The Stanford Prison Experiment

The Stanford Prison Experiment

TheStanford Prison Experiment

Analysis of the Stanford PrisonExperiment

Thepurpose of this paper is to discuss and analyze the Zimbardo StanfordPrison Experiment of 1971. The experiment was carried out in StanfordUniversity, led by the psychologist Professor Philip Zimbardo amongothers. In the experiment, twenty four students were selected fromseventy five candidates to be used as subjects for the experiment.The students were then arrested and put in a prison like environmentcreated in the basement of a building in Stanford University wherethey were treated as prison inmates for a period of seven days. Thepaper will focus on the merits, demerits evaluate data collectionprocedures, the validity of the experiment and the issues concerningethics concerning the Zimbardo experiment (Zimbardo, 1971)

Advancingthe Knowledge Base

TheZimbardo Stanford prison experiment advances the scientific knowledgein several ways. First, it dismisses Dr. Zimbardo’s hypothesis thatstated that the inmate personality attributes of prisoners and guardswere the main reason for prison behavior. In the Prison Experiment,subjects chosen were of stable minds and did not have any history ofunlawfulness. They nevertheless started behaving like any otherinmates do when they were imprisoned. This affirms that the prisonbehavior of fear and mob psychology also shown in schools is as aresult of a great contribution of the environmental factorsavailable. According to the results of the experiment, adequateconditional forces can influence people’s behavior more than theirpersonality and their ability to choose right or wrong. Theexperiment concludes that if power is established among a group ofpeople over another group, it is most likely that there would beabusive action against weaker ones as in the case of guards againstthe prisoners in the experiment.

Contributionsto Theories

TheZimbardo experiment contributed to the theory that situations andenvironments triumph over personality and morality. In theexperiment, the study subjects started behaving like actual prisonersand guards respectively according to the groups they had beenrandomly placed in. They even started to assume the numbers they hadbeen assigned as identity instead of their actual names. Forinstance, Prisoner #819 when asked his name by the priest in theexperiment, instead of saying his name he said he was #819. He hadstopped differentiating between reality and illusions. He had startedbelieving like he was a prisoner just because of the environment. Dr.Zimbardo himself says he got affected as he allowed psychologicaltorture as he played the role of a superintendent (Zimbardo, 1971).They all started believing their roles were true. Bad situationscould induce evil into normal people. This was seen by the guards asthey started abusing the inmates by virtue of being more powerful inthe situation created.

Descriptionand Evaluation of the Data Collection Procedures

TheStanford Prison Experiment involved mostly qualitative data.Therefore, the methods of collecting data used included videotaping,audio taping and direct observation by the researchers. The methodswere relevant for the type of data collected and the result of theexperiment in question. The experiment would be unsuccessful ifmethods such as questionnaires were used. This is because, as ithappened, the inmates started believing they were inmates, and if theexperiment manipulated their states of mind, then they would notanswer questionnaires correctly. There was a need for a collectionmethod that would also not the influence the results of theexperiment. The experimental subjects were not to know they werebeing experimented on. Therefore, collection methods that could workin secret were more useful for the experiment (Zimbardo, 1971).


Theexperiment was designed to last fourteen days. The independent factorwas the conditions or roles the experimental subjects were allocatedin the study, which would either be guarded or prisoner as randomlygrouped at the beginning of the experiment. The subjects were pickedfrom the respondents of a newspaper advertisement, advertised for thepositions of willing participants in a study that would analyzeprison psychology for a wage of fifteen dollars per day. Seventy fivepeople responded to the advertisement and they were givenquestionnaires that they answered questions about their family andsocial background. Twenty four participants were picked from theinitial pool of seventy five candidates. The twenty four participantswere young college students of middle, class, economy, maleindividuals with no signs of psychological disorders and fit for theexperiment according to Zimbardo. Data collection methods were pickedand they included use of video cameras, audio tapes and directobservation. They were ‘arrested’ by police at random on anafternoon, and transported in police vehicles to a police stationwhere all the normal legal procedure that takes place was followedsuch a taking finger prints and filling in the occurrence book toensure that the conditions emulated actual arrests as much aspossible. The participants were then transported to a ‘prison’. Amodel prison was built in the underground basement of a psychologylaboratory located at Stanford University. The ‘prison’ was madeup of three prisons-like cells of dimensions, six feet by nine feetcontaining beddings such as mattresses, pillows and sheets enough foreach of the three occupants during the experiments. The ‘prison’also had a small room called ‘the hole’. The hole was a solitaryconfinement room of dimensions that measured two feet by two feet onthe sides and a height of seven feet. There were also several otherrooms in the opposite side of the building of the building used by‘guards’ as their quarters (for changing clothes), rooms used forinterviewing inmates and the superintendent’s bedroom which wasused by Dr. Zimbardo. Video recorders were placed in secret locationsin the mock prison. For all the period of the experiment, the inmateswere required to remain enclosed in the ‘prison establishment’for twenty four hours a day. A small room was used as the prison yardfor the inmates to interact in. Each of the rooms was assigned threeprisoners such that nine of the prisoners were locked in the mockprison while the remaining three who were randomly nominated wereleft to remain in their homes on standby. The guards worked three ineach shift that took a period of eight hours (Zimbardo,1971).

