💡 Diagnostic Label series For the full picture of why more testing leaves you less certain of who you are — and where the exit lies — start with the cluster pillar. → Are Personality Tests Accurate?
Introduction: The Feeling of Recognition Seems Like the Surest Thing
Many people have read the result of a personality test or a reading and been convinced, almost to the point of a shiver, that this is completely me. Line by line, memories are called up, and their vividness feels like corroboration of the description. That strong impression of accuracy seems the surest thing available. Which is precisely why we receive it as evidence that the assessment was correct: it landed, so it must have been right.
Material on using the Barnum effect is plentiful. What this article treats is the ground beneath it: the mechanism by which a vague description fitting anybody at all comes to feel as though it named you alone.
Here is the conclusion first. The sensation of accuracy is generated not on the side of the description but on the side of the person receiving it. The one doing the fitting is you. And a name supplies a description only — never an explanation, never a fate. Landing and being accurate are two different things.
📖 Contents
The Experiment That Handed Everyone the Same Text
In 1949 the psychologist Bertram Forer set an experiment for his students. Each took a personality test and was later handed a text described as your individual result, then asked to rate how well it fitted on a five-point scale. The average the students awarded was 4.26 out of five. Almost all of them felt this is exactly me [Forer, 1949].
There was a device in it, however. The individual result handed out was the same text for every one of them. Forer had assembled innocuous general descriptions of personality from sources such as astrology books and given the identical text to everybody. An ordinary description fitting anybody at all, received by each person as naming them alone with precision. The phenomenon later came to be called the Barnum effect.
The ingenuity of the experiment lies in what followed the reveal. Until told that everyone had read the same text, not a single student had noticed that it fitted anybody at all. On the contrary, each was certain it was a specific description that had named them deeply. While we are projecting, we cannot notice that we are projecting. And when we take an assessment, nobody is standing beside us to explain the device.
Three Workings That Manufacture the Sensation of Accuracy
Why does a vague description feel accurate? Three workings of the mind overlap.
First, projection. Reading a vague description, we unconsciously pour our own specific experience into the words. Read too hard on yourself and the harsh scenes surface; read anxious underneath and the anxious nights do. The description is an empty vessel and we fill it with our own memories.
Second, gathering the convenient evidence. Read highly sensitive and only the scenes of sensitivity come to mind, never the scenes of obtuseness. We gather the evidence matching the description and never set out to look for evidence that does not match. We are selecting and assembling the confirming material ourselves.
Third, the substitution of relief. Receiving a name eases a suspended anxiety, and that relief lends the sensation of accuracy a colouring of certainty. A deep-seated tilt operates — what feels good must be right — and pleasure is substituted for evidence of correctness. It is not that it feels good because it is accurate; it feels accurate because it feels good. The order has quietly reversed.
▸ How this sensation of accuracy connects with belief surviving a miss is treated in why fortune-telling feels accurate.
A Name Supplies Neither Explanation Nor Fate
Alongside the sensation of accuracy failing to guarantee correctness, there is a second confusion we are prone to: receiving a description as an explanation or a fate.
What an assessment hands over is a description. You find crowds difficult states a condition and says nothing whatever about why. Yet once a name is attached, we feel we understand: crowds are difficult because I am this type. This explains nothing. Because I am this type has merely attached another name to finds crowds difficult. It is a repetition of the description wearing the face of an explanation. The more technical the name sounds, the more thoroughly it conceals the absence of an explanation.
A description supplies no fate either. I currently find speaking in public difficult is one cross-section of the present, not an arrow extending into the future. Today’s difficulty need not mean difficulty a year from now. Yet we splice an arrow of time onto that cross-section of our own accord and read it as this is how it will always be. A name gives a description only, and we ourselves write in the explanation and the fate that were never supplied.
Conclusion: Landing Is Not Evidence of Accuracy
The sensation of accuracy was the result of pouring your own contents into a vague vessel, selecting only the matching evidence, and mistaking relief for correctness. And a name supplies a description only, never an explanation or a fate. Landing and being accurate are not merely different; in that the vaguer a description is, the more people it fits and the more people it lands with, they stand at times in an inverse relation.
What is required is to know the mechanism and then doubt, once more, the impression of having understood. As a magic trick whose device is known no longer astonishes in the same way, knowing the Barnum effect from the inside is reliable preparation against being seized by it undefended. Receive the overall design as your next step. How this illusion operates across diagnosis as a whole is set out in are personality tests accurate.
References
Academic papers and theory
- Forer, B. R. “The Fallacy of Personal Validation: A Classroom Demonstration of Gullibility” (1949) Journal of Abnormal and Social Psychology, 44(1)
- Bartlett, F. C. Remembering: A Study in Experimental and Social Psychology (1932) Cambridge University Press
