What percent of participants delivered the maximum number of volts in the classic Milgram study?

The Milgram Experiment was a 1963 study conducted by Yale Professor Stanley Milgram that aimed to test obedience and the extent of which participants accepted authority and followed orders. The study involved 40 male participants who were under the impression they were involved in a study on the effects of punishment in learning. The participants were individually observed and asked to test another person in a separate room, the learner, on a series of word pair questions; when the learner got a question wrong, the participant was instructed to administer an electric shock to the learner that would increase in voltage per every subsequent wrong answer. The electric shock started at 15 volts (slight shock) and extended up to 450 volts (XXX or lethal shock). An “experimenter” was also present in the room with the participant and would prompt and prod them to continue when it appeared as though the participant was uncomfortable or questioned the safety of the learner.

The Milgram experiment collected both quantitative and qualitative data. Quantitative data was collected through the voltage in which participants went up to before defying the experimenter or administering the maximum voltage on three occasions which would create an “obedience score”. Qualitative data was collected through post-experiment interviews with the participants to gain understanding of their subjective experiences, as well as via photographic and audio recordings, as well as video recordings at later stages. Of the 40 participants who took part in the initial study, 26 (or 65%) reached the maximum shock of 450 volts, with no participants defying the experimenter before 300 volts (an intense shock).

The experiment has become infamous for not only its findings, but arguably more so for the ethical issues interlaced with how it was conducted. It should be noted that no electric shock was actually administered to the learner, who was acting the part of a fellow participant but was entirely planned and scripted. However, the Milgram Experiment was seen as unethical due to the emotional and psychological damage that might have been caused towards the participants due to undue stress, as well as the issue of deception (they believed they were taking part in a completely different study altogether).

Overall, the study found that participants were much more susceptible to authority and obeyed beyond what was initially predicted by Milgram and other psychologists. The initial prediction by many was that only a small handful of participants, as low as 1%, would fulfil the maximum voltage during the experiment, and so it was a surprise for many to find that the majority of participants administered the lethal voltage to the learner. Milgram’s research comprised of 24 variations of this experiment to test different variables, such as gender, different experimenter characteristics, etc. which all yielded similar results to his initial findings.

https://youtu.be/mOUEC5YXV8U

Background

The initial research for Milgram’s experiment was conducted in 1961, less than two decades after the end of the Second World War. The inhumane suffering that was caused by the Nazis during WWII was the basis of Milgram’s study into obedience as a hypothesis that ‘Germans are different’ was the main reasoning adopted by many as to how the Nazis were able to organise and conduct such a widescale operation that led to the deaths of more than six million people. The hypothesis that Germans are different maintains that:

• Hitler would not have been able to put his plans into effect without the cooperation of thousands of people;
• Germans have a basic character defect which cause a readiness to obey authority without question regardless of what is asked of them;
• It is this readiness that allowed Hitler to put his plans in motion by giving him the cooperation that was required.

Milgram wanted to test this theory that Germans were different than others by testing obedience. Milgram was already familiar with Asch’s conformity study in which participants were manipulated into answering wrongly about which line out of three they thought was the same as the fourth line through getting them to conform to group consensus. However, Milgram was dissatisfied with testing the judgement of lines due to ecological validity. Milgram’s study took place in the psychology building of Yale University and was meant to be preliminary research ahead of his trip to Germany in which he would compare American obedience levels with German obedience levels. However, it was evident from the high levels of obedience found in American participants that travelling to Germany was not required.

Hypothesis

As the data collected from the Yale experiment was to be compared to that of German participants, it can be inferred that there was expected to be a low level of obedience from American participants. As such, Milgram asked 14 Yale seniors, all psychology majors, to predict the percentage of participants who would administer the highest shock during the experiment. A consensus was agreed among the group that an insignificant minority would go through to the end of the shock series, with estimates places between 0%-3%. As Milgram states in his research paper:

“the most “pessimistic” member of the class predicted that of 100 persons, 3 would continue through to the most potent shock available on the shock generator–450 volts.”

Participants

The participants comprised of 40 males between to ages of 20-50 years old, coming from a wide range of educational and occupational backgrounds. Participants were obtained through advertisements which were placed in local newspapers and sent through the post. These advertisements asked for volunteers for a study of memory and learning at Yale University which would take an hour to complete and compensation of $4.00 plus $0.50 for travel would be paid for participation.

The advertisement listed a range of job types that would be suitable, discounting high school and college students, specified the age to be between 20 and 50 years old and further specified that the study was to use males only.

