The Undoing Project: A Friendship That Changed Our Minds

Michael Lewis chronicles the intellectual partnership between Israeli psychologists Daniel Kahneman and Amos Tversky. The narrative tracks how their collaboration dismantled the assumption that human beings are rational actors. By documenting their joint research, Lewis explains cognitive biases and heuristics, such as availability and representativeness, which lead to systematic errors in judgment. The book details the development of prospect theory, showing how people value gains and losses differently. These findings eventually dismantled classical economic models and birthed the field of behavioral economics, influencing how professional sports teams, medical doctors, and government agencies evaluate risk and probability.

This book serves students of psychology, behavioral economists, and decision-makers in high-stakes fields like finance or public policy. Readers gain a technical understanding of why their intuition often fails when processing statistics or predicting future outcomes. It provides a historical framework for the shift from rigid mathematical modeling to an observation of human fallibility. Those who finish the text will recognize specific mental shortcuts in their own choices, walking away with a vocabulary for identifying cognitive illusions and a clearer method for making objective calculations in business and daily life.