Contemporary study: Burger (2009)

Aims and the 150-volt solution

Aims: to see whether obedience levels had changed in the 45 years since Milgram; whether seeing a peer refuse reduces obedience; whether gender matters; and whether empathy and desire for control predict obedience.

The 150-volt solution: in Milgram's Experiment 5, 26 of the 33 participants who went past 150 V went on to 450 V (78.8%). 150 V is when the learner first protests and asks to be released. So the proportion willing to go past 150 V is a good estimate of full obedience, and stopping there avoids the most stressful part.

Participants and screening

70 adults (29 men, 41 women), aged 20 to 81 (mean 42.9), recruited through newspaper and online adverts and flyers, paid $50 for two 45-minute sessions.

Two-step screening: (1) a phone interview excluded people who had taken more than two psychology classes or had certain psychiatric, medical or trauma histories (about 30%); (2) a clinical psychologist interviewed the rest and excluded anyone who might react badly (47 of 123, 38.2%). Five people who knew about Milgram's research were removed from the analysis.

Procedure

A rigged draw always made the participant the teacher. The learner (a confederate) mentioned a heart condition. The teacher read word pairs and gave 'shocks' from a replica generator (30 switches, 15 V to 450 V), going up one switch per error. Teachers received a real 15 V sample shock. The learner grunted at 75 V and at 150 V cried out that he wanted to stop. Four standard prods were used; the study ended after the fourth prod or as soon as the participant read the next item after 150 V.

• Base condition: participant alone with the experimenter.
• Modeled refusal condition: a second confederate teacher went first and stopped at 90 V; the real participant then took over.

Results, conclusions and evaluation

• Base: 28 of 40 (70%) continued past 150 V, compared with Milgram's 33 of 40 (82.5%): not a significant difference.
• Modeled refusal: 19 of 30 (63.3%) continued: not significantly different from the base condition.
• No significant gender difference (base: men 66.7%, women 72.7%).
• Empathy did not predict stopping; in the base condition stoppers scored higher on desire for control.

Conclusion: obedience rates are only slightly lower than in the 1960s; the situational forces Milgram found still operate.

Evaluation: much more ethical (screening, 150 V cut-off, clear right to withdraw) and a good test of reliability; but we cannot be sure participants would have gone to 450 V; the screened, older, more diverse sample differs from Milgram's; the single peer's refusal may have been too weak a model.

Worked example

Calculate the percentage of Burger's base-condition participants who continued past 150 V, and compare it with Milgram's equivalent figure.

1. 28 / 40 x 100 = 70%.
2. Milgram: 33 / 40 x 100 = 82.5%.
3. Difference = 12.5 percentage points, which was not statistically significant.

Answer: 70% against Milgram's 82.5%: slightly lower, not a significant difference.

Check yourself

1. In Burger's base condition, 28 of 40 participants continued past 150 V. What percentage is that?
   Show answer

   70 %. 28 / 40 x 100 = 70%.

2. In the modeled refusal condition, 19 of 30 continued past 150 V. What percentage is that? Give your answer to 1 decimal place.
   Show answer

   63.3 %. 19 / 30 x 100 = 63.3%.

3. At the second screening step, the clinical psychologist excluded 47 of 123 people. What percentage is that? Give your answer to 1 decimal place.
   Show answer

   38.2 %. 47 / 123 x 100 = 38.2%.

4. Why did Burger stop the procedure at 150 V?
   • Most of Milgram's participants who passed 150 V went on to 450 V, so it predicts full obedience while avoiding the most stressful part
   • The generator could not go higher than 150 V
   • Milgram's participants all stopped at 150 V
   • The ethics committee banned any shocks
   Show answer

   Most of Milgram's participants who passed 150 V went on to 450 V, so it predicts full obedience while avoiding the most stressful part. In Milgram's Experiment 5, 78.8% of those who passed 150 V went to the end.

5. What did Burger find about gender?
   • Women were much less obedient than men
   • Men were much less obedient than women
   • There was no significant difference between men and women
   • Only women were tested
   Show answer

   There was no significant difference between men and women. Men 66.7% and women 72.7% in the base condition: not significant.

6. What happened in the modeled refusal condition?
   • A confederate teacher refused at 90 V, but this did not significantly reduce obedience
   • A confederate refused at 90 V, and obedience fell to zero
   • The experimenter gave orders by telephone
   • Two confederates rebelled and obedience fell to 10%
   Show answer

   A confederate teacher refused at 90 V, but this did not significantly reduce obedience. 63.3% still continued past 150 V.

7. Explain one way Burger's study was more ethical than Milgram's.
   Show answer

   He screened participants with a clinical psychologist to exclude anyone vulnerable, and stopped at 150 V so no one experienced the most stressful part.. Screening and the 150 V cut-off reduced risk of harm.

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Sources

• Pearson Edexcel International Advanced Subsidiary/Advanced Level in Psychology specification (issue January 2026)
• Pearson International A Level Psychology component guide: WPS01
• Burger (2009) Replicating Milgram: Would people still obey today? American Psychologist 64(1) (full text)
• IAL Psychology revision site: Burger (2009)

Last updated 8 November 2026. Spotted a mistake? Tell us.