***** NOT A TEACHER *****
I think that the passage means that if you tell someone that The Parser is "intelligent, handsome, and awesome," your
listener may think "That's too good to be true." On other hand, if you tell someone that The Parser is "stupid, old, and
ignorant," your listener will believe your words more.
Here in the United States, we are getting ready to elect a president in November. According to what we are taught in
school, the two candidates should be positive. That is, they should tell the people their plans to improve the country.
But in real life, "everyone" says this is going to be a very dirty (negative) campaign. Just as the writer of your
passage said, throwing dirt (being negative) at the other candidate seems to work. Sadly, the writer says, the more
negative you are about another person, the more your listener will believe that you are telling the truth!
Student or Learner