Bobo doll experiment
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The Bobo doll experiment was conducted by Albert Bandura in 1961 and studied patterns of behaviour associated with aggression. Additional studies of this type were conducted by Bandura in 1963 and 1965. A Bobo doll is an inflatable toy that is approximately the same size as a prepubescent child.
This experiment is important to psychology because it was a precedent that sparked many more studies about the effects of viewing violence on children.
Method
The subjects studied in this experiment involved 36 boys and 36 girls from the Stanford University Nursery School ranging in age between 3 and 6 (with the average age being 4 years and 4 months). The control group was composed of 24 children. The first experimental group comprised 24 children exposed to aggressive model behavior. The second experimental group comprised 24 children exposed to nonaggressive model behavior. The first and second experimental group were divided again based on sex. Finally, the experimental groups were divided into groups exposed to same-sex models and opposite-sex models. In this test, there were a total of eight experimental groups and one control group. To avoid skewed results due to the fact that some children were already predisposed to being more aggressive, the experimenter and the teacher (both knew the children well) rated each child based on physical aggression, verbal aggression, and object aggression prior to the experiment. This allowed Bandura to group the children based on average aggression level.
It is important to note that each child was exposed to the experiment individually so as not to be influenced or distracted by their classmates. The first part of the experiment involved bringing a child and the adult model into a playroom. In the playroom, the child was seated in one corner filled with highly appealing activities such as potato prints and stickers and the adult model was seated in another corner containing a tinker toy set, a mallet, and an inflatable Bobo doll (which is about 5 feet tall). Before leaving the room, the experimenter explained that these particular toys were only for the model to play with.
After a minute of playing with the tinker toy set, the aggressive model would attack the Bobo doll by hitting it. For each subject, the aggressive model reacted identically with a sequence of physical violence and verbal violence. The mallet was also used to continually hit the Bobo doll on the head. After a period of about 10 minutes, the experimenter came back into the room, dismissed the adult model, and took the child into another playroom. The nonaggressive model simply played with the tinker toys for the entire 10 minute-period. In this situation, the Bobo doll was completely ignored by the model.
Following the 10 minute-period with the models, each child was taken into another playroom filled with highly entertaining toys including a fire engine, a jet, a complete doll set with clothes and carriage, and so on. In order to spark anger or frustration in the child, he or she was only allowed to play with the toys for a very short period of time before being told that these toys were reserved for other children. The children were also told that there were toys in the next room they could play with.
The final stage of the experiment took place in the last room in which the child was left alone for 20 minutes with a series of aggressive and nonaggressive toys to play with. The Bobo doll, a mallet, two dart guns, and tether ball with a face painted on it were among the aggressive toys to choose from. The nonaggressive toys the children could choose from were a tea set, paper and crayons, a ball, two dolls, cars and trucks, and plastic farm animals. Judges watched each child behind a one-way mirror and evaluated the subject based on various measures of aggressive behavior.
Although the experimenters judged the children based on eight different measures of aggression, this article only focuses on four of them. The first measure recorded was based on physical aggression. This included punching or kicking the Bobo doll, sitting on the Bobo doll, hitting it with a mallet, and tossing it around the room. Verbal aggression was the second measure. The judges counted each time the children imitated one of the phrases the aggressive adult model said and recorded their results. The third measure of aggression was based on how many times the child used the mallet in other forms of aggression besides hitting the Bobo doll. The fourth measurement calculated all nonimitative forms of aggression exhibited by the children that were not demonstrated by the adult models.
Results
Bandura found that the children exposed to the aggressive model were more likely to act in physically aggressive ways than those who were not exposed to the aggressive model. For those children exposed to the aggressive model, the number of imitative physical aggressions exhibited by the boys was 38.2 and 12.7 for the girls. The same pattern applied to the instances of imitative verbal aggression exhibited by the child exposed to the aggressive model as opposed to those exposed to the nonaggressive model or no model at all. The number of imitative verbal aggressions exhibited by the boys was 17 times and 15.7 times by the girls. Both the imitative physical and verbal aggression were rarely, if ever, exhibited by the children exposed to the nonaggressive model or no model at all.
