The Barnum Effect

You seem upbeat on the outside, but sometimes you feel a loneliness no one knows about. Hear that, and most people gasp and nod. But think about it for a second. Is there anyone in the world who never feels lonely?

Taking a common feeling and treating it like your own special secret is where the Barnum effect begins. When we hear something about ourselves, we unconsciously have a habit of stretching our past memories and experiences to make them fit.

Personality quizzes and horoscopes tap into exactly this. They stack up positive but fairly fuzzy sentences, so anyone can slap their knee and say, "That's totally me!"

The most famous person to demonstrate this in an experiment was psychologist Bertram Forer. In 1948, Professor Forer ran a fascinating study with college students. He had them take a detailed personality test, then a week later handed each student a personal analysis.

The students were amazed. When asked to rate from 0 to 5 how well the analysis matched their true personality, the average score was a whopping 4.26.

But here's the twist. Forer hadn't used the students' test answers at all. He had pulled lines from an astrology book, stitched them together, and given every single student the exact same sheet, word for word. Statements like "You have a strong need for other people to like you" and "You seem confident on the outside, but you're anxious inside" fit just about anyone, and the students fell for them.

To be more precise, people don't believe just any random statement. For the Barnum effect to hit with an eerie punch, a few psychological ingredients need to be in the mix.

First, you have to believe the information was made just for you. Second, it helps to include some flattery. People accept positive comments about themselves far more easily than criticism. Third, trust shoots up when the test or the fortune teller looks professional and authoritative.

Add confirmation bias, our habit of remembering only the information we already believe, and the illusion gets even stronger. We shrug off the off-target lines with "Well, maybe," and then burn the few lucky hits into memory.