Wrong. Media wasnt the reason for their fear back in the 40's 50's etc..etc.. It's just in their nature.
If thats the case, why do you have ethinc Ghettos all over the world, even in countries, where you have no white people?
E.g. I just read some shit about Islamabad, Pakistan. The bad part of that city is called "Little Kabul" cause all the refugees from Afghanistan settled down there.
I would say, simplified its like this:
Poor people move in, rich/wealthier people move out, no matter if they are white, green, purple or yellow.
And when back in the day blacks moved to the big cities on the east and west coast they were anything but rich.