Michael Lewis is the talented nonfiction author whose books “Moneyball,” “The Blind Side,” and “The Big Short” have been made into excellent and popular movies. His latest work, “The Undoing Project,” has an odd title, but is very much worth a read. It would take a creative genius to turn it into a movie, but Adam McKay pulled off such a miracle with “The Big Short,” so perhaps it can be done again.

The heart of the book tells the story of the productive research relationship of two academics—Amos Tversky and Daniel Kahneman. Their individual stories are fascinating. Kahneman was a small boy in Nazi-occupied France during World War II who eventually found his way to Israel. Tversky was a quirky genius who seemed straight out of central casting. Those who knew him said: “The smarter you are, the faster you will figure out that Amos is smarter than you.”

When they worked together, as they were able to do for a time before various personality differences and egotistic pressures pulled them apart, Kahneman and Tversky were a dynamic duo.   The laughed hysterically as they worked, finished each other’s sentences, and rewrote much of the received knowledge regarding how human beings make decisions. They challenged the established orthodoxy and their work laid the foundation for much of the research that underlies the field of behavioral ethics and the videos in our Concepts Unwrapped  and Ethics Defined series. Daniel Kahneman, a psychologist, won the Nobel Prize for economics in 2002. Tversky would no doubt have shared the award had he still been alive.

Before Kahneman and Tversky began their research stream, scholars in economics, finance, law and elsewhere simply assumed that humans are rational decision makers who know their own preferences. Such assumptions led to certain types of policy prescriptions. Kahneman, Tversky, and their academic progeny have completely blown up the assumptions underlying the “rational man” model, which in turn dramatically changed which policy prescriptions seem sensible for a wide variety of human problems. “Rational man” has been replaced by what I, paying homage to Kahneman and Tversky, once referred to in a law review article as “K-T Man.”

Lewis, as well as any writer could, summarizes many of Kahneman & Tversky’s academic papers for a lay audience. Unfortunately, the work he summarizes is not directly applied to ethical decision making. But that work and other academic research built upon it created the entire field of behavioral ethics.

Kahneman and Tversky not only laid the groundwork for the field of behavioral ethics; they also served in many ways as moral exemplars. Though flawed as all of us are, they had a fierce loyalty to Israel, which they manifested by rejoining the army every time a war broke out. Some of the book’s more vivid passages come from the Six-Day War. And, more importantly for our purposes, Kahneman and Tversky had an undying devotion to truth-seeking in their academic research. Unwilling to adopt accepted orthodoxy, their creativity and hard work shined an insightful and revolutionary light on human decision making.

All around him remarked upon Kahneman’s amazing ability to drop a theory and move on when the evidence did not support that theory. For most of us, and certainly for most of our leaders in politics today, beliefs are not easily forfeited. Every day in the news we see people hold on to beliefs that have long been abandoned by all reasoned evidence. We need leaders (and voters) who can go where the evidence leads. To be truly moral, our beliefs and public policy stances must be based on what the evidence indicates is true, not simply what we wish to be true.



Amos Tversky & Daniel Kahneman, “The Framing of Decisions and the Psychology of Choice,” Science, Jan. 30, 1981.

Amos Tversky & Daniel Kahneman, “Judgment under Uncertainty: Heuristics and Biases,” Science, Sept. 27, 1974.

Daniel Kahneman, Thinking, Fast and Slow (2011).

Michael Lewis, The Undoing Project: A Friendship that Changed Our Minds (2017).

Michael Lewis, The Big Short (2011).

Robert Prentice, “Chicago Man, K-T Man, and the Future of Behavioral Law and Economics,” Vanderbilt Law Review (Nov. 2003).