The prisoners all consented toplay their respective roles for the specified wages of fifteendollars per day for the two weeks that the experiment that theexperiment would last. The experimental subjects signed a consentform that ensured their basic living rights would not be denied inthe course of the study. These rights included access to an adequatediet and medical attention in case of sickness. As part of theexperimental methodology, they also had to agree that some of theirrights such as privacy and movement would be denied during theexperiment. The subjects were not informed about what would happenduring the experiments to avoid prior expectations which wouldinfluence the outcome of the study. The experimental subjects wererandomly grouped into their categories by flipping a coin andinformed by the use of a phone to be present in their respectivehomes on Sunday in which the experiment would start. The subjectsassigned to be guards had an induction meeting with the‘superintendent’ Dr. Zimbardo before the arrival of the prisonersinto the mock prison for the experiment. In the induction, the seniorresearchers, Dr. Zimbardo (the superintendent) and his undergraduateresearch assistant (the warden) told the ‘guards’ that the aim ofthe researchers was to study the environment of the prisons and thelimits put by ethical factors. The ‘guards’ were given roe toensure enforcement of sixteen rules. These rules were such as onlyeating at stipulated times and requesting for consent before visitingthe toilets. The ‘guards’ were prohibited from inflictingphysical pain to the ‘prisoners’, apart from the constraint putand the rules from the principle experimenters, the ‘guards weregiven power to run the ‘prison’ the way they saw well. Dr.Zimbado asked the ‘guards’ to inflict a feeling of loneliness andfright. He further asked the ‘guards’ to make the ‘prisoners’feel like their lives was controlled by the ‘prison’administration and the ‘guards’. The prison system was designedin such a way to strip, he prisoners of their ‘individuality’(Zimbardo, 1971).

During the meeting, the ‘guards’were also given instruction about their administrative workinformation that included work shifts and filling critical occurrencereports and administration of meals to the prisoners.

On the Sunday that the experimentbegan, as the participants waited to be called to attend the study,they were arrested by actual policemen in police vehicles withsirens. The participants were the thoroughly searched before beinghandcuffed and transported to the police station where statementswere recorded before they were taken to their different role in themock prison in Stanford University. During the process of arrestingthe participants, the police maintained the standard officialinteraction with the ‘suspects’.

The ‘prisoners’ wereblindfolded and driven to the ‘prison’ where they were strippednaked and searched thoroughly in embarrassing ways before beingordered to dress in prison uniforms that were ill fitting. Theexperiment was carried out until the six day of the planned fourteendays of the proposed experiment.

Validityand Reliability

Thevalidity and reliability of the experiment are quite questionable.The experiment was used to test important variable in the prisonenvironment and gave relevant results. The results of the experimentscannot be viewed as accurate as the part as the observers were partof the experiment itself. Dr. Zimbardo, who was the chiefexperimenter was also part of the experimental system and wastherefore affected by the variables he and his colleagues werestudying. As he says in the part where he was convincing prisoner#819 that it was just an experiment and that the actual name of thesubject was not #819, but at the same time convincing himself that hehad just made up the statement and that it was not true. In view ofthis the analyst himself was not in a clear state of mind to makereasonable observations about the study he was conducting. He hadactually subconsciously convinced himself that he was an actualsuperintendent. The study was also stopped before it ended. The studywas halted on day six, almost halfway into the period stipulated forthe study to be concluded. Therefore, the results taken cannot be thesame as the ones that would have been collected by the end of thefifteen days of the study period. The study also involved a verysmall sample. Twenty four is a small number that cannot be used torepresent all the inmates in the prisons in the world. Theexperimenters did not also involve a control group that would bestudied simultaneously alongside the two variables. In light of theissues discussed above among others, the results of the experimentare not valid.


Ethics is the philosophical studyof morality. In the experiment, number ethical issues can be raised.One of them involves the involvement of informed consent. Accordingto the Helsinki and Nuremburg declarations, before any human trialsin experiments, there must be informed consent(Annas, &amp Grodin, 1992).Informed consent requires that adequate knowledge about the study isshared with the human subjects before the experiment is begun(Goodyear, Krleza-Jeric, &amp Lemmens, 2007).Is it is, the participants were not told what to expect before hebeginning of the experiment. Therefore, the aspect of informedconsent in the experiment was breached. There was also psychologicalsuffering inflicted on the participants during the study.

OverallScientific Merit of the Study

Theoverall scientific merit of the study is that it managed to collectinformation and test the hypothesis. The experiment established thathuman nature is influenced by the situation and the environment.Abuse in the institutions of learning and jails is the main reasonfor the evil traits shown by the occupants of the institution (Luban,2007). The experiment results asserted the theory that power corruptspeople and when one group has power over another group, regardless ofthe inherent characters of the individuals with power or their moralstatus, tyranny is bound to prevail over the weak individuals in thesystem (Barnyard,2007). Human nature is influenced by the environment and theprevailing circumstances (Zimbardo, 2007).


TheStanford Prison Experiment was a study funded by United States Navyas its officials wanted to investigate the reason for disagreementbetween the prisoners and guards in the prisons of the navy(Haney, Banks &amp Zimbardo, 1973).The experiment was conducted by Dr. Zimbardo and his studentassistant researcher on twenty four subjects in a prisonlikeenvironment created in the basement of a psychology laboratory inStanford University. The experiment was supposed to take fourteendays, but it was stopped only after six days. There were severalconcerns with regards to the experiment as in arose ethical questionsand the subjects and the experimenters were getting affected by thestudy. The experiment proved that the prison environment plays a veryimportant role in the violent and bad behaviors of both the inmatesand the prison guards. The findings have helped understand prisonpsychology and generally human nature.


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