How can I produce better quality research?

Answer: Form close, synergistic collaborative friendships.

The remarkable collaborative friendship between psychologists Daniel Kahneman and Amos Tversky is a beautiful example of what is possible.


Daniel Kahneman, in his autobiography, describes his remarkable friendship with Amos Tversky. Kahneman won the Nobel prize for Economics in 2002, which would have been awarded to both of them, had Tversky been alive:

From 1968 to 1969, I taught a graduate seminar on the applications of psychology to real-world problems. In what turned out to be a life-changing event, I asked my younger colleague Amos Tversky to tell the class about what was going on in his field of judgment and decision-making. Amos told us about the work of his former mentor, Ward Edwards, whose lab was using a research paradigm in which the subject is shown two bookbags filled with poker chips. The bags are said to differ in their composition (e.g., 70:30 or 30:70 white/red). One of them is randomly chosen, and the participant is given an opportunity to sample successively from it, and required to indicate after each trial the probability that it came from the predominantly red bag. Edwards had concluded from the results that people are “conservative Bayesians”: they almost always adjust their confidence interval in the proper direction, but rarely far enough. A lively discussion developed around Amos’s talk. The idea that people were conservative Bayesian did not seem to fit with the everyday observation of people commonly jumping to conclusions. It also appeared unlikely that the results obtained in the sequential sampling paradigm would extend to the situation, arguably more typical, in which sample evidence is delivered all at once. Finally, the label of ‘conservative Bayesian’ suggested the implausible image of a process that gets the correct answer, then adulterates it with a bias. I learned recently that one of Amos’s friends met him that day and heard about our conversation, which Amos described as having severely shaken his faith in the neo-Bayesian idea. I do remember that Amos and I decided to meet for lunch to discuss our hunches about the manner in which probabilities are “really” judged. There we exchanged personal accounts of our own recurrent errors of judgment in this domain, and decided to study the statistical intuitions of experts.

I spent the summer of 1969 doing research at the Applied Psychological Research Unit in Cambridge, England. Amos stopped there for a few days on his way to the United States. I had drafted a questionnaire on intuitions about sampling variability and statistical power, which was based largely on my personal experiences of incorrect research planning and unsuccessful replications. The questionnaire consisted of a set of questions, each of which could stand on its own – this was to be another attempt to do psychology with single questions. Amos went off and administered the questionnaire to participants at a meeting of the Mathematical Psychology Association, and a few weeks later we met in Jerusalem to look at the results and write a paper.

The experience was magical. I had enjoyed collaborative work before, but this was something different. Amos was often described by people who knew him as the smartest person they knew. He was also very funny, with an endless supply of jokes appropriate to every nuance of a situation. In his presence, I became funny as well, and the result was that we could spend hours of solid work in continuous mirth. The paper we wrote was deliberately humorous – we described a prevalent belief in the “law of small numbers,” according to which the law of large numbers extends to small numbers as well. Although we never wrote another humorous paper, we continued to find amusement in our work – I have probably shared more than half of the laughs of my life with Amos.

And we were not just having fun. I quickly discovered that Amos had a remedy for everything I found difficult about writing. No wet-mush problem for him: he had an uncanny sense of direction. With him, movement was always forward. Progress might be slow, but each of the myriad of successive drafts that we produced was an improvement – this was not something I could take for granted when working on my own. Amos’s work was always characterized by confidence and by a crisp elegance, and it was a joy to find those characteristics now attached to my ideas as well. As we were writing our first paper, I was conscious of how much better it was than the more hesitant piece I would have written by myself. I don’t know exactly what it was that Amos found to like in our collaboration – we were not in the habit of trading compliments -but clearly he was also having a good time. We were a team, and we remained in that mode for well over a decade. The Nobel Prize was awarded for work that we produced during that period of intense collaboration.

