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In 1948, psychologist Bertram Forer gave his students a personality test, then handed each one a supposedly individual write-up. In fact everyone got the same vague paragraph, taken largely from a newsstand astrology book, yet on average they rated it as highly accurate.

Bertram Forer, 1948 classroom study

MindScience

The story behind the card

The effect is named after the showman P. T. Barnum, whose shows were said to offer something for everyone; the psychologist Paul Meehl coined 'Barnum effect' in 1956, and it is also called the Forer effect. Forer's 39 students had first taken a real questionnaire, the Diagnostic Interest Blank, so the result felt scientific. Asked to rate from 0 to 5 how well the write-up described them, they gave it an average of 4.3. The statements were broad and mostly flattering, such as 'You have a tendency to be critical of yourself', so almost anyone could find themselves in them. The same mechanism makes horoscopes and online personality quizzes feel personal.

Türkçe oku
Psikolog Bertram Forer 1948'de öğrencilerine bir kişilik testi uyguladı, ardından her birine kişiye özel olduğu söylenen bir değerlendirme verdi. Oysa herkes aynı belirsiz paragrafı almıştı; paragrafın büyük kısmı gazete bayilerinde satılan bir astroloji kitabından alınmıştı. Öğrenciler yine de bu yazıyı ortalamada son derece isabetli buldu.

Etki, gösterilerinde herkese göre bir şey bulunduğu söylenen şovmen P. T. Barnum'un adını taşır; “Barnum etkisi” terimini 1956'da psikolog Paul Meehl ortaya attı. Forer etkisi diye de bilinir. Forer'ın 39 öğrencisi önce Diagnostic Interest Blank adlı gerçek bir ankete yanıt vermişti; bu yüzden sonuç bilimsel görünüyordu. Yazının kendilerini ne kadar iyi anlattığını 0 ile 5 arasında puanlamaları istendiğinde ortalama 4,3 verdiler. İfadeler geniş ve çoğunlukla gönül okşayıcıydı, örneğin “Kendini eleştirmeye yatkınsın” gibi; hemen herkes kendinden bir şey bulabiliyordu. Burç yorumlarını ve internetteki kişilik testlerini bu kadar kişisel hissettiren de aynı düzenektir.

Sources and further reading

Background reading: Barnum effect
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