Bandura, Ross & Ross (1961) Transmission of aggression through imitation of aggressive models

AIM  To show that children can learn aggressive behavior through imitation

Hypotheses: 1."...subjects exposed to aggressive models will reproduce aggressive acts resembling those of the models..." 2."...the observation of non-aggressive models will have a generalized inhibiting effect on the subject's subsequent behavior..." 3."...subjects will imitate the behavior of a same-sex model to a greater degree than a model of the opposite sex..." 4."...boys will be more predisposed than girls towards imitating aggression..."

Participants  36 boys and 36 girls  Stanford Nursery  Mean age-4 years 4 months

Method  The method was a laboratory experiment.  The design of the experiment has three conditions: The group exposed to the aggressive model The group exposed to the passive model The control group

Method  Independent variable: Condition to which the child was exposed Gender of the child Gender of the model  Dependent variable Imitation / behaviors after the exposure

Total 72 boys and girls Aggressive condition 24 Control group 24 Non-aggressive condition 24 Procedures The children who were exposed to the adult models were subdivided by their gender, and by the gender of the model to whom they were exposed

Procedures  Control group - 24 subjects  Aggressive model condition – 24 subjects 6 boys w/ same sex model 6 boys w/ opposite sex model 6 girls w/ same sex model 6 girls w/ opposite sex model  Non-aggressive model condition - 24 subjects 6 boys w/ same sex model 6 boys w/ opposite sex model 6 girls w/ same sex model 6 girls w/ opposite sex model

Procedures MF M66 F66 Aggressive Models MF M66 F66 Subjects Models Non-Aggressive Control 24 subjects

Procedures  Because the groups were small the researchers needed to ensure that each group contained equally aggressive children  Pre-tested (observation): physical aggression verbal aggression aggression to inanimate objects aggression inhibition (self control)  Matched pairs design  Inter-rater reliability

Stage 1  The children tested individually & taken to the experimental room Shown to a play area with a table & chair, potato prints, stickers and other toys chosen for being of interest The adult model was invited to the opposite corner which had a table & chair, tinker toys, mallet and a Bobo Doll

Stage 1

 Non-aggressive condition The model played with the tinker toys in a quiet subdued manner ignored Bobo  Aggressive condition The model started to assemble the tinker toys After one minute turned to Bobo and was aggressive to the doll in a stylized and distinctive way.  Physical-"raised the Bobo doll and pummeled it on the head with a mallet"  Verbal-"Pow!“ & "Sock him in the nose“  After ten minutes the experimenter returned and took the child to another room

Stage 2  Mild aggression arousal  Taken to a room with attractive toys, but told that these were the very best toys and she had decided to reserve them for the other children  This was done to provoke the children

Stage 3  Child taken to the next room  A variety of toys Non-aggressive- three bears, crayons etc. Aggressive toys- mallet & peg board, dart guns, etc. & a 3 foot Bobo Doll  The experimenter stayed in the room "otherwise a number of children would either refuse to stay alone, or would leave before termination of the session” [*(Un)Ethics]

Stage 3  The child was kept in this room for 20 minutes  Their behavior was observed by judges through a one-way mirror  Observations were made at 5 second intervals giving 240 observations per child

Response Measures  Recorded 3 measures of imitation (Copying the model): Imitative physical aggression Imitative verbal aggression Imitative non-aggressive verbal responses  Recorded 2 measures of incomplete imitations (Similar to the model): Mallet aggression Sits on Bobo  Recorded 3 aggressive behaviors that were not imitations (the kids created): Punching Bobo Non-imitative physical and verbal aggression Aggressive gun play

Sock him in the nose!Sock him in the nose! video

Results/Findings 1.The children who saw the aggressive model made more aggressive acts than the children who saw the non-aggressive model 2. Boys made more aggressive acts than girls 3. The boys in the aggressive conditions showed more aggression if the model was male than if the model was female

Results/Findings 4. The girls in the aggressive conditions also showed more physical aggression if the model was male but more verbal aggression if the model was female 4.a. The exception to this general pattern was the observation of how often they punched Bobo, and in this case the effects of gender were reversed

Bandura’s Explanations  Supports Bandura's Social Learning Theory Children learn social behavior such as aggression through the process of observation learning – through watching the behavior of another person.  Central to Social Learning Theory is identifying which types of models are more likely to be imitated

Bandura’s Explanations  Aggressive male models were more likely to be imitated than aggressive female models.  Why?

Appropriateness of the model sex role stereotypes  Probably sex role stereotypes. Western Culture finds it to be more appropriate for men to be aggressive than for women to be aggressive Even children this young are learning the stereotypes that relate to sex-roles

Bandura’s Explanations  Found that boys were more likely to imitate the aggressive male model than were girls  Why?

Relevance of Model  The greater relevance of the male model's behavior for boys lies in the fact that boys perceive the similarity between themselves and the model gender identification Again gender identification

Bandura’s Explanations  Found that children of both sexes were more likely to copy the same sex  Why?

Similarity of the model  Similarity between the model and the child is another important factor the child's gender identity  Perception of this similarity is based upon development of the child's gender identity ability to classify itself (and others) as a girl or boy, female or male. The first stage of this ability is not usually reached until 2 -2 ½ years of age

Bandura’s Explanations  Appropriateness of the model  Relevance of Model  Similarity of the model

NEW WORD ALERT  Construct validity The extent to which a test or method measures a specific psychological construct (trait)  For instance: What might Bandura be testing instead of aggression? Imitation? Innocent play? What evidence might point to a problem with construct validity? Did this experiment really measure aggression?

NEW WORD ALERT  Inter-Rater Reliability Inter-Observer reliability Used to assess the degree to which different raters/observers give consistent (reliable) estimates of the same phenomenon  We could say that this was used in the Piliavin study. Two confederates monitored the critical area

Conclusions Aggression can be learned Learning can take place in absence of any reinforcement, only via observation and modeling Implications for parents, teachers, psychotherapists (treatment of phobias) Implications for media violence

Evaluation of procedure There are 3 main advantages of the experimental method. 1.Cause and effect can be established. In Bandura’s experiment: It could be demonstrated that the model did have an effect on the child's subsequent behavior because all variables other than the independent variable are controlled.

Evaluation of procedure There are 3 main advantages of the experimental method. 2.Precise control of variables. In Bandura’s experiment: Many variables were controlled, such as the gender of the model, the time the children observed the model, the behavior of the model, etc. 3. Replication In Bandura’s experiment: Standardized procedures and instructions were used allowing for replicability. The study has been replicated with slight changes, such as using videos and similar results were found.

Evaluation of procedure  Another advantage of experiments is that they produce quantitative data which can be analyzed using inferential statistics.  Inferential statistics allow us to see how likely the results are due to chance

Limitations of the procedure:  Lacks ecological validity A limited social situation-no interaction between the child and the model at any point, the child has no chance to influence the model in any way, the model and the child are strangers. Unlike 'normal' modeling which usually takes place within the family  Measured almost immediately Can a single exposure have long-term effects?  Construct Validity Maybe the children interpreted their own behavior as play instead of aggression

Bandura’s experiment  Sampling  Ethics Apply each of these to the research done by Bandura. How could this study have been done differently? How would these changes affect the outcome?

(Un) Ethics  Withdrawal The experimenter stayed in the room "otherwise a number of children would either refuse to stay alone, or would leave before termination of the session  Distress Did the “Arousal” cause distress? Did the children suffered any long-term consequences as a result of the study? Did this encourage aggression?

before it kills you!