag

&Hans,

1999).Thus,

underconditions

ofhigh

stress,thedegree

towhich

parentscan

maintain

sensitive,responsiveorientation

toward

childrenmaybe

anadditional

predictorofchild

outcomesthan

children’sanger

profilesorlife

stress.Examinations

ofangerprofileswithin

vari-ous

parentingcontexts

willbeanimportant

avenuefor

futureresearch.Theories

abouthowthe

socialenvironmentinteracts

withtem

-peram

entalcharacteristics,suchasanger,to

predictmentalhealth

outcomeslargely

centeronthe

ideathatgenetic

and/orbiologicalfactors

canshape

individualsensitivity

toenvironm

entalinflu-

ences(Reiss,Leve,&

Neiderhiser,2013).W

emightask

whether

ourresults

areconsistentw

iththese

theories.Ourresults

donot

implicate

asingle

profileofearly

angerthatishighly“susceptible”

accordingtoexisting

definitions.Additionally,although

associa-tions

between

profilesand

behaviorproblemsdiffered

undercon-ditions

ofhighand

lowstress,these

were

notclearconditionsof

bothdisrupted

andenriched

development,w

hichisacentraltenet

ofbiological

susceptibility.That

is,the

identificationofhighly

sensitiveprofilesdependson

measuresthatinclude

afullrange

ofpositive

andnegative

environmental

conditions.Although

ourmeasure

ofenvironm

entalstress

enabledparents

toreport

veryhigh

levelsofearlystress,they

didnottap

enrichedenvironm

entsonthe

samespectrum

.Rather,our“lowstress”

environmentbetter

reflectedalack

ofenvironmentalstressors.

Limitations

Thecurrent

studyisnot

without

limitations.

First,unequal

numbers

ofinfantsineach

oftheprofiles

ledtodifferentdegrees

ofpow

ertodetectsignificantdifferences

acrosspairings

oftra-

jectoryclasses.A

dditionally,clinicalassessments

ofparents

andwithchildren

atfollow-up

areunavailable

forthecurrentsam

ple.Thus,although

wecan

testassociationsbetw

eenearly

angerand

parent-reportedpreschoolbehaviorproblem

s,thedegree

towhich

anytrajectory

isassociatedwithsubsequentdiagnosesisunknow

n.Finally,although

wedonotview

thetwindesign

asalimitation,

werecognize

thattheremaybeconcerns

thattwinsam

plesmay

notrepresent

thegeneral

populationonone

ormore

aspectsof

behaviorthat

maybias

resultsinsom

esystem

aticway.In

fact,there

aredifferences

between

twins

andnontw

insearly

inlife

infactors

suchasgestationalage

atbirth,birthweight,and

rateof

languageacquisition

(Plomin,D

eFries,McClearn,&

McGuffin,

2008).However,m

anyofthese

differencesdecline

anddisappear

bythe

earlyschoolyears.Results

fromtwinstudies

largelygen-

eralizetonontw

ins(Andrew

etal.,2001),includingonmeasures

relevanttothe

currentwork,such

asearly

temperam

ent(Gold-

smith&Cam

pos,1990),personality(Johnson,M

cGue,K

rueger,&Bouchard,

2004)and

psychopathology(Christensen,

Vaupel,

Holm

,&Yashin,1995).

ConclusionIndividual

differencesinprofiles

ofanger

arepresent

duringinfancy

andare

associatedwithvariability

inbehaviorproblem

satage

36months.In

addition,atlow—butnothigh—

levelsoflife

stress,nonnorm

ativepatterns

ofinfant

angerpredicted

greaterparent-reported

preschoolbehaviorproblems.O

urresultsprovide

additionalevidence

thatstress

inthe

earlyfam

ilycontext,even

when

notsevere,

isrelated

todevelopm

entaloutcom

es.Impor-

tantly,thiswork

underscoresthe

needtoconsider

individualdif-


2350BRO

OKER

ETAL.

ferences,bothinearly

experiencesand

earlyprofiles

ofanger,instudies

ofdevelopingbehaviorproblem

sinchildren.

References

Achenbach,

T.M.,&Rescorla,

L.A.(2000).

Manual

forthe

ASEBApreschool

formsand

profiles.Burlington,

VT:Research

Centerfor

Children,Youth,and

Families.

Aiken,

L.S.,

&West,

S.G.(1991).

Multiple

regression:Testing

andinterpreting

interactions.ThousandOaks,CA

:Sage.Alessandri,

S.M.,Sullivan,

M.W.,&Lew

is,M.(1990).

Violation

ofexpectancy

andfrustration

inearly

infancy.Developm

entalPsychology,26,738–744.doi:10.1037/0012-1649.26.5.738

Alink,L.R.A

.,Mesm

an,J.,VanZeijl,J.,Stolk,M

.N.,Juffer,F.,K

oot,H.M.,...Van

IJzendoorn,M.H.(2006).