At the beginning of our collaboration, we quickly established a rhythm that we maintained during all our years together. Amos was a night person, and I was a morning person. This made it natural for us to meet for lunch and a long afternoon together, and still have time to do our separate things. We spent hours each day, just talking. When Amos’s first son Oren, then fifteen months old, was told that his father was at work, he volunteered the comment “Aba talk Danny.” We were not only working, of course – we talked of everything under the sun, and got to know each other’s mind almost as well as our own. We could (and often did) finish each other’s sentences and complete the joke that the other had wanted to tell, but somehow we also kept surprising each other.

We did almost all the work on our joint projects while physically together, including the drafting of questionnaires and papers. And we avoided any explicit division of labor. Our principle was to discuss every disagreement until it had been resolved to mutual satisfaction, and we had tie-breaking rules for only two topics: whether or not an item should be included in the list of references (Amos had the casting vote), and who should resolve any issue of English grammar (my dominion). We did not initially have a concept of a senior author. We tossed a coin to determine the order of authorship of our first paper, and alternated from then on until the pattern of our collaboration changed in the 1980s.

One consequence of this mode of work was that all our ideas were jointly owned. Our interactions were so frequent and so intense that there was never much point in distinguishing between the discussions that primed an idea, the act of uttering it, and the subsequent elaboration of it. I believe that many scholars have had the experience of discovering that they had expressed (sometimes even published) an idea long before they really understood its significance. It takes time to appreciate and develop a new thought. Some of the greatest joys of our collaboration-and probably much of its success – came from our ability to elaborate each other’s nascent thoughts: if I expressed a half-formed idea, I knew that Amos would be there to understand it, probably more clearly than I did, and that if it had merit he would see it. Like most people, I am somewhat cautious about exposing tentative thoughts to others – I must first make sure that they are not idiotic. In the best years of the collaboration, this caution was completely absent. The mutual trust and the complete lack of defensiveness that we achieved were particularly remarkable because both of us – Amos even more than I – were known to be severe critics. Our magic worked only when we were by ourselves. We soon learned that joint collaboration with any third party should be avoided, because we became competitive in a threesome.

Amos and I shared the wonder of together owning a goose that could lay golden eggs – a joint mind that was better than our separate minds. The statistical record confirms that our joint work was superior, or at least more influential, than the work we did individually (Laibson and Zeckhauser, 1998). Amos and I published eight journal articles during our peak years (1971-1981), of which five had been cited more than a thousand times by the end of 2002. Of our separate works, which in total number about 200, only Amos’ theory of similarity (Tversky, 1977) and my book on attention (Kahneman, 1973) exceeded that threshold. The special style of our collaborative work was recognized early by a referee of our first theoretical paper (on representativeness), who caused it to be rejected by Psychological Review. The eminent psychologist who wrote that review – his anonymity was betrayed years later – pointed out that he was familiar with the separate lines of work that Amos and I had been pursuing, and considered both quite respectable. However, he added the unusual remark that we seemed to bring out the worst in each other, and certainly should not collaborate. He found most objectionable our method of using multiple single questions as evidence – and he was quite wrong there as well.

Alas, the close, collaborative friendship was unable to last. Kahneman wrote:
Anne Treisman and I married and moved together to U.B.C. in 1978, and Amos and Barbara Tversky settled in Stanford that year. Amos and I were then at the peak of our joint game, and completely committed to our collaboration. For a few years, we managed to maintain it, by spending every second weekend together and by placing multiple phone calls each day, some lasting several hours. We completed the study of framing in that mode, as well as a study of the ‘conjunction fallacy’ in judgment (Tversky and Kahneman, 1983). But eventually the goose that had laid the golden eggs languished, and our collaboration tapered off. Although this outcome now appears inevitable, it came as a painful surprise to us. We had completely failed to appreciate how critically our successful interaction had depended on our being together at the birth of every significant idea, on our rejection of any formal division of labor, and on the infinite patience that became a luxury when we could meet only periodically. We struggled for years to revive the magic we had lost, but in vain.

