Conservatives are fond of identifying “enemies” and using strong negative words and images to describe them. I wrote about this in the essay Conservatives Depending on Emotional Words to Persuade where excerpts of a GOP memo from Newt Gingrich suggest words to describe “our opponents” including: failure, pathetic, lie, liberal, betray, hypocrisy, radical, etc.
Psychologists have already discovered that emotions affect higher brain functions including attention, memory, vision and motor control. Now, researchers are discovering that negative language inhibits the lower level retrieval of knowledge and subconscious information processing. A Bangor University study initially expected that negative emotional words would be arousing and stimulate reasoning capacity. Instead, they found that negative words suppressed certain cognitive responses.
I suggest that combining these two observations may show that repeatedly describing liberals [or another race, or immigrants, or non-believers] in negative terms may reduce the audiences’ ability to reason critically about the information they are receiving.