Psychology 3 Core study Transmission of aggression through imitation of aggressive models Albert Bandura, Dorothea Ross and Sheila A. Ross Psychology Aim • to see if imitated behaviour would be displayed in new settings Psychology Background • Bandura and Huston (1961) found that children imitated behaviour exhibited by an adult model. Psychology Hypotheses 1. Subjects exposed to aggressive models would reproduce aggressive acts resembling those of their models. 2. Observation of non-aggressive models would inhibit aggressive behaviour. 3. Subjects will imitate the behaviour of a samesex model more than model of the opposite sex. 4. Boys would display more aggression than girls. Psychology Method • laboratory experiment with controlled observation Psychology Independent variables • whether children observe model or not • whether children observe aggressive or not aggressive model • whether children observe same or opposite sex model • gender of child Psychology Dependent variables (1) • Number of aggressive acts • imitation of physical aggression • e.g. striking Bobo with mallet • imitative verbal aggression • e.g. saying ‘Sock him!’ • imitative non-aggressive verbal responses • e.g. saying ‘He sure is a tough fella.’ • sitting on Bobo doll • sits on Bobo doll but is not aggressive with it Psychology Dependent variables (2) • mallet aggression • e.g. striking object other than Bobo doll with mallet • non-imitative aggression • e.g. punches Bobo doll • non-imitative physical and verbal aggression • aggressive gun play • Number of the times they were observed (behaviour units) in which children played nonaggressively or sat quietly and did not play at all. Psychology Participants • 72 children from Stanford University nursery school • 36 boys and 36 girls • age range 37–69 months • mean age 52 months Psychology Procedure • Children were observed in nursery by a male model and a teacher and given an aggression rating on physical and verbal aggressions, aggressive inhibition and aggression toward inanimate objects. • Children were divided into eight groups of 6 plus a control group of 24. • They were matched on age, gender and aggression rating. Psychology Stage 1 10 minutes • Children in experimental group were taken by an adult to a room and invited by role model to come in and play. • The child was sat at a table with potato prints and stickers. • Model was taken to corner of room with the Bobo doll (5 foot), mallet and a tinker toy. Psychology Stage 1 cont (1) • In the non-aggressive condition • the adult played with the tinker toys. Psychology Stage 1 cont (2) • In aggressive condition • the adult began assembling tinker toys • after one minute the adult began being aggressive with Bobo doll: • three repetitions of • laying Bobo doll down, sitting on it and hitting its nose • raising Bobo up and hitting it with the mallet • throwing Bobo up and kicking it around the room • this was interspersed with verbally aggressive responses • ‘Sock him in the nose’, ‘Kick him’, ‘He sure is a tough fella’. Psychology Stage 2 2 minutes approximately • The child was taken by experimenter to a second room. • There were lots of attractive toys: • fire engine, doll set, jet fighter plane, doll’s pram • Child was told by experimenter he/she could play. • As soon as child involved, the experimenter told child they were best toys and they were reserved for other children. Psychology Stage 3 20 minutes • The child was taken to room not in nursery with variety of toys: •e.g. Bobo doll (3 foot), mallet, dart gun, tea set, crayons, farm animals. • Child was observed through one-way mirror every 5 seconds by male model and one other researcher. Psychology Results Hypothesis 1 • Subjects exposed to aggressive models produced significantly more aggressive acts than non-aggressive and control groups. Psychology Results Hypothesis 2 • Boys who observed non-aggressive models produced significantly less aggression than control group boys. • No significant differences for girls • Subjects in non-aggressive condition showed significantly more non-aggressive play with dolls than either aggressive or control. • Subjects in non-aggressive condition spend more than twice as much time sitting quietly and not playing than in the aggressive condition. Psychology Results Hypothesis 3 • Subjects did imitate the behaviour of samesex model more than model of opposite sex. •Boys showed more imitation of male models •Girls showed more imitative verbal and more non-imitative aggression of female models. Psychology Results Hypothesis 4 • Boys did display more imitative physical aggression than girls. •No difference in verbal aggression •Boys played significantly more with guns and less with tea set, dolls and colouring. Psychology Conclusions 1. Subjects exposed to aggressive models did reproduce aggressive acts resembling those of their models. 2. Observation of non-aggressive models did inhibit aggressive behaviour. 3. Subjects did generally imitate the behaviour of same-sex model more than model of opposite sex. However, both boys and girls imitated male model’s aggression more than female model’s aggression. 4. Boys did display more physical aggression than girls. Psychology Controls • Adults • One male and one female served the role of model. • One experimenter conducted the study of 72 children. • Toys • All toys in stage 3 were arranged in a fixed order. • Observation • Inter-rater reliability of observers was checked by correlation. • There was a one-way mirror. • Blind condition: observers didn’t know the condition the child was in (apart from male model in cases where he was model).