We were again trying when Amos died. When he learned in the early months of 1996 that he had only a few months to live, we decided to edit a joint book on decision-making that would cover some of the progress that had been made since we had started working together on the topic more than twenty years before (Kahneman and Tversky, 2000). We planned an ambitious preface as a joint project, but I think we both knew from the beginning that we would not be granted enough time to complete it. The preface I wrote alone was probably my most painful writing experience.

Kahneman wrote a beautiful eulogy to Amos Tversky, with this touching ending:

Much of the joy was social. Almost all of Amos’ work was collaborative. He enjoyed working with colleagues and students, and he was supremely good at it. And his joy was infectious. The 12 or 13 years in which most of our work was joint were years of interpersonal and intellectual bliss. Everything was interesting, almost everything was funny, and there was the recurrent joy of seeing an idea take shape. So many times in those years we shared the magical experience of one of us saying something which the other would understand more deeply than the speaker had done. Contrary to the old laws of information theory, it was common for us to find that more information was received than had been sent. I have almost never had that experience with anyone else. If you have not had it, you don’t know how marvelous collaboration can be …

How to handle scientific disagreements the mature way

from Thinking, Fast and Slow by Daniel Kahneman, p 234-5:

Professional controversies bring out the worst in academics. Scientific journals occasionally publish exchanges, often beginning with someone’s critique of another’s research, followed by a reply and a rejoinder. I have always thought that these exchanges are a waste of time. Especially when the original critique is sharply worded, the reply and the rejoinder are often exercises in what I have called sarcasm for beginners and advanced sarcasm. The replies rarely concede anything to a biting critique, and it is almost unheard of for a rejoinder to admit that the original critique was misguided or erroneous in any way. On a few occasions I have responded to criticisms that I thought were grossly misleading, because a failure to respond can be interpreted as conceding error, but I have never found the hostile exchanges instructive. In search of another way to deal with disagreements, I have engaged in a few “adversarial collaborations,” in which scholars who disagree on the science agree to write a jointly authored paper on their differences and sometimes  conduct research together. In especially tense situations, the research is moderated by an arbiter.

My most satisfying and predictive adversarial collaboration was with Gary Klein, the intellectual leader of an association of scholars and practitioners who do not like the kind of work I do. They call themselves students of Naturalistic Decision Making, or NDM, and mostly work in organizations where they often study how experts work. The NDMers adamantly reject the focus on biases in the heuristics and biases approach. They criticize this model as overly concerned with failures and driven by artificial experiments rather than by the study of real people doing things that matter. They are deeply skeptical of the value of using rigid algorithms to replace human judgment, and Paul Meehl is not among their heroes. Gary Klein had eloquently articulated this position over many years.

This is hardly the basis for a beautiful friendship, but there is more to the story. I had never believed that intuition is always misguided. I had also been a fan of Klein’s studies of expertise in firefighters since I first saw a draft of a paper he wrote in the 1970s, and was impressed by his book Sources of Power, much of which analyzes how experienced professionals develop intuitive skills. I invited him to join in an effort to map the boundary that separates the marvels of intuition from its flaws. He was intrigued by the idea and we went ahead with the project—with no certainty that it would succeed. We set out to answer a specific question:  When can you trust an experienced professional who claims to have an intuition? It was obvious that Klein would be more disposed to be trusting, and I would be more skeptical. But could we agree on principles for answering the general question? Over seven or eight years we had many discussions, resolved many disagreements, almost blew up more than once, wrote many drafts, became friends, and eventually published a joint article with a title that tells the story: “Conditions for Intuitive Expertise: A Failure to Disagree.” Indeed, we did not encounter real issues on which we disagreed—but we did not really agree.


from Learned Optimism by Martin Seligman, p 31-2; 40-3:

