Orne and Holland (1966) argue that Milgram’s experiment lacks internal validity, as participants believed the experiment was set up. This could lead to demand characteristics, thus not providing a true reflection of obedience from the results. Perry (2013) supported this notion when she listened to the recordings of participants’ responses. She noted that many expressed disbelief that the confederate was actually being shocked. Milgram himself argued this and believed that at least 70% of his participants thought they were administering real shocks.

Sheridan and King (1972) supported Milgram with a replication of his study using puppies and real shocks. From their results, they found that 54% of male participants reached the maximum of 450 V, while 100% of female participants did.

As Milgram’s experiment was a laboratory experiment, it could be argued to have good internal validity, suggesting causation due to its controls, standardization, and replicability. However, some argue that the experimenter would often go off script.

The external validity of this experiment is also highly debated, as it was conducted in a laboratory setting and lacked ecological validity, thus not representing a real-life scenario. However, others argue that the research focused on the relationship between the participant and authority figure, which is evident in his experiment.

Hofling et al. (1966) devised an experiment where nurses, during a night shift, were given instructions over the phone by an unknown doctor named “Dr. Smith” to administer an unknown drug called “Astroten” to a patient named Mr. James. They were told to administer 20mg to the patient, even though the label of the drug indicated a maximum dosage of 10mg. Dr. Smith also mentioned that he was in a hurry and would sign the authorization later when he saw the patient. Nurses have strict guidelines and should never take orders over the phone or administer drugs they are not familiar with, especially exceeding dosage limits. Despite this, 21 out of 22 nurses attempted to administer this placebo drug to the patient.

Although the drug was harmless, this experiment demonstrates the social pressure and power of authority figures, showing how people may obey even with strict guidelines. The experiment was highly standardized and reliable, with orders over the phone followed by a script. This experiment was compared to a control group of 33 nurses in a different hospital, who responded to a questionnaire regarding how they would handle such a request. Thirty-one out of the 33 stated they would not comply with the instructions. However, it’s essential to consider social desirability bias when interpreting questionnaire responses.

Rank and Jacobson (1977) argue that Hofling’s experiment also lacks ecological validity as it does not represent a real-life situation. They conducted a similar study, but this time doctors gave orders in person, and a familiar drug, Valium, was used. When doctors asked nurses to administer three times the recommended dosage, only 2 out of 18 nurses complied. Nurses were halted before they could administer the drugs to any patients.