Barnum Effect, also known as Forer Effect, is the tendency to take general statements and interpret it from a personal point of view. A very common example where the Barnum Effect is exploited is in horoscopes and fortune telling. You can commonly see sentences like “When something good lands in our lap, we frequently fail to appreciate it, because we immediately begin the process of protecting, coveting, and ultimately hoarding our treasures.” This sentence can have different meaning because as we read it we relate it to our life experiences.
The more personal input you give in the process, even stronger is the effect. Personality tests like MBTI can seem more accurate then they are. Especially if it is combined with confirmation bias. If the tests, for any reason tells you something that you knew or wanted to be true. It is highly likely that you will believe it. People won’t believe or pay attention to general statements that are considered negative.