Download The Bobo Doll Experiments

BANDURA’S SOCIAL MODELLING APPROACH TO AGGRESSION
THE BOBO DOLL EXPERIMENTS
Theoretical Background
BEHAVIOURISM
 Focus on the observable (behaviour)
 All that cannot be observed is ignored
 Nearly all behaviour is learned
 Focus on experimentation rather than
speculation
 Environmental determinism: tabula rasa, little
importance attached to genes
 Animal research can be generalized to humans
Theoretical Background /
BEHAVIOURISM
Classical
Conditioning
Operant
Condicioning
• PAVLOV
• SKINNER
Social
Learning
Theory
• Stimulus-Response
(S-R)
• Reinforcement (+,-)
& punishment
• BANDURA
• StimulusObservationresponse
(S-O-R)
HYPHOTHESIS
 MAJOR HYPOTHESIS
 H1. Participants exposed to aggressive
models will reproduce aggressive acts
resembling those of the models to a
significantly greater extent than both
participants exposed to non-aggressive
models and those not exposed to any models
at all.
HYPHOTHESIS
 SECONDARY HYPOTHESIS
 H2. Participants exposed to subdued, non-agressive
models will display significantly less imitative aggression
than control group participants (i.e. those who are not
exposed to any models at all)
 H3. participants will imitate the behaviour at same sex
models to a greater degree than opposite sex models.
 H4. Boys will be more likely to imitate aggression than girls,
especially when they are exposed to aggressive male
models
DESIGN
VARIABLES
Independent
Variable
Dependent
Variable
• Exposure to aggressive
model or non-aggressive
model
• Imitation / behaviour
after the exposure
Response measures
Imitation of physical aggression
• This category included acts of striking the Bobo doll with the
mallet, sitting on the doll and punching it in the nose, kicking
the doll, and tossing it in the air.
Imitation of verbal aggression
• Subject repeats the phrases “sock him”, “hit him down”, “kick
him”, “throw him in the air”, or “pow”.
Imitation of non-aggressive verbal responses
• Subjects repeat, “he keeps coming back for more”, or “he sure is a
tough fella”.
DESIGN
PARTICIPANTS / 36 girls & 36 boys from Stanford Nursery
mean age: 4 years and 4 months
Total
72 boys and girls
Aggressive
condition
24
Control
24
Non-aggressive
condition24
Experimental DESIGN
 Matched pairs design
- all the kids where matched for their normal levels
of aggressive behaviour in the nursery school
Physical aggression
Verbal aggression
Experimenter and Nursery school teacher
- the kids where arranged in groups of 3
then, assigned randomly to one of the two
experimental conditions or the control group
Experimental DESIGN
Control group
24
AGGRESSIVE
CONDITION
Model
Participants
male
female
male
6
6
female
6
6
NONAGGRESSIVE
CONDITION
Model
Participants
male
female
male
6
6
female
6
6
RESULTS
Scores of children in the
aggressive condition where
significantly higher than
those of either the nonaggressive or control
groups
H1. supported or rejected?
RESULTS /mean
aggression scores for
experimental and control subjects
Response category
Experimental groups
Aggressive
Non-aggressive
Control
Groups
F model
M model
F model
M model
Imitative physical aggression
Female subjects
Male subjects
5.5
12.4
7.2
25.8
2.5
0.2
0.0
1.5
1.2
2.0
Imitative verbal aggression
Female subjects
Male subjects
13.7
4.3
2.0
17.2
0.3
1.1
0.0
0.0
0.7
1.7
Mallet aggression
Female subjects
Male subjects
17.2
15.5
18.7
28.8
0.5
18.7
0.5
6.7
13.1
13.5
Punches Bobo doll
Female subjects
Male subjects
6.3
18.9
16.5
11.9
5.8
15.6
4.3
14.8
11.7
15.7
RESULTS
h1
H1
confirmed
Subjects in
the
aggression
condition
reproduce
a good
deal of
physical
and verbal
aggressive
behaviour
h2
h3
H2
rejected
No
significant
differences
were found
between
nonaggressive
and control
groups
H3
confirmed
Subjects
imitate
more when
the
aggressive
behaviour
was done
by the
same sex
model
h4
H4 partially
confirmed
Boys
reproduced
more
imitative
physical
aggression
than girls
but no
more
imitative
verbal
aggression
DISCUSSION
 Social imitation may hasten or short-cut the
acquisition of new behaviours without the necessity
of reinforcing successive aproximations.