Oxford University is an intimidating place to give a lecture. It’s not so much the spires and gargoyles, or even the knowledge that for over seven hundred years this place has led the intellectual world. It’s Oxford’s dons. They had turned out in force that day in April 1975 to hear the upstart American psychologist who was on sabbatical at Maudsley Hospital’s Institute of Psychiatry in London and who had traveled to Oxford to talk about his research As I arranged my speech on the rostrum and looked nervously out into the hall, I could see the ethologist Niko Tinbergen, a 1973 Nobel laureate. I could see Jerome Bruner, a celebrated academic who had recently come to Oxford from Harvard to take the Regius professorship in child development. There too was Donald Broadbent, the founder of modern cognitive psychology and the foremost “applied” social scientist in the world, and Michael Gelder, the dean of British psychiatry. And there was Jeffrey Gray, the renowned expert on anxiety and the brain. These were the greats of my profession. I felt like an actor who has been pushed out onto a stage to do a soliloquy before Guinness, Gielgud, and Olivier.

I launched into my speech about learned helplessness, and I was relieved to find the dons reasonably responsive, some of them nodding at my conclusions, most of them chuckling at my jokes. But in the middle of the front row was an intimidating stranger. He was not laughing at my jokes, and at several crucial points he conspicuously shook his head no. He seemed to be keeping a running total of mistakes I had unknowingly made.

At last the speech was finished. The applause was appreciative, and I was relieved, for the occasion was now over except for the polite platitudes traditionally offered by the professor assigned to be the “discussant.” The discussant, however, turned out to be the naysayer from the front row. His name was given as John Teasdale. I had heard the name before but knew almost nothing about him. Teasdale, it proved, was a new lecturer in the psychiatry department, fresh up from the psychology department at Maudsley Hospital in London.

“You really shouldn’t be carried away by this enchanting story,” he told the audience. “The theory is wholly inadequate. Seligman has glossed over the fact that one-third of his human subjects never become helpless. Why not? And of the ones who did, some bounced back right away; others never recovered. Some were helpless only in the very situation they learned to be helpless about; they no longer tried to escape from noise. Yet others gave up in brand-new situations. Let us ask ourselves why. Some lost self-esteem and blamed themselves for failing to escape the noise, while others blamed the experimenter for giving them unsolvable problems. Why?”

Baffled looks appeared on many of the dons’ faces. Teasdale’s piercing critique had thrown everything into doubt. Ten years of research, which had looked definitive to me when I began the talk, now seemed full of loose ends.

I was almost dumbstruck. I thought Teasdale was right, and I was embarrassed I hadn’t thought of these objections myself. I mumbled something about this being the way science progresses and by way of rejoinder asked if Teasdale himself could solve the paradox he had set before me.

“Yes, I think I can,” he said. “But this is neither the time nor the place.”

. . .

Explanatory Style

When John Teasdale raised his objections after my speech at Oxford, I felt for a moment as if years of work might have been for nothing. I had no way of knowing at the time that the Teasdale challenge would result in the thing I wanted most of all–using our findings to help needful and suffering human beings.

Yes, Teasdale had granted in his rebuttal, two out of three people became helpless. But, he’d stressed, one out of three resisted: No matter what happened to them to make them helpless, they would not give up. It was a paradox, and until it was resolved, my theory could not be taken seriously.

Leaving the hall with Teasdale after the address, I asked him if he’d be willing to work with me to see if we could construct an adequate theory. He agreed, and we began meeting regularly. I’d come down from London and we’d take long walks through the manicured Oxford grounds and the tree-lined meadows called The Backs, talking out his objections. I asked for his solution to the problem he had posed, about who is vulnerable to helplessness and who is not. I learned that for Teasdale the solution came down to this: how people explain to themselves the bad things that happen to them. People who made certain kinds of explanations, he believed, are prey to helplessness. Teaching them to change these explanations might prove an effective way to treat their depression.

Every two months or so during this period in England, I made week-long trips back to the United States. On my first trip I returned to the University of Pennsylvania to find that my theory was being assaulted by challenges almost identical to Teasdale’s. The challengers were two fearless students in my own research group, Lyn Abramson and Judy Garber.

