Don't be afraid of the dark
I know that this kind of fear is not something rational, and my friend is not the only person with such feelings, it’s a very common thing.
Research has shown that seeing a black face gives a reaction of fear more often than a white face.
See this article: "Many people of either race may not be happy to find out that a part of their brain involved in responding to potential threats responds more to African Americans than Caucasians," Lieberman said. "Even people who believe to their core that they do not have prejudices may still have negative associations that are not conscious."
So it doesn’t mean my friend is a racist, since this process happens at an unconscious level. Still it was shocking for me to hear him say that. I have many Senegalese friends, both in Senegal and in the Netherlands. I would find it very weird to be afraid of them. I immediately see their faces when I imagine how somebody could be afraid of Africans. Of course I know that a lot of fear towards black people / Muslims / the unknown can be found among Dutch people, but it’s shocking to hear it from a friend. Otherwise I could just think that those people are stupid / crazy, that normal people don’t think like that. My being shocked was not because my friend expressed this thought, I don’t blame him or judge him. I was shocked by the idea that his feeling is probably a common one, that many people will consider an African quarter as a dangerous place because there are so many black people there. This is exactly the principle of racism as it is explained by Levinas. My friend said that he once had a negative experience with a black man, and now he puts all people with the same skin colour in that category: “potentially dangerous / bad”. The skin colour is attached to a supposed characteristic. By reducing humans to a category in such a way, they are being dehumanized.
Fortunately this article says that there is a solution. If you want to stop being afraid, to stop thinking in general categories, just ask yourself if the person in front of you would like celery ;)