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In a 1981 experiment, the psychologists Amos Tversky and Daniel Kahneman described the same imaginary disease outbreak to two groups in different words. When the options were framed as lives saved, most chose the certain option. When the same outcomes were framed as deaths, most people in the other group chose the gamble.

Amos Tversky & Daniel Kahneman, Science, 1981

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The outbreak was expected to kill 600 people, and the participants were university students. In one version, a programme would certainly save 200 people; in the other, it would let exactly 400 die, which is the same result. About 72% picked the sure option when it was worded as saving lives, but when the identical choice was worded in terms of deaths, about 78% picked the gamble instead. Tversky and Kahneman called this the framing effect: the wording of a choice, not only its real odds and outcomes, changes what people pick. Kahneman received the 2002 Nobel Memorial Prize in Economic Sciences for research he had largely done with Tversky, who had died in 1996; the prize is not awarded after death.

Türkçe oku
Psikologlar Amos Tversky ve Daniel Kahneman, 1981'deki bir deneyde iki gruba aynı hayali salgını farklı sözlerle anlattı. Seçenekler kurtulacak insan sayısıyla anlatıldığında çoğunluk kesin sonucu seçti. Aynı sonuçlar ölecek insan sayısıyla anlatıldığında ise öteki gruptakilerin çoğu riski göze aldı.

Salgının 600 kişiyi öldürmesi bekleniyordu; katılımcılar üniversite öğrencileriydi. Bir anlatımda, önerilen plan 200 kişiyi kesinlikle kurtaracaktı; öteki anlatımda aynı plan tam 400 kişinin ölmesine yol açacaktı. Yani sonuç aynıydı. Seçenek “kurtarmak” diye anlatıldığında katılımcıların yaklaşık yüzde 72'si kesin sonucu seçti; aynı seçenek “ölüm” diye anlatıldığında ise yaklaşık yüzde 78'i riskli yolu tercih etti. Tversky ve Kahneman buna çerçeveleme etkisi adını verdi: Bir seçeneğin nasıl ifade edildiği, gerçek olasılıklar değişmese bile tercihleri değiştirir. Kahneman 2002'de, büyük ölçüde Tversky ile birlikte yaptığı çalışmalar için Nobel Ekonomi Ödülü'nü aldı. 1996'da ölen Tversky ödülü paylaşamadı, çünkü Nobel ölümünden sonra verilmiyor.

Sources and further reading

Background reading: Framing effect (psychology)
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