Saturday, September 1, 2007

Classic Psychological Experiments

Classic Experiments

What are the classic social psychological experiments which revealed important understandings about prejudice, stereotyping and aggression?

Prejudice is an unjustifiable, usually negative, attitude towards a group and its members. It generally involves stereotyped beliefs, negative feelings, and a predisposition to discriminatory action (Myers 2004). Prejudice often leads to aggression, that is, any behaviour intended to harm another person who is motivated to avoid the harm (Baurmeister & Bushman 2008). Four incredibly well known studies that outline these behaviours are Zimbardo’s Stanford Prison Experiment, Bandura’s Bobo dolls and imitative learning of children, Jane Elliotts now infamous blue-eyed / brown-eyed exercise and the Milgram experiment of conformity to authority figures. Each of these studies outlines the ease with which behaviours and attitudes can be changed.


The director of the Stanford Prison Experiment was renowned social psychologist Phillip Zimbardo. Along with his colleagues he comprised probably one of the most influential, notorious and controversial experiments in social psychology (1999-2004). A group of 24 young men were divided randomly into two groups, prisoners and guards. The prisoners were given identity numbers, smock dresses and ankle chains, while the guards were given uniforms, nightsticks and mirrored sunglasses, and were told to run their pretend prison as they saw fit as long as they refrained from physical abuse. The prisoners were placed in tiny cells for the entire stay without any contact from their usual social network. The guards worked only eight hour shifts and returned to their normal routines while not on shift.

The results surprised everyone including the researchers. The basement smelt of human excrement, guards were forcing the prisoners to simulate sex with each other and prisoners were depressed and on hunger strikes. Most seemed to have become lost in the roles they’d been allocated. The illusion became reality, the boundary between the role the person was playing and his real identity was erased. Nice boys became brutal guards and the prisoners who were healthy and active became passive and sick, some even developed severe stress reactions and had to be released. No one ever said ‘I quit the experiment’, as they had lost all perspective. Although the experiment was meant to last two weeks it was called off on the morning of just the sixth day.
Sadism and submission to sadism became the organising principles behind life in the basement. What happened in the basement demonstrated that any given situation can lead apparently good people to commit terrible and violent acts.


More formally known as the Transmission of Aggression through Imitation of Aggressive Models was a study conducted by A. Bandura, D. Ross and S.A. Ross (1963), and is a classic psychological experiment focused on the social learning of aggression (Baumeister & Bushman, 2008). 72 male and female children (equal numbers boys and girls) aged between 3 and 6 years old, were exposed to an aggressive model of behaviour, a non-aggressive model, or no model (control group). The aggressive model showed adults (one male, one female) abusing a large inflated clown called a Bobo doll. The aggression was in the form or physical kicking, punching, and beating coupled with verbal abuse such as “hit him down!” and “Sock him in the nose!” The non-aggressive model showed the adults playing with the doll along with Tinker Toys where there was no aggressive behaviour. After 10 minutes of exposure the children were removed from the room and taken into another ‘game’ room where they were confronted with both aggressive toys including a Bobo doll, a mallet and dart guns as well as non-aggressive toys like a tea set, crayons and teddy bears.

The results showed that the children who had watched the aggressive model had the highest levels of aggression thus proving the hypothesis that there would be a high level of imitative learning in a new situation in the absence of the model. Male children also had higher levels of aggression than the female participants (Burger 2004).
Bandura and his Colleagues later proved that aggression does not need to be live, and filmed models of aggression are also highly influential.


The day after Martin Luther King Jr. was murdered in 1968, Jane Elliott gave her third-grade students a first-hand experience in the meaning of discrimination. In an all white, all Christian community she strived to make her students understand racism, discrimination and prejudice. She adopted the ‘Blue-eyed / Brown-eyed’ exercise which is now famous around the world. Participants were treated as inferior or superior based solely on the colour of their eyes. Jane Elliott told her pupils a pseudo-scientific explanation of how eye colour defined people: blue eyes showed people who were cleverer, quicker and more likely to succeed. They were superior to people with brown eyes who were described as untrustworthy, lazy and stupid. The following day the roles were reversed.

Results from this original demonstration showed how quickly children can succumb to discriminatory behaviour and how easily prejudicial attitudes can lead to frustration, broken friendships and vicious behaviour. The children with blue eyes began exercising their new found status over the brown eyed children with hurtful remarks. ‘I watched what had been marvelous, cooperative, wonderful, thoughtful children turn into nasty, vicious, discriminating little third graders in the space of 15 minutes’ (Jane Elliott, Frontline – a class divided). Thus was born the now famous blue-eyed, brown-eyed exercise which has been taken around the world. The only difference between the original exercise and the one used today is that she now sets it up so that the blue-eyed people are ghettoized in the middle of the room and the brown-eyed people are sitting on each side of the blues and are able to keep them under surveillance at all times. Also, the roles are not reversed as this would destroy the reality of the experience.


