1961 was a year for copycats. The Cold War heated up a notch, when the Russians responded to previous American hydrogen bomb tests by detonating their own massive bombs in test ranges. The Berlin Wall was built overnight and American and Russian tanks glared at each other across the German border. When American citizens weren't building fallout shelters in their back gardens they were watching tit-for-tat gang violence in the year's big movie, West Side Story. Not all the imitation was aggressive: the Russians put Yuri Gagarin into space and the Americans followed with Alan Shepard a month later.
Albert Bandura had already done a lot of research into aggression, particularly in teenagers (he would have loved the choreographed fight at the start of West Side Story, I'm sure) and used the term "Social Learning" to explain his theory that aggression is learned by watching how adults behave. In 1961 he carried out the first of his famous "Bobo doll" experiments at Stanford University to try to identify the causes of aggression under controlled conditions.
Or if you prefer,
Maybe something more detailed? Read a full account of the study from Classics In The History of Psychology
Or finally, Wikipedia has a description of the Bobo-doll study
In this video clip Albert Bandura describes his own experiment - watch the kids beat Bobo!
Fancy a poster summing up the study? OCR has one here (PDF format)
Aggression takes a lot of forms, from backbiting and sarcasm to raised voices and physical violence. Human beings have always tried to control aggression and psychologists have always tried to explain it. Some researchers studied animals and pointed out there seems to be an aggressive instinct that makes creatures fight other members of the same species. Sigmund Freud suggested we feel cleansed and healed when we release pent-up aggression - he called this "Catharsis" and his famous study of Little Hans shows how children have aggressive feelings towards their parents.
Another view is that we are not born with aggressive urges but we do learn to be aggressive as we grow up. A popular view was that aggression came from frustration - when we don't get something we were expecting, we get frustrated and lash out. Psychologists from the BEHAVIOURIST school of thought were interested in how aggression is rewarded, maybe because aggressive people are praised and admired or just because aggression tends to get you what you want in life.
These two views roughly fall into the NATURE (we are born to be aggressive) or NURTURE (we learn to be aggressive) camps. Bandura's study tries to settle the debate by looking at how aggressive behaviour develops in young children.
Research has always shown that children will copy things they see an adult do. But will they still copy behaviour when the adult model has gone and they are in a new setting? Bandura has four predictions (hypotheses):
Bandura collected an opportunity sample of children from a university kindergarten. There were 36 boys and 36 girls, all between the ages of 3 and 5. Bandura also used two adult models - one male, one female - and a female Experimenter who told the children what to do.
First, the individual child was taken to a room in the kindergarten and left to play in the company of the model. The child could play with stickers or paints but the model had a 5-foot tall inflatable clown doll called "Bobo" and a plastic mallet. The Experimenter left the child and the model in the room for 10 minutes.
Next, the child was taken to another room full of colourful toys (doll sets, toy fire engines, etc). This was called the Arousal Room because, after about 2 minutes, the Experimenter told the child to stop playing because these toys were meant for other children. This was done to provoke the child and make sure all the children were in a similar mood.
Finally, the child was taken to the Observation Room. This contained a mixture of "aggressive toys" (plastic mallet, dart gun) and "non-aggressive toys" (tea set, crayons, plastic animals) as well as a 3-foot tall inflatable Bobo doll. The Experimenter sat quietly in the corner while the child played for 20 minutes. The room had a one-way mirror allowing two observers to record everything the child did.
There were three IVs in this experiment:
The two observers gave each child an "aggression score" by recording the following categories:
Bandura used several controls to make sure nothing interfered with the experiment or reduced its validity.
The 72 children were split into 3 group of 24 (aggressive model, non-aggressive model or no model). In order to make sure each group had equally-aggressive children, each child was rated by a teacher and an experimenter for aggression. Children were put into groups of 3 with similar scores and then asigned one to each condition on a random basis.
The model behaved in a pre-scripted way to make sure every child saw and heard the same thing. The aggressive model would spend he first minute playing quietly then the rest of the time attacking the Bobo doll. The aggressive routine included putting the doll on its side, sitting on it, repeatedly punching it on the nose, hitting it on the head with the mallet, throwing it in the air and kicking it round the room. The model would say specific things like: "Hit him down!", "Pow!" or "He keeps coming back for more!"
Every child went into the Arousal Room. This made sure they were all in a similar mood (frustrated).
There were usually two observers (INTER-RATER RELIABILITY). The one-way mirror made sure the observation was COVERT and the child didn't know about it. The observation was STRUCTURED so that it could produce quantitative data.
In the aggressive-model condition, children imitated many of the models physical actions and verbal comments. One third of the imitations were of non-aggressive verbal behaviours but all aggressive behaviours were higher than the control group.
In the non-aggressive model condition, aggressive behaviour was lower than the control group, with many scores of zero.
Boys showed higher physical aggression than girls and performed significantly more aggressive gun-play. However, levels of verbal aggression were roughly similar for girls and boys.
The boys also had a definite tendency for same-sex imitation, but this was only noticeable for the girls when it came to verbal imitation. In general, the male model had more effect on the children than the female model and this was true in both the aggressive and non-aggressive conditions - in other words, the aggressive male prompted moe aggression from everyone and the non-aggressive male reduced aggressive behaviour more.
Bandura collected some qualitative data - remarks made by the children about the models, such as:
Children learn aggression through imitation. Bandura calls this VICARIOUS LEARNING. The important thing about vicarious learning is hat children can learn quite complicated sets of behaviours just by oberving a model then produce these behaviours in a new setting, without needing to be rewarded.
Aggression sems to be a male behaviour. The male models had greatest influence and the children were impressed by the aggressive male model but surprised or shocked by the aggressive female model. Bandura argues that this is because of sex-typing in society in general, which children pick up from their parents, stories, TV, etc.
Bandura also links his findings with Freud's IDENTIFICATION WITH THE AGGRESSOR. This theory says that we fear aggression from authority figures who remind us of our parents, so we become just like the aggressor in order to reduce this anxiety. Bandura goes a bit further, suggesting children don't need to have a close relationship with the aggressor in order to imitate them.
Bandura's experiment has been criticised. Bobo dolls are designed to be knocked down then bounce up again and children will recognise this. If the children felt they were supposed to be aggressive towards this toy, then that is DEMAND CHARACTERISTICS.