Charles K. Hofling (1966) created a more realistic study of obedience than Milgram’s by carrying out field studies on nurses who were unaware that they were involved in an experiment.


The procedure involved a field experiment involving 22 (real) night nurses. Dr. Smith (the researcher) phones the nurses at a psychiatric hospital (on night duty) and asks them to check the medicine cabinet to see if they have the drug astroten. 

When the nurse checks she can see that the maximum dosage is supposed to be 10mg.  When they spoke with the ‘Doctor’, they were told to administer 20mg of the drug to a patient called ‘Mr. Jones’.  Dr. Smith was in a desperate hurry and he would sign the authorization form when he came to see Mr. Jones later on.

The phone called ended when the nurse either (i) obeyed the doctor’s order; (ii) resisted the order; (iii) went to get advice; (iv) became upset; (v) could not find the medication; (vi) or if the call lasted longer than 10 minutes.

The medication was not real, though the nurses thought it was. The drug itself was a harmless sugar pill (it was a placebo) invented just for the experiment.

If the nurse administers the drug, they will have broken three hospital rules:

1. They are not allowed to accept instructions over the phone.

2. The dose was double the maximum limit stated on the box.

3. The medicine itself as unauthorized, i.e. not on the ward stock list.

The study also used a control group to make comparisons with the findings from the experimental group.

In another hospital 21 student nurses and 12 graduate nurses were asked to complete a questionnaire asking them what they would do if confronted by the experimental situation.


In the experimental group 21 out of 22 (95%) nurses obeyed the doctor’s orders and were about to administer the medication to the patient when a hidden observer stopped them.

Only one nurse questioned the identity of the researcher (‘Doctor Smith’) and why he was on the ward. The nurses were not supposed to take instructions by phone, let alone exceed the allowed dose.

11 nurses who went to administer the drug admitted to being aware of the dosage for Astroten. The other 10 did not notice but judged that it was safe as a doctor had ordered them to do so.

When other nurses were asked to discuss what they would do in a similar situation (i.e. a control group), 31 out of 33 said they would not comply with the order.


Hofling demonstrated that people are very unwilling to question supposed ‘authority’, even when they might have good reason to.

When the nurses were interviewed later, they pointed out that many doctors were in the habit of giving orders by telephone and became seriously annoyed if they were not obeyed.Although such obedience was against regulations, the unequal power relations between doctors and nurses meant life would be very difficult if nurses did not do what they were told.Hofling’s study showed how the social pressure brought about by the imbalance of power could lead to a nurse actually putting a patient at risk, rather than disobeying orders.


A strength of this study is that it has high levels of ecological validity, due to the fact it was conducted in a real life environment.

Nurses were unaware of an experiment so there were no demand characteristics as they were going about their everyday job, acting as they would normally.

Another strength is the high level of reliability, as the study followed a standardised procedure (the ‘doctor’ gave the same ‘scripted’ instructions to each nurse over the phone), so it can be replicated. Deciding when the phone call ended was also operationalized.

Finally, a control group was also used which allowed comparisons to be made. Participants variables were minimized as the nurses in the experimental and control groups were closely matched for age, sex, marital status, length of working week, professional experience and area of origin (matched participants).


The control group comprised 33 nurses, whereas there is only data for 22 nurses in the experiment. This indicates that the study had a high rate of attrition (i.e. high drop out rate).

The study broke the ethical guideline of deception, as neither the doctor was real. Also, some were left distressed by the study so lacked protection from harm. All nurses were debriefed within 30 minutes of the phone call.

Rank and Jacobson (1977) tried to replicate Hoflings study using a real drug which the nurses had heard of, but did not get similar results. They believed that the nurse’s knowledge of the drug, specifically the consequence of an overdose, meant they could justify their defiance to the doctor more easily.

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APA Style References

Hofling, C. K., Brotzman, E., Dalrymple, S., Graves, N. & Bierce, C. (1966). An experimental study of nurse-physician relations. Journal of Nervous and Mental Disease, 143, 171-180.

Rank, S. G., & Jacobson, C. K. (1977). Hospital nurses’ compliance with medication overdose orders: a failure to replicate. Journal of Health and Social Behavior, 188-193.

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