Stanley milgram's shock experiment illustrates the phenomenon of

I believe the answer is: Obedience

In the experiment, a test subject is being made to sit with someone that he/she regarded to has high authority.

The authority then tell the subject to press a button that would cause electric shock to other people. and the subject was being told the limit that could cause danger to other people.

As it turned out, test subjects tend to obey the authority even if being told to give shock that exceed the dangerous limit.