Today, for an experiment to be approved, the potential benefits of the research must exceed the potential risks to participants. This is especially pertinent for experiments that involve deception, due to an increased possibility that participants may be harmed. Milgram used several forms of deception in his study. Which of them had the greatest potential to cause harm?

Making participants believe the shocks were real.

Explanation:

This deception cause a psychological harm to the subject rather physical ones.

Let me elaborate.

In the study, milligram wants to prove whether the subjects are willing to do something that hurt other people if they are pressured by another person who they perceive as 'someone with authority'

They were given a button and being told that the button will deliver fatal/hurtful shock to a person in another room. After that, the person with 'perceived authority' somehow coerce the subject to push that button.

The result of the study was shocking.

Even after convinced that the shocks were real and fatal, the subjects still willing to push the button to the other person when being pressured by the authority. This could caused a massive trauma to the subject since they are forced to confront the fact that they are someone who are capable in hurting others when being pressured.