TheEarly

ChildhoodAggression

Curve:Developm

entofphysical

aggressionin10-

to50-

month-old

children.Child

Developm

ent,77,

954–966.doi:10.1111/j

.1467-8624.2006.00912.xAndrew

,T.,Hart,D

.J.,Snieder,H.,de

Lange,M.,Spector,T.D

.,&MacG

regor,A.J.(2001).A

retwins

andsingletons

comparable?

Astudy

ofdisease-relatedand

lifestylecharacteristics

inadultw

omen.

Twin

Researchand

Hum

anGenetics,

4,464–477.

doi:10.1375/1369052012803

Attar,B.K

.,Guerra,N

.G.,&

Tolan,P.H.(1994).N

eighborhooddisad-

vantage,stressfullifeeventsandadjustm

entsinurban

elementary-school

children.Journal

ofClinical

Child

Psychology,23,

391–400.doi:

10.1207/s15374424jccp2304_5Belsky,J.,Friedm

an,S.L.,&Hsieh,K

.-H.(2001).Testing

acoreemotion-

regulationprediction:

Does

earlyattentional

persistencemoderate

theeffect

ofinfant

negativeemotionality

onlater

development?

ChildDevelopm

ent,72,123–133.doi:10.1111/1467-8624.00269Braungart-Rieker,J.M

.,Hill-Soderlund,A

.L.,&Karrass,J.(2010).Fear

andanger

reactivitytrajectories

from4to16

months:

Theroles

oftem

perament,regulation,and

maternalsensitivity.D

evelopmentalPsy-

chology,46,791–804.doi:10.1037/a0019673Cam

pbell,S.B.,

Shaw,D.S.,

&Gilliom

,M.(2000).

Earlyexternalizing

behaviorproblem

s:Toddlersand

preschoolersatrisk

forlater

maladjust-

ment.

Developm

entand

Psychopathology,12,

467–488.doi:10.1017/

S0954579400003114Cam

pos,J.J.,Mumme,D

.L.,Kerm

oian,R.,&Cam

pos,R.G.(1994).A

functionalistperspectiveonthe

natureofemotion.M

onographsofthe

Societyfor

ResearchinChild

Developm

ent,59,284–303.doi:10.1111/j.1540-5834.1994.tb01289.x

Camras,L.A

.(1992).Expressivedevelopm

entandbasic

emotions.Cog-

nitionand

Emotion,6,269–283.doi:10.1080/02699939208411072

Christensen,K.,Vaupel,

J.W.,Holm

,N.V.,&Yashin,

A.I.(1995).

Mortality

among

twins

afterage6:Fetalorigins

hypothesisversus

twin

method.British

Medical

Journal,310,432–436.doi:10.1136/bmj.310

.6977.432Cicchetti,

D.,&Aber,

J.L.(1998).

Contextualismand

developmental

psychopathology.Developm

entandPsychopathology,10,137–141.doi:

10.1017/S0954579498001540Cohen,

J.,&Cohen,

P.(1983).

Appliedmultiple

regression/correlationanalyses

forthe

behavioralsciences(2nd

ed.).Hillsdale,N

J:Erlbaum.

Cole,P.M.,M

ichel,M.K.,&

Teti,L.O.(1994).The

development

ofemotion

regulationand

dysregulation:Aclinical

perspective.Mono-

graphsofthe

Societyfor

ResearchinChild

Developm

ent,59,73–102.doi:10.1111/j.1540-5834.1994.tb01278.x

Cole,P.M.,Teti,L.,&

Zahn-Waxler,C.(2003).M

utualemotion

regula-tion

andthe

stabilityofconductproblem

sbetw

eenpreschooland

earlyschoolage.D

evelopmentand

Psychopathology,15,1–18.doi:10.1017/S0954579403000014

Cole,P.M.,Zahn-W

axler,C.,Fox,N.A.,U

sher,B.A.,&

Welsh,J.D

.(1996).Individualdifferences

inemotion

regulationand

behaviorprob-

lemsinpreschool

children.Journal

ofAbnorm

alPsychology,

105,518–529.doi:10.1037/0021-843X

.105.4.518Com

pas,B.E.,Connor-Smith,J.K

.,Saltzman,H

.,Thomsen,A

.H.,&

Wadsw

orth,M.E.(2001).

Copingwith

stressduring

childhoodand

adolescence:Problems,progress,and

potentialintheory

andresearch.

