Final answer:
In Milgram's experiment, obedience decreased notably when the humanity of the learner was made more evident, particularly when the learner screamed.
Step-by-step explanation:
In Stanley Milgram's experiment regarding obedience to authority, compliance dropped significantly when participants could directly perceive the humanity of the learner, thus when the learner screamed. Milgram's variations of the original experiment demonstrated that when learners displayed more signs of human suffering, or when the presence of authority was lessened, obedience decreased. This shows that the psychological distance between the 'teacher' and the 'learner' affected the level of obedience. For instance, when the learners were in the same room, or when the instructions were given over the phone, compliance with the authority figure's orders dropped substantially. The strongest indicator in decreasing compliance was when the humanity of the learner was made more evident through actions such as screaming.