In Milgrams's original study, participants were introduced to a person they believed to be a fellow participant. The other person was actually a confederate of the experimenter, an actor. Participants then had to take part in a task, whereby they would be a 'teacher' and the other participant (the confederate) would be the 'learner'.

Each time the learner gave the wrong answer, the teacher had to give them an electric shock. The first shock was 15 volts and subsequent shocks increased by 15 volts each time (i.e., shock 1 - 15V, shock 2 - 30V, shock 3 45V, etc.). At particular points in the procedure, the participant recieved feedback from the 'learner'

• At 150 volts, the learner makes an explicit request that the experiment be stopped
• At 180 volts the victim yells “I can’t stand the pain”
• At 270 volts he gives out an agonised scream and insists on being released
• At 300 volts he shouts out that he will no longer provide answers
• At 330 volts there is an ominous silence

When participants expressed doubts about continuing with the shock, the experimenter, dressed in a grey lab coat gave verbal prods, such as "the experiment requires that you continue"

Milgram found that, after hearing the learner's first cries of pain at 150 volts, 82.5 percent of participants continued administering shocks; of those, 79 percent continued to the shock generator's end, at 450 volts.

In the new replication by Jerry M. Burger, PhD, the obedience rates were only slightly lower than those found by Milgram. As was the case in Milgram's study there was no difference in obedience rates between males and females.

"People learning about Milgram's work often wonder whether results would be any different today," said Burger, a professor at Santa Clara University. "Many point to the lessons of the Holocaust and argue that there is greater societal awareness of the dangers of blind obedience. But what I found is the same situational factors that affected obedience in Milgram's experiments still operate today."

Burger's findings are reported in the January issue of American Psychologist, the flagship journal of the American Psychological Association. The issue includes a special section reflecting on Milgram's work 24 years after his death on Dec. 20, 1984, and analyzing Burger's study.

In Burger's replication, 70 percent of the participants had to be stopped as they continued past 150 volts – a difference that was not statistically significant.

"Nearly four out of five of Milgram's participants who continued after 150 volts went all the way to the end of the shock generator," Burger said. "Because of this pattern, knowing how participants react at the 150-volt juncture allows us to make a reasonable guess about what they would have done if we had continued with the complete procedure."

Milgram's techniques have been debated ever since his research was first published. As a result, there is now an ethics codes for psychologists and other controls have been placed on experimental research that have effectively prevented any precise replications of Milgram's work. "No study using procedures similar to Milgram's has been published in more than three decades," according to Burger.

Burger implemented a number of safeguards that enabled him to win approval for the work from his university's institutional review board. First, he determined that while Milgram allowed his subjects to administer "shocks" of up to 450 volts in 15-volt increments, 150 volts appeared to be the critical point where nearly every participant paused and indicated reluctance to continue. Thus, 150 volts was the top range in Burger's study.

In addition, Burger screened out any potential subjects who had taken more than two psychology courses in college or who indicated familiarity with Milgram's research. A clinical psychologist also interviewed potential subjects and eliminated anyone who might have a negative reaction to the study procedure.

In Burger's study, participants were told at least three times that they could withdraw from the study at any time and still receive the $50 payment. Also, these participants were given a lower-voltage sample shock to show the generator was real – 15 volts, as compared to 45 volts administered by Milgram.

Several of the psychologists writing in the same issue of American Psychologist questioned whether Burger's study is truly comparable to Milgram's, although they acknowledge its usefulness.

"…there are simply too many differences between this study and the earlier obedience research to permit conceptually precise and useful comparisons," wrote Arthur G. Miller, PhD, of Miami University in Oxford, Ohio.

"Though direct comparisons of absolute levels of obedience cannot be made between the 150-volt maximum of Burger's research design and Milgram's 450-volt maximum, Burger's 'obedience lite' procedures can be used to explore further some of the situational variables studied by Milgram, as well as look at additional variables," wrote Alan C. Elms, PhD, of the University of California, Davis. Elms assisted Milgram in the summer of 1961.

Source: Adapted from materials provided by EurekAlert (Press Release)