40 participants were selected with their age ranges and occupations detailed below:

Method & Procedure

The experimenter (E) orders the teacher (T) to give what the teacher believes to be increasingly harmful electric shocks to the learner (L) in relation to wrong answers given.
Image courtesy of Fred the Oyster 

The experimental setup was the same for all participants who were first met by the experimenter who went by the name Jack Williams, a comrade of Milgram’s who was acting the part and was, in actuality, a 31-year-old high-school biology teacher. The experimenter wore a long grey technician’s coat and was characterised in post-experimental interviews as being impassive and stern. The experimenter introduced the participant to Mr Wallace, supposedly another participant but was also a comrade of Milgram’s and was in fact a 47-year-old accountant. Mr Wallace was characterised by participants as being likeable and mild-mannered. Everything that the experimenter and Mr Wallace said and did was pre-planned, staged, and scripted, with only the dependent variables lying with the participants changing.

The participant and Mr Wallace were sat together and told by the experimenter that they would be involved in a study concerning the effects of punishment on learning. This was a cover story which would lay the foundations to justify the use of electric shock.

Mr Wallace and the participant were then asked to pick their roles, either teacher or learner, seemingly at random from pieces of paper from a hat. However, this was also pre-planned and rigged so that Mr Wallace would always be the learner and the participant would always be the teacher.

The experimenter led the other two into an adjoining room where Mr Wallace, now the learner, was sat in a chair and strapped to it by the wrists; this was explained as to prevent excessive movement while being shocked. Electrode paste was applied to the learner’s wrists ‘to avoid blisters and burns’ with electrodes then applied to the same area. In response to a scripted question asked by Mr Wallace, the experimenter stated in the presence of the participant, “although the shocks can be extremely painful, they cause no permanent tissue damage”.

The Learning Task

The participant was lead into a separate room and sat in front of a dummy shock generator on a desk that, while supposedly seeming real to the participant, would not actually generate a shock for the learner. The shock generator had 30 lever switches in sequence that were labelled in 15 volt increments with descriptor labels alongside them. The descriptors for each voltage were as follows:

• 15-60 volts – Slight shock
• 75-120 volts – Moderate shock
• 135-180 volts – Strong shock
• 195-240 volts – Very strong shock
• 255-300 volts – Intense shock
• 315-360 volts – Intense to extreme shock
• 375-420 volts – Danger: severe shock
• 435-450 volts – XXX

Ahead of starting the exercise, the participant was asked to receive a test shock by the experimenter and to guess the strength of the shock. The shock received by the participant was 45 volts and was given to increase internal validity and to provide the participant with a threshold for what they believed Mr Wallace would be receiving in the other room.

The participant was asked to read out a series of paired-words (i.e. a series of words categorised into sets of two); the teacher (participant) would then repeat the first word in the pair and offer four others words for Mr Wallace to choose from which he would do so by flicking a switch in his room that would light up one of four lights in the teacher’s room. If Mr Wallace answered correctly, they would move onto the next question; if Mr Wallace answered incorrectly, the participant was instructed to administer a shock to Mr Wallace, starting at 15 volts and increasing in 15-volt increments for each subsequent wrong answer.

Feedback from Mr Wallace

During the initial Milgram experiment, Mr Wallace was instructed to pound loudly on the adjoining wall between the two rooms at 300 volts and to provide no further answers to the paired-word questions at and after 315 volts. The participant would, at this time, be informed by the experimenter that no answer would mean non-compliance or an error which would ensure the participant to continue with the study and to continue administering shocks despite no response from Mr Wallace.

Experimenter Feedback

As previously stated, all interactions from Mr Wallace and the experimenter were planned and scripted ahead of the experiment. The experimenter was instructed to give a series of prods and prompts whenever the participant showed resistance or reluctance to continue with administering shocks in the experiment. These prods, in order of when they should be given, were the following:

1. “Please continue” or “please go on”
2. “The experiment requires that you continue”
3. “It is absolutely essential that you continue”
4. “You have no other choice, you must go on.”

The experimenter also had special prompts in place which were used to reassure the participant that there would be no permanent tissue damage for the learner.

End of Experiment

The end of the experiment would occur under one of two conditions. The first would be if the participant expressed resistance to all four prods given by the experimenter. The second would be if the participant administered the maximum 450 volts to Mr Wallace on three occasions.

Results

Quantitative Data

The initial study was conducted using data from 40 participants. Of the 40 participants, 0 participants stopped before or including 285 volts (marked as ‘intense shock’ on the shock generator). 5 participants stopped at 300 volts which was when Mr Wallace was instructed to bang loudly on the adjoining wall. 4 Participants stopped at 315 volts which was when Mr Wallace was instructed to give no answer to the question and the experimenter instructed the participant to continue due to error. 2 Participants stopped at 330 volts, and 1 participant stopped at 345, 360, and 375 volts respectively. 26 (65%) participants reached the maximum voltage of shock of 450 volts despite no response or answer from Mr Wallace.