PsychologicalBulletin,127,87–127.doi:10.1037/0033-2909.127.1.87Denham

,S.A.,Caverly,S.,Schm

idt,M.,Blair,K

.,DeMulder,E.,Caal,S.,

...Mason,T.(2002).Preschoolunderstanding

ofemotions:Contribu-

tionstoclassroom

angerand

aggression.JournalofChildPsychology

andPsychiatry,43,901–916.doi:10.1111/1469-7610.00139

Denham

,S.A.,Lehm

an,E.B.,Moser,M

.H.,&

Reeves,S.L.(1995).Continuity

andchange

inemotionalcom

ponentsofinfanttemperam

ent.Child

StudyJournal,25,289–308.

Eisenberg,N.,Cum

berland,A.,Spinrad,

T.L.,

Fabes,R.A.,Shepard,

S.A.,Reiser,M

.,...Guthrie,I.K

.(2001).Therelations

ofregulationand

emotionality

tochildren’s

externalizingand

internalizingproblem

behavior.Child

Developm

ent,72,1112–1134.doi:10.1111/1467-8624

.00337Essex,M

.J.,Armstrong,J.M

.,Burk,L.R.,Goldsm

ith,H.H.,&

Boyce,W.T.(2011).Biologicalsensitivity

tocontextm

oderatesthe

effectsof

theearly

teacher–childrelationship

onthe

developmentofm

entalhealthby

adolescence.Developm

entalPsychopathology,

23,149–161.

doi:10.1017/S0954579410000702

Gilliom

,M.,&

Shaw,D.S.(2004).Codevelopm

entofexternalizing

andinternalizing

problemsinearly

childhood.Developm

entandPsychopa-

thology,16,313–333.Goldsm

ith,H.H.,&

Campos,J.J.(1990).The

structureoftem

peramental

fearand

pleasureininfants:A

psychometric

perspective.ChildDevel-

opment,61,1944–1964.doi:10.2307/1130849

Goldsm

ith,H.H.,&

Rothbart,M.K.(1996).TheLaboratoryTem

perament

AssessmentBattery:

Locomotor

Version(Version

3.00,technicalman-

ual).Departm

entofPsychology,University

ofWisconsin,M

adison,WI.

Gore,S.,A

seltine,R.H.,Jr.,&

Colten,M.E.(1992).Socialstructure,life

stress,anddepressive

symptom

sinahigh

school-agepopulation.Jour-

nalofHealth

andSocialBehavior,33,97–113.doi:10.2307/2137249

Hauser-Cram

,P.,

Warfield,

M.E.,

Shonkoff,J.P.,

&Krauss,

M.W.

(2001).Childrenwithdisabilities:A

longitudinalstudyofchild

devel-opm

entandparentw

ell-being.Monographs

oftheSociety

forResearch

inChild

Developm

ent,66(3),1–114.doi:10.1111/1540-5834.00151Izard,

C.E.(1977).

Hum

anemotion.

New

York,

NY:Plenum

Press.doi:10.1007/978-1-4899-2209-0

Jackson,Y.,&

Warren,J.S.(2000).A

ppraisal,socialsupport,and

lifeevents:Predicting

outcomebehavior

inschool-age

children.ChildDe-

velopment,71,1441–1457.doi:10.1111/1467-8624.00238

Johnson,W.,M

cGue,M

.,Krueger,R.F.,&

Bouchard,T.J.,Jr.(2004).Marriage

andpersonality:A

geneticanalysis.JournalofPersonality

andSocialPsychology,86,285–294.doi:10.1037/0022-3514.86.2.285

Kopp,

C.B.

(1982).Antecedents

ofself-regulation:

Adevelopm

entalperspective.

Developm

entalPsychology,

18,199–214.

doi:10.1037/0012-1649.18.2.199

Lemery,K

.S.,Essex,M.J.,&

Smider,N

.A.(2002).Revealing

therelationbetw

eentem

peramentand

behaviorproblem

symptom

sbyelim

inatingmeasurem

entconfounding:

Expertratings

andfactor

analyses.Child

Developm

ent,73,867–882.doi:10.1111/1467-8624.00444Levenson,.W

.(2003).Autonom

icspecificity

andemotion.In

R.J.David-

son,K.R.Scherer,&

H.H.Goldsm

ith(Eds.),H

andbookofaffective

sciences(pp.214–224).N

ewYork,N

Y:Oxford

University

Press.Lew

is,M.(1990).Thedevelopm

entofintentionalityandtheroleofconsciousness.PsychologicalInquiry,1,230–247.doi:10.1207/s15327965pli0103_13

Loyd,B.H.,&Abidin,

R.R.(1985).

Revisionofthe

ParentingStress

Index.Journal

ofPediatric

Psychology,10,

169–177.doi:10.1093/

jpepsy/10.2.169Malatesta,C.Z.,Culver,C.,Tesm

an,J.R.,&Shepard,B.(1989).The

developmentof

emotion

expressionduring

thefirsttw

oyears

oflife.



