By this logic if I were a black man and a bunch of swastika wearing skinheads were on the path in front of me, I ought not to be afraid (or anticipate trouble) because they haven't done anything yet? (True, they might be SHARP skinheads whose wearing of the swastika is ironic, but I wouldn't place too much faith in that possibility.)

Coincidentally there's a book about 50s US sci-fi films called rational fears:

http://www.amazon.com/Rational-Fears-American-Horror-1950s/dp/0719036240/ref=sr_1_1?ie=UTF8&s=books&qid=1273141462&sr=8-1