The table below shows the results of the initial experiment:

As can be seen, the majority of participants administered the maximum voltage of shock during the experiment.

Qualitative Data

Qualitative data for the Milgram experiment was obtained through observations, audio recordings, post-experiment interviews and, in later variations of the Milgram experiment, video recordings. Through the observations, several participants showed signs of nervousness, especially when giving more powerful shocks. Alongside this, several exhibited signs of stress; participants were observed sweating, trembling, some stuttered, groaned, bit their lips, and, on occasion, dug their fingernails into their flesh. 14 of the 40 participants had laughing fits during the experiment while 3 had uncontrollable seizures, one of which had to have the experiment stopped due to violent convulsions.

Critical Analysis

The Milgram experiment was a pioneering study that set the foundations for our understanding of obedience but has since become infamous due to ethical issues surrounding the methods used during the research. While contemporary psychological research is monitored and controlled by representative bodies such as the British Psychological Society in the UK and the American Psychological Association in the USA, ethical guidelines and committees at the time of the Milgram experiment were usually localised to the institution under which the research occurred. In the context of the Milgram experiment, it is likely that ethics would have been considered by a Yale University ethics committee. However, it is clear from the qualitative data in the study that high levels of stress were exhibited in the participants which, in today’s BPS Code of Human Research Ethics, poses an ethical problem.

Furthermore, the study relied on the participant feeling as if they were not able to leave the experiment. The experimenter’s prods could be seen as a battle against the participant’s consent to continue which may have put some in feelings of further distress and discomfort. At the same time, the participant attended the experiment under deception, believing that they were taking part in a study that was looking at the effects of punishment on learning, a popular concept in the behaviourist approach at the time. Deception is a contentious issue in psychological research as many studies require some form of deception in order to be able to measure a certain effect. As such, the BPS does allow deception in studies if it has passed through an ethics committee and that their are no alternatives available in order to measure the effect of the study. That see, it is evident that the Milgram experiment had a dilemma regarding ethics of the study.

While the Milgram experiment suggests that the majority of participant obeyed the orders of the experimenter to the extent of causing major harm or possible death to Mr Wallace, some critics have suggested that other variables may have contributed to the findings. The study was conducted at Yale University, a highly prestigious Ivy League establishment in the USA which may have had an impact on the behaviour of participants. In a variation of the study, Milgram moved the experiment to another location outside of Yale University and found that the obedience score dropped to 47.5%, suggesting the status of the location affects obedience. As we can see in Milgram’s variations of the experiment, many variables can contribute to obedience.

Variations of the Experiment

The following are variations of the baseline experiment:

• Uniform – In the baseline study, the experimenter was seen to be wearing a grey laboratory coat. In one variation of the experiment, it was planned that the experimenter would be called away to the phone and replaced with another person in everyday clothing. As such, obedience levels dropped to 20%.
• Location – As stated in the last section, Milgram changed the location of the study in one variation and found that the obedience score dropped to 47.5%.
• Two teacher condition – In another variation, the participant was able to instruct an assistant to administer the shock. The assistant was an actor who was planned and scripted. As such, the obedience score was 92.5%.
• Touch proximity condition – The participant had to force the learner’s hand down onto the shock plate for each incorrect answer after 150 volts. As you might imagine, the obedience score dropped to 30% as the participant could no longer hide from the physical and visual consequences of their actions.
• Social support condition – In this variation, the teacher was with two other participants (who were actually confederates scripted and planned by Milgram) who would also be in the teacher role alongside the real participant. One of them would disobey the experimenter at 150 volts while the other would stop at 210 volts. The support of two other participants caused obedience scores to drop to 10%.
• Absent experimenter condition – The experimenter was absent from the room in this variation and instead gave prods and prompts from the telephone. Several participants missed out shocks or lowered the shock level due to the physical absence of the experimenter. The obedience score for this variation was 20.5%.

References

Gross, R. (2012). Key studies in psychology. Hodder Education Group.

Milgram, S. (1963). Behavioral study of obedience. The Journal of abnormal and social psychology, 67(4), 371.

Oates, J., Carpenter, D., Fisher, M., Goodson, S., Hannah, B., Kwiatkowski, R., Prutton, K., Reeves, D., & Wainwright, T. (2001), BPS Code of Human Research Ethics. British Psychological Society.