How?

Sometimes I wonder how people can do things; like touch their tongue to their nose, or do the splits. Then I wonder how people can be so cruel. I never thought people could be so blind to the world that they will kill innocent for a simple act of saying bye to a white lady. In class today we were showed a video of how back in the day whites would kill blacks for and simple act. How could we be so blind, that we would kill because of different skin tone. And now I fear that that is happening once again but with Muslims being the target. in one of my classes we read this article on terrorists and how not all of them are Muslim. But because of this type of thinking an boy in the class said that if someone wore Muslim clothing he would be afraid of him. I almost said if I wore my cultures clothing you would be afraid of me? (I am half Persian) And I wish that I did say this but I bit my tongue and said nothing. I fear that one day I will be stripped of my rights and hung like the blacks were not to long ago. I wonder how someone can do this to someone else. Do I even need to fear this, probably not but it is still in their.