Why do people blindly conform?

When I think about genocide the main question that comes to my mind is, how can people not speak up and stand up the oppressed? This question was made a little clearer to me in class when we discussed the Asch study in class. A group was given a set of lines and had to determine what ones were of equal size. Although there was one clear answer a majority of the group went with the wrong answer just because that is what everyone else picked.
This relates to Genocide because it demonstrates to what effect people will conform to a group. To relate it to a larger event, one could say that this relates to the Nazi regime. People likely disagreed with Hitler’s extreme methods but no one dared say anything. This power of coercing a group to do what you want to do is how the Holocaust was one of the greatest genocides the world has ever or will ever see.