Cognitive biases
The Barnum effect: why a general description feels written about you
On a day off, Oleg takes an online quiz called “Who are you really?” Six simple questions: get up early or sleep in, a book or a movie, decide fast or take your time. A minute later comes “your personal portrait,” five sentences about his character. Oleg reads it and is amazed: “That’s exactly me. How did they guess?”
This is the Barnum effect: a vague description that fits almost anyone seems accurate and written personally about us. Especially if it is flattering. That is why horoscopes and random “psychological portraits” are easily taken for an accurate analysis of personality.
Below, we look at how the effect was discovered, why general words sound so personal, and how to tell a vague description from a real assessment. In the middle of the article you will take the same quiz as Oleg.
Contents
In short: how the Barnum effect works
What the Barnum effect is
Imagine the sentence: “You know how to enjoy small things, but sometimes everything gets boring.” It is true for almost everyone. But if it is handed to you as a quiz result, it sounds like an exact observation. The Barnum effect is the tendency to accept such general, vague phrases as an accurate description of our own, one-of-a-kind personality.
The name comes from Phineas Barnum, the famous circus owner. According to a 1985 review of research, his recipe for success was: “we’ll have something for everyone.” A good “Barnum” description is built the same way: everyone finds something about themselves in it.
The same review lists typical phrases of such a description. Vague ones: “You enjoy a certain amount of variety in life.” Two-sided ones: “You are usually cheerful, but sometimes you feel sad.” True of almost everyone: “Studying doesn’t always come easily.” And flattering ones: “The people around you respect you.”
Try it yourself: Oleg’s quiz
The game takes a couple of minutes. Here is what will happen.
Step 1. You answer six easy questions, like Oleg. There are no right answers, just pick whatever is closer to you.
Step 2. You get your portrait and rate how accurately it describes you.
Step 3. We show how the portrait was put together. You will find out the rest in the game.
This is not a psychological test but a game. The questions and the portrait were made up for this article.
What usually happens. The classic experiment was done by the psychologist Bertram Forer (a 1949 paper). We could not read the paper itself, so we give the details as they are retold in the 1985 review. Forer had students fill out a personality questionnaire. A week later each of them received “their own” description and rated its accuracy from 0 to 5. In fact, everyone was given the same text. Forer took its phrases mostly from a popular astrology book. On average the students gave about 4.3 out of 5, and nobody gave less than 2.
The important conclusion Forer drew was about tests. If a person agrees with a description, that does not mean the test measured anything. General phrases fit almost everyone, so agreement says nothing about how this person differs from others.
What the game can and can’t show. You already know the name of the effect: it is in the title of the article. So the game can’t catch you out, and it doesn’t try to trick you. It shows something else: how a text that took none of your answers into account can still sound like it is about you. A high rating here does not mean you are gullible: the phrases in the portrait really do fit many people.
When it is not a mistake. Recognizing yourself in the phrase “sometimes I want to be alone” is not foolish: it really is about you. The authors of the review say directly that people accept such phrases largely because they actually fit. The mistake begins when we go from “this fits” to “the test understood me exactly.”
Why general words sound personal
The phrases really do fit many people. Almost everyone sometimes doubts their decisions and wants to be appreciated. When this is written in “your” portrait, it seems the test guessed it. Though there was nothing to guess.
“This is about you” strengthens the impression. According to the review of research, the same description is rated as more accurate if people are told it was made “especially for you.” If they are told it is “true of people in general,” it is rated lower.
We accept the pleasant more readily. People consider flattering descriptions more accurate than unflattering ones. This is also one of the findings of the review.
We fill in the meaning ourselves. A vague phrase leaves room for your own interpretation: everyone plugs in an example of their own. The authors of the review name this as one possible reason. Perhaps the hits are also remembered better than the misses. Confirmation bias works in a similar way: we notice what supports a thought we already have.
Who delivers the description matters less than it seems. In one experiment, the same description was given by either a psychologist or an inexperienced student. The ratings barely differed, and many participants even praised the person who had tested them.
Where it happens
Horoscopes. In one study, people who believe in astrology generally agreed with descriptions of themselves more often than skeptics did. But skeptics, too, rated a description as more accurate when it was called astrological. And skeptics who got a flattering horoscope became warmer toward astrology afterward.
Online quizzes. “Which flower are you?” “Which character from the series are you?” This is entertainment, and there is nothing wrong with it. But a bull’s-eye in such a quiz tells you the phrases were well chosen, not that the quiz understood you.
“Portraits” by handwriting or birth date. General phrases sound convincing no matter who says them.
Reports by professionals. This applies even to honest work. If general phrases get into a report, it seems more accurate than it is. The review notes the flip side too: a person praises a vague description, and it is easy for the specialist to believe they got it right.
How to tell a general description from a real assessment
- Ask: “Would this fit someone I know?” According to the review, when people are asked directly whether the text describes them in particular rather than just anyone, many notice that it is general.
- Ask: “Would the description change if I had answered differently?” If the conclusion does not depend on your answers, it is not about you.
- Look for specifics that can be checked. A specific claim can turn out to be wrong, and that is good: it can be checked against your life. People often notice specific mistakes. General phrases cannot be wrong, so they tell you nothing.
- Be wary if it is all pleasant. A description without a single thought that is uncomfortable for you is easy to take for an accurate one.
- Ask what the conclusion is based on. When a test is given by a professional, it is reasonable to ask what exactly your answers showed and what this test cannot tell. A good result can be discussed and clarified.
- Make yourself a reminder. For example: “If I think ‘this is definitely about me,’ I ask whether it would fit my friend.” Such rules are easy to put together in the If-then plans tool.
The Barnum effect is one of the biases on the cognitive bias map, in the section on how we make sense of things. Next to it is survivorship bias: conclusions drawn from those we can see, without those we can’t.
Frequently asked questions
So is every psychological test just the Barnum effect?
No. The effect says something else: the feeling of “that’s exactly me” does not by itself prove that a test works. That was Forer’s main point. This is why a test’s quality is not judged by whether the result was to your liking.
What if the description really is accurate?
That happens: many phrases in such descriptions really are about you. The question is a different one: is it about you more than about any other person?
Do flattering descriptions really seem more accurate?
According to the 1985 review, yes: people rate flattering descriptions as more accurate than unflattering ones. The same description also gets a higher rating if people are told it was made especially for them.
