What does the barnum effect demonstrate? circus owners have excellent skills for detecting true personality traits. people are willing to believe interpretations about themselves. people are easy to swindle. a person should be cautious about spending time at the wrong events.

I believe the answer is: People are willing to believe interpretations about themselves.
According to Barnum effect, even if we make an interpretation that vague and general enough to apply to a wide range of people and say it to a specific person, that specific person would most likely see it as true and believe the people who give the interpretation.