对思考的思考

人类与决策

对思考的思考

迈克尔·刘易斯剖析丹尼尔·卡尼曼和阿莫斯·特沃斯基之间长青的情谊

Humans and decision-making

Thinking about thinking

Michael Lewis dissects the enduring friendship between Daniel Kahneman and Amos Tversky

DURING the second world war a young Jewish boy was caught after curfew on the streets of Nazi-occupied Paris by an SS soldier. The soldier picked him up, hugged him, showed him a photograph of another boy and gave him money. The young Daniel Kahneman left more certain than ever that his mother was right: “People were endlessly complicated and interesting.” His curiosity about human thinking would lead him to a pioneering career in psychology, exploring the systematic flaws of decision-making, in a remarkable partnership with his collaborator, Amos Tversky. In 2002 Mr Kahneman (pictured) won a Nobel prize in economics, for work on how people overvalue losses relative to gains. Tversky would have shared it had he not died in 1996. 第二次世界大战期间，在被纳粹占领的巴黎街头，一个年轻的犹太男孩在宵禁时被党卫军士兵抓到了。这名士兵把他抱起来，拥抱他，给他看了另一个男孩的照片，还给了他钱。这让年轻的丹尼尔·卡尼曼（Daniel Kahneman）前所未有地确信他的母亲是对的：“人的复杂和有趣是无止境的。”正是出于对人类思维的好奇心，造就了他在心理学上的开创性工作。他与阿莫斯·特沃斯基（Amos Tversky）成了杰出的搭档，共同探索决策中的系统性缺陷。2002年，卡尼曼（如图）因对人们更看重损失而非收益的研究获得诺贝尔经济学奖。要不是特沃斯基已于1996年去世，他也会分享这一奖项。

This is the terrain of Michael Lewis’s new book, “The Undoing Project: A Friendship that Changed our Minds”. It is part biography of a friendship and part account of psychology’s impact, while also taking in much of modern Israel’s history. It is a fine showcase of Mr Lewis’s range. 这正是迈克尔·刘易斯（Michael Lewis）在新书《回退工程：一场改变人类思维的友谊》（The Undoing Project: A Friendship that Changed our Minds）中所描述的。该书一部分是这场友谊的传记，另一部分讲的是心理学的影响，此外还谈到了很多以色列近代史。这很好地展现了刘易斯的涉猎之广。

Mr Kahneman was introverted, formal and pessimistic, and worked conventional hours; Tversky was extroverted, informal and incorrigibly optimistic, keeping the hours of a bat. But the two shared a fascination with how people repeatedly make the same kinds of irrational mistakes. “We study natural stupidity,” Tversky quipped. At times, the two were “sharing a mind”, Mr Kahneman said, sitting at the typewriter together and blissfully unaware of who had contributed what to their work. They also had their tensions: Mr Kahneman was, for example, envious of Tversky, who attracted far more attention. But they remained so close that when Tversky was diagnosed with cancer, Mr Kahneman was the second person he told. 卡尼曼内敛、严肃而悲观，工作时间也很传统；特沃斯基则外向、随性且乐观得不可救药，像蝙蝠一样昼伏夜出。但两人对为什么人们会反复犯下同一种非理性错误这个问题都十分迷恋。“我们研究与生俱来的愚蠢。”特沃斯基打趣说。卡尼曼说，有时两人会“共用一个大脑”，一起坐在打字机前，而对谁为工作做了多少贡献毫不在意。他们也有关系紧张的时候：比如特沃斯基吸引了比卡尼曼多得多的关注，卡尼曼对此心怀妒忌。但二人却仍然如此亲近——特沃斯基被确诊患癌时，卡尼曼是他告知的第二个人。

Academic work can be intellectual navel-gazing. But the Kahneman-Tversky partnership was always engaged in the real world, thanks to both men’s early experiences in Israel. At 21 Mr Kahneman was assigned to the army’s psychology unit. He overhauled the assessment of recruits, improving judgments by reducing the weight given to gut feelings; the methods have barely been tweaked since. During the Yom Kippur war in 1973, the two psychologists told the army to see what food soldiers threw into the rubbish in order to give them food they really wanted, and persuaded the air force to scrap investigations into a squadron suffering terrible losses: with a small sample size, the extra deaths were probably random. As their work on irrational decision-making has made its way into the wider world, it has also irritated incumbent pundits. When Daryl Morey, the general manager of the Houston Rockets basketball team, used behavioural economics to influence his choice of players, Charles Barkley, a commentator and former NBA star, denounced him and those like him: “They never got the girls in high school and they just want to get in the game.” In decision-making certain flaws are much easier to identify than amend, it seems. 学术工作完全可能只是在智力上钻牛角尖，但卡尼曼与特沃斯基的搭档则总是着眼于现实世界，这要归功于二人早期在以色列的经历。卡尼曼21岁时被分配到军队的心理学部门。他全盘推翻了新兵的考核方法，降低了直觉所占的权重，由此改进了判断；这些方法自此以后几乎再未变过。在1973年的赎罪日战争中，两位心理学家告诉军队去看看哪些食物被士兵扔进了垃圾桶，以此提供给他们真正想要的食品，并说服空军放弃调查一个遭受重大损失的中队：样本量如此小，过多的死亡很可能是随机的。随着他们关于非理性决策的工作进入了大众的视野，这也惹恼了在位的权威。当休斯敦火箭队的总经理达里尔·莫雷（Daryl Morey）用行为经济学来影响球员的选择时，评论员兼前NBA球星巴克利谴责他和他的同类：“这些人在高中时就没追到过女生，只是想混进比赛而已。”看来修正决策中的某些缺陷比单单找出缺陷要难多了。

Some governments have tried to act on these insights. Barack Obama hired Cass Sunstein, a scholar heavily influenced by Mr Kahneman and Tversky, to design behavioural “nudges” that encourage people to do the right thing without forcing them. Britain created its own “nudge unit”, which for example reworded a request for organ donation by first asking people if they would want to receive an organ if they needed one. Positive response rates jumped by enough to increase the donor rolls by 100,000 per year. 一些政府已经尝试根据这些观点来采取行动。奥巴马聘请了深受卡尼曼和特沃斯基影响的学者卡斯·桑斯坦（Cass Sunstein）来设计行为“助推”——鼓励而非强迫人们做正确的事情。英国政府设立了自己的“助推小组”，比如将器官捐献的请求换了个说法：先问人们如有需要是否想得到器官。正面响应的比率由此大幅飙升，以至于每年的登记捐献者增加了10万人。

Like Mr Lewis’s 13 previous books, “The Undoing Project” is a story of remarkable individuals succeeding through innovative ideas. Here, the balance is geared more towards the ideas, and the pace is slower than, say, “Liar’s Poker”, his first book. Yet, with his characteristic style, Mr Lewis has managed the unusual feat of interweaving psychology and the friendship between the two men. Two decades after he died, Tversky’s partnership with Mr Kahneman is still changing the world. 与刘易斯先前的13本书一样，《回退工程》是关于杰出人士通过创新理念获得成功的故事。在这本书中，天平更向思想倾斜，节奏也要舒缓一些，比如就比他的第一本书《说谎者的扑克牌》（Liar’s Poker）来得要慢。然而，刘易斯以其特有的风格，完成了将心理学与两个男人之间的友谊交融在一起的非凡壮举。在特沃斯基去世二十年后，他与卡尼曼的合作仍然改变着世界。