 The fact that subjects expressed their aggression in
ways that clearly resembled the novel patterns
exhibited by the models, provides striking evidence
for the occurence of learning by imitation.
 Imitation was found to be differentially influenced
by the sex of the model with boys showing more
aggression than girls following exposure to the male
model, the difference being particularly marked on
high masculine-typed behaviour.
ACTIVITY
 EVALUATION
 theoretical issues
 subsequent research
 methodological issues
 aplications and implications
TRANSMISSION OF AGGRESSION THROUGH IMITATION OF AGGRESSIVE MODELS
EVALUATION OF THE EXPERIMENT – 1PSY
Theoretical issues
Subsequent research
Methodological issues
Applications and implications
People only aggres under
appropiate social conditions which
facilitate such behaviour:
Behaviour is learned.
1) Bandura, Ross & Ross: 4 year old
watched 2 films involded aggression
betweem 2 men. 1st video:
aggressive model won. 2nd video:
the agressor was beaten up.
Children exposed to a new toy act
differently than children who have
been previously exposed to the toy
–familiarity.
Mass media has an important rol,
children will imitate this behavior
(specially aggressive).
Learning may occur without any
reinforcement; exposure to a
behaviour is sufficient for learning
(Bandura)
R&R Results:
1st video: participants imitated
aggression. 2nd video: participants
imitated non aggression. The
control group in the middle of both.
Did they learn or only reproduce
aggression?
The behavior performed by the
adult is very bizarre, it is very
unlikely that an adult will act like
that in front of a child.
Physical punishments are the
demonstration of the behavior
parents are trying to eliminate (the
child becomes more aggressive).
2)Bandura’s 2nd experiment:
1st phase; participants tested in 3
conditions (model rewarded, model
punished and model neither
rewarded nor ppunished).
2nd phase; children were offerer
rewards for imitating the model’s
behaviour.
Long term effects and ethical issues
were not considered in the
experiment. 6-8 months later,
children showed the same
aggression (40% of them).
If you have been the victim of
physical abuse as a child, you are
very much likely to be an abusing
parent than if you haven´t.
Bandura’s Results:
1st phase; 1st group more aggressive
than 2nd group (but no more than
control group)
2nd phase; under those conditions
the 3 groups reproduced the same
number of imitative aggressive acts.
The bobo doll is an inanimate
object, a toy. Therefore the child
sees the situation as play. It is not
applicable to real life, how that the
toy s purpose is to be hit.
When people believe they have
control over their behavior and can
achieve their goals they have “selfefficacy”.
It is a laboratory experiment,
therefore it lacks of ecological
validity. It doesn´t represent the
child´s real and home life, it only
shows the behavior in that certain
condition.
Anxiety is experienced when we
think of ourselves of being “illequipped” to manage potentially
painful situations.
TRANSMISSION OF AGGRESSION THROUGH IMITATION OF AGGRESSIVE MODELS
EVALUATION OF THE EXPERIMENT – 2PSY
Theoretical issues
Subsequent research
Methodological issues
Applications and
implications
Bandura: sees aggression as a
social learning behaviour
(aggression is a learned
behaviour.
Learning is different than
performance.
Not generalizable.
Bandura´s experiment stimulated
further studies on media violence.
Presence of models:
- Facilitate aggressive behaviour
- Shapes behaviour + attitude
There are two types of
reinforcement:
Direct and vicarious (indirect)
The long term effects aren´t
defined but could depend on the
previous characteristics of the
participants.
This lead to the theory of the
“cycle of violence”.
Reinforcement:
- Direct; reinforced to imitate
behaviour
- Vicarious; behaviour
(reinforcement or punished)
Behaviour + Reward:
More imitation
Observational learning is still
considerable in explaining the
impact of media violence.
Factors leading to aggressivenes:
-Being abused
- witnessing violence.
People learn from actions, as well
as from symbolic
representations (images / verbal)
Learnes by classical conditioning:
can lead to phobias.
There are three therapies for
phobias, and the modelling one
was the most effective.
http://www.youtube.com/watch?v=eqNaLerMN
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