Lyn and Judy had both been caught up in a vogue-enthusiasm for the work of a man named Bernard Weiner. In the late 1960s Weiner, a young social psychologist at the University of California’s Los Angeles campus, had started to wonder why some people are high achievers and other people are not. He concluded that the way people think about the causes of successes and failures was what really mattered. His approach was called attribution theory. (That is, it asked to what factors people attributed their successes and failures.)

This view ran against the existing belief about achievement, the classic demonstration of which was called PREE-the partial reinforcement extinction effect. PREE is an old chestnut of learning theory. If you give a rat a food pellet every time he presses a bar, this is called “continuous reinforcement”; the ratio of reward to effort is one-to-one, one pellet for one bar-press. If you then stop giving him food for pressing the bar (“extinction”), he’ll press the bar three or four times and then quit completely, because he can see he’s never getting fed anymore, since the contrast is so great. If, on the other hand, instead of one-for-one reinforcement, you give the rat “partial” reinforcement-say, an average of only one pellet for every five or ten times he presses-and then start extinction, he’ll press the bar a hundred times before he gives up.

PREE had been demonstrated in the 1930s. It was the kind of experiment that made the reputation of B. F. Skinner and established him as the panjandrum of the behaviorists. The PREE principle, however, though it worked with rats and pigeons, didn’t work very well with people. Some would give up as soon as extinction began; others would keep going.

Weiner had an idea why it didn’t work with people: Those people who thought the cause of extinction was permanent (who concluded, for example, “The experimenter has decided not to reward me anymore”) would give up right away, while those who thought the cause was temporary (“There’s a short circuit in this damned equipment”) would keep on going, because they thought the situation might change and the reward would resume. When Weiner performed this experiment, he found just the results he predicted. It was the explanations people made, and not the schedule of reinforcement they’d been on, which determined their susceptibility to PREE. Attribution theory went on to postulate that human behavior is controlled not just by the “schedule of reinforcement” in the environment but by an internal mental state, the explanations people make for why the environment has scheduled their reinforcements in this way.

This work had great impact in the field, especially upon younger scholars like Lyn Abramson and Judy Garber. It had shaped their whole outlook, and it was the lens through which they examined the theory of learned helplessness. When, during my first trip home from England, I told my colleagues what John Teasdale had said, Lyn and Judy replied that he was right and I was wrong, and the theory would have to be reformulated.

. . .Throughout my career, I’ve never had much use for the tendency among psychologists to shun criticism. It’s a longstanding tradition acquired from the field of psychiatry, with its medical authoritarianism and its reluctance to admit error. Going back at least to Freud, the world of the research psychiatrists has been dominated by a handful of despots who treat dissenters like invading barbarians usurping their domain. One critical word from a young disciple and he was banished.

I’ve preferred the humanistic tradition. To the scientists of the Renaissance, your critic was really your ally, helping you advance upon reality. Critics in science are not like drama critics, determining flops and successes. Criticism to scientists is just another means of finding out whether they’re wrong, like running another experiment to see if it confirms or refutes a theory. Along with the advocacy principle of the courtroom, it is one of the best ways human beings have evolved to get closer to the truth.

I had always stressed to my students the importance of welcoming criticism. “I want to be told,” I had always said. “In this lab, the payoff is for originality, not toadyism.” Now Abramson and Garber, not to mention Teasdale, had told me, and I was not about to bristle with hostility. I promptly enlisted the three of them as allies in making the theory better. I argued with my two brilliant students, sometimes for twelve hours without a break, working to make my theory incorporate their objections.

I launched into two sets of conversations. The first, in Oxford, was with Teasdale. John’s commitment was to therapy, and so, as we discussed how to change the theory, we explored the possibility of treating depression by changing the ways depressive people explained to themselves the causes of bad events. The second, with Abramson and Garber back in Philadelphia, took its character from Lyn’s strong interest in the etiology—the causes—of mental illness.

