The Undoing Project: A Friendship That Changed Our Minds

Lewis shifts the spotlight to Amos Tversky. The chapter starts with Amnon Rapoport, who later became one of Amos’s closest friends, remembering the first time he ever met Amos, in line to compete for a spot at Hebrew University’s growing psychology department. Amnon recalls that at the time, Amos was a “small, baby-faced soldier. He looked about fifteen but he wore, almost absurdly, the high, rubber-soled boots and crisp uniform and red beret of the Israeli paratrooper” (87). This was Amos, the outspoken, magnetic extrovert. Amos was Israeli through and through, loyal to the nation’s causes and intent on proving that he possessed the necessary bravery to defend it. During his teenage years, Amos joined the Nahal, or “Fighting Pioneer Youth,” which motivated him to volunteer as a paratrooper, which in turn led to him becoming a platoon commander.

Amos was fully invested in his commitment as a member of the Israeli Defense Forces, until he began his career in academia. He decided to pursue psychology as a field of study, and from that point on he pulled at every thread imaginable, so long as the topic interested him. Like Danny, he was interested in people and what made them tick. After studying at Hebrew University, he eventually pursued his PhD at the University of Michigan, where Ward Edwards, one of his recent inspirations, worked. Edwards had been working on a theory of how human beings make judgments and was particularly interested in whether people generally make decisions that reveal transitivity, which is a term that refers to logical, linear decisions.

Later, Amos was captivated by another University of Michigan faculty member: Clyde Coombs, who was trying to understand which mechanisms were at work when people made decisions that were “fuzzier” than the average problem. Amos in turn started to put together theories of his own, such as one called “features of similarity,” in which “he argued that when people compared two things, and judged their similarity, they were essentially making a list of features” (113). Amos then devised “a mathematical model to describe what he meant—and to invite others to test his theory, and prove him wrong” (113). The more Amos studied, theorized, and expressed his thinking, the more confident he became in his role as a paradigm shifter, all motivated by his desire to better understand the practical implications of how the human mind works.