fei75766_ch17_534-568.indd 558  02/24/20 10:49 AM
Part VI    Learning-Cognitive Theories558
Once established, people continue toaggress foratleastfivereasons: (1)They 
enjoy inflicting injury onthevictim (positive reinforcement); (2)theyavoid orcounter 
theaversive consequences ofaggression byothers (negative reinforcement); (3)they
receive injury orharm fornotbehaving aggressively (punishment); (4)theyliveupto
theirpersonal standards ofconduct bytheiraggressive behavior (self-reinforcement); 
and(5)theyobserve others receiving rewards foraggressive actsorpunishment for
nonaggressive behavior.
Bandura believes thataggressive actions ordinarily leadtofurther aggression. 
Thisbelief isbased onthenowclassic study ofBandura, Dorrie Ross, andSheila 
Ross (1963), which found thatchildren whoobserved others behaving aggres -
sively displayed more aggression thanacontrol group ofchildren whodidnotview
aggressive acts.Inthisstudy, theexperimenters divided Stanford University nurs-
eryschool boysandgirlsintothree matched experimental groups andonecontrol 
group.
Children inthefirstexperimental group observed alivemodel behaving with
bothverbal andphysical aggression toward anumber oftoys,including alarge 
inflated Bobo doll;thesecond experimental group observed afilmshowing thesame 
model behaving inanidentical manner; thethird experimental group sawafantasy 
filminwhich amodel, dressed asablack cat,behaved equally aggressively against 
theBobo doll.Children inthecontrol group werematched withthose intheexperi -
mental groups onprevious ratings ofaggression, buttheywerenotsubjected toan
aggressive model.
After children inthethree experimental groups observed amodel scolding, kick-
ing,punching, andhitting theBobo dollwithamallet, theyproceeded intoanother 
room where theyweremildly frustrated. Immediately following thisfrustration, each
child went intotheexperimental room, which contained some toys(such asasmaller 
version oftheBobo doll) thatcould beplayed withaggressively. Inaddition, some 
nonaggressive toys(such asateasetandcoloring materials) werepresent. Observers 
watched thechildren’s aggressive ornonaggressive response tothetoysthrough a
one-way mirror.
Ashypothesized, children exposed toanaggressive model displayed more 
aggressive responses thanthose whohadnotbeen exposed. Butcontrary toexpecta -
tions, theresearchers found nodifferences intheamount oftotalaggression shown 
bychildren inthethree experimental groups. Children whohadobserved thecartoon 
character wereatleastasaggressive asthose exposed toalivemodel ortoafilmed 
model. Ingeneral, children ineachexperimental group exhibited about twice asmuch 
aggressive behavior asdidthose inthecontrol group. Inaddition, theparticular kind
ofaggressive response wasremarkably similar tothatdisplayed bytheadult models. 
Children scolded, kicked, punched, andhitthedollwithamallet inclose imitation to
thebehavior thathadbeen modeled.
Thisstudy, nowmore than40years old,wasconducted atatimewhen peo-
plestilldebated theeffects oftelevision violence onchildren andadults. Some 
people argued thatviewing aggressive behaviors ontelevision would have acathar -
ticeffect onchildren: That is,children whoexperienced aggression vicariously 
would have little motivation toactinanaggressive manner. Thestudy byBandura, 
Ross, andRoss (1963) offered some oftheearliest experimental evidence thatFinal PDF to printer