Teasdale and I started writing a manuscript together, on how therapy for helplessness and depression should be based on changing people’s explanations. Concurrently, Abramson and I  started one on how people’s explanatory style could cause helplessness and depression.

At that moment, as it happened, the editor-in-chief of the Journal of Abnormal Psychology contacted me.  The learned helplessness  controversy, he said, had  generated  a great many submissions to the journal, many of them attacks of just the sort John and Lyn and Judy had made. The editor was planning to devote a whole issue of the journal to the battle, and he asked if I would write one of the articles. I agreed and then persuaded Lyn and John to let me merge the  two articles  we had been working on separately. I felt it important that when the new theory got  this very prominent airing, it would already contain our responses to the attacks. . .

The special issue of the Journal of Abnormal Psychology was published in February 1978. It contained the article by Lyn, John and me, answering in advance the main objections to the original learned-helplessness theory. It was well received and itself generated more research than the original helplessness theory had.

Collection of Daniel Kahneman videos

http://www.charlierose.com/view/interview/12185

How can I make better decisions?

Answer: Conduct a “premortem” just before you decide to go ahead with an important decision.

 


Gary Klein, author of  Sources of Power: How People Make Decisions, thought up the premortem idea. He spells out why and how to do a premortem in this Harvard Business Review article:

Performing a Project Premortem


Daniel Kahneman glowingly describes the premortem technique in his book Thinking, Fast and Slow. He writes:

“The procedure is simple: When the organization has almost come to an important decision but has not formally committed itself, Klein proposes gathering for a brief session a group of individuals who are knowledgeable about the decision.

The premise of the session is a short speech:

‘Imagine that we are a year into the future. We implemented the plan as it now exists The outcome was a disaster. Please take 5 to 10 minutes to write a brief history of that disaster.’

Gary Klein’s idea of the premortem usually evokes immediate enthusiasm. After I described it casually at a session in Davos, someone behind me muttered, “It was worth coming to Davos just for this!” (I later noticed the speaker was the CEO of a major international corporation.)

The premortem has two main advantages: it overcomes the groupthink that affects many teams once a decision  appears to be made, and it unleashes the imagination of knowledgeable individuals in a much needed direction. . .The main virtue of the premortem is that is legitimizes doubts.  Furthermore, it encourages even supporters of the decision to search for possible threats that they had not considered earlier.” (p 264-5)

Kahneman again explains the technique  in this video–watch from 12 minutes 17 seconds:

Are interdependent, loving friendships possible where each person helps the other to flourish and together they achieve remarkable synergy?

Answer: Such friendships are rare, but they do happen–and they are worth shooting for.


Here’s a lovely example: the remarkable friendship between psychologists Daniel Kahneman and Amos Tversky, as described by Kahneman in his autobiography (Kahneman won the Nobel prize for Economics in 2002 and Tversky would have also shared the prize had be been alive):

From 1968 to 1969, I taught a graduate seminar on the applications of psychology to real-world problems. In what turned out to be a life-changing event, I asked my younger colleague Amos Tversky to tell the class about what was going on in his field of judgment and decision-making. Amos told us about the work of his former mentor, Ward Edwards, whose lab was using a research paradigm in which the subject is shown two bookbags filled with poker chips. The bags are said to differ in their composition (e.g., 70:30 or 30:70 white/red). One of them is randomly chosen, and the participant is given an opportunity to sample successively from it, and required to indicate after each trial the probability that it came from the predominantly red bag. Edwards had concluded from the results that people are “conservative Bayesians”: they almost always adjust their confidence interval in the proper direction, but rarely far enough. A lively discussion developed around Amos’s talk. The idea that people were conservative Bayesian did not seem to fit with the everyday observation of people commonly jumping to conclusions. It also appeared unlikely that the results obtained in the sequential sampling paradigm would extend to the situation, arguably more typical, in which sample evidence is delivered all at once. Finally, the label of ‘conservative Bayesian’ suggested the implausible image of a process that gets the correct answer, then adulterates it with a bias. I learned recently that one of Amos’s friends met him that day and heard about our conversation, which Amos described as having severely shaken his faith in the neo-Bayesian idea. I do remember that Amos and I decided to meet for lunch to discuss our hunches about the manner in which probabilities are “really” judged. There we exchanged personal accounts of our own recurrent errors of judgment in this domain, and decided to study the statistical intuitions of experts.

