This week’s post comes of This Week Magazine, a very popular Sunday newspaper supplement from the 1930s through the 1960s.  The publication contained fiction, cartoons, and news related articles. The copy displayed below contains an article about the dangers of gossip that was printed sometime in the late 1940s. Unless there was an anti-gossip movement in the 1940s I do not think that this item relates specifically to extremism, but it does seem to reflect a heightened awareness to reputation and character assassination as the Cold War was beginning to ramp up in the 1940s. (The House Committee on Un-American Activities became a standing (permanent) committee in 1945 with black list hearings in 1947.)
In addition there seem to be many sermons online that reference Dr. Cantril, (who is referenced in the article as well) highlighting the dangers of slander by using this anecdote:
Several years ago Dr. Albert H. Cantril, a professor at Princeton University, conducted a series of experiments to demonstrate how quickly rumors spread. He called six students to his office and in “strict confidence” informed them that the Duke and Duchess of Windsor were planning to attend the university dance. Within a week, that completely fictitious story had reached nearly every student on campus.
The article was written by Howard Whitman.