Bandura also predicted that the nonaggressive models would have an aggressive-inhibiting effect on the children. However, the results supporting this hypothesis were ambiguous. In certain instances, such as mallet aggression, the male subjects exposed to nonaggressive male models exhibited far less aggressive mallet behavior than the control male subjects but the male subjects exposed to nonaggressive female models exhibited more aggressive mallet behavior than the control male subjects. Because of this inconsistency, Bandura determined the results for this prediction inconclusive.
The results concerning gender differences strongly supported Bandura's prediction that children are more influenced by same-sex models. Boys exhibited more aggression when exposed to aggressive male models than boys exposed to aggressive female models. When exposed to aggressive male models, the number of aggressive instances exhibited by boys averaged 104 compared to 48.4 aggressive instances exhibited by boys exposed to aggressive female models. While the results for the girls shows similar findings, the results were less drastic. When exposed to aggressive female models, the number of aggressive instances exhibited by girls averaged 57.7 compared to 36.3 aggressive instances exhibited by girls exposed to aggressive male models.
Lastly, the evidence strongly supports that males have a tendency to be more aggressive than females. When all instances of aggression are tallied, males exhibited 270 aggressive instances compared to 128 aggressive instances exhibited by females.
Discussion
Bandura and his associates never successfully supported their theory of social learning in that specific behaviors such as aggression can be learned through observing and imitating others even if reinforcement is not used either on the model or the subject. They came to the conclusion that children observing adult behaviour are influenced to think that this type of behaviour is acceptable thus weakening the child's aggressive inhibitions. The result of reduced aggressive inhibitions in children means that they are more likely to respond to future situations in a more aggressive manner.
Also important in this experiment is the result that males are drastically more inclined to physically aggressive behaviours than females. Bandura explains that in our society, aggression is considered to be a distinct male trait. Because of this, boys are raised and cultured to be more aggressive and, therefore, it is more acceptable when males exhibit this trait. Girls, not confident of displaying physical aggression, almost matched the boys in Bandura's experiments in terms of verbal aggression, indicating that although the manifestation of the aggressive impulse is different from male to female, this is chiefly a reflection of the sexes' respective strengths in terms of verbal and physical abilities.
To many psychologists, Bandura (1961) and other "Bobo doll" experiments suffer from a central methodological shortcoming. The sole purpose of a "Bobo doll" is to bounce back up when knocked over; to act as a target. Therefore, the researcher's perceived expectations of the participants' behaviour may have a significant effect on their observed behaviour. The 1963 experiment found that observing aggressive behaviour via video playback is less influential on a subject than is observing the same aggressive act in person.
In a follow-up study, Bandura (1965) found that when children viewed aggressive behaviour and then viewed that behaviour being either rewarded or punished that children were less likely to emit aggressive behaviours when they had viewed an adult model being punished for aggressive behavior. Children who saw the model rewarded did not differ in aggressive behaviors from those that saw a model receive no reward. Bandura then offered an incentive for all three groups of children to recall what had happened in the video, and all three groups recalled the modeled aggression at approximately similar levels.
See also
References
- Bandura, A., Ross, D., & Ross, S. A. (1961). Transmission of aggressions through imitation of aggressive models. Journal of Abnormal and Social Psychology, 63(3), 575-582. Full text
- Bandura, A., Ross, D., & Ross, S. A. (1963). Imitation of film-mediated aggressive models. Journal of Abnormal and Social Psychology, 66, 3-11.
- Kosslyn, Stephen M. and Robin S. Rosenberg. Psychology: The Brain, The Person, The World. 2nd ed. Boston: Pearson, 2004. 246-248.