I spent the summer of 1969 doing research at the Applied Psychological Research Unit in Cambridge, England. Amos stopped there for a few days on his way to the United States. I had drafted a questionnaire on intuitions about sampling variability and statistical power, which was based largely on my personal experiences of incorrect research planning and unsuccessful replications. The questionnaire consisted of a set of questions, each of which could stand on its own – this was to be another attempt to do psychology with single questions. Amos went off and administered the questionnaire to participants at a meeting of the Mathematical Psychology Association, and a few weeks later we met in Jerusalem to look at the results and write a paper.

The experience was magical. I had enjoyed collaborative work before, but this was something different. Amos was often described by people who knew him as the smartest person they knew. He was also very funny, with an endless supply of jokes appropriate to every nuance of a situation. In his presence, I became funny as well, and the result was that we could spend hours of solid work in continuous mirth. The paper we wrote was deliberately humorous – we described a prevalent belief in the “law of small numbers,” according to which the law of large numbers extends to small numbers as well. Although we never wrote another humorous paper, we continued to find amusement in our work – I have probably shared more than half of the laughs of my life with Amos.

And we were not just having fun. I quickly discovered that Amos had a remedy for everything I found difficult about writing. No wet-mush problem for him: he had an uncanny sense of direction. With him, movement was always forward. Progress might be slow, but each of the myriad of successive drafts that we produced was an improvement – this was not something I could take for granted when working on my own. Amos’s work was always characterized by confidence and by a crisp elegance, and it was a joy to find those characteristics now attached to my ideas as well. As we were writing our first paper, I was conscious of how much better it was than the more hesitant piece I would have written by myself. I don’t know exactly what it was that Amos found to like in our collaboration – we were not in the habit of trading compliments -but clearly he was also having a good time. We were a team, and we remained in that mode for well over a decade. The Nobel Prize was awarded for work that we produced during that period of intense collaboration.

At the beginning of our collaboration, we quickly established a rhythm that we maintained during all our years together. Amos was a night person, and I was a morning person. This made it natural for us to meet for lunch and a long afternoon together, and still have time to do our separate things. We spent hours each day, just talking. When Amos’s first son Oren, then fifteen months old, was told that his father was at work, he volunteered the comment “Aba talk Danny.” We were not only working, of course – we talked of everything under the sun, and got to know each other’s mind almost as well as our own. We could (and often did) finish each other’s sentences and complete the joke that the other had wanted to tell, but somehow we also kept surprising each other.

We did almost all the work on our joint projects while physically together, including the drafting of questionnaires and papers. And we avoided any explicit division of labor. Our principle was to discuss every disagreement until it had been resolved to mutual satisfaction, and we had tie-breaking rules for only two topics: whether or not an item should be included in the list of references (Amos had the casting vote), and who should resolve any issue of English grammar (my dominion). We did not initially have a concept of a senior author. We tossed a coin to determine the order of authorship of our first paper, and alternated from then on until the pattern of our collaboration changed in the 1980s.

