Friday, March 8, 2013

Daniel Kahneman

There aren't many psychologists among Nobel Prize recipients. Daniel Kahneman (born March 5, 1934) is one (although, annoyingly, he was awarded the Nobel Prize in Economic Sciences in 2002). Everyone should become familiar with his work on judgement and decision making. He (and his now deceased colleague Amos Tversky) essentially created the field of behavioral economics.

Daniel Kahneman (b. 1934)

Two of Tversky and Kahneman's original papers, published for general scientific audience in Science, are available here (1974) and here (1981). They are certainly worth working your way through. This chapter (1973) is somewhat more accessible. However, if you want the popular version of his work, his recent book, Thinking Fast and Slow, is excellent. You will, almost effortlessly, feel smarter after reading this book.

This article by Freeman Dyson in the New York Review of Books is also fun to read, with interesting anecdotes about military personnel selection, the survival of bomber crews over Germany, and a surprising (and very effective) defense of Sigmund Freud.

Excerpt 1:

"At the age of twenty I was doing statistical analysis of the operations of the British Bomber Command in World War II [writes Dyson]. ...[T]en years before Kahneman discovered it and gave it its name...the illusion of validity was already doing its deadly work. All of us at Bomber Command shared the illusion. We saw every bomber crew as a tightly knit team of seven, with the gunners playing an essential role defending their comrades against fighter attack, while the pilot flew an irregular corkscrew to defend them against flak. An essential part of the illusion was the belief that the team learned by experience. As they became more skillful and more closely bonded, their chances of survival would improve.

When I was collecting the data in the spring of 1944, the chance of a crew reaching the end of a thirty-operation tour was about 25 percent. The illusion that experience would help them to survive was essential to their morale. After all, they could see in every squadron a few revered and experienced old-timer crews who had completed one tour and had volunteered to return for a second tour. It was obvious to everyone that the old-timers survived because they were more skillful. Nobody wanted to believe that the old-timers survived only because they were lucky.

...I had the job of examining the statistics of bomber losses. I did a careful analysis of the correlation between the experience of the crews and their loss rates, subdividing the data into many small packages so as to eliminate effects of weather and geography. My results were as conclusive as those of Kahneman. There was no effect of experience on loss rate. So far as I could tell, whether a crew lived or died was purely a matter of chance. Their belief in the life-saving effect of experience was an illusion.

...As Kahneman found out later, the illusion of validity does not disappear just because facts prove it to be false. Everyone at Bomber Command, from the commander in chief to the flying crews, continued to believe in the illusion. The crews continued to die, experienced and inexperienced alike, until Germany was overrun and the war finally ended."

Excerpt 2:

"One thing that is notably absent from Kahneman’s book is the name of Sigmund Freud. In thirty-two pages of endnotes there is not a single reference to his writings. This omission is certainly no accident.


Freud is now hated as passionately as he was once loved. Kahneman evidently shares the prevalent repudiation of Freud and of his legacy of writings.

Freud wrote two books, The Psychopathology of Everyday Life in 1901 and The Ego and the Id in 1923, which come close to preempting two of the main themes of Kahneman’s book. The psychopathology book describes the many mistakes of judgment and of action that arise from emotional bias operating below the level of consciousness. These “Freudian slips” are examples of availability bias, caused by memories associated with strong emotions. The Ego and the Id decribes two levels of the mind that are similar to the System Two and System One of Kahneman, the Ego being usually conscious and rational, the Id usually unconscious and irrational.

There are huge differences between Freud and Kahneman, as one would expect for thinkers separated by a century. The deepest difference is that Freud is literary while Kahneman is scientific. The great contribution of Kahneman was to make psychology an experimental science, with experimental results that could be repeated and verified. Freud, in my view, made psychology a branch of literature, with stories and myths that appeal to the heart rather than to the mind.


It is understandable that Kahneman has no use for Freud, but it is still regrettable. The insights of Kahneman and Freud are complementary rather than contradictory. Anyone who strives for a complete understanding of human nature has much to learn from both of them. The scope of Kahneman’s psychology is necessarily limited by his method. His method is to study mental processes that can be observed and measured under rigorously controlled experimental conditions. Following this method, he revolutionized psychology. He discovered mental processes that can be described precisely and demonstrated reliably. He discarded the poetic fantasies of Freud.
But together with the poetic fantasies, he discarded much else that was valuable. Since strong emotions and obsessions cannot be experimentally controlled, Kahneman’s method did not allow him to study them. The part of the human personality that Kahneman’s method can handle is the nonviolent part, concerned with everyday decisions, artificial parlor games, and gambling for small stakes. The violent and passionate manifestations of human nature, concerned with matters of life and death and love and hate and pain and sex, cannot be experimentally controlled and are beyond Kahneman’s reach. Violence and passion are the territory of Freud. Freud can penetrate deeper than Kahneman because literature digs deeper than science into human nature and human destiny."

Here is Kahneman speaking at a TED conference:

And here he is at GoogleTalks, which have to be the best brown bag lunchtime talks in the world. If you want to get the gist of Thinking Fast and Slow in a hour, this is probably the best way to do so.

1 comment:

  1. I have made tons of notes while reading this book. It starts off a little slowly and it takes some time getting used to - beware, it's not a light book; each page is thought-provoking. The author is a fine educator and one can see it in the quality of his thought-process. There is wit and there is loads to think about while reading, and as this book describes, when the mind thinks, one tends to slow down :)


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