STRESS,ANDBEH

AVIORPRO

BLEMS

Monographs

ofthe

Societyfor

Researchin

ChildDevelopm

ent,54,

1–104.McEw

en,B.S.(2012).Brainonstress:H

owthe

socialenvironmentgets

undertheskin.Proceedings

oftheNationalAcadem

yofSciences

oftheUnited

StatesofAm

erica,109(Suppl.

2),17180–17185.

doi:10.1073/pnas.1121254109

NationalInstitute

ofChild

Health

andHumanDevelopm

entEarlyChild

CareResearch

Network.(2005).D

urationand

developmentaltim

ingof

povertyand

children’scognitive

andsocial

development

frombirth

throughthird

grade.Child

Developm

ent,76,

795–810.doi:10.1111/j

.1467-8624.2005.00878.xOster,H

.(2005).Therepertoire

ofinfantfacialexpression:Anontogenetic

perspective.InJ.N

adel&D.M

uir(Eds.),Emotionaldevelopm

ent(pp.261–292).N

ewYork,N

Y:Oxford

University

Press.Plom

in,R.,

DeFries,

J.C.,

McClearn,

G.E.,

&McGuffin,

P.(2008).

Behavioralgenetics(5th

ed.).New

York,N

Y:W

orth.Reiss,D

.,Leve,L.D.,&

Neiderhiser,J.M

.(2013).How

genesand

thesocial

environment

moderate

eachother.

American

JournalofPublic

Health,103(S1),S111–S121.doi:10.2105/A

JPH.2013.301408

Sameroff,A

.J.,Seifer,R.,Barocas,R.,Zax,M.,&

Greenspan,S.(1987).

Intelligencequotient

scoresof

4-year-oldchildren:

Social–environm

entalriskfactors.Pediatrics,79,343–350.

Schmidt,N

.L.,VanHulle,C.A

.,Brooker,R.J.,Meyer,L.R.,Lem

ery-Chalfant,K

.,&Goldsm

ith,H.H.(2013).W

isconsintwinresearch:Early

development,

childhoodpsychopathology,

autism,and

sensoryover-

responsivity.TwinResearch

andHum

anGenetics,16(SpecialIssue

1),376–384.doi:10.1017/thg.2012.105

Shirtcliff,E.A.,&

Ruttle,P.(2010).Immunologicaland

neuroendocrinedysregulation

following

earlydeprivation

andstress.In

K.Heinz

Brisch(Ed.),Attachm

entand

earlydisorders

ofdevelopm

ent.Stuttgart,Ger-

many:K

lett-Cotta,Munich.

Stein,N.L.,&

Jewett,J.J.(1986).A

conceptualanalysisofthe

meaning

ofnegativeemotions:Im

plicationsforatheory

ofdevelopment.In

C.E.Izard

&P.B.Read

(Eds.),Measuring

emotions

ininfants

andchildren

(Vol.2,pp.238–267).N

ewYork,N

Y:Cam

bridgeUniversity

Press.Swearingen,E.M

.,&Cohen,L.H

.(1985).Lifeevents

andpsychological

distress:Aprospective

studyofyoung

adolescents.Developm

entalPsy-chology,21,1045–1054.doi:10.1037/0012-1649.21.6.1045

Vaux,A

.,&Ruggiero,M

.(1983).Stressfullife

changeand

delinquentbehavior.Am

ericanJournal

ofCom

munity

Psychology,11,169–183.doi:10.1007/BF00894365

Wakschlag,L.S.,&

Hans,S.L.(1999).Relation

ofmaternalresponsive-

nessduring

infancytothe

developmentof

behaviorproblem

sinhigh-

riskyouths.

Developm

entalPsychology,

35,569–579.

doi:10.1037/0012-1649.35.2.569

Wang,

X.,Trivedi,

R.,Treiber,

F.,&Sneider,

H.(2005).

Genetic

andenvironm

entalinfluences

onanger

expression,John

Henryism

,and

stressfullifeevents:The

Georgia

CardiovascularTwinStudy.Psycho-

somatic

Medicine,

67,16–23.

doi:10.1097/01.psy.0000146331.10104.d4

Zeanah,C.H.,Boris,N

.W.,&

Larrieu,J.A.(1997).Infantdevelopm

entand

developmentalrisk:A

reviewofthe

past10years.Journalofthe

American

Academyof

Child&

AdolescentPsychiatry,

36,165–178.

doi:10.1097/00004583-199702000-00007

ReceivedSeptem

ber3,2013Revision

receivedJune

10,2014Accepted

June18,2014

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Profiles of observed infant anger predict preschool behavior problems: Moderation by life stress

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