One consequence of this mode of work was that all our ideas were jointly owned. Our interactions were so frequent and so intense that there was never much point in distinguishing between the discussions that primed an idea, the act of uttering it, and the subsequent elaboration of it. I believe that many scholars have had the experience of discovering that they had expressed (sometimes even published) an idea long before they really understood its significance. It takes time to appreciate and develop a new thought. Some of the greatest joys of our collaboration-and probably much of its success – came from our ability to elaborate each other’s nascent thoughts: if I expressed a half-formed idea, I knew that Amos would be there to understand it, probably more clearly than I did, and that if it had merit he would see it. Like most people, I am somewhat cautious about exposing tentative thoughts to others – I must first make sure that they are not idiotic. In the best years of the collaboration, this caution was completely absent. The mutual trust and the complete lack of defensiveness that we achieved were particularly remarkable because both of us – Amos even more than I – were known to be severe critics. Our magic worked only when we were by ourselves. We soon learned that joint collaboration with any third party should be avoided, because we became competitive in a threesome.

Amos and I shared the wonder of together owning a goose that could lay golden eggs – a joint mind that was better than our separate minds. The statistical record confirms that our joint work was superior, or at least more influential, than the work we did individually (Laibson and Zeckhauser, 1998). Amos and I published eight journal articles during our peak years (1971-1981), of which five had been cited more than a thousand times by the end of 2002. Of our separate works, which in total number about 200, only Amos’ theory of similarity (Tversky, 1977) and my book on attention (Kahneman, 1973) exceeded that threshold. The special style of our collaborative work was recognized early by a referee of our first theoretical paper (on representativeness), who caused it to be rejected by Psychological Review. The eminent psychologist who wrote that review – his anonymity was betrayed years later – pointed out that he was familiar with the separate lines of work that Amos and I had been pursuing, and considered both quite respectable. However, he added the unusual remark that we seemed to bring out the worst in each other, and certainly should not collaborate. He found most objectionable our method of using multiple single questions as evidence – and he was quite wrong there as well.

Alas, the close, collaborative friendship was unable to last. Kahneman wrote:
Anne Treisman and I married and moved together to U.B.C. in 1978, and Amos and Barbara Tversky settled in Stanford that year. Amos and I were then at the peak of our joint game, and completely committed to our collaboration. For a few years, we managed to maintain it, by spending every second weekend together and by placing multiple phone calls each day, some lasting several hours. We completed the study of framing in that mode, as well as a study of the ‘conjunction fallacy’ in judgment (Tversky and Kahneman, 1983). But eventually the goose that had laid the golden eggs languished, and our collaboration tapered off. Although this outcome now appears inevitable, it came as a painful surprise to us. We had completely failed to appreciate how critically our successful interaction had depended on our being together at the birth of every significant idea, on our rejection of any formal division of labor, and on the infinite patience that became a luxury when we could meet only periodically. We struggled for years to revive the magic we had lost, but in vain.

We were again trying when Amos died. When he learned in the early months of 1996 that he had only a few months to live, we decided to edit a joint book on decision-making that would cover some of the progress that had been made since we had started working together on the topic more than twenty years before (Kahneman and Tversky, 2000). We planned an ambitious preface as a joint project, but I think we both knew from the beginning that we would not be granted enough time to complete it. The preface I wrote alone was probably my most painful writing experience.

Kahneman wrote a beautiful eulogy to Amos Tversky, with this touching ending:

Much of the joy was social. Almost all of Amos’ work was collaborative. He enjoyed working with colleagues and students, and he was supremely good at it. And his joy was infectious. The 12 or 13 years in which most of our work was joint were years of interpersonal and intellectual bliss. Everything was interesting, almost everything was funny, and there was the recurrent joy of seeing an idea take shape. So many times in those years we shared the magical experience of one of us saying something which the other would understand more deeply than the speaker had done. Contrary to the old laws of information theory, it was common for us to find that more information was received than had been sent. I have almost never had that experience with anyone else. If you have not had it, you don’t know how marvelous collaboration can be …

What are some other great collaborative friendships that have stood the test of time and borne great fruit and delight for the participants?

  1. Warren Buffett and Charlie Munger
  2. Bill Gates and Warren Buffett
  3. ???