Cousins claimed that Psycho was influenced by the 1960 documentary Primary. Yet Hitchcock started shooting Psycho on 11th November 1959 and finished on 1st Fenruary 1960 and the Wisconsin Primary was held on 21st January 1960 - which means that not only was the documentary not finished until after Hitchcock made Psycho, but the events in it didn't even happen until Psycho's final week of shooting!