Can a breakfast question produce a personality reading?
Horoscopes, coffee-ground readings, “which coffee are you?” quizzes and apps promising to decode your personality all play on the same feeling: that someone or something has read you. In this experiment we want you to see that feeling with your own eyes. First we ask a few odd questions; then we show you a 12-sentence personality reading that seems to come from your answers.
You rate how accurate it is from 0 to 5, then say for each sentence whether it fits you. On the results screen we reveal the real secret: the reading is word-for-word the same for everyone. There you can see the crowd’s average rating, which sentence “fit” most often, and how you compare with Forer’s students in 1949.
Forer’s classroom
In 1949 the psychologist Bertram Forer gave 39 students in his introductory psychology class a personality test. A week later he handed each student a “personal” assessment with their name on it and asked them to rate its accuracy from 0 (poor) to 5 (perfect). The assessments were in fact identical; he had taken most of the sentences from an astrology book bought at a newsstand.
As reported by Dickson and Kelly (1985), the students’ mean rating was 4.3. Nobody rated it below 2, and only five students rated it below 4. Forer’s warning is clear: an assessment feeling accurate does not show that the method behind it can tell one person from another. A text that fits everyone equally well doesn’t describe anyone in particular.
Why “Barnum”?
Paul Meehl named the phenomenon the “Barnum effect” in 1956 while criticising personality reports in clinical psychology. The name comes from the circus owner P. T. Barnum, famous for offering “something for everyone”. Meehl’s concern was that sentences true of almost anyone were being written into reports as if they told us something about a particular patient.
Many studies in the following decades reproduced Forer’s finding. Dickson and Kelly’s (1985) review highlights two factors that raise acceptance in particular: being told the text is about you, and the text being favourable. In Snyder and Larson’s (1972) study, people told that the same text had been prepared “specifically for them” rated it as more accurate than people told it was “generally true of people”.
Anatomy of a Barnum sentence
We wrote the 12 sentences in this experiment from scratch, without using Forer’s text, following the well-known techniques. Double-headed sentences state a trait and its opposite at once: “you hang back at first, then relax once you trust people.” Almost everyone has lived both. Universal sentences describe experiences everyone shares, like a song carrying you back years. Flattering sentences (“you value deep connections”) are accepted more readily; people attribute positive traits to themselves more easily.
Vague sentences can’t be falsified: who can give a firm “no” to “you’re still looking for the place where you can show what you’re capable of”? While reading, we match each sentence with an example from our own life; we find the fitting example quickly and don’t search for the ones that don’t fit. In the solution on the results screen you can see which technique each sentence uses and what share of the crowd said it fits them.
Why does this matter?
The Barnum effect doesn’t only explain horoscopes. Some personality reports used in hiring, “scientific-looking” online quizzes and personalised advertising can all draw on the same feeling. A result fitting you well doesn’t mean it knows anything about you; the real question is how well the same result would fit everyone else.
The best defence against Barnum texts is to put your result next to other people’s. Forer’s students only realised their assessments were identical when they showed them to each other. If you share your result, remember that your friends will see the same reading; that may be the most fun part of this experiment.