Although the Milgram experiment (2003) does not directly study aggression or prejudice it outlines how social surroundings and interactions influence a persons behaviour. In 1961 participants answered local advertisements to take part in an experiment on 'the effect of punishment on learning' at Yale University. They assumed the role of a 'Teacher' while a 'Learner', would try to learn word pairs read out by the them . The 'Learner would then receive a punishment for every incorrect answer. The Teacher was instructed by the experimenter to give the Learner increasingly severe shocks every time he made a mistake. The shocks started at 15 volts and increased by 15 volts in thirty levels to 450 volts. The learner was taken to an adjoining room, strapped to a chair with an electrode attached on his forearm. As the experiment progressed and the shocks increased, the learner began reacting heavily to the shocks' and asked for the experiment to stop, to be let out of the room and eventually begins screaming with pain until finally nothing is heard. The 'Learner' was in fact an actor as was the experimenter who instructed to 'Teacher' to continue with the shocks.

Contrary to what was expected, instead of the anticipated 1%, 65% of participants were completely obedient and continued administering the maximum shock until they were told by the experimenter to stop (Full Results). The results surprised Milgram and his associate psychologists. Although participants showed distress due to differing behaviour dispositions, his experiment showed the susceptibility of human behaviour to conform and respond to authoritative social structures irrespective of any moral and ethical dilemma.

I have ranked these studies based on their findings and in order of which studies I believe should be exposed to the outside community. By seeing studies such as these I would hope that awareness will be raised and hopefully attitudes and behaviours can be changed. Firstly, the Stanford Prison experiment will go down in history as a compelling but controversial experiment. It proved just how easily healthy and mentally stable people can be changed simply by gaining authority over others in the form of a label and uniform. in less than a week seemingly good people had borken the spirits of their less fortunate counterparts. Secondly, Albert Bandura brought to light just how impressionable children are at learning behaviours and attitudes. The ‘Children see, children do’ ad campaign run by the Australian Government takes a similar approach and is extremely confronting, as were the results from this enlightening experiment. Through her blue-eyed / brown-eyed exercise Jane Elliott has brought awareness to many people the prejudice and discrimination certain people are subjected to everyday. It is unjustified and inappropriate behaviour that no one deserves to be exposed to. Finally, the results of Milgram’s experiment showed how influential figures of authority can make a person go against their morals and beliefs just to conform to the authority figures expectations.

Prejudice, aggression and stereotyping are unprovoked negative thoughts and behaviours towards a particular group or its members. Be it healthy adults or young children, these four infamous psychological experiments showed how easily figures of authority and tokens can influence behaviour. All these studies go to show that no matter how strong ones moral and ethical beliefs are, when placed in a confronting social situation where the possibility of prejudice and therefore aggression is introduced, role playing may become reality.

To view a summarised table of these four experiments click here.


Bandura, A., Ross. D. & Ross S. (1963) Imitation of film-mediated aggressive models. The Journal of Abnormal and Social Psychology. 66(1) 3-11.

Elliott, J. (1968-2007). The Eye of the Storm. Retrieved September 1, 2007.

Milgram, S. (2003). Behavioural study of obedience. In Lesko, W. (ed). Readings in Social Psychology (5th ed.). Boston: Allyn & Bacon. pp. 242-252.

Myers, D. G. (2004). Psychology (7th ed). New York: Worth.

Burger, J. M. (2004) Personality (6th ed.) Belmont, CA: Wadsworth/Thomson Learning.

Baumeister, R.F., & Bushman, B.J. (2008). Social psychology and human nature (1st ed.) Belmont, CA: Thomson Wadsworth.

Zimbardo, P.G. (1994-2004). Stanford Prison Experiment; a simulation study of the psychology of inprinsonment conducted at the Stanford University. Retrieved September 1, 2007.

More links:
The Stanford Prison Experiment Homepage: click here
To watch a film on the Stanford Prison Experiment: click here
To view a Bandura's Bobo Dolls Video: click here
Milgram experiment reenactment: click here
To test your own stereotyping behaviour: click here


Mark said...

That prison experiment is really fascinating. Did you find anything particularly interesting in your research?

Alex said...

Comments and Feedback


More attention should have been devoted to outlining and discussing the implications arising from the study findings, rather than just describing the studies in detail. It might have been useful to outline a theoretical rationale for the order in which you ranked the studies, as this was not clear in your discussion. You also needed to spend more time linking relevant social psychology theory to the studies and the findings obtained.


The research studies appear to have been described in too much detail and could have been described more succinctly.

Written Expression

Written expression was generally clear and easy to follow; however, some grammatical errors were present. In-text references and references in the reference list were not correctly presented, according to APA (5th ed.) format. In the introduction, you needed to outline a clearer plan for your blog discussion; what angle and perspective were you going to adopt when discussing the studies?

On-line Engagement

Some on-line engagement was present, based on the useful links and internet sites in your blog discussion. The You-Tube Link containing the Stanford Prison Experiment was very interesting. You might find the film, 'The Experiment' interesting (and hopefully worth watching!). It is a German film (with subtitles) and is based on the Stanford Prison Experiment; it has been aired on